Ivarsson 2014.

Study characteristics
Methods	Randomised controlled trial
Participants	Sample size: 62 Diagnosis: DSM‐IV PTSD Method of recruitment: adverts in local and national newspapers Method of diagnosis: CAPS by telephone Trauma type: various (apart from childhood abuse) Age (mean): immediate treatment: 44.8 (SD 11.2) years; delayed treatment: 47.2 (SD 12.2) years Sex: 82.3% women; 17.7% men Location: Sweden Comorbidities: no structured screening for comorbid conditions Adjunctive therapy: excluded Adjunctive medication: 25.8% (stable for 3 months) Unemployment: 8.1% University education: 56.5% Exclusion criteria: imminent suicide risk; concurrent psychological treatment; presence of alcohol abuse; ongoing trauma, or trauma within the past 3 months; symptoms following childhood abuse. Baseline PTSD: all participants met diagnostic criteria for PTSD. Baseline IES‐R Scores (mean): immediate treatment: 54.65 (SD 13.16); delayed treatment: 54.87 (SD 15.48)
Interventions	Internet programme based on trauma‐focused CBT versus treatment as usual Experimental arm Duration: 8 weeks Treatment protocol 8 text‐based modules delivered once a week. Included psychoeducation, anxiety coping skill training (controlled breathing and conditioned relaxation, with skills training to facilitate trauma exposure, and some information on sleep); exposure (imaginal exposure carried out through writing and reading trauma narratives); and cognitive restructuring (psychoeducation about common thoughts and beliefs related to trauma and their impact on emotions and behaviour, especially avoidance behaviour). Participants given an opportunity to make a personal commitment for change through a treatment contract. Final module aimed at relapse prevention and maintenance of progress. Mostly text and images with a "basic layout." All modules accompanied by written homework assignments sent to therapist once a week. New modules only made available once previous one had been completed. Therapist contact: once a week and occasional reminders via website. Type of contact: encrypted web‐service Automated contact: none Type of therapist: clinical psychology students (towards the end of course) Treatment fidelity: weekly supervision with an experienced clinical psychologist to monitor fidelity Comparator arm Duration: 8 weeks Participants in treatment group who did not finish all modules within 8 weeks were able to continue using the website without therapist support after post‐treatment data had been collected. Treatment protocol Voluntarily answering questions on well‐being, stress, and sleep on a weekly basis. Participants not required to answer questions and were told that this would not affect their later treatment. Weekly questions were neutral to minimise spontaneous trauma writing. Clinician monitored responses for suicidal ideation and answered questions about trial. Therapist contact: kept to a minimum. Therapist screened responses for suicidal ideation and was available to answer questions on the trial.
Outcomes	Time points for assessment: pretreatment, post‐treatment, 1‐year follow‐up Primary outcome: IES‐R, PDS Secondary outcome: BDI‐II, BAI, QOLI, CGI‐I
Notes	Funding source: grant from Linköping University Declarations of interest among primary researchers: unclear
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "Randomization was conducted by an individual who was not otherwise involved in the research project, using an online true random number service (www.random.org)."
Allocation concealment (selection bias)	Unclear risk	Quote: "Randomization was conducted by an individual who was not otherwise involved in the research project, using an online true random number service (www.random.org)."
Blinding of participants and personnel (performance bias) All outcomes	High risk	Impossible to blind participants or therapists.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "The post‐treatment interviewers were blind to participant status (i.e. treatment or control)." Blinding impossible at 1‐year follow‐up since there was no longer a control group.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Quote: "All analyses, both the pre‐ to post‐treatment and the pre‐treatment to one year follow‐up analysis, made use of all available data from all randomized participants, following the principle of intention‐to‐treat. Prior to conducting primary analyses, the missing data assumption was tested by exploring associations between baseline characteristics and the presence of missing data."
Selective reporting (reporting bias)	Low risk	Study protocol not available but it was clear that the published reports included all expected outcomes, including those that were prespecified.
Other bias	High risk	Evaluated by the originators of the intervention.