A Scoping Review of Implementation Science Studies in the Field of Traumatic Brain Injury: State of the Science and Future Directions

Abstract

Objective:

Implementation research is essential to accelerating the public health benefits of innovations in health settings. However, the U.S. National Academies of Sciences, Engineering, and Medicine 2022 report identified a lag in published implementation research applied to traumatic brain injury (TBI). Our objectives were to characterize implementation science studies published to date in TBI clinical care and rehabilitation, and provide recommendations for future directions.

Methods:

A scoping review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews. Articles published between 2011 – 2023 were identified (Medline, PubMed, PsychInfo, Web of Science), and included if the study focused on the TBI population, measured at least one Proctor (2011) implementation outcome,¹ and aligned with implementation research designs. Data were charted using an extraction template.

Results:

Of the 38 articles, 80% were published between 2018 – 2023. About 34% of articles were in the pre-implementation phase and 57.9% were in the implementation phase. Over half of articles used a theory, model, or framework to guide the research. Fifteen studies were descriptive, ten were qualitative, seven were mixed methods, and four were randomized controlled trials. Most studies investigated implementation outcomes regarding national guidelines following TBI or TBI symptom management. Adoption (42.1%) and fidelity (42.1%) were the most commonly studied implementation outcomes, followed by feasibility (18.4%), acceptability (13.2%), and penetration (10.5%). Only 55% of studies used or tested the effectiveness of one or more implementation strategies, with training and education used most commonly, followed by data warehousing techniques.

Conclusions:

Future research should prioritize the selection and investigation of implementation strategy effectiveness and mechanisms across contexts of care, and use implementation research reporting standards to improve study rigor. Additionally, collaborative efforts between researchers, community partners, individuals with TBI, and their care partners could improve the equitable translation of innovations across service contexts.

INTRODUCTION

Implementation science is defined as “the scientific study of methods to promote the systematic uptake of research findings and other evidence-based practices into routine practice, and, hence, to improve the quality and effectiveness of health services and care.”[2] Implementation research involves the study of determinants (i.e., barriers and facilitators) that affect the uptake (i.e., adoption) of innovations (i.e., guidelines, interventions, policies), but focuses more centrally on understanding what and how multilevel implementation strategies increase the adoption, penetration (i.e., reach), fidelity/adherence, acceptability, cost-effectiveness, and sustainment of innovations within and across health and social services contexts to improve the health of individuals.[1,3]

Substantial scientific investment has been devoted to improving the detection and treatment of traumatic brain injury (TBI) and related sequalae. However, in 2022, the United States (U.S.) National Academies of Sciences, Engineering, and Medicine (NASEM) report described a lack of implementation studies relating to TBI, and emphasized the critical importance of implementation research applied to TBI clinical care and rehabilitation to improve the translation of research into clinical practice.[4] The NASEM report identified implementation science as an important priority that could accelerate progress in the care of individuals with TBI, specifically calling for implementation research studies that engage researchers, clinicians, and community partners in collaborative efforts to leverage implementation strategies to reduce disparities among individuals with TBI.[4] Yet, despite decades of research focused on developing and testing the effectiveness of innovations to improve clinical management and outcomes for individuals living with TBI, less is known about the extent to which innovations are used in the contexts for which they were meant to be delivered.

Describing the current state of implementation research evidence with respect to TBI rehabilitation is essential to advance care for individuals with TBI and their care partners. The identification of gaps in the research can guide researchers, practitioners, and community partners in accelerating the uptake, reach, adherence, and sustained use of innovations for individuals living with TBI and their care partners. Hence, the objectives of this scoping review were to characterize implementation science studies in the field of TBI by (1) identifying the population, TBI severity, and setting for implementation, (2) determining the types of clinical innovations addressed, (3) identifying the implementation outcomes investigated, including at what phase these outcomes were investigated (pre-implementation, implementation, sustainment), (4) identifying the research designs and methods used to study implementation outcomes; and (5) identifying and characterizing the implementation strategies applied.

METHODS

This scoping review was conducted following the Preferred Reporting Items for Systematic Review and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR)[5] to describe the implementation studies published to date in the field of TBI clinical care and rehabilitation. Following PRISMA-ScR guidelines, our protocol was not preregistered.[6]

SEARCH STRATEGY

Published studies were searched between July and August 2023. Studies published between January 1, 2011 and July 25, 2023 were identified through Medline, PubMed, PsychInfo, and Web of Science. Additional articles were identified through hand-searching citations of articles that met criteria and from the authors’ knowledge of relevant publications. Initial search terms were identified in consultation with a librarian at the University of Maine and with reference to a published scoping review in stroke rehabilitation.[7] Search terms and strategy were then discussed/revised with several authors with expertise in implementation science (KH, JR, AK). See Appendix A for specific search terms, phrases, and Boolean search logic.

ELIGIBILITY CRITERIA

Peer-reviewed research articles published in English were included if they met the following criteria: (a) Published between 2011 – 2023; (b) studies of only the TBI population; (c) measured at least one implementation outcome as defined by Proctor et al. (2011) (i.e., acceptability, appropriateness, adoption, feasibility, fidelity, implementation cost, penetration/reach, and/or sustainability) (for definitions see https://pubmed.ncbi.nlm.nih.gov/20957426/);[1] and (d) aligned with implementation science study designs (i.e., exploratory studies aimed at identifying determinants, observational studies of implementation strategies or relationships between determinants and implementation outcomes, hybrid effectiveness-implementation studies,[8] and implementation research trials.[9] Studies were excluded if they examined only the efficacy or effectiveness of a clinical intervention with no regard to implementation determinants or strategies, focused on determinants without regard to implementation strategy identification or mapping, and/or if implementation outcomes did not align with the Proctor et al., (2011) definitions.

STUDY SELECTION

Articles were managed using Covidence[10] and reviewed in two stages. First, title and abstract screening was conducted by two undergraduate or masters students trained on identifying implementation research studies through key words, definitions, and outcomes. Second, each full text was reviewed independently by all authors and articles not meeting inclusion criteria were eliminated, with reasons for elimination recorded. Discrepancies were resolved through discussion between two authors, and when necessary, a third author made the final determination. See Figure 1, PRISMA-ScR Diagram.

Figure 1.

Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) Diagram

DATA EXTRACTION

Using a data extraction template created by the lead author and updated with input from all authors, data were extracted on the (a) study aims/objectives, (b) funding information, (c) research design, (d) TBI population (i.e., pediatric, civilian adult, military or service member), (e) TBI severity (mild [mTBI], complicated mild [defined as a head computerized tomography scan positive for an intracranial traumatic finding with a nonfocal neurological examination and a Glasgow Coma Scale score between 13 and 15],[11] moderate, severe), (f) a description of the clinical innovation, (g) study setting, (h) implementation phase, (i) implementation outcomes and their definitions, (j) measures and/or data sources used to investigate the implementation outcomes, and (k) implementation strategies used and their description. Each author was assigned a set of articles for independent data extraction and then data were verified by another author. Any discrepancies were discussed between both authors until resolved, and when necessary, a third author made the final determination. Data were then synthesized by the first author using a combination of notetaking and Excel to tabulate study characteristics to facilitate synthesis and analysis of articles.[12] Results were reviewed by all contributing authors.

RESULTS

A total of 38 articles met study inclusion criteria. Among these, about 76% (n = 29) were published between 2018 and 2023.[13–41] Approximately half of studies (n = 20) were conducted in the United States, [13,14,19,21,23,25–27,29–33,35,38,40,42–45] five in Australia,[16,17,20,46,47] five in Canada,[15,22,24,34,39] three in the United Kingdom,[18,28,48] two in Africa,[37,49] one in Norway,[50] and two spanned more than one country.[36,41] Most studies reported receiving funding support from federal, foundation, or local funding mechanisms. In the United States, most studies reported receiving full or partial funding support through the National Institutes of Health (n = 4; 10.5%). One-third of all studies reported no funding source. See Appendix B for details on funding.

Patient Population, TBI Severity, and Setting

Most studies focused on civilian adults (n = 14),[13,15–20,22,28,36,44–47] followed by pediatric populations (n = 12),[14,21,29–35,38,40,42] and veterans or service members (n = 6).[23–27,43] Three studies included a mix of participants from pediatrics through adults,[39,41,50] and three did not specify the population with TBI.[37,48,49] Half of studies focused on mTBI [14, 17,21,23,24,29,30,32,34,35,38,42–47] and one on complicated mTBI.[19] Seven studies included mixed TBI severity (mTBI through severe),[13,18,27,28,33,41,50] four focused on moderate to severe,[20,37,39,49] three on severe,[22,31,36] and four did not specify TBI severity.[25,26,40,48] The majority of studies focused implementation efforts in emergency departments (n = 10).[16,17,19,21,33,37,44–47] Fewer were in acute care or inpatient rehabilitation settings (n = 5),[18,19,27,39,48] and level 1 trauma or intensive care units (n = 4).[20,27,31,36] Three studies were situated in primary care settings in Canada,[15,24,34] and three studies centered specifically on individuals living with TBI in the community.[18,22,26] Other settings included behavioral healthcare,[13,24] public high schools in the U.S.,[14,32] Veterans Health Affairs Polytrauma System of Care outpatient clinics,[23,43] yoga programs,[41] and pediatrician offices.[42] See Table 1, Study Characteristics.

Table 1.

Study Characteristics (n = 38)

Study and Country	Patient population and Setting	Research design	Clinical innovation	Implementation phase and Theory, model, or framework [TMF]	Implementation strategies	Implementation outcomes and Definition used in the study
Avery, 2023 USA	Population: Pediatric TBI Severity: Mild Setting: High school	Non-randomized stepped wedge	Student-centered RTL program: symptom-tailored academic accommodations and standardized RTL program for all students with concussion	Phase: Implementation TMF: None	1) Selecting champions for each school; 2) monthly coaching to facilitate implementation; 3) toolkit to track and guide concussion care; 4) concussion education for school champions; 5) RTL program support	Implementation: Not defined
Behn, 2020 UK	Population: Not reported TBI Severity: Not reported Setting: Multiple	Cross-sectional survey	Communication partner training	Phase: Implementation TMF: Theoretical Domains Framework (TDF); Capability, Opportunity, Motivation, Behavior Theory (COM-B)	None	Adoption: Rating of whether their clinical practice was consistent with best practice
Bosch, 2019 Australia	Population: Adult TBI Severity: Mild Setting: Emergency department	Cluster RCT	Screening for PTA, CT scans, information sheet for patients	Phase: Implementation TMF: 1) TDF; 2) Diffusion of Innovations (DOI)	1) Stakeholder meeting; 2) local opinion leader; 3) training and education; 4) local training workshops; 5) tools/materials to prompt behaviors	Adoption: Odds of using each of the clinical practice components
Coxe, 2020 USA	Population: Pediatric TBI Severity: Mild Setting: High school	Qualitative interviews	U.S. national concussion laws	Phase: Implementation TMF: None	None	Implementation: Not defined
Daugherty, 2021 USA	Population: Pediatric TBI Severity: Mild Setting: Rural primary care	Qualitative interviews	CDC guideline on the diagnosis and management of mTBI among children	Phase: Pre-implementation TMF: None	None	Adoption: Not defined
Dillahunt-Aspillaga, 2020 USA	Population: Veterans TBI Severity: Not reported Setting: Community	Prospective concurrent mixed methods	Resource facilitation	Phase: Pre-implementation TMF: None	Coalition building	Implementation: Not defined
Donnell, 2018 USA	Population: Pediatric TBI Severity: Mild Setting: Multiple	Qualitative interviews	CDC guideline on the diagnosis and management of mTBI among children	Phase: Pre-implementation TMF: None	Educational tools for providers and patients	Implementation: Not defined
Donnelly, 2021 Multiple	Population: Multiple TBI Severity: Multiple Setting: Community	Concurrent triangulation mixed methods	LoveYourBrain Yoga	Phase: Implementation TMF: None	1) Educational materials; 2) ongoing training and mentorship; 3) formal commitment; 4) eliciting feedback from stakeholders	Feasibility: Indicators of treatment engagement (e.g., enrollment, attendance, retention) Acceptability: Positive participant ratings of the intervention
Gagnon-Roy, 2022 Canada	Population: Adult TBI Severity: Severe Setting: Community	Qualitative interviews	Cognitive orthosis tool for meal preparation	Phase: Pre-implementation TMF: None	None	Feasibility: Not defined Acceptability: Not defined Appropriateness: Not defined
Gantner, 2022 Multiple	Population: Adult TBI Severity: Severe Setting: Acute inpatient	Qualitative interviews	Recommended practices for the acute management of severe TBI	Phase: Pre-implementation TMF: TDF	None	Fidelity: Not defined
Greenburg, 2022 USA	Population: Pediatric TBI Severity: Mild Setting: Acute inpatient	Mixed methods (design not specified)	Level-of-care recommendations for mTBI management	Phase: Pre-implementation TMF: RE-AIM	Electronic clinical decision support tool	Feasibility: Not clearly defined Acceptability: Not clearly defined
Gupta, 2014 USA	Population: Adults TBI Severity: Mild Setting: Emergency department	Secondary analysis of medical records	Recommended practices for head CT imaging	Phase: Implementation TMF: None	Computerized clinical decision support tool	Fidelity: Documented adherence to guidelines for head CT imaging
Heskestad, 2012 Norway	Population: Multiple TBI Severity: Multiple Setting: Acute inpatient	Secondary analysis of medical records	Scandinavian guidelines for management of minimal, mild and moderate head injury	Phase: Implementation TMF: None	1) Education; 2) audit and feedback	Fidelity: Documented adherence to guidelines
Holmes, 2022 UK	Population: Adult TBI Severity: Multiple Setting: Community	Embedded mixed methods process evaluation	Individually tailored vocational rehabilitation	Phase: Implementation TMF: Conceptual Framework of Implementation Fidelity	None	Fidelity: The degree to which programs are implemented as intended by the program developers
Hyzak, 2023 USA	Population: Adult TBI Severity: Multiple Setting: Behavioral healthcare organizations	Explanatory sequential mixed methods	OSU TBI-ID	Phase: Pre-implementation TMF: Theory of Planned Behavior	None	Adoption: Providers’ intentions to screen for TBI and providers’ utilization of the OSU TBI-ID, as measured by the number of TBI screens conducted
Ip, 2015 USA	Population: Adults TBI Severity: Mild Setting: Emergency department	Prospective observational cohort	Head CT imaging	Phase: Implementation TMF: None	Computerized clinical decision support tool	De-adoption: Proportion of head CT scans ordered among those with mTBI
Jones, 2021 Canada	Population: Service members TBI Severity: Mild Setting: Canadian Forces Health Services rehabilitation, mental health, and primary care settings	Qualitative interviews	Cognitive screening and assessment using unspecified standardized tools	Phase: Pre-implementation TMF: Active Implementation Frameworks	None	Adoption: Not defined
Kinney, 2022 USA	Population: Veterans TBI Severity: Mild Setting: VHA Polytrauma System of Care	Convergent parallel mixed methods design	Recommended practices for the management of post-concussive sleep disturbances and headaches specified in the VA/DoD Clinical Practice Guideline for mTBI	Phase: Pre-implementation TMF: Consolidated Framework for Implementation Research (CFIR)	None	Implementation: Not defined
Knighton, 2022 USA	Population: Pediatric TBI Severity: Mild Setting: Emergency department	Non-randomized stepped wedge	Head CT imaging	Phase: Implementation; Sustainment TMF: None	1) Change record systems; 2) educational materials; 3) clinical champions; 4) audit and feedback	Adoption: Not clearly defined Sustained adherence: Not performing a head CT scan when it was not clinically indicated
Lamontagne, 2018 Canada	Population: Multiple TBI Severity: Moderate-severe Setting: Multiple	Cross-sectional survey	Ontario Neurotrauma Foundation clinical practice guideline for moderate-severe TBI	Phase: Implementation TMF: None	None	Feasibility: Extent to which the treatment can be successfully used or carried out within a given agency or setting Implementation: Self-reported proportion of patients with whom the recommendations are implemented
Lee, 2018 Australia	Population: Adults TBI Severity: Not reported Setting: Acute inpatient	Cross-sectional survey	Pupillometer	Phase: Implementation TMF: None	Education	Adoption: Frequency and consistency of use Acceptability: User-friendliness
Lindamer, 2022 USA	Population: Veterans TBI Severity: Not reported Setting: Multiple	Multi-method survey design	CogSMART and CCT	Phase Implementation TMF: RE-AIM	None	Reach: Who is intended to benefit and who participated in the intervention Effectiveness: What were the benefits according to patients and providers Adoption: Who delivered CogSMART/CCT and where was it delivered Implementation: How consistently CogSMART/CCT was administered and ways in which it was adapted
Mäkelä, 2019 UK	Population: Adult TBI Severity: Multiple Setting: Multiple	Mixed methods (design not specified)	Supported self‐management	Phase: Pre-implementation; Implementation TMF: Normalization Process Theory	Interactive training in multi-professional groups	Feasibility: Level of integration of the intervention into healthcare processes
Martinez, 2017 USA	Population: Veterans TBI Severity: Mild Setting: VHA Polytrauma System of Care outpatient settings	Qualitative interviews	Comprehensive TBI evaluation delivered via clinical video Telehealth	Phase: Implementation TMF: None	None	Adoption: Not defined
Masterson Creber, 2018 USA	Population: Pediatric TBI Severity: Multiple Setting: Emergency department	Mixed methods (specific design not specified)	Head CT imaging	Phase: Implementation; Sustainment TMF: RE-AIM	Clinical decision support tool	Reach: Extent to which the intervention was delivered to a representative proportion of the target population Adoption: Delivery of the intervention across a broad and representative proportion of settings Implementation: Consistency with which a program is delivered across programs and settings as intended Maintenance: Continued delivery of the intervention
Mortimer, 2018 Australia	Population: Adult TBI Severity: Mild Setting: Emergency department	Cluster RCT	Neurotrauma Evidence Translation clinical intervention components (screening for PTA, CT scans, information sheet for patients)	Phase: Implementation Theory: 1) TDF; 2) Model of Diffusion of Innovations	1) Local stakeholder meetings; 2) identification of local opinion leader teams; 3) train-the-trainer workshop for appointed local opinion leaders; 4) local training workshops for delivery by trained local opinion leaders; 5) provision of tools and materials to prompt recommended behaviors	Cost-effectiveness: Incremental cost (impact of the intervention on care utilization and total cost and then combining treatment effects with respect to cost) divided by incremental effectiveness (impact of the intervention on health service utilization and total cost and then combining treatment effects with respect to effectiveness)
Reisner, 2017 USA	Population: Pediatric TBI Severity: Mild Setting: Community	Pre-post survey	Unspecified practice guidelines for the management of concussion	Phase: Implementation TMF: None	Provider education	Adoption: Use of guideline recommendations, per self-report and evaluation via test scenario
Sarmiento, 2021 USA	Population: Pediatric TBI Severity: Mild Setting: Multiple	Cross-sectional survey	CDC guideline on the diagnosis and management of mTBI	Phase: Pre-implementation TMF: None	None	Adoption: Not defined
Silverburg, 2021 Canada	Population: Pediatric TBI Severity: Mild Setting: Primary care	Stepped wedge RCT	Return to activity guidelines	Phase: Implementation TMF: TDF	Education outreach visits by local opinion leaders on providing return-to-activity advice after concussion	De-implementation: The abandonment of clinical practices that are ineffective or harmful
Silverberg, 2020 Canada	Population: Adult TBI Severity: Mild Setting: Primary care	Cluster RCT	Ontario Neurotrauma Foundation clinical practice guidelines for mTBI	Phase: Implementation TMF: TDF	Change electronic health records (i.e., actionable messages for physicians tailored to the patient, with point-of-care reminders)	Feasibility: Not defined
Stassen, 2015 South Africa	Population: Not specified TBI Severity: Moderate-severe Setting: Emergency medical services	Prospective observational	Brain Trauma Foundation Clinical Practice Guideline	Phase: Implementation TMF: None	1) Online training program; 2) monitoring tool based on medical record data	Fidelity: Adherence to specific guideline recommendations
Stippler, 2021 USA	Population: Adult TBI severity: Complicated mild Setting: Emergency department, acute inpatient	Prospective cohort	Head CT imaging	Phase: Implementation TMF: None	Change record systems	De-adoption: Number of head CT scans avoided Protocol adherence: Violations of the protocol, the reason for the violation, and the violating service
Tavender, 2014 Australia	Population: Adult TBI Severity: Mild Setting: Emergency department	Qualitative interviews	Key evidence-based recommended practices for managing mTBI in the Emergency Department (e.g., validated assessment of PTA)	Phase: Pre-implementation TMF: TDF	None	Adoption: Uptake of the recommended practices
Tavender, 2015 Australia	Population: Adult TBI Severity: Mild Setting: Emergency Department	Process paper	Clinical practice guidelines for the management of mTBI in emergency departments	Phase: Pre-implementation TMF: 1) TDF; 2) DOI	1) Local stakeholder meetings; 2) identification of local opinion leader teams; 3) train-the-trainer workshop for appointed local opinion leaders; 4) local training workshops for delivery by trained local opinion leaders; 5) provision of tools and materials to prompt recommended behaviors	Feasibility: Not defined Appropriateness: Not defined Acceptability: Not defined
Vavilala, 2019 USA	Population: Pediatric TBI Severity: Severe Setting: Acute inpatient	Hybrid implementation-effectiveness design	Brain Trauma Foundation Guidelines for the Acute Medical Management of Severe Traumatic Brain Injury in Infants, Children, and Adolescents	Phase: Implementation TMF: CFIR	A clinical care pathway which specifies desired timing and ordered processes of TBI care	Fidelity: Not defined Penetration: Not defined
Vitale, 2022 USA	Population: U.S. Service Members TBI Severity: Multiple Setting: Acute inpatient	Secondary analysis of medical records	Brain Injury Guidelines, which describe a classification system for head injuries and an appropriate management algorithm for each category	Phase: Implementation TMF: None	Reminder system designed to help clinicians recall information and/or prompt them	Implementation: Not defined
Wade, 2023 USA	Population: Pediatric TBI Severity: Not reported Setting: Multiple	Descriptive	Teen Online Problem-Solving (TOPS)	Phase: Implementation TMF: RE-AIM	1) Learning collaborative; 2) distributed training and materials; 3) adaptation of intervention; 4) site-specific procedures for streamlining program delivery; 5) engage leadership in marketing; 6) identify and prepare champions	Reach: Number of patients screened, referred and treated Adoption: Number of therapists trained and delivering the program
Wynveen, 2018 Uganda	Population: Not specified TBI Severity: Moderate-severe Setting: Emergency department	Qualitative interviews	Assessment and monitoring of vital signs	Phase: Pre-implementation TMF: None, but discussed use of a general framework for educational development	1) Education; 2) provision of a chart template	Implementation: Not defined

Abbreviations: Capability, Opportunity, Motivation, Behavior Theory (COM-B); Centers for Disease Control and Prevention (CDC); Cognitive Symptom Management and Rehabilitation Training (CogSMART); Compensatory Cognitive Training (CCT); Computerized tomography (CT); Consolidated Framework for Implementation Research (CFIR); Department of Defense (DoD); Diffusion of Innovations (DOI); Mild traumatic brain injury (mTBI); Ohio State University Traumatic Brain Injury Identification Method (OSU TBI-ID); Post traumatic amnesia (PTA); Randomized controlled trial (RCT); Reach, Effectiveness, Adoption, Implementation, and Maintenance Framework (RE-AIM); Return-to-Learn (RTL); Theory, Model, Framework (TMF); Theoretical Domains Framework (TDF); United States (US); United Kingdom (UK); Veterans Affairs (VA)

Clinical Innovations and Conditions Addressed in Implementation Research

Most studies sought to address implementation outcomes for innovations related to national guidelines for early interventions following TBI or managing symptoms of TBI.[15,17,17,27,29–32,34,35,39,46,47,49,50] Two studies focused on implementation of the U.S. National Concussion Laws[14] or return-to-learn guidelines for pediatric sports and/or recreation-related concussions.[32] Additional innovations included cognitive orthosis for home-based meal preparation,[22] pharmacologic and non-pharmacologic interventions for sleep disturbance,[23] Cognitive Symptom Management and Rehabilitation Training (CogSMART) for cognitive impairment,[25] resource facilitation,[26] a yoga program for symptom management,[41] or intravenous fluid resuscitation and use of decompressive craniectomy for severe TBI.[36]

Implementation Outcomes of Study

Adoption (42.1%)[13,16,20,21,24,25,29,30,32,33,37,40,42,43,47,48] and fidelity (42.1%)[14,19,21,23,25–28,33,35–37,44,49,49,50] were the most commonly studied implementation outcomes, followed by feasibility (18.4%),[15,18,22,37–39,46] acceptability (13.2%),[20,22,37,38,46] and penetration/reach (10.5%).[25,31,33,40] Two studies examined sustainability (i.e., maintenance),[21,33] one studied cost-effectiveness of the implementation efforts,[17] and one appropriateness of the intervention.[46] Three studies examined de-adoption of outdated or ineffective interventions.[19,34,45] Approximately 66% of studies examined only one implementation outcome. See Figure 2. Overall, fidelity and adoption were most frequently measured using quantitative methods. Notably, implementation outcomes were often poorly defined, with about 47% of studies (n = 18) either not providing clear definitions or not defining their implementation outcome(s) at all.[14,15,21–24,26,27,29–32,35–38,43,46]

Figure 2.

Percentage of Studies Investigating Each Implementation Outcome

About 34% of studies (n = 13) were identified as being in the pre-implementation phase,[13,22–24,26,29,30,35–38,46,47] and 57.9% were identified as in the implementation phase (n = 22).[14–17,19,20,25,27,28,31,32,34,39–45,48–50] One study spanned pre-implementation and implementation phases [18], and two studies spanned implementation and sustainment phases.[21,33] Appropriateness was studied only during the pre-implementation phase. Adoption, fidelity, feasibility, and acceptability were investigated during pre-implementation and implementation phases. One study specifically examined adherence during implementation and sustainment phases.[21] See Figure 3.

Figure 3.

Implementation Outcomes Studied by Implementation Phase

Notably, over half of articles (52.6%) used a theory, model, or framework to study implementation outcomes, with the most common being the Theoretical Domains Framework.[15–17,34,36,46–48] Only one study used theory to test relationships between determinants and implementation outcomes.[13]

Study Designs and Methods Used to Study Implementation Outcomes

Fifteen studies (39.5%) were descriptive, with the majority using a prospective observational design[19,31,40,44,45,49,50]or cross-sectional survey to study implementation outcomes.[20,25,29,39,42,48] Two studies investigated implementation outcomes retrospectively, where one examined intervention adherence through chart review,[27] and the other examined intervention acceptability through participant self-report, as well as feasibility based on sessions attended.[41] Ten studies were purely qualitative studies[14,18,22,24,30,35–37,43,47] and seven were mixed methods.[13,23,26,28,33,38,41] One was a process paper describing theory-informed implementation strategy development to increase the feasibility, acceptability, and relevance of emergency department guidelines for managing mTBI across Australia.[46]

Only four studies used an experimental design, three of which were cluster randomized controlled trials (RCT),[15–17] and one was a stepped wedge cluster RCT.[34] Of these, one examined the feasibility of implementing guidelines to proactively address psychological symptoms following TBI in primary care settings in Canada,[15] another examined the adoption of an early neurotrauma intervention in emergency departments in Australia,[16] one was the cost-effectiveness of this implementation effort,[17] and one examined the de-implementation of prolonged rest recommendations following pediatric concussions in primary care settings in Canada.[34]

Two studies used non-randomized stepped wedge designs.[21,32] One was a hybrid type 3 effectiveness-implementation study using a non-randomized stepped wedge design to examine the effectiveness of a multifaceted implementation strategy on the adoption and sustained adherence (primary outcomes), as well as clinical effectiveness (secondary outcome) of a risk stratification intervention in emergency departments.[21] The other study used a non-randomized stepped wedge design to examine adoption of return-to-learn guidelines.[32]

Additionally, one other study clearly identified itself as a hybrid effectiveness-implementation study, but did not specify the hybrid type.[31] This study used an observational design to prospectively examine the adherence, reach, and clinical effectiveness of acute medical management guidelines for severe TBI using a multifaceted implementation strategy. In addition, seven studies were hybrid studies that examined the clinical effectiveness of an intervention alongside implementation outcomes, but these studies did not self-identify as hybrid studies.[15–18,27,41,45]

Use of Implementation Strategies

Over half of articles (55.2%) used or tested the effectiveness of one or more implementation strategies,[15–20,20,26,27,31–35,40–42,44,45,49,50] while the rest of the articles focused on assessing contextual determinants to innovation implementation with recommendations for potential implementation strategies addressed in the discussion.[13,14,22–25,28–30,36–39,43,46–48] Of the 21 articles that used or tested implementation strategies, nearly 60% (n = 12) used more than one strategy to improve implementation and/or clinical effectiveness outcomes.[16–18,21,31–33,40–42,49,50] The most common implementation strategy used was training and/or educating providers to deliver the clinical intervention,[16–21,31,32,34,35,40–42,49,50] followed by using data warehousing techniques (i.e., the integration of clinical records within or across organizations) to facilitate innovation adoption or implementation.[15,19,21,44,45] Three articles used education as the only implementation strategy for improving implementation efforts,[20,35] one of which did so through a key opinion leader.[34] Four articles included clinical site champions[21,31,32,40] and only three articles explicitly discussed engaging leadership to build buy-in for implementation.[16,17,40] See Figure 4.

Figure 4.

Number of Articles Using Each Implementation Strategy

Note. Article total is greater than 38 due to the use of more than one strategy.

DISCUSSION

To our knowledge, this is the first review to synthesize implementation research studies published to date in the field of TBI clinical care and rehabilitation. Our findings begin to address a critically important question regarding the extent to which researchers, practitioners, and community collaborators are engaging in systematic efforts to incorporate innovations into routine TBI care. Overall, despite the relative lag of published implementation studies specific to TBI, results are encouraging and reflect the field’s collective, deliberate efforts to increase the uptake, reach, fidelity, and sustainment of innovations, and ultimately, the effectiveness of clinical outcomes.[1] Nonetheless, more work is needed to improve the integration of innovations across contexts - guided by theories, models, and frameworks - as well as the application of more advanced implementation research designs to specifically study the effectiveness of implementation strategies and their mechanisms on implementation and clinical outcomes.[51] Furthermore, greater attention should be taken with regard to defining the implementation outcome, delineating how the outcome was measured, and specifying the units of analysis so that implementation, clinical, and service outcomes can be distinguished, thereby improving the rigor and reproducibility of implementation research and the pace at which innovations are used by front-line providers.[52,53] In addition, more research is needed to examine the relationships between implementation and clinical effectiveness outcomes,[54] as well as proper methods for implementation strategy selection and reporting.[55]

Of the 38 articles included in this review, most focused on adoption or fidelity outcomes. This finding differentiates the field of TBI from the broader implementation research literature, wherein acceptability was the most commonly studied outcome.[54] Notably, only four articles in this review focused on reach as an implementation outcome and only one investigated the cost-effectiveness of implementing the innovation. Reach is an important outcome for assessing how many individuals actually receive the innovation,[1,56] which is particularly important in the context of known healthcare disparities in TBI rehabilitation.[57] When examined in relation to race, ethnicity, gender, socioeconomic status, and structural forces that drive health disparities, reach of the innovation could be an indicator of implicit bias during innovation adoption and delivery.[58] Furthermore, the cost of innovations and the efforts it takes to implement those innovations must be considered to ensure equitable distribution of resources across contexts,[59] and to inform decisions about implementation success and sustainment[60] for public health impact.

Importantly, about half of the articles in this review did not clearly define their implementation outcomes or did not define their outcomes at all. In these cases, we ascertained how the implementation outcome was operationalized and/or reported through measurement. For example, one article clearly stated the aim of the study was to examine the adoption of a return-to-learn program as the effect of the multifaceted implementation strategy (i.e., RISE Bundle [Return to Learn Implementation Bundle for Schools]), but did not provide any formal definition of adoption.[32] Instead, the author’s operationalized adoption as: a) the completion rates for all 12 RISE Bundle tasks at the school-level and b) the number of schools that completed the tracking toolkit. The former operationalization of adoption in this study could potentially be misconstrued as process fidelity since the completion of all components associated with the program was a main outcome metric. These results stress the importance of clearly defining implementation outcomes and delineating definitions of outcomes from measurement to improve the rigor of implementation science and to meet basic implementation research reporting standards.[52,61]

None of the studies in this review examined the relationships between implementation outcomes, and only one study examined relationships between implementation determinants and outcomes. As discussed in Proctor et al. (2023), more precise hypotheses need to be investigated regarding the relationships between implementation outcomes in order to determine the ideal temporal sequence of such outcomes over the implementation lifecycle (i.e., pre-implementation, implementation, and sustainment).[54] Similarly, investigating determinants as predictors to implementation outcomes might lead to more precise implementation strategy deployment, including what, when, where, and how specific strategies should be applied sequentially for optimized success.[13,54] This sequential ordering also has strong implications for building more robust mechanistic models differentiating determinants, mediators, moderators, and outcomes in the greater pursuit of implementation strategy effectiveness.[51,54]

About 55% of the articles used or tested the effectiveness of a discrete implementation strategy or implementation strategy bundle on improving the implementation of an innovation. Although a variety of strategies were used or tested for their effectiveness on implementation and/or clinical outcomes, education and training were the most commonly reported strategies. In this review, only three articles discussed leadership engagement strategies[16,17,40] despite the robust literature demonstrating leadership engagement as a critical determinant to success within early and mid-phased implementation efforts.[62–64] We urge greater attention be paid to how inner-setting contextual determinants (e.g., leadership engagement, implementation climate) may be impacting change efforts, as well as the investigation of implementation strategies aimed at modifying[51] inner-setting determinants in future implementation research in the field of TBI. Relatedly, although the focus of this scoping review was to broadly characterize the state-of-science of implementation research in TBI, it should be noted that overall, studies did not follow Proctor et al. (2013) guidelines for specifying and reporting implementation strategies (i.e., actor, action, targets, temporality, dose, implementation outcomes, and theoretical justification).[55] This is particularly salient for strategies used across pre-implementation and implementation phases, for example, aimed to improve the overall effectiveness of implementation efforts. Specifically, the pre-implementation phase is a critical planning phase that should occur prior to innovation roll-out in the implementation phase. A recent study examined implementation process fidelity data from over 1280 sites to determine if the proportion of activities conducted during the pre-implementation phase and the implementation phase impacted implementation effectiveness, including program delivery competence and delivery of services to clients.[65] The results demonstrated that the more time teams spent doing pre-implementation activities in preparation for innovation delivery, the more successful the overall implementation efforts were. Hence, detailing specific aspects of the strategies used during each phase using implementation strategy reporting standards is critical not only to the effectiveness of implementation efforts, but also to improve the replicability of these strategies, and when they should be deployed.[61]

Despite the array of medical and psychosocial innovations available for individuals with TBI and their care partners, the majority of studies focused on the implementation of national guidelines for symptom management.[15,17,17,27,29–32,34,35,39,46,47,49,50] This finding might be reflective of the cross-cutting nature and prevalence of TBI across populations globally, as well as the complexities in treating TBI and TBI-related comorbidities which invariably requires more wide-ranging innovation availability as well as continual improvements to existing innovations. Consequently, this may complicate the degree to which innovations become adopted and implemented with fidelity and may require more deliberate de-adoption efforts in the future as innovations are updated. Regardless, with notable exception from a research program in Australia,[16,17,46,47] our results demonstrated an overall lack of systematic, long-standing efforts to increase the use of specific clinical interventions or policies for TBI. While more implementation research is needed across all contexts and TBI populations, we encourage greater use of implementation research methods into current and future research efforts. In this regard, we hope that superficial use of implementation research questions and methods will be reduced in lieu of more systematic, longstanding programs that will contribute to the advancement of the science of implementation in TBI care, ultimately improving client and care partner outcomes. Greater progress toward more effective clinical practices may be best facilitated through collaborations between individuals with TBI, their care partners, clinicians, organizations, and researchers (including implementation scientists) to systematically identify how to best incorporate research into practice.

This review has limitations. First, we included articles published in English, thus potentially excluding implementation research studies published in other languages. Second, our review focused solely on Proctor et al. (2011) outcomes, which may have excluded studies that defined implementation outcomes by other taxonomies, such as the Reach, Effectiveness, Adoption, Implementation, and Maintenance (RE-AIM) framework.⁵⁶ Third, because our review was aimed to broadly characterize implementation research studies in TBI, we did not include details on the implementation strategies used or tested in these articles, hence limiting a comprehensive assessment of what specific strategies work and under what context. Future research that examines the use, effectiveness, and generalizability of strategies in TBI is encouraged.

Conclusions

The implementation of innovations into clinical practice is critical to optimizing outcomes for individuals with TBI. While many innovations have been demonstrated as effective for improving outcomes for individuals with TBI and their care partners, systematic investigation of how to best implement these innovations has lagged behind, with a few notable exceptions identified in this review.[15–17,31,32] Results from this scoping review of implementation research articles applied to TBI clinical care and rehabilitation demonstrate several areas for growth that are needed to advance the translation and impact of innovations for survivors of TBI and their families. We urge greater collaborative efforts between researchers, practitioners, community partners, survivors, carers, and policy makers when developing research questions and employing implementation efforts for greatest impact. In addition, investigators should be careful when designing implementation studies to ensure clarity of implementation outcomes studied, as well as using proper guidelines and methods for implementation outcome and strategy reporting. Finally, significant advancements are needed with regard to precise implementation strategy selection, application, and testing across all contexts of care, which will dually advance the science of implementation and TBI care.