Pragmatic-Explanatory Continuum Indicator Summary Research Articles

Improving the relevance of randomised trials to primary care: a qualitative study investigating views towards pragmatic trials and the PRECIS-2 tool

BackgroundPragmatic trials have been suggested as a way to improve the relevance of clinical trial results to practice. PRECIS-2 (Pragmatic Explanatory Continuum Indicator Summary-2) is a trial design tool which considers how pragmatic a trial is across a number of domains. It is not known whether a pragmatic approach to all PRECIS-2 domains leads to results being more relevant to primary care. The aim of this study was to investigate the views of people with influence on primary care practice towards the design of randomised trials, pragmatic approaches to trial design, and the PRECIS-2 domains.MethodsWe carried out semi-structured interviews with people who influence practice in primary care in the UK. A thematic analysis was undertaken using the framework approach.ResultsWe conducted individual or small group interviews involving an elite sample of 17 individuals. We found that an exclusively pragmatic approach to randomised trials may not always make the results of trials more applicable to primary care. For example, it may be better to have less flexibility in the way interventions are delivered in randomised trials than in practice. In addition, an appropriate balance needs to be struck when thinking about levels of resourcing and the intensity of steps needed to improve adherence in a trial. Across other aspects of a trial’s design, for example the population and trial setting, a pragmatic approach was viewed as more appropriate.ConclusionsTo maximize the relevance of research directed at primary care, trials should be conducted with the same populations and settings that are found in primary care. Across other aspects of trials it is not always necessary to match the conditions found in practice.

Are trials of psychological and psychosocial interventions for schizophrenia and psychosis included in the NICE guidelines pragmatic? A systematic review

The NICE clinical guidelines on psychosocial interventions for the treatment of schizophrenia and psychosis in adults are based on the results of randomized controlled trials (RCTs), which may not be studies with a pragmatic design, leading to uncertainty on applicability or recommendations to everyday clinical practice. To assess the level of pragmatism of the evidence used to develop the NICE guideline for psychosocial interventions in psychoses. We conducted a systematic and critical appraisal of RCTs used to develop the 'psychological therapy and psychosocial interventions' section of the NICE guideline on the treatment and management of psychosis and schizophrenia in adults, published in 2014. For each study we assessed pragmatism using the pragmatic-explanatory continuum indicator summary-2 (PRECIS-2) and the Cochrane risk of bias tool. The mean score of PRECIS-2, averaging across nine domains, was calculated to describe the level of pragmatism of each individual study. A total of 143 studies were included in the analysis. Based on the PRECIS-2 tool, 16.8% were explanatory, 33.6% pragmatic, and 49.7% were rated in an intermediate category. Compared to explanatory studies, pragmatic studies showed a lower risk of bias. Additionally, pragmatism did not significantly improve over time, and no associations were found between pragmatism and a number of trial characteristics. However, studies with a UK leading investigator had the highest mean score of pragmatism. Cognitive behavioural therapy (CBT), art therapy, family intervention, psychoeducation, and adherence therapy, showed the higher average pragmatism scores. Two third of studies used to produce NICE recommendations on psychosocial interventions for the treatment of schizophrenia and psychosis in adults are based on studies that did not employ a pragmatic design.

Pragmatic randomized trial of a distress screening program using an effectiveness-implementation hybrid design.

5 Background: Implementation of guideline-recommended distress screening in oncology remains challenging. Evidence suggests that multicomponent care pathways to identify distress severity with algorithm-based referral and management are effective, yet testing of pragmatic implementation in community settings remains limited. We conducted a pragmatic randomized trial of a distress screening program in a large healthcare system to evaluate effectiveness and simultaneously examined implementation outcomes. Methods: We designed a highly pragmatic study per the Pragmatic-Explanatory Continuum Indicator Summary-2 with adaptive workflow design. Randomization was at the medical center level (N=6); eligible patients had a new diagnosis of breast cancer (no exclusions). Eligible patients were offered the distress screening program as part of usual care: PHQ-9 screening, algorithm-based scoring and referral, referral tracking, and audit and feedback of performance data. Control sites had access to the PHQ-9 and scoring algorithm. We compared number screened, distress severity, and referral. We conducted qualitative interviews with stakeholders on implementation barriers and facilitators. Results: We enrolled 1,436 eligible patients; 692 control, 744 intervention. Groups were similar in demographic and tumor characteristics (Table); 80% of patients completed screening at intervention sites vs <1% at control sites. Of those screened at intervention sites, 10% scored in the medium/high range indicating need for referral; 94% received an appropriate referral. We conducted 20 interviews; the program was found to be highly feasible and acceptable. Conclusions: Our pragmatic, adaptive approach resulted in the large majority of patients screened and appropriately referred with a high degree of acceptability and feasibility. Our results can promote more widespread, sustained adoption of effective distress screening programs. Clinical trial information: NCT02941614. [Table: see text]

Study characteristics impacted the pragmatism of randomized controlled trial published in nursing: a meta-epidemiological study

ObjectivesThe objective of this study was to examine the impact of study characteristics on the score of the pragmatism/explanatory continuum of randomized controlled trials (RCTs) published in nursing journals using the PRagmatic Explanatory Continuum Indicator Summary (PRECIS)-2 tool. Study Design and SettingRCTs concerning five themes of nursing care indexed in the PubMed and CINAHL databases published from 2002 to 2005 and 2012 to 2015 were selected by title/abstract. A sample of 400 was randomly selected and evaluated with the PRECIS-2 tool and reading grid. ResultsThe median PRECIS score was 32 of a possible 45 [28; 36] corresponding to a medium level of pragmatism. Studies with “medication” as an intervention had a more explanatory PRECIS score than studies with other intervention types (P = 0.015). Studies with “placebo” and “no usual care” as comparators had a more explanatory PRECIS score (P = 0.0027). The pragmatism/explanatory level was unaffected by impact factor (P = 0.42), h-index of the first and last author (P = 0.27 and P = 0.25, respectively), funding (P = 0.32), blinding (P = 0.41), sample size (P = 0.22), and time (P = 0.11). ConclusionThis study highlights the pragmatism/explanatory level of nursing RCTs, the impact of the field of the article, and the comparator type on the pragmatism of these studies. Further studies are needed to confirm the astonishing result that blinding resulted in no significant difference in the PRECIS score.

Pragmaticism of Randomized Controlled Trials of Biologic Treatment With Methotrexate in Rheumatoid Arthritis: ASystematic Review.

Randomized controlled trials (RCTs) exist along a spectrum, from explanatory, designed to evaluate interventions under ideal conditions, to pragmatic, designed to reflect usual care. This study assessed the pragmatism of RCTs of advanced therapeutics in rheumatoid arthritis (RA). A systematic review was conducted to identify RA RCTs comparing biologic or targeted synthetic therapy in combination with methotrexate, to placebo or any other disease-modifying antirheumatic drugs (DMARDs). Trials were rated using the Pragmatic Explanatory Continuum Indicator Summary-2 (PRECIS-2) tool in 9 domains, each rated from 1 (very explanatory) to 5 (very pragmatic). Latent class and regression analyses examined the heterogeneity in PRECIS-2 scores and the relationship to trial characteristics. In total, 96 trials were included. Eligibility, follow-up, and flexibility of delivery of the intervention were rated as explanatory, with mean ± SD PRECIS-2 scores of 2.0 ± 0.7, 2.0 ± 1.1, and 2.1 ± 0.7, respectively, reflecting strict inclusion criteria, intensive follow-up, and rigid protocols. Studies were rated as pragmatic in setting (3.6 ± 1.5) because many were international, multicenter trials, and in primary analysis (4.1 ± 1.3), because most used intent-to-treat analyses. In latent class analyses, 2 groups were identified; the majority (74%) were rated as explanatory for most domains assessed. These trials had larger sample sizes, were more likely to be industry-funded, and enrolled patients with higher Disease Activity Score in 28 joints and Health Assessment Questionnaire disability index scores, but were less likely to be at high risk of bias. RCTs of biologic DMARD treatment in combination with methotrexate for RA were rated as predominantly explanatory, which may affect the generalizability of trial results to clinical practice.

Lessons from Outside and Within: Exploring Advancements in Methodology for Naturopathic Medicine Clinical Research.

Introduction: Naturopathy is a mixture of both traditional and complementary medicine. It incorporates a broad set of health care practices that may or may not be traditional to that country or conventional medicine and are not fully integrated into the dominant health care system. Research required to evaluate or substantiate naturopathic medicine may not fall under the testing of randomized clinical trials, which opens up discussions on what is the best practice for research in naturopathic medicine.Discussion: Not only do advances in health research methodology offer important opportunities to progress naturopathic research, there are also areas where the unique characteristics of naturopathic philosophy and practice can impact other areas of health research. Some of the new advances in health research methodology involve whole-system research, pragmatic trials, template for intervention description and replication protocols for complex interventions, patient-centered care models, and the pragmatic-explanatory continuum indicator summary tool for designing pragmatic trials. Discussion and critique of these health-related methodologies shows that these research methods are more suited for the philosophy and treatment options that naturopathy is based on.Conclusions: Successful implementation of naturopathic research methodologies, and translation and dissemination of research will require a substantial paradigm shift in which naturopathic practitioners adopt a greater level of responsibility for developing an evidence base for naturopathic medicine.

A randomized pragmatic care trial on endovascular acute stroke interventions (EASI): criticisms, responses, and ethics of integrating research and clinical care

BackgroundThe Endovascular Acute Stroke Intervention (EASI) trial was conceived as a pragmatic care trial, designed to integrate trial methods with clinical practice. Reporting the EASI experience was met with objections and criticisms during peer review concerning both scientific and ethical issues. Our goal is to discuss these criticisms in order to promote the pragmatic approach of care trials in outcome-based medical care.MethodsThe comments and criticisms of 11 reviewers from 5 journals were collected and analyzed. The EASI protocol was also compared to the protocols of seven thrombectomy trials using the pragmatic-explanatory continuum indicator summary (PRECIS).ResultsMain criticisms of EASI concerned selection criteria that were judged to be too vague and too inclusive, brain and vascular imaging methods that were not sufficiently prescribed by protocol, lack of blinding of outcome assessment, and lack of power. EASI was at the pragmatic end of the spectrum of thrombectomy trials.ConclusionThe pragmatic care trial methodology is not currently well-established. More work needs to be done to integrate scientific methods and ethical care in the best medical interest of current patients.

Integrative Oncology Trials in the Real World: Assessing the Pragmatism of an Ongoing Integrative Oncology Trial of Mindfulness and T'ai Chi/Qigong

The aim of this study was to highlight features of pragmatic real-world integrative oncology research by applying the PRagmatic Explanatory Continuum Indicator Summary (PRECIS-2) criteria to an ongoing integrative oncology clinical trial. The ongoing trial is a preference-based randomized comparative effectiveness trial of mindfulness-based cancer recovery (MBCR) versus t'ai chi/qigong (TCQ) for cancer survivors (the Mindfulness and T'ai Chi for Cancer Health [MATCH] study). The primary outcome of the MATCH study is distress, and secondary outcomes are quality of life, sleep disturbance, and physical functioning. The clinical trial is being undertaken at tertiary care cancer centers across two sites in Canada: Calgary (AB) and Toronto (ON), with a sample of 600 cancer survivors who have finished all cancer treatments and are distressed. The MATCH trial was scored on the explanatory-pragmatic continuum for each of the nine domains of the PRECIS-2 criteria on a scale of 1-5, and was rated as more explanatory than pragmatic, despite initial design efforts being more pragmatic. Areas that were least pragmatic were methods of recruitment, follow-up, and intervention delivery. The more pragmatic areas were setting, outcomes, and data analysis. More efforts toward conducting pragmatic trials are needed in the field of integrative oncology, as cancer-care institutions and policy makers are looking for sustainable interventions within already established treatment models. The PRECIS-2 criteria can help researchers meet these goals in the planning stages of trial development.

A dynamic application of PRECIS-2 to evaluate implementation in a pragmatic, cluster randomized clinical trial in two nursing home systems

BackgroundPRECIS-2 (PRagmatic Explanatory Continuum Indicator Summary-2) can assess how clinical trial design decisions (along the explanatory-pragmatic continuum) influence the applicability of trial results to intended stakeholders. The tool has been used to assess features of trials during the trial design phase and also upon completion. The ongoing PRagmatic trial Of Video Education in Nursing homes (PROVEN), which is evaluating the effectiveness of a suite of videos to improve advance care planning, is one of the first large pragmatic, cluster randomized trials within nursing home health care systems. While certain features of pragmatic trials remain static once designed (e.g., recruitment, outcomes), successful implementation of a system-wide program requires on-going evaluation and adaptation. This report’s objectives were to apply PRECIS-2 in a novel manner during the actual conduct of the PROVEN trial to assess how dynamic adaptations shifted implementation to either a more explanatory or a more pragmatic approach.MethodsWe assessed PROVEN’s protocol as initially designed according to the three PRECIS-2 domains pertinent to implementation: (1) Organization, (2) Flexibility-Delivery, and (3) Flexibility-Adherence. We then applied this framework to conduct a formative evaluation of decisions made while the trial was ongoing to adapt the implementation approach along the pragmatic versus the explanatory continuum in response to emergent challenges.ResultsBased on the PRECIS-2 rubric, the initial design of the PROVEN implementation approach reflected a hybrid of pragmatic and explanatory features. Most notably, within the Flexibility-Delivery, the trial had a relatively pragmatic approach to protocol delivery by front-line nursing home providers, balanced with a more explanatory approach to protocol monitoring enabled by the analytic capabilities of the research team. This more intensive monitoring proved critical in revealing implementation problems once the study began. Dynamic adaptations made in response to these challenges generally reflected shifts to more explanatory approaches within the Flexibility-Delivery and Flexibility-Adherence domains including ever more intensive compliance monitoring, as well as detailed coaching of front-line providers delivering the intervention by the research team.ConclusionsPragmatic trials conducted in the nursing home setting may benefit from a more dynamic approach to implementation. Allowing fluidity between pragmatic and explanatory features may still preserve the trial's applicability to intended stakeholders’ needs. PRECIS-2 provides a useful formative evaluation tool to assess these adaptations in “real-time.”Trial registrationUS National Library of Medicine, ClinicalTrials.gov, ID: NCT02612688. Registered on 19 November 2015

Applying the pragmatic-explanatory continuum indicator summary to the implementation of a physical activity coaching trial in chronic obstructive pulmonary disease

BackgroundObservational studies show that physical inactivity is associated with worse outcomes in chronic obstructive pulmonary disease (COPD). Despite practice guidelines recommending regular physical activity (PA), there are no large-scale experimental studies to confirm that patients at high risk for COPD exacerbations can increase their PA and consequently, have improved outcomes. PurposeThe purpose of this case study is to describe the use of a widely accepted pragmatic trials framework for the design and implementation of a pragmatic clinical trial (PCT) of PA coaching for COPD in a real-world setting. MethodThe aim of the trial was to determine the effectiveness of a 12-month PA coaching intervention (Walk On!) compared to standard care for 2,707 patients at high risk for COPD exacerbations from a large integrated health care system. The descriptions of our implementation experiences are anchored within the pragmatic-explanatory continuum indicator summary (PRECIS-2) framework. DiscussionFacilitators of PCT implementation include early and ongoing engagement and support of multiple stakeholders including patients, health system leaders, administrators, physician champions, and frontline clinicians, an organizational/setting that prioritizes positive lifestyle behaviors, and a flexible intervention that allows for individualization. Pragmatic challenges include reliance on electronic data that are not complete or available in real-time for patient identification, timing of outreach may not synchronize with patients’ readiness for change, and high turnover of clinical staff drawn from the existing workforce. DiscussionPRECIS-2 is a useful guide for organizing decisions about study designs and implementation approaches to help diverse stakeholders recognize the compromises between internal and external validity with those decisions.

Comparative effectiveness trials in asthma - how will I recognize one?

Comparative efficacy trials are designed to evaluate the harms and benefits of health care in a research environment. There is increasing interest in the results of comparative effectiveness trials, which are intended to fill gaps in evidence to inform decision-making in real-life clinical environments. The objective of this report is to review various tools to classify trials along the efficacy to effectiveness continuum. Three tools [Pragmatic-Explanatory Continuum Indicator Summary (PRECIS), PRECIS-2, and PRAgmatic Clinical Trial Assessment Scale (PRACTAS)] are available that use a star diagram to illustrate where each element of a clinical trial design falls along the efficacy to effectiveness continuum (e.g., selectivity of eligibility criteria, supports to promote participant adherence). The number and type of design element to be classified varies (e.g., 10 elements for PRECIS and PRACTAS vs. nine elements for PRECIS-2; only the PRACTAS tool includes stakeholder engagement). There is substantial interrater reliability when using all three tools and interrater reliability varies across the different design elements (intraclass correlation of coefficient 0.4-0.8). The PRECIS, PRECIS-2, and PRACTAS tools are options when classifying trials along the efficacy to effectiveness continuum. Researchers and decision-making stakeholders are likely to disagree about the extent to which clinical trials employ efficacy or effectiveness designs.

User involvement in adolescents’ mental healthcare: protocol for a systematic review

IntroductionUser involvement has become a growing importance in healthcare. The United Nations state that adolescents have a right to be heard, and user involvement in healthcare is a legal right...

Framing the conversation: use of PRECIS-2 ratings to advance understanding of pragmatic trial design domains

BackgroundThere continues to be debate about what constitutes a pragmatic trial and how it is distinguished from more traditional explanatory trials. The NIH Pragmatic Trials Collaborative Project, which includes five trials and a coordinating unit, has adopted the Pragmatic-Explanatory Continuum Indicator Summary (PRECIS-2) instrument. The purpose of the study was to collect PRECIS-2 ratings at two points in time to assess whether the tool was sensitive to change in trial design, and to explore with investigators the rationale for rating shifts.MethodsA mixed-methods design included sequential collection and analysis of quantitative data (PRECIS-2 ratings) and qualitative data. Ratings were collected at two annual, in-person project meetings, and subsequent interviews conducted with investigators were recorded, transcribed, and coded using NVivo 11 Pro for Windows. Rating shifts were coded as either (1) actual change (reflects a change in procedure or protocol), (2) primarily a rating shift reflecting rater variability, or (3) themes that reflect important concepts about the tool and/or pragmatic trial design.ResultsBased on PRECIS-2 ratings, each trial was highly pragmatic at the planning phase and remained so 1 year later in the early phases of trial implementation. Over half of the 45 paired ratings for the nine PRECIS-2 domains indicated a rating change from Time 1 to Time 2 (N = 24, 53%). Of the 24 rating changes, only three represented a true change in the design of the trial. Analysis of rationales for rating shifts identified critical themes associated with the tool or pragmatic trial design more generally. Each trial contributed one or more relevant comments, with Eligibility, Flexibility of Adherence, and Follow-up each accounting for more than one.ConclusionsPRECIS-2 has proved useful for “framing the conversation” about trial design among members of the Pragmatic Trials Collaborative Project. Our findings suggest that design elements assessed by the PRECIS-2 tool may represent mostly stable decisions. Overall, there has been a positive response to using PRECIS-2 to guide conversations around trial design, and the project’s focus on the use of the tool by this group of early adopters has provided valuable feedback to inform future trainings on the tool.

The application of PRECIS-2 ratings in randomized controlled trials of Chinese herbal medicine.

This study tests the feasibility of applying the pragmatic-explanatory continuum indicator summary (version “PRECIS-2”) tool to randomized controlled trials of Chinese herbal medicine. A search was conducted to identify potentially eligible randomized controlled trials. Using the PRECIS-2 tool, assessment of trials was performed independently by 2 evaluators using a scale of 1–5 for each criterion (1 = maximal efficacy, 5 = maximal effectiveness). A total of 7,166 reports were retrieved from databases and 159 were included in the full text. Though PRECIS-2 describes quantitative scoring in detail, evaluators were uncertain about several specific operationalizations and found high evaluator variation in the first independent ratings. After discussion and reaching consensus, inter-evaluator reliability improved. For PRECIS-2 ratings over time, there was no evidence that the design and performance of RCTs of CHM paid more attention to “efficacy” criteria after the implementation of PRECIS (all P > 0.05). More research is needed to establish the easiest and most useful tool to distinguish between effectiveness and efficacy results.

The role of pragmatism in explaining heterogeneity in meta-analyses of randomised trials: a protocol for a cross-sectional methodological review

IntroductionThere has been increasing interest in pragmatic trials methodology. As a result, tools such as the Pragmatic-Explanatory Continuum Indicator Summary-2 (PRECIS-2) are being used prospectively to help researchers design randomised...

How can clinical practices pragmatically increase physical activity for patients with type 2 diabetes? A systematic review.

Although regular physical activity (PA) is a cornerstone of treatment for type 2 diabetes (T2D), most adults with T2D are sedentary. Randomized controlled trials (RCTs) have proven the effectiveness of PA behavioral interventions for adults with T2D but have rarely been conducted in healthcare settings. We sought to identify PA interventions that are effective and practical to implement in clinical practice settings. Our first aim was to use the valid Pragmatic-Explanatory Continuum Indicator Summary 2 (PRECIS-2) tool to assess the potential for future implementation of PA interventions in clinical practice settings. Our second aim was to identify interventions that effectively increased PA and glycemic control among the interventions in the top tertile of PRECIS-2 scores. We searched PubMed MEDLINE from January 1980 through May 2015 for RCTs of behavioral PA interventions coordinated by clinical practices for patients with T2D. Dual investigators assessed pragmatism by PRECIS-2 scores, and study effectiveness was extracted from original RCT publications. The PRECIS-2 scores of the 46 behavioral interventions (n=13,575 participants) ranged from 3.0 to 4.8, where 5 is the most pragmatic score. In the most pragmatic tertile of interventions (n=16) by PRECIS-2 scores, 30.8 and 31.3% of interventions improved PA outcomes and hemoglobin A1c, respectively. A minority of published evidence-based PA interventions for adults with T2D were both effective and pragmatic for clinical implementation. These should be tested for dissemination using implementation trial designs.

Evaluating the design and reporting of pragmatic trials in osteoarthritis research.

Among the challenges in health research is translating interventions from controlled experimental settings to clinical and community settings where chronic disease is managed daily. Pragmatic trials offer a method for testing interventions in real-world settings but are seldom used in OA research. The aim of this study was to evaluate the literature on pragmatic trials in OA research up to August 2016 in order to identify strengths and weaknesses in the design and reporting of these trials. We used established guidelines to assess the degree to which 61 OA studies complied with pragmatic trial design and reporting. We assessed design according to the pragmatic-explanatory continuum indicator summary and reporting according to the pragmatic trials extension of the CONsolidated Standards of Reporting Trials guidelines. None of the pragmatic trials met all 11 criteria evaluated and most of the trials met between 5 and 8 of the criteria. Criteria most often unmet pertained to practitioner expertise (by requiring specialists) and criteria most often met pertained to primary outcome analysis (by using intention-to-treat analysis). Our results suggest a lack of highly pragmatic trials in OA research. We identify this as a point of opportunity to improve research translation, since optimizing the design and reporting of pragmatic trials can facilitate implementation of evidence-based interventions for OA care.

CHARTing a Path to Pragmatic Tobacco Treatment Research.

It is important to consider the degree to which studies are explanatory versus pragmatic to understand the implications of their findings for patients, healthcare professionals, and policymakers. Pragmatic trials test the effectiveness of interventions in real-world conditions; explanatory trials test for efficacy under ideal conditions. The Consortium of Hospitals Advancing Research on Tobacco (CHART) is a network of seven NIH-funded trials designed to identify effective programs that can be widely implemented in routine clinical practice. A cross-sectional analysis of CHART trial study designs was conducted to place each study on the pragmatic-explanatory continuum. After reliability training, six raters independently scored each CHART study according to ten PRagmatic Explanatory Continuum Indicator Summary (PRECIS) dimensions, which covered participant eligibility criteria, intervention flexibility, practitioner expertise, follow-up procedures, participant compliance, practitioner adherence, and outcome analyses. Means and SDs were calculated for each dimension of each study, with lower scores representing more pragmatic elements. Results were plotted on "spoke and wheel" diagrams. The rating process and analyses were performed in October 2014 to September 2015. All seven CHART trials tended toward the pragmatic end of the spectrum, although there was a range from 0.76 (SD=0.23) to 1.85 (SD=0.58). Most studies included some explanatory design elements. CHART findings should be relatively applicable to clinical practice. Funders and reviewers could integrate PRECIS criteria into their guidelines to better facilitate pragmatic research. CHART study protocols, coupled with scores reported here, may help readers improve the design of their own pragmatic trials.

The HCV care continuum among people who use drugs: protocol for a systematic review and meta-analysis.

IntroductionThe diagnosis, management, and treatment for hepatitis C virus (HCV) infection (the “HCV care continuum”) have improved in recent years. People who use drugs (PWUD) have a prevalence of HCV infection from 30 to 70 %, yet rates of testing, engagement in care, and treatment for HCV are disproportionately low compared to other populations. Delineating the progression of PWUD through the steps in the HCV care continuum in the USA is important in informing efforts to improve HCV outcomes among PWUD.Methods/designScientific databases will be searched using a comprehensive automated search strategy; gray literature and reference lists will be manually searched. Eligible reports will provide original research data related to the HCV care continuum in the USA including proportions of PWUD engaging in the following discrete steps: screening/testing, engagement in care (including receiving an HCV clinical assessment), treatment initiation and completion, and rates of those with successful HCV treatment. A quality-rating tool will be developed to ascertain the level of bias (including selection bias) in each report, and a quality score will be assigned to each eligible report. A tool adapted from the Pragmatic Explanatory Continuum Indicator Summary-2 instrument will be developed to assess the extent to which an included report reflects an effectiveness or efficacy study design. Pooled estimates and measures of association will be calculated using random effects models, and heterogeneity will be assessed at each stage of data synthesis.DiscussionThrough this review, we hope to quantify the proportion of PWUD at each progressive step and to help identify key individual, social, and structural points of leakage in the HCV care continuum for PWUD. In meeting these objectives, we will identify predictors to progress along the HCV care continuum, which can be used to inform policy to directly improve HCV care for PWUD.Systematic review registrationPROSPERO CRD42016034113Electronic supplementary materialThe online version of this article (doi:10.1186/s13643-016-0293-6) contains supplementary material, which is available to authorized users.

Progress in research of pragmatic-explanatory continuum indicator summary

Randomized controlled trial (RCT) can be designed as explanatory trial and pragmatic/practical trial (PCT) for clinical effect evaluation. The pragmatic/practical trial reflects the intervention effect under actual clinical condition, which has relatively good extrapolation, but its internal validity is relatively poor. In contrast, explanatory trials conducted under ideal conditions have better inner validity but inferior external validity. However, in the design of RCT, PCT and explanatory trials are not always opposite. Many RCTs have the properties of the two designs at the same time, Pragmatic-explanatory continuum indicator summary (PRECIS) can be used in the design of RCT for the balance between internal validity and external validity. There are few available reports about the application of PRECIS in China at present, so this paper summarizes the basic principles, characteristics of PRECIS and the application of PRECIS in order to provide reference for the clinical trial design in China.