Present‐centered therapy (PCT) for post‐traumatic stress disorder (PTSD) in adults

Bradley E Belsher; Erin Beech; Daniel Evatt; Derek J Smolenski; M Tracie Shea; Jean Lin Otto; Craig S Rosen; Paula P Schnurr

doi:10.1002/14651858.CD012898.pub2

. 2019 Nov 18;2019(11):CD012898. doi: 10.1002/14651858.CD012898.pub2

Present‐centered therapy (PCT) for post‐traumatic stress disorder (PTSD) in adults

Bradley E Belsher ^1,^2,^✉, Erin Beech ¹, Daniel Evatt ^1,², Derek J Smolenski ¹, M Tracie Shea ^3,⁴, Jean Lin Otto ^1,², Craig S Rosen ^5,⁶, Paula P Schnurr ^7,⁸

Editor: Cochrane Common Mental Disorders Group

PMCID: PMC6863089 PMID: 31742672

Abstract

Background

Present‐centered therapy (PCT) is a non‐trauma, manualized psychotherapy for adults with post‐traumatic stress disorder (PTSD). PCT was originally designed as a treatment comparator in trials evaluating the effectiveness of trauma‐focused cognitive‐behavioral therapy (TF‐CBT). Recent trials have indicated that PCT may be an effective treatment option for PTSD and that patients may drop out of PCT at lower rates relative to TF‐CBT.

Objectives

To assess the effects of PCT for adults with PTSD. Specifically, we sought to determine whether (1) PCT is more effective in alleviating symptoms relative to control conditions, (2) PCT results in similar alleviation of symptoms compared to TF‐CBT, based on an a priori minimally important differences on a semi‐structured interview of PTSD symptoms, and (3) PCT is associated with lower treatment dropout as compared to TF‐CBT.

Search methods

We searched the Cochrane Common Mental Disorders Controlled Trials Register, the Cochrane Library, Ovid MEDLINE, Embase, PsycINFO, PubMed, and PTSDpubs (previously called the Published International Literature on Traumatic Stress (PILOTS) database) (all years to 15 February 2019 search). We also searched the World Health Organization (WHO) trials portal (ICTRP) and ClinicalTrials.gov to identify unpublished and ongoing trials. Reference lists of included studies and relevant systematic reviews were checked. Grey literature searches were also conducted to identify dissertations and theses, clinical guidelines, and regulatory agency reports.

Selection criteria

We selected all randomized clinical trials (RCTs) that recruited adults diagnosed with PTSD to evaluate PCT compared to TF‐CBT or a control condition. Both individual and group PCT modalities were included. The primary outcomes of interest included reduced PTSD severity as determined by a clinician‐administered measure and treatment dropout rates.

Data collection and analysis

We complied with the Cochrane recommended standards for data screening and collection. Two review authors independently screened articles for inclusion and extracted relevant data from eligible studies, including the assessment of trial quality. Random‐effects meta‐analyses, subgroup analyses, and sensitivity analyses were conducted using mean differences (MD) and standardized mean differences (SMD) for continuous data or risk ratios (RR) and risk differences (RD) for dichotomous data. To conclude that PCT resulted in similar reductions in PTSD symptoms relative to TF‐CBT, we required a MD of less than 10 points (to include the 95% confidence interval) on the Clinician‐Administered PTSD Scale (CAPS). Five members of the review team convened to rate the quality of evidence across the primary outcomes. Any disagreements were resolved through discussion. Review authors who were investigators on any of the included trials were not involved in the qualitative or quantitative syntheses.

Main results

We included 12 studies (n = 1837), of which, three compared PCT to a wait‐list/minimal attention (WL/MA) group and 11 compared PCT to TF‐CBT. PCT was more effective than WL/MA in reducing PTSD symptom severity (SMD ‐0.84, 95% CI ‐1.10 to ‐0.59; participants = 290; studies = 3; I² = 0%). We assessed the quality of this evidence as moderate. The results of the non‐inferiority analysis comparing PCT to TF‐CBT did not support PCT non‐inferiority, with the 95% confidence interval surpassing the clinically meaningful cut‐off (MD 6.83, 95% CI 1.90 to 11.76; 6 studies, n = 607; I² = 42%). We assessed this quality of evidence as low. CAPS differences between PCT and TF‐CBT attenuated at 6‐month (MD 1.59, 95% CI ‐0.46 to 3.63; participants = 906; studies = 6; I² = 0%) and 12‐month (MD 1.22, 95% CI ‐2.17 to 4.61; participants = 485; studies = 3; I² = 0%) follow‐up periods. To confirm the direction of the treatment effect using all eligible trials, we also evaluated PTSD SMD differences. These results were consistent with the primary MD outcomes, with meaningful effect size differences between PCT and TF‐CBT at post‐treatment (SMD 0.32, 95% CI 0.08 to 0.56; participants = 1129; studies = 9), but smaller effect size differences at six months (SMD 0.17, 95% CI 0.05 to 0.29; participants = 1339; studies = 9) and 12 months (SMD 0.17, 95% CI 0.03 to 0.31; participants = 728; studies = 5). PCT had approximately 14% lower treatment dropout rates compared to TF‐CBT (RD ‐0.14, 95% CI ‐0.18 to ‐0.10; participants = 1542; studies = 10). We assessed the quality of this evidence as moderate. There was no evidence of meaningful differences on self‐reported PTSD (MD 4.50, 95% CI 3.09 to 5.90; participants = 983; studies = 7) or depression symptoms (MD 1.78, 95% CI ‐0.23 to 3.78; participants = 705; studies = 5) post‐treatment.

Authors' conclusions

Moderate‐quality evidence indicates that PCT is more effective in reducing PTSD severity compared to control conditions. Low quality of evidence did not support PCT as a non‐inferior treatment compared to TF‐CBT on clinician‐rated post‐treatment PTSD severity. The treatment effect differences between PCT and TF‐CBT may attenuate over time. PCT participants drop out of treatment at lower rates relative to TF‐CBT participants. Of note, all of the included studies were primarily designed to test the effectiveness of TF‐CBT which may bias results away from PCT non‐inferiority.The current systematic review provides the most rigorous evaluation to date to determine whether PCT is comparably as effective as TF‐CBT. Findings are generally consistent with current clinical practice guidelines that suggest that PCT may be offered as a treatment for PTSD when TF‐CBT is not available.

Plain language summary

Present‐centered therapy (PCT) for post‐traumatic stress disorder (PTSD) in adults

Review Question

Is present‐centered therapy (PCT) an effective treatment option for adults with post‐traumatic stress disorder (PTSD) as compared to the recommended trauma‐focused cognitive‐behavioral therapies (TF‐CBT)?

Background

PTSD is a psychiatric disorder that can develop in individuals who are exposed to a traumatic event. Although most trauma survivors experience gradual diminishment of symptoms and recover from the trauma exposure, some will go on to develop PTSD and experience persistent symptoms that disrupt biological, psychological, and social functioning.

TF‐CBT is considered one of the most effective treatments for PTSD. Trauma‐focused therapies require patients to think about and/or talk about their prior traumas, which may prevent some patients from accessing or engaging in these treatments. PCT is a non‐trauma based treatment that incorporates common psychotherapeutic components, and which may appeal to patients reluctant to engage in trauma‐focused treatments. Although originally developed to be a treatment comparator in TF‐CBT trials, PCT has performed well in these trials and may be associated with lower treatment dropout rates. If PCT is deemed to be comparably as effective as TF‐CBT and also has lower treatment dropout rates, then it may be a preferred treatment option for those who do not want to participate in trauma‐focused treatments. This systematic review seeks to determine whether PCT is an effective treatment option compared to TF‐CBT for adults with PTSD.

Study Characteristics

This review included 12 studies that comprised a total of 1837 participants. Eleven studies that included 1826 participants contributed to the quantitative syntheses. Participants were all adults, but ranged in demographics and trauma types. All studies recruited participants in the United States and there was a predominance of studies conducted on military veterans.

Key Results

PCT does not appear to be as effective as trauma focused treatments in reducing PTSD severity at post‐treatment. However, PCT is associated with reduced treatment dropout rates compared to TF‐CBT.

Quality of the Evidence

Several of the TF‐CBT trials included in this review were well designed and executed. However, we assessed the overall quality of evidence for our primary outcome (post‐treatment PTSD severity) as low based on inconsistent outcomes and some imprecision in the results. We rated the quality of the evidence on differential treatment dropout as moderate.

Summary of findings

Background

Description of the condition

Post‐traumatic stress disorder (PTSD) is a psychiatric condition that can develop in individuals following exposure to a traumatic event. Common post‐traumatic symptoms include re‐experiencing of the traumatic event (e.g. nightmares, flashbacks), avoidance of people or situations that trigger memories of the traumatic event, negative beliefs and feelings, and hyperarousal symptoms such as difficulty sleeping and hypervigilance (APA 2013). Although most trauma survivors experience a gradual diminishment of symptoms and recover from the traumatic exposure (Morina 2014; Sayed 2015), some individuals develop PTSD and experience persistent post‐trauma symptoms that disrupt biological, psychological, and social functioning (APA 2013).

Over 80% of the general population may experience a traumatic event, with over one out of two of these individuals exposed to multiple traumatic events in their lifetime (Benjet 2016). The World Health Organization (WHO) estimates that lifetime PTSD prevalence rates range from 0.3% in China to 6.1% in New Zealand, although methodological differences limit direct interpretation of differences in prevalence rates between countries (Kessler 2008). Approximately 5% of the general USA population may currently have PTSD, with close to 6% experiencing PTSD at some point in their lifetime (Goldstein 2017). Lifetime PTSD prevalence rates of USA military veterans are consistent with these estimates (Smith 2016). From a societal perspective, mental illness is costly (Whiteford 2013). A 2008 report estimated that the economic impact of PTSD among USA military personnel ranged between USD 4 billion and USD 6 billion over two years (Tanielian 2008).

Description of the intervention

Present‐centered therapy (PCT) was originally developed as a strong comparator treatment that captured many of the effective components of 'good psychotherapy', to test whether trauma‐focused cognitive‐behavioral therapy (TF‐CBT) demonstrated effects beyond nonspecific psychotherapeutic benefits (Schnurr 2001; Schnurr 2005; Schnurr 2007b; Shea 2018). The nonspecific therapeutic components of PCT include the establishment of positive interpersonal connections through the therapeutic relationship(s), normalization of symptoms, validation of experiences, provision of emotional support, and increasing a sense of mastery and self‐confidence in dealing with problems (Schnurr 2005; Schnurr 2007b; Shea 2018). As PCT was developed as a treatment comparator for TF‐CBT, treatment components exclude trauma exposure, cognitive restructuring, or behavioral activation. PCT has elements of supportive therapy, but is a more structured approach that follows a manual and includes the use of a diary to record problems throughout the week. In clinical trials, PCT is typically modified to mirror the active treatment under investigation in terms of length, number of sessions, and modality (group versus individual).

How the intervention might work

The goals of PCT are to improve patients’ insight into their current symptoms, enhance interpersonal connectedness, and promote a greater sense of mastery via use of effective approaches to solving problems. In treatment, patients gain increased insight into how current behaviours are influenced by PTSD symptoms, explore adaptive solutions to these problems, and are encouraged to implement some of these chosen solutions. Through the application and practice of more effective solutions to daily stressors, patients experience enhanced psychosocial functioning and decreased symptoms. Additional mechanisms underlying PCT may rely on the therapeutic benefits that emerge from a caring relationship, including instillation of hope and optimism, shared goal setting, and increased positive self‐regard (Schnurr 2001; Schnurr 2007a; Schnurr 2007b; Shea 2018). As patients learn and practice more adaptive approaches to dealing with problems, they develop a greater sense of mastery over their environment and experience improved functioning and alleviated symptoms (Shea 2018).

Why it is important to do this review

Several psychological therapies to treat PTSD have been developed and tested to include TF‐CBT, non‐trauma‐focused CBT, eye movement desensitization and reprocessing (EMDR), acceptance and commitment therapy (ACT), and psychodynamic psychotherapy. These active treatments have typically been compared to PCT, supportive therapies, or wait‐list control conditions. Several previous systematic reviews have evaluated the effectiveness of the different active PTSD treatments (Bisson 2005; Bisson 2007; Bisson 2013; Lee 2016; Watts 2013). The most recent Cochrane systematic review concluded that TF‐CBT is more effective than other therapies, although TF‐CBT was also associated with higher treatment dropout rates (Bisson 2013). Notably, in this systematic review, PCT was categorized with "other therapies" that included supportive counselling, hypnotherapy, and psychodynamic therapy. However, PCT is distinct from these other therapies, and a growing body of literature suggests that PCT is an effective treatment for patients with PTSD. Several TF‐CBT trials using PCT as the comparator treatment failed to detect any post‐treatment differences on clinician‐rated PTSD symptoms (Foa 2018; Resick 2015; Schnurr 2003). PCT is also associated with lower treatment dropout rates relative to TF‐CBT across several trials (Imel 2013). Patients express high satisfaction and confidence in PCT as an effective PTSD treatment (Schnurr 2007b), and its has been deemed a well‐established treatment with promising research support (APA 2016). These recent findings raise questions on whether PCT, a non‐trauma based treatment, is comparably as effective as TF‐CBT and potentially more acceptable for patients based on lower treatment dropout rates. Although a previous meta‐analysis concluded PCT was as efficacious as TF‐CBT (Frost 2014), the review only included the five trials available at the time and did not apply a strict non‐inferiority framework to compare the treatments (AHRQ 2012). Applying a non‐inferiority analysis in such circumstances is needed as it evaluates whether a new treatment (i.e. PCT), which may have lower treatment dropout rates, is comparably as effective as the standard recommended treatment using established thresholds (AHRQ 2012). To date, no systematic reviews using Cochrane standards have been conducted to explicitly evaluate PCT in comparison to TF‐CBT. This systematic review provides the most rigorous evaluation of PCT to date by applying a non‐inferiority framework to determine whether PCT demonstrates comparable effectiveness to TF‐CBT and lower treatment dropout rates.

Objectives

To assess the effects of PCT for adults with PTSD. Specifically, we sought to determine whether PCT (1) is more effective in alleviating symptoms relative to control conditions (i.e. wait list, standard care, or other minimal attention groups); (2) results in similar reduction of PTSD severity as compared to TF‐CBT as based on clinician‐rated PTSD symptoms; and (3) is associated with lower treatment dropout rates when compared to TF‐CBT.

Methods

Criteria for considering studies for this review

Types of studies

We included any RCTs that evaluated PCT compared to TF‐CBT or a control condition. We did not use setting, sample size, or publication status to determine study inclusion.

Types of participants

Participant characteristics

This review included trials with a study population consisting of adults of any gender, aged 18 years and over.

Diagnosis

Any individual diagnosed with PTSD according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM‐IV) (APA 2000) or Fifth Edition (DSM‐V) (APA 2013), or the International Classification of Diseases, Tenth Edition (ICD‐10) (WHO 1992), as determined by a structured interview or clinician diagnosis. At least 70% of participants were required to have a PTSD diagnosis. A minimum of one month must have passed since the trauma occurred. We applied no restrictions based on severity of PTSD symptoms or type of traumatic event.

Comorbidities

We applied no restrictions based on the absence or presence of comorbid conditions, although PTSD was required to be the primary diagnosis.

Setting

We applied no restrictions based on study setting.

Types of interventions

Experimental intervention

PCT (see previous description): Present‐centered therapy is a non‐trauma focused, time‐limited treatment for adults with PTSD. Nonspecific therapeutic factors, such as therapist support, are considered part of the treatment. Introductory sessions involve education about PTSD; later sessions involve discussion of daily difficulties and assistance for patients in managing current symptoms through the acquisition of effective coping strategies. We did not include interventions with an active exposure component, or any that emphasized cognitive restructuring. We included therapies given in both group and individual settings. As PCT is typically modified to mirror the active treatment under investigation, we did not limit the number and length of sessions of PCT. When review authors had serious doubts about whether a trial treatment qualified as PCT, we attempted to obtain the treatment manual. In these cases, treatment protocols were reviewed by two authors (BB, EB) to determine whether main features of the treatment were consistent with PCT. A third expert in PCT (TS) reviewed the ratings and made a final decision about whether the treatment under investigation should be categorized as PCT.

Comparator interventions

Control conditions: wait list, standard care, minimal attention, repeated assessment, or other minimal attention groups
Trauma‐focused CBT: refers to a category of evidence‐based psychological treatments for PTSD that incorporate CBT techniques as a primary component, trauma exposure and/or trauma processing, and psychoeducation.

Types of outcome measures

We included studies that met the above inclusion criteria, regardless of whether they reported on the following outcomes.

Primary outcomes

Efficacy outcomes
- Reduced severity of PTSD symptoms as determined by a clinician‐administered standardized measure (e.g. the Clinician Administered PTSD Symptom Scale (CAPS; Weathers 2001)).

Non‐inferiority outcomes: the goal of non‐inferiority research is to determine whether a new treatment has comparable efficacy to an existing treatment, such that the new treatment results in differences that are no worse than a prespecified margin. Conclusions of non‐inferiority are determined based on whether the confidence interval (CI) exceeds this prespecified minimally important difference (MID).
- Reduced PTSD severity as assessed by the CAPS, with the 95% CI excluding the MID value. We also calculated standardized mean differences to include studies that did not use the CAPS to confirm the direction of the effect and provide an estimate of the effect size. Based on existing guidelines (Berliner 2019), any effect size < 0.2 was considered not clinically meaningful.

Adverse events outcomes
- Rates of dropout at post‐treatment for any reason

Secondary outcomes

Reduced severity of PTSD symptoms as determined by a standardized self‐report measure (e.g., the PTSD Checklist (Weathers 1993), the Post‐traumatic Diagnostic Scale (Foa 1995))
Loss of PTSD diagnosis
Reduced severity of depression symptoms as determined by a standardized self‐report measure (e.g., the Beck Depression Inventory (Beck 1961), the Quick Inventory of Depressive Symptomatology (Rush 2003))
Reduced severity of anxiety symptoms as determined by a standardized self‐report measure (e.g. the Spielberger State Trait Anxiety Inventory (Spielberger 1983))
Reduced severity of dissociative symptoms as determined by a standardized self‐report measure (e.g. the Dissociative Experiences Scale (Bernstein 1986))

Timing of outcome assessment

Meta‐analyses took into account the timing of outcome assessments, using data from completion of the intervention, shorter‐term follow‐up (one to six months), and long‐term follow‐up (longer than six months). All data in the shorter‐term follow‐up ended up being between five to seven months, and all studies with longer‐term assessments were at 12 months. Therefore, we decided to focus on post‐treatment outcomes as our primary time point, and to evaluate shorter‐term follow‐up that was five to seven months post‐treatment (labelled as six‐month post‐treatment follow‐up, for convenience), and longer‐term follow‐up (labelled as 12‐month follow‐up, for accuracy).

Hierarchy of outcome measures

When several measures were included for a single outcome, we selected measures in the order laid out for each outcome, as above, and any other validated scales after those. We prioritised clinician‐administered scales over self‐reported scales.

Search methods for identification of studies

Cochrane Common Mental Disorders Controlled Trials Register (CCMD‐CTR)

The Cochrane Common Mental Disorders Group retains a specialized register of RCTs ‐ the CCMD‐CTR. This Register contains over 40,000 reference records (reports of RCTs) for anxiety and depressive disorders, bipolar disorder, eating disorders, self‐harm, and other mental disorders within the scope of this Group. The CCMD‐CTR is a partially studies‐based register with more than 50% of reference records tagged to about 12,500 individually PICO‐coded study records. Reports of trials for inclusion in the Register are collated after (weekly) generic searches of MEDLINE (1950‐), Embase (1974‐), and PsycINFO (1967‐); quarterly searches of the Cochrane Central Register of Controlled Trials (CENTRAL); and review‐specific searches of additional databases. Reports of trials are also sourced from international trial registries, drug companies, key journals (upon handsearching), conference proceedings, and other (non‐Cochrane) systematic reviews and meta‐analyses. Details of CCMD's core search strategies (used to identify RCTs) can be found on the Group website; an example of the core MEDLINE search is displayed in Appendix 1. The register is current to June 2016 only.

Electronic searches

CCMD's Information Specialist searched the CCMD‐CTR to 1 June 2016, as follows:

Cross‐search of the studies and reference registers using the following terms to identify relevant reports on RCTs: (present centred or present centered or present focused or present focussed).

As the CCMDCTR was only current to June 2016, CCMD's Information Specialist ran additional searches on the following databases in February 2018 and February 2019 (Appendix 2):

Ovid MEDLINE (1946 to 15 February 2019);
Ovid Embase (1974 to 2019 Week 07);
Ovid PsycINFO (1806 to February Week 1 2019);
Cochrane Central Register of Controlled Trials (CENTRAL) (all years to Issue 2, February 2019);
WHO ICTRP (all years to 15 February 2019);
Clinicaltrials.gov (all years to 15 February 2019);
ProQuest PTSDpubs (all years to 15 February 2019);
ProQuest Dissertations & Theses Global (all years to 15 February 2019).

Two review authors screened all references to check for eligibility. When appropriate, we tagged reports of the same trial together to ensure that no trial was counted twice.

We applied no restrictions based on date, language, or publication status to the searches.

We also searched international trial registries via the trials portal of the World Health Organization (ICTRP) and ClinicalTrials.gov, to identify unpublished and ongoing studies.

We searched reference lists of included studies for additional relevant studies and screened other systematic reviews of psychological interventions for PTSD to identify additional studies not retrieved by our search.

Searching other resources

Grey literature

We searched the grey literature for dissertations and theses, clinical guidelines, and regulatory agency reports (when appropriate), using the following sources.

Digital Access to Research Theses (DART)‐Europe E‐theses Portal (http://www.dart‐europe.eu/).
Electronic Theses Online System (EThOS) ‐ service of the British Libraries (http://ethos.bl.uk/).
Open Access Theses and Dissertations (https://oatd.org).
National Guideline Clearing House (http://guideline.gov/).
Open Grey (http://www.opengrey.eu/).

Correspondence

We contacted trialists and subject experts for information on unpublished and ongoing studies, and to request additional trial data.

Data collection and analysis

Selection of studies

Two review authors (BB, EB) independently screened titles and abstracts for potential inclusion of all studies identified as a result of the search and coded them as 'retrieve' (eligible or potentially eligible/unclear) or 'do not retrieve.' We retrieved full‐text study reports/publications, and two review authors (BB, EB) independently screened full texts to identify studies for inclusion, and to identify and record reasons for exclusion of ineligible studies. We resolved disagreements through discussion, or, if required, we consulted a third review author (DE). We identified and excluded duplicate records and collated multiple reports that related to the same study, so that each study rather than each report was the unit of interest in the review. We recorded the selection process in sufficient detail to complete a PRISMA flow diagram and a 'Characteristics of excluded studies' table.

Data extraction and management

We used a data collection form that was piloted on at least one study in the review to extract study characteristics and outcome data. Two review authors (BB, EB) extracted the following study characteristics and outcome data from included studies.

Methods: study design, study duration, study setting, recruitment, number of study centers and locations, withdrawals, and dates of study.
Participants: N, mean age, age range, gender, severity of condition, trauma type, duration of time since trauma, comorbid conditions, diagnostic criteria, inclusion criteria, and exclusion criteria.
Interventions: interventions and comparisons.
Outcomes: primary and secondary outcomes specified and collected, method of collection, and time points reported.
Notes: funding for trial and notable conflicts of interest of trial authors.

We noted in the Characteristics of included studies table if outcome data were not reported in a usable way. We resolved disagreements by consensus or by consultation with a third review author (DE). One review author (EB) transferred data into the Review Manager (RevMan 2014) file. A second review author (BB) double‐checked that data were entered correctly by comparing data presented in the systematic review with data provided in the study reports.

Main planned comparisons

PCT versus control conditions (standard care, wait list, minimal attention, or repeated assessment)
PCT versus TF‐CBT

Assessment of risk of bias in included studies

Two review authors (BB, EB) independently assessed risk of bias for each study using the criteria outlined in the Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2011). We resolved disagreements by discussion or by consultation with another review author (DS). We assessed risk of bias according to the following domains. If information was not reported in the trial publications, then authors were contacted and this information was requested.

Random sequence generation: describes the method used to generate the allocation sequence in sufficient detail to allow an assessment of whether it should produce comparable groups. We considered this domain to be at 'low' risk of bias if investigators described a process by which each participant had an equal chance of being randomized to each group; at 'high' risk of bias if investigators describe a non‐random component in the sequence generation process; and at 'unclear' risk of bias if information was insufficient for a judgment of high or low risk of bias.
Allocation concealment: describes the method used to conceal the allocation sequence in sufficient detail to determine whether intervention allocations could have been foreseen in advance of, or during, enrolment. We considered this domain to be at 'low' risk of bias if there was no chance of investigators foreseeing participant assignment; at 'high' risk of bias if investigators could possibly foresee assignments, such as allocation based on alternation or rotation, or an open random allocation schedule (e.g. a list of random numbers); and at 'unclear' risk of bias if information was insufficient for a judgment of high or low risk of bias.
Blinding of participants and personnel: describes all measures used, if any, to blind study participants and personnel from knowledge of which intervention a participant received. When administering psychological interventions, it is not feasible to blind participants or personnel administering the intervention.
Blinding of outcome assessment: describes all measures used, if any, to blind outcome assessors from knowledge of which intervention a participant received. We considered lack of blinding separately for patient‐reported and clinician‐rated outcomes. We considered this domain to be at 'low' risk of bias for an outcome if outcome assessors were blinded; at 'high' risk of bias for an outcome if outcome assessors were not blinded; and at 'unclear' risk of bias for an outcome when information was insufficient for a judgment of high or low risk of bias. For self‐report measures, we rated all outcomes as 'high'.
Incomplete outcome data: describes the completeness of outcome data for each main outcome, including attrition and exclusions from analysis. We considered this domain to be at 'low' risk of bias for an outcome if no data were missing, or if data were imputed appropriately; at 'high' risk of bias for an outcome if missing data were likely related to true outcomes, if analyses considered only the data of treatment completers, or if missing data were imputed inappropriately; and at 'unclear' risk of bias for an outcome when information was insufficient for a judgment of high or low risk of bias. In sum, we considered the effect of incomplete outcome data separately for each outcome and took into account whether reasons for missing data were acceptable, whether trial authors conducted an intention‐to‐treat (ITT) analysis, and the potential impact of missing data on the particular outcome.
Selective outcome reporting: describes how the possibility of selective outcome reporting was examined by the review authors, and what they found. We considered this domain to be at 'low' risk of bias if the study protocol was available and all prespecified outcomes were reported, or if a study protocol was not available but it is clear that published reports included all expected outcomes; at 'high' risk of bias if not all of the study's prespecified outcomes were reported, if they were reported incompletely, or if primary outcomes were not prespecified or outcomes of interest were reported incompletely; and at 'unclear' risk of bias if information was insufficient for a judgment of high or low risk of bias.
Other bias: describes any important concerns about bias not addressed by the other domains in the tool but arising during our assessment process. We judged other risks of bias as 'low' or 'high' based on their threats to validity. We considered this domain to be at 'unclear' risk of bias if information was insufficient for a judgment of high or low risk of bias.

Measures of treatment effect

Continuous data

PCT vs control conditions:

We calculated SMDs and the 95% confidence intervals to combine information across studies. The SMDs were calculated using the baseline standard deviation in each study consistent with recommendations of Feingold (Feingold 2009).

PCT vs TF‐CBT non‐inferiority analysis:

We used CAPS unstandardized MD and 95% confidence intervals (CIs) as the target measure from each study. Regression coefficients from longitudinal models for change or direct comparisons of the amount of change between the study groups were extracted, when reported. For studies that only provided data on pre and post‐treatment means, we calculated a difference score and used a correlation estimate of 0.50 to calculate a standard error for the difference score. Meta‐analysis was measure‐specific to retain the unstandardized scale of each target measure. Measures of summary differences and associated 95% confidence intervals were compared with the minimal important difference (MID) for each outcome based on the following anchors, which indicate clinically important changes: ≥ 10‐point MD on the Clinician‐Administered PTSD Scale (CAPS) (Schnurr 2001); ≥ 10‐point MD on the PTSD Checklist (PCL) (Monson 2008); and ≥ 5‐point MD on the Beck Depression Inventory (BDI) (Beck 1993). To conclude that PCT resulted in symptom reductions no worse than those observed for the TF‐CBT groups, the 95% CI had to exclude the MID value for that particular outcome. To incorporate studies that did not use the CAPS, we also calculated SMD and 95% confidence intervals to combine information across studies that used different measurement instruments to assess the overall direction of any association. An effect size of > 0.2 was considered a clinically important difference as based on existing guidelines (Berliner 2019). The SMDs were calculated using the baseline standard deviation in each study consistent with recommendations of Feingold (Feingold 2009).

Dichotomous data

We analyzed dichotomous data as both the absolute difference and the risk ratio in terms of the proportion experiencing the outcome of interest between two treatment groups. We calculated 95% CIs for both measures.

Unit of analysis issues

Cluster‐randomized trials

Application of meta‐analysis is conventionally based on the assumption that the primary unit of randomization is the individual study participant. However, many clinical RCTs have primarily randomized intact social units of individuals to intervention groups. If clustering was incorporated in some of the studies in this review, we planned to adjust for the clustering effect by dividing clusters by a 'design effect.' Operationally, the design effect in cluster‐randomized trials is the ratio of the variance estimate with clustering to the variance estimate derived from simple random sampling (Kish 1995). In the proposed research, we planned to calculate the design effect (DE) by using a standard formula for cluster sampling (Kish 1995). The equation is DE = 1 + (n ‐ 1) × ICC, where n is the mean number of participants per cluster and ICC is the intraclass correlation coefficient. If the ICC was not reported, we planned to borrow an estimate from a similar study. After taking design effects into account for cluster‐randomized trials, we planned to derive the summary effect size estimate by using the weighted average approach, with weight for each study operationally defined as the inverse variance of the effect size estimator for that study (Borenstein 2009).

Studies with multiple treatment groups

For trials with three or more arms, we planned to first consider conducting pairwise meta‐analysis, with each pair of arms serving as a preliminary analysis. For dichotomous data, we planned to also compare differences in multiple proportions by using a Chi² approach, as proposed by Cohen (Cohen 1977). After careful examination through these preliminary analyses, we planned to consider combining data from arms with similar intervention effects.

Dealing with missing data

We contacted investigators or study sponsors to verify key study characteristics and to obtain missing numerical outcome data when possible (e.g. when a study was identified as abstract only). We documented all correspondence with trialists and reported which trialists responded.

We did not use data from an outcome measure when more than 50% of data were missing. For continuous outcomes, we calculated missing standard deviations from other available data, such as confidence intervals, standard errors, and P, T, or F values. As we used only summary measures for the analysis, we assumed that missing data for each study were randomly distributed and thus did not influence the quality of estimates.

Assessment of heterogeneity

Studies brought together in a systematic review will inevitably present various types of heterogeneity, conventionally classified as clinical, methodological, and statistical heterogeneity in the Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2011). In assessing clinical heterogeneity, we closely examined differences between factors associated with intervention or participant characteristics across studies included in the meta‐analysis. When inspecting methodological heterogeneity, we identified differences between methodological factors across studies that could result in substantial diversity in outcome measurements. We paid particular attention to whether outcome variables were defined in the same fashion; whether they were measured by the same quantity and scale; and whether, if differences did exist, methodological diversity affected the quality of the summary effect size estimate. When clinical and methodological heterogeneity does occur in meta‐analysis, statistical heterogeneity becomes inevitable. We measured the degree of inconsistency in findings across studies by using the I² statistic (Higgins 2003). Specifically, the I² statistic indicates the percentage of observed variation that is attributed to true differences across studies; accordingly, we interpreted the I² score by adhering to the following criteria, as proposed in the Cochrane Handbook for Systematic Review of Interventions (Higgins 2011).

0% to 40%: might not be important.
30% to 60%: may represent moderate heterogeneity.
50% to 90%: may represent substantial heterogeneity.
75% to 100%: considerable heterogeneity.

Assessment of reporting biases

For all its advantages and strengths, meta‐analysis is a rough statistical approach used to estimate a summary effect size, and it is subject to several limitations. Perhaps most notably, much of the meta‐analysis literature relies on results from publications and other accessible sources, resulting in strong selection bias in a weighted average. In the fields of medicine and psychology, study results displaying negative results or insignificant findings are much less likely to be accepted by scientific journals for publication. As many study results failing to show significance presumably still lie in researchers' file drawers, this publication bias is often referred to as the 'file drawer' problem (Rosenthal 1979). To date, no sufficiently satisfactory solution has been found for correcting this type of bias. If the studies included in a meta‐analysis are not randomly selected, which we believe is generally the case, the distribution of effect sizes tends to be skewed, resulting in a biased weighted average of effect sizes.

In our analyses, we viewed the summary effect size estimate from meta‐analysis as representing the statistic for a sample of studies that tends to be skewed. Statistically, the distribution of effect size estimates for selected studies will likely be truncated, leading to non‐normally distributed data. Because studies not accessible for meta‐analysis are usually those with low or even reversed effect sizes, the summary effect size from meta‐analysis tends to be overestimated. We prepared a funnel plot and examined it for asymmetry.

Data synthesis

We applied the random‐effects meta‐analysis to incorporate heterogeneity across studies. Through this statistical approach, the summary effect size estimate measures the mean of systematically different effects in different studies, while its confidence interval describes uncertainty in the estimate. We calculated between‐study variance to measure such uncertainty; its square root was the estimated standard deviation of study‐specific effects from which the 95% confidence interval can be readily derived.

Subgroup analysis and investigation of heterogeneity

To investigate heterogenous results and to evaluate whether PCT had different effects based on treatment modality and type we carried out the following subgroup analysis for the primary outcomes. (1) As group and individual TF‐CBT tend to have differential effects, we were interested to see whether PCT performed differently across these modalities. (2) Given that PE and CPT are two of the most common TF‐CBT treatments used, we also explored whether PCT had differential effects based on these specific trauma treatments.

Treatment modality (individual or group). PCT is administered in both individual and group formats; this variable may affect heterogeneity and treatment outcomes.
Treatment type (PE or CPT). PCT may have differential efficacy based on the comparator treatment.

Sensitivity analysis

We conducted sensitivity analyses for the primary outcomes, focusing on those trials with lowest risk of bias as based on the following criteria: outcome masking, appropriate handling of missing data (ITT; mixed‐model analysis), adequate power, and low levels (< 40%) of post‐randomization treatment loss.

'Summary of findings' table

We used the GRADE approach to summarize and interpret findings, and we used the GRADE profiler to import data from RevMan 2014 to create 'Summary of findings' tables. We assessed the quality of evidence by examining the following.

Limitations in study design and implementation.
Indirectness of evidence.
Unexplained heterogeneity or inconsistency of results.
Imprecision of effect estimates.
Potential publication bias.

For each outcome, we graded the quality of evidence according to the following categories.

High quality: Further research is very unlikely to change our confidence in the estimate of effect.
Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
Very low quality: We are very uncertain about the estimate.

We downgraded evidence from 'high quality' by one level for serious study limitations, indirectness of evidence, serious inconsistency, imprecision of effect estimates, or potential publication bias, and by two levels for 'very serious' concerns. We included the primary outcomes of PTSD severity and dropout rates.

Results

Description of studies

See the Characteristics of included studies and the Characteristics of excluded studies tables.

Results of the search

The search was originally conducted in February 2018 and was run again in February 2019. The search identified 850 records via electronic database searches and 27 additional records through complementary searches of the grey literature, and backwards and forwards citation chasing of included studies and relevant systematic reviews. After removing duplicates, we screened 416 titles and abstracts, excluding 340 records. Two studies (three references) are still awaiting full‐text review as they were completed but not yet published and no data were posted on clinical trial registries or could be obtained from the authors (Characteristics of studies awaiting classification). We identified one ongoing study (Characteristics of ongoing studies). We reviewed 72 full‐text reports and included 35 references, representing 12 unique studies (Figure 1).

We contacted authors of the following studies to obtain clarification about study eligibility: Classen 2011; Ford 2011; NCT00607815; Ready 2010; Ready 2018; Schnurr 2003; Schnurr 2007; Suris 2013. All authors provided the requested information.

Included studies

Design

All studies were randomized controlled trials with a parallel group design.

Sample size

The 12 studies randomized a total of 1837 participants. Two of the studies were small, with fewer than 50 participants recruited (Rauch 2015; Ready 2010). Three of the studies were large, with greater than 200 participants recruited (Foa 2018; Schnurr 2003; Schnurr 2007).

Setting

All studies were conducted in outpatient mental health settings in the USA.

Participants

All studies recruited adult participants. Five of the studies included only male participants (NCT00607815; Ready 2010; Ready 2018; Schnurr 2003; Sloan 2018), and three of the studies included only female participants (Ford 2011; McDonagh 2005; Schnurr 2007). The study population in seven of the studies consisted of veterans only (NCT00607815; Rauch 2015; Ready 2010; Ready 2018; Schnurr 2003; Sloan 2018; Suris 2013), while one study included only active duty USA Army soldiers (Resick 2015), and two studies included both veterans and active duty military (Foa 2018; Schnurr 2007). The remaining study populations were mothers or primary caregivers of young children (Ford 2011) and women who experienced childhood sexual abuse (McDonagh 2005). All studies used a structured clinical interview based on the DSM‐IV or DSM‐V to confirm PTSD diagnosis, and all but one study required that participants meet criteria for full PTSD. One study included participants with 'partial PTSD' (Ford 2011). In this study, at least 70% of participants met DSM‐IV criteria for PTSD, as specified in our inclusion criteria.

Interventions

In the majority of included studies, PCT was based on the original manual used in Schnurr 2003 for group present‐centered treatment (GPCT) and Schnurr 2007 for individual PCT. Two studies used a different version of PCT (Ford 2011; McDonagh 2005) that was deemed to be consistent with the original PCT manuals. Eight studies conducted PCT in an individual format (Foa 2018; Ford 2011; McDonagh 2005; NCT00607815; Rauch 2015; Ready 2010; Schnurr 2007; Suris 2013), and the remaining four studies conducted PCT in a group format (Ready 2018; Resick 2015; Schnurr 2003; Sloan 2018). The number of PCT sessions for all of the TF‐CBT trials was between 10 and 14, except for two trials in which there were approximately 30 sessions (Ready 2018; Schnurr 2003).

Comparisons

Present‐centered therapy was compared to a control condition (wait list or minimal contact) in three studies (Foa 2018; Ford 2011; McDonagh 2005); PCT was compared to a TF‐CBT in eleven studies. Trauma‐focused treatments included CPT (NCT00607815; Resick 2015; Suris 2013), prolonged exposure (Foa 2018; Rauch 2015; Schnurr 2007), group‐based exposure therapy (Ready 2018), virtual reality exposure therapy (Ready 2010), cognitive behavioral therapy (McDonagh 2005), group cognitive behavioral therapy (Sloan 2018), and trauma‐focused group therapy (Schnurr 2003). One study comparing PCT to a control condition included an additional treatment arm, "trauma affect regulation: guide for education and therapy" (TARGET; Ford 2011). This treatment arm was not included in any analyses because it was not trauma‐focused (Ford 2011).

Outcomes

Primary outcomes were reduction in severity of clinician‐rated PTSD symptoms and treatment dropout rates. Two studies used the CAPS to compare PCT to a wait‐list/minimal attention group (Ford 2011; McDonagh 2005) and one trial used the Posttraumatic Symptom Scale‐Interview (PSS‐I; Foa 2018). Six studies used the CAPS to compare post‐treatment PTSD scores between PCT and TF‐CBT groups (NCT00607815; McDonagh 2005; Rauch 2015; Ready 2018; Schnurr 2007; Suris 2013). Two trials used the PSS‐I to compare post‐treatment PTSD scores (Foa 2018; Resick 2015). One trial used the CAPS‐5 to compare post‐treatment PTSD scores (Sloan 2018). Definition of dropout varied across trials (see Table 3).

1. Treatment dropout definitions across TF‐CBT trials.

Trial	Dropout Definition
Chard 2018	Dropout numbers were obtained from results provided on the study’s clinicaltrials.gov trial registration, which includes the number of participants who started the treatment, completed the treatment, and did not complete the treatment for each group. We considered participants who did not complete the treatment to be dropouts.
Foa 2018	Manuscript provided the number of participants that did and did not receive the 'full intervention' in each group, with reasons provided. 'Full intervention' was not explicitly defined. We considered participants who did not receive the 'full intervention' to be dropouts.
Ford 2011	Dropout rates were provided based on the following definition in the manuscript: “…stringent criterion of attending fewer than half of the 12 treatment sessions and not completing a posttherapy or follow‐up assessment.”
McDonagh 2005	Definition of dropout was not explicitly defined in the manuscript, but appeared to be defined as participants who did not complete treatment, based on the description of the dropout analysis.
Rauch 2015	The manuscript defined treatment completers as those who received at least seven sessions and a mid‐ or post‐treatment assessment. To obtain dropout numbers, we subtracted the number provided for treatment completers from the number randomized for each group.
Ready 2010	The manuscript stated that two participants did not complete treatment, with reasons, but did not provide an explicit definition. We considered those participants described as not completing the treatment to be dropouts.
Ready 2018	The manuscript included the number of dropouts during treatment, but did not provide an explicit definition.
Resick 2015	The manuscript included the number of participants who completed the intervention, for each treatment group, with reasons, but did not provide an explicit definition. To obtain dropout numbers, we subtracted the number provided for treatment completers from the number randomized for each group.
Schnurr 2003	The manuscript provided the number of participants who dropped out of either active treatment or booster sessions.
Schnurr 2007	The manuscript provided the numbers of participants who completed treatment, received some treatment, and did not receive any treatment. We considered participants who did not complete the treatment to be dropouts.
Sloan 2018	Treatment completers were defined as participants who completed at least ten treatment sessions. To obtain dropout numbers, we subtracted the number provided for treatment completers from the number randomized for each group.
Suris 2013	The manuscript provided the number of participants who did and did not complete treatment in each group. Treatment completers were defined as those completing all 12 sessions of therapy. We considered participants who did not complete the treatment to be dropouts.

Present‐centered therapy compared to control conditions for post‐traumatic stress disorder (PTSD) in adults
Patient or population: post‐traumatic stress disorder (PTSD) in adults  Setting:   Intervention: present‐centered therapy  Comparison: control conditions
Outcomes	*Anticipated absolute effects^ (95% CI)**		Relative effect  (95% CI)	№ of participants  (studies)	Certainty of the evidence  (GRADE)	Comments
	Risk with control conditions	Risk with present‐centered therapy
PTSD severity (post‐treatment) ‐ standardized difference		SMD 0.84 SD lower (1.1 lower to 0.59 lower)	‐	290  (3 RCTs)	⊕⊕⊕⊝  MODERATE ¹	This corresponds to a clinically meaningful effect as based on current guidelines (Berliner 2019).
Dropout	Study population		RR 1.30  (0.51 to 3.29)	290  (3 RCTs)	⊕⊕⊝⊝  LOW ^{2 3}
	120 per 1,000	156 per 1,000  (61 to 396)
*The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).    CI: Confidence interval; RR: Risk ratio; OR: Odds ratio;
GRADE Working Group grades of evidence  High certainty: We are very confident that the true effect lies close to that of the estimate of the effect  Moderate certainty: We are moderately confident in the effect estimate: The true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different  Low certainty: Our confidence in the effect estimate is limited: The true effect may be substantially different from the estimate of the effect  Very low certainty: We have very little confidence in the effect estimate: The true effect is likely to be substantially different from the estimate of effect

Present‐centered therapy compared to trauma‐focused cognitive behavioral therapy for post‐traumatic stress disorder (PTSD) in adults
Patient or population: post‐traumatic stress disorder (PTSD) in adults  Setting:   Intervention: present‐centered therapy  Comparison: trauma‐focused cognitive behavioral therapy
Outcomes	*Anticipated absolute effects^ (95% CI)**		Relative effect  (95% CI)	№ of participants  (studies)	Certainty of the evidence  (GRADE)	Comments
	Risk with trauma‐focused cognitive behavioral therapy	Risk with present‐centered therapy
CAPS PTSD severity (post‐treatment) ‐ mean difference	Median post‐treatment CAPS = 53 (range: 30 to 72)	MD 6.83 higher  (1.9 higher to 11.76 higher)	‐	607  (6 RCTs)	⊕⊕⊝⊝  LOW ^{1 2 3}
PTSD severity (post‐treatment) ‐ standardized difference		SMD 0.32 SD higher  (0.08 higher to 0.56 higher)	‐	1129  (9 RCTs)	⊕⊕⊝⊝  LOW ^{1 2 3}	This corresponds to a clinically meaningful effect as based on current guidelines (Berliner 2019).
Treatment dropout	Study population		RR 0.58  (0.49 to 0.69)	1542  (10 RCTs)	⊕⊕⊕⊝  MODERATE ⁵
	341 per 1,000	198 per 1,000  (167 to 235)
*The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).    CI: Confidence interval; RR: Risk ratio; OR: Odds ratio;
GRADE Working Group grades of evidence  High certainty: We are very confident that the true effect lies close to that of the estimate of the effect  Moderate certainty: We are moderately confident in the effect estimate: The true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different  Low certainty: Our confidence in the effect estimate is limited: The true effect may be substantially different from the estimate of the effect  Very low certainty: We have very little confidence in the effect estimate: The true effect is likely to be substantially different from the estimate of effect

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Clinician‐administered PTSD, standardized difference	3	290	Std. Mean Difference (Random, 95% CI)	‐0.84 [‐1.10, ‐0.59]
2 Dropout, post‐treatment ‐ Risk Ratio	3	290	Risk Ratio (IV, Random, 95% CI)	1.30 [0.51, 3.29]
3 Dropout, post‐treatment ‐ Risk Difference	3	290	Risk Difference (IV, Random, 95% CI)	0.07 [‐0.02, 0.16]
4 PTSD Checklist, post‐treatment	1	147	Mean Difference (Random, 95% CI)	‐7.52 [‐10.99, ‐4.05]
5 Loss of PTSD diagnosis, post‐treatment ‐ Risk Ratio	3	290	Risk Ratio (Random, 95% CI)	0.45 [0.30, 0.67]
6 Loss of PTSD diagnosis, post‐treatment ‐ Risk Difference	3	290	Risk Difference (Random, 95% CI)	‐0.23 [‐0.33, ‐0.12]
7 BDI, post‐treatment	2	143	Mean Difference (Random, 95% CI)	‐5.06 [‐8.60, ‐1.52]
8 STAI, post‐treatment	1	45	Mean Difference (IV, Random, 95% CI)	‐5.10 [‐11.56, 1.36]
9 DES, post‐treatment	1	45	Mean Difference (Random, 95% CI)	‐13.30 [‐21.26, ‐5.34]

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 CAPS	7		Mean Difference (Random, 95% CI)	Subtotals only
1.1 Post‐treatment	6	607	Mean Difference (Random, 95% CI)	6.83 [1.90, 11.76]
1.2 6 Months Follow‐up	6	906	Mean Difference (Random, 95% CI)	1.59 [‐0.46, 3.63]
1.3 12 Months Follow‐up	3	485	Mean Difference (Random, 95% CI)	1.22 [‐2.17, 4.61]
2 Clinican‐administered PTSD, standardized difference	10		Std. Mean Difference (Random, 95% CI)	Subtotals only
2.1 Post‐treatment	9	1129	Std. Mean Difference (Random, 95% CI)	0.32 [0.08, 0.56]
2.2 6 Months Follow‐up	9	1339	Std. Mean Difference (Random, 95% CI)	0.17 [0.05, 0.29]
2.3 12 Months Follow‐up	5	728	Std. Mean Difference (Random, 95% CI)	0.17 [0.03, 0.31]
3 Dropout ‐ Risk Ratio	10	1542	Risk Ratio (IV, Random, 95% CI)	0.58 [0.49, 0.69]
4 Dropout ‐ Risk Difference	10	1542	Risk Difference (IV, Random, 95% CI)	‐0.14 [‐0.18, ‐0.10]
5 PCL	8		Mean Difference (Random, 95% CI)	Subtotals only
5.1 Post‐treatment	7	983	Mean Difference (Random, 95% CI)	4.50 [3.09, 5.90]
5.2 6 Months Follow‐up	8	1181	Mean Difference (Random, 95% CI)	3.44 [1.86, 5.02]
5.3 12 Months Follow‐up	5	791	Mean Difference (Random, 95% CI)	1.60 [‐0.17, 3.37]
6 Loss of PTSD diagnosis ‐ Risk Ratio	4		Risk Ratio (Random, 95% CI)	Subtotals only
6.1 Post‐treatment	4	749	Risk Ratio (Random, 95% CI)	1.36 [1.03, 1.81]
7 Loss of PTSD diagnosis ‐ Risk Difference	4		Risk Difference (Random, 95% CI)	Subtotals only
7.1 Post‐treatment	4	749	Risk Difference (Random, 95% CI)	0.11 [0.04, 0.19]
8 BDI	5		Mean Difference (Random, 95% CI)	Subtotals only
8.1 Post‐treatment	5	705	Mean Difference (Random, 95% CI)	1.78 [‐0.23, 3.78]
9 Depression, standardized difference	7		Std. Mean Difference (Random, 95% CI)	Subtotals only
9.1 Post‐treatment	7	887	Std. Mean Difference (Random, 95% CI)	0.19 [0.04, 0.33]
10 Anxiety, standardized difference	4	612	Std. Mean Difference (Random, 95% CI)	0.32 [‐0.08, 0.71]
11 DES	1	51	Mean Difference (Random, 95% CI)	4.0 [‐3.51, 11.51]

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Treatment Modality: CAPS Mean Difference	6		Mean Difference (Random, 95% CI)	Subtotals only
1.1 Individual Treatment (CAPS MD)	5	526	Mean Difference (Random, 95% CI)	7.38 [1.21, 13.54]
1.2 Group Treatment (CAPS MD)	1	81	Mean Difference (Random, 95% CI)	4.92 [‐3.49, 13.33]
2 Treatment Modality: PTSD SMD	9		Std. Mean Difference (Random, 95% CI)	Subtotals only
2.1 Individual Treatment (PTSD SMD)	6	742	Std. Mean Difference (Random, 95% CI)	0.40 [0.03, 0.77]
2.2 Group Treatment (PTSD SMD)	3	387	Std. Mean Difference (Random, 95% CI)	0.23 [0.03, 0.43]
3 Trauma Treatment: CAPS Mean Difference	6		Mean Difference (Random, 95% CI)	Subtotals only
3.1 Prolonged Exposure (CAPS MD)	4	442	Mean Difference (Random, 95% CI)	7.15 [‐0.92, 15.21]
3.2 Cognitive Processing Therapy (CAPS MD)	2	165	Mean Difference (Random, 95% CI)	6.91 [0.64, 13.18]
4 Trauma Treatment: PTSD SMD	9		Std. Mean Difference (Random, 95% CI)	Subtotals only
4.1 Prolonged Exposure (PTSD SMD)	5	658	Std. Mean Difference (Random, 95% CI)	0.36 [‐0.06, 0.78]
4.2 Cognitive Processing Therapy (PTSD SMD)	4	471	Std. Mean Difference (Random, 95% CI)	0.29 [0.10, 0.48]

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 CAPS Mean Difference	1	284	Mean Difference (Random, 95% CI)	7.21 [1.51, 12.91]
1.1 Post‐treatment PTSD	1	284	Mean Difference (Random, 95% CI)	7.21 [1.51, 12.91]
2 PTSD SMD	4	806	Std. Mean Difference (Random, 95% CI)	0.21 [0.02, 0.41]
2.1 Post‐treatment PTSD	4	806	Std. Mean Difference (Random, 95% CI)	0.21 [0.02, 0.41]
3 Treatment Dropout: Risk Ratio	5	1166	Risk Ratio (IV, Random, 95% CI)	0.60 [0.49, 0.74]
4 Treatment Dropout: Risk Difference	5	1166	Risk Difference (IV, Random, 95% CI)	‐0.13 [‐0.18, ‐0.08]

Methods	Design: parallel group RCT Dates of study: January 2011 ‐ July 2016 Number of study centers and locations: one, Ft. Hood, Texas Recruitment: service members who screened out from other STRONG STAR studies were offered recruitment. Potential participants were also identified through referrals from various providers. Potential participants could also self‐refer in response to flyers and pamphlets. Study duration: six months
Participants	Participants: 370 Age: mean (SD) 32.7 (7.5) for massed PE group, 32.9 (7.1) for spaced PE group, 32.5 (7.5) for PCT group, 32.7 (7.7) for MCC group Sex: 85.5% male for massed PE group, 90.8% male for spaced PE group, 85.0% male for PCT group, 95.0% male for MCC group Baseline PSS‐I score: mean (CI) 25.20 (23.81 to 26.59) for massed PE group, 25.31 (23.95 to 26.66) for spaced PE group, 25.96 (24.69 to 27.23) for PCT group, 24.83 (23.00 to 26.66) for MCC group Trauma type: exposure to a DSM‐IV‐TR criterion A combat‐related traumatic event (PTSD could be indexed to a noncombat‐related event) Duration of time since trauma: not reported Comorbid conditions: not reported Diagnostic criteria: DSM‐IV‐TR criteria, assessed with the PSS‐I Inclusion criteria: active duty military, activated Reservist, activated National Guard, or veterans who had deployed to OEF/OIF/OND ages 18 to 65 years PTSD diagnosis according to DSM‐IV‐TR, assessed via PSS‐I exposure to a DSM‐IV‐TR criterion A combat‐related traumatic event command support to attend treatment Exclusion criteria: current bipolar or psychotic disorders alcohol dependence moderate to severe traumatic brain injury suicidal ideation other disorders warranting immediate attention
Interventions	Group I: massed prolonged exposure therapy (PE) Description: a manualized CBT consisting of imaginal exposure followed by processing thoughts and feelings related to the imaginal experience; in‐vivo exposure, psychoeducation about PTSD, and controlled breathing training Delivered by: therapists were 2 credentialed psychologists and 1 credentialed social worker who had completed a 4‐day PE workshop, a 2‐day PCT workshop, and 2 supervised cases of PE and PCT Number of sessions: daily sessions were administered on 10 consecutive weekdays over a 2‐week period Format: individual Group II: spaced prolonged exposure therapy (PE) Description: a manualized CBT consisting of imaginal exposure followed by processing thoughts and feelings related to the imaginal experience; in‐vivo exposure, psychoeducation about PTSD, and controlled breathing training Delivered by: therapists were 2 credentialed psychologists and 1 credentialed social worker who had completed a 4‐day PE workshop, a 2‐day PCT workshop, and 2 supervised cases of PE and PCT Number of sessions: 10 sessions were delivered over 8 weeks: 6 once weekly, and 2 twice weekly during the first and last weeks Format: individual Group III: PCT Manual/Model: CSP 494 version Delivered by: therapists were 2 credentialed psychologists and 1 credentialed social worker who had completed a 4‐day PE workshop, a 2‐day PCT workshop, and 2 supervised cases of PE and PCT Number of sessions: ten 90‐minute sessions were scheduled similarly to spaced therapy Format: individual Group IV: minimal contact control (MCC) Description: participants were asked about their well‐being, offered support as needed, and received contact information in case symptoms worsened Delivered by: therapists were 2 credentialed psychologists and 1 credentialed social worker who had completed a 4‐day PE workshop, a 2‐day PCT workshop, and 2 supervised cases of PE and PCT Number of sessions: 10‐ to 15‐minute therapist telephone calls once weekly for 4 weeks Format: individual
Outcomes	PTSD: self‐assessment by PCL clinician‐rated assessment by PSS‐I, including PTSD symptom severity and PTSD diagnosis
Notes	Out of 110 randomized to massed PE, 17 did not complete post‐treatment follow‐up, 25 did not complete 2‐week follow‐up, 44 did not complete 12‐week follow‐up, and 48 did not complete 6‐month follow‐up. Out of 110 randomized to spaced PE, 31 did not complete post‐treatment follow‐up, 34 did not complete 2‐week follow‐up, 46 did not complete 12‐week follow‐up, and 54 did not complete 6‐month follow‐up. Out of 110 randomized to PCT, 22 did not complete post‐treatment follow‐up, 29 did not complete 2‐week follow‐up, 39 did not complete 12‐week follow‐up, and 50 did not complete 6‐month follow‐up. Out of 10 randomized to MCC, 0 did not complete post‐treatment follow‐up, and 1 did not complete 2‐week follow‐up.
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "The randomization sequence was entered by a study statistician into a secure, web‐based application using SAS version 9.4 (SAS Institute Inc), which was accessed by the project coordinator on enrolment of each participant."
Allocation concealment (selection bias)	Low risk	Quote: "The randomization sequence was entered by a study statistician into a secure, web‐based application using SAS version 9.4 (SAS Institute Inc), which was accessed by the project coordinator on enrolment of each participant."
Blinding of participants and personnel (performance bias)   All outcomes	High risk	Not feasible in psychotherapy trials
Blinding of outcome assessment (detection bias)   Patient reported symptoms	High risk	Blinding of participants to treatment allocation not feasible
Blinding of outcome assessment (detection bias)   Observer rated symptoms	Low risk	PTSD symptom severity was assessed by independent evaluators blinded to treatment condition, before and after treatment, and at 2‐week, 12‐week, and 6‐month follow‐up
Incomplete outcome data (attrition bias)   All outcomes	Unclear risk	Four randomized participants were not included in analyses. Investigators stated that, Quote: "...pattern mixture modelling found no significant differences in the change in outcome over time between participants with missing data and those without missing data." Higher dropout rates in the TF‐CBT arm relative to PCT
Selective reporting (reporting bias)	Low risk	All outcome measures listed in the study's protocol were reported in the publication.
Other bias	Unclear risk	Potential concerns of bias due to investigator allegiance; principal investigator is a developer of treatment under investigation (PE).

Study	Reason for exclusion
Bormann 2018	PCT was not compared to TF‐CBT or a control condition.
Bremner 2017	PCT was not compared to TF‐CBT or a control condition.
Classen 2001	Present‐focused group therapy was not consistent with our definition of PCT.
Classen 2011	Participants were not required to have a diagnosis of PTSD.
Davis 2019	PCT was not compared to TF‐CBT or a control condition.
Foa 1991	Present‐focused group therapy was not consistent with our definition of PCT.
Grant 2005	Not an RCT
Harris 2018	PCT was not compared to TF‐CBT or a control condition.
Haynes 2012	PCT was not compared to TF‐CBT or a control condition.
Hong 2013	Participants were required to have experienced or witnessed DSM‐IV‐TR Criterion A traumatic event, but were not required to have clinically significant levels of PTSD.
King 2016	PCT was not compared to TF‐CBT or a control condition.
Lang 2017	PCT was not compared to TF‐CBT or a control condition.
NCT00607412	Present‐centered therapy was not an intervention.
NCT01274741	Present‐centered therapy was not an intervention.
NCT02081417	Present‐centered therapy was not an intervention.
NCT02233517	PCT was not compared to TF‐CBT or a control condition.
NCT02398227	PCT was not compared to TF‐CBT or a control condition.
NCT03056157	PCT was not compared to TF‐CBT or a control condition.
NCT03429166	PCT was not compared to TF‐CBT or a control condition.
NCT03760731	Participants were not required to have a diagnosis of PTSD.
NCT03764033	PCT was not compared to TF‐CBT or a control condition.
Polusny 2015	PCT was not compared to TF‐CBT or a control condition.
Resick 2009	Conference presentation that did not present the results of an RCT
Rosner 2018	Participants were not required to have a diagnosis of PTSD.

Methods	RCT
Participants	Age 55 or older; PTSD according to DSM‐IV criteria
Interventions	Narrative Exposure Therapy vs PCT
Outcomes	Primary outcomes: PTSD (CAPS, HTQ‐16)
Notes	No full text, manuscript in preparation and data not provided by study investigators

Methods	RCT
Participants	18 to 67 years old; PTSD according to DSM‐IV criteria resulting from sexual assault, and at least 12 weeks after sexual assault
Interventions	Prolonged exposure vs supportive counseling vs treatment‐as‐usual group therapy
Outcomes	Primary outcomes: Severity of PTSD pre‐ and post‐treatment Severity of depression pre‐ and post‐treatment Severity of anxiety pre‐ and post‐treatment General function pre‐ and post‐treatment
Notes	No full text, manuscript in preparation and data not provided by study investigators

Trial name or title	A comparison of web‐prolonged exposure (Web‐PE) and present‐centered therapy (PCT) for PTSD among active‐duty military personnel
Methods	RCT
Participants	18 to 65 years old; adult male and female active duty military personnel who had deployed since 9/11; seeking treatment for PTSD; PTSD according to DSM‐5; DSM‐5 Criterion A event is combat‐related or an operational experience that occurred during deployment
Interventions	Web‐PE vs PCT
Outcomes	Primary outcomes: PTSD severity (CAPS) PTSD diagnosis Severity scores on measures of depression, general anxiety, anger, and PTSD‐related cognitions Associated biomarkers (e.g. cortisol response to awakening, cortisol response to script‐driven imagery, salivary and serum neurosteroids)
Starting date	05/2016
Contact information	Dr Carmen McLean Center for the Treatment and Study of Anxiety University of Pennsylvania Philadelphia, Pennsylvania
Notes	https://clinicaltrials.gov/ct2/show/NCT02556645

PERMALINK

Present‐centered therapy (PCT) for post‐traumatic stress disorder (PTSD) in adults

Bradley E Belsher

Erin Beech

Daniel Evatt

Derek J Smolenski

M Tracie Shea

Jean Lin Otto

Craig S Rosen

Paula P Schnurr

Abstract

Background

Objectives

Search methods

Selection criteria

Data collection and analysis

Main results

Authors' conclusions

Plain language summary

Summary of findings

Background

Description of the condition

Description of the intervention

How the intervention might work

Why it is important to do this review

Objectives

Methods

Criteria for considering studies for this review

Types of studies

Types of participants

Participant characteristics

Diagnosis

Comorbidities

Setting

Types of interventions

Experimental intervention

Comparator interventions

Types of outcome measures

Primary outcomes

Secondary outcomes

Timing of outcome assessment

Hierarchy of outcome measures

Search methods for identification of studies

Cochrane Common Mental Disorders Controlled Trials Register (CCMD‐CTR)

Electronic searches

Searching other resources

Grey literature

Correspondence

Data collection and analysis

Selection of studies

Data extraction and management

Main planned comparisons

Assessment of risk of bias in included studies

Measures of treatment effect

Continuous data

PCT vs control conditions:

PCT vs TF‐CBT non‐inferiority analysis:

Dichotomous data

Unit of analysis issues

Cluster‐randomized trials

Studies with multiple treatment groups

Dealing with missing data

Assessment of heterogeneity

Assessment of reporting biases

Data synthesis

Subgroup analysis and investigation of heterogeneity

Sensitivity analysis

'Summary of findings' table

Results

Description of studies

Results of the search

1.

Included studies

Design

Sample size

Setting

Participants

Interventions

Comparisons

Outcomes