Emulation of randomized trials of direct oral anticoagulants with claims data and implications for new Factor XI inhibitors.

Direct oral anticoagulants (DOACs) revolutionized the management of thromboembolic disorders. Clinical care may be further improved as Factor XIs undergo large-scale outcome trials. What role can non-randomized database studies play in expediting understanding of these drugs in clinical practice? The RCT-DUPLICATIVE Initiative emulated the design of eight DOAC randomized clinical trials (RCT) using non-randomized claims database studies. RCT study design parameters and measurements were closely emulated by the database studies and produced highly concordant results. The results of the single database study that did not meet all agreement metrics with the specific RCT it was emulating were aligned with a meta-analysis of six trials studying similar questions, suggesting the trial result was an outlier. Well-designed database studies using fit-for-purpose data came to the same conclusions as DOAC trials, illustrating how database studies could complement RCTs for Factor XI inhibitors-by accelerating insights in underrepresented populations, demonstrating effectiveness and safety in clinical practice, and testing broader indications.

Validation of alopecia coding in US claims data among women of childbearing age.

BACKGROUND: Accurately identifying alopecia in claims data is important to study this rare medication side effect. OBJECTIVES: To develop and validate a claims-based algorithm to identify alopecia in women of childbearing age. METHODS: We linked electronic health records from a large healthcare system in Massachusetts (Mass General Brigham) with Medicaid claims data from 2016 through 2018 to identify all women aged 18 to 50 years with an ICD-10 code for alopecia, including alopecia areata, androgenic alopecia, non-scarring alopecia, or cicatricial alopecia, from a visit to the MGB system. Using eight predefined algorithms to identify alopecia in Medicaid claims data, we randomly selected 300 women for whom we reviewed their charts to validate the alopecia diagnosis. Positive predictive values (PPVs) were computed for the primary algorithm and seven algorithm variations, stratified by race. RESULTS: Out of 300 patients with at least 1 ICD-10 code for alopecia in the Medicaid claims, 286 had chart-confirmed alopecia (PPV = 95.3%). The algorithm requiring two diagnosis codes plus one prescription claim for alopecia treatment identified 55 patients (PPV = 100%). The algorithm requiring 1 diagnosis code for alopecia plus 1 procedure claim for intralesional triamcinolone injection identified 35 patients (PPV = 100%). Across all 8 algorithms tested, the PPV varied between 95.3% and 100%. The PPV for alopecia ranged from 94% to 100% in White and 96%-100% in 48 non-White women. The exact date of alopecia onset was difficult to determine in charts. CONCLUSION: At least one recorded ICD-10 code for alopecia in claims data identified alopecia in women of childbearing age with high accuracy.

Data Checks Before Registering Study Protocols for Health Care Database Analyses.

This Viewpoint discusses the challenges involved with secondary health care data collection vs primary data collection and provides a list of suggested data checks before registration of a study protocol using secondary data.

Patient Characteristics Associated With Using Transcatheter Left Atrial Appendage Occlusion Versus Oral Anticoagulants for Atrial Fibrillation.

BACKGROUND: Transcatheter left atrial appendage occlusion (LAAO) is an alternative to oral anticoagulants (OACs) for stroke prevention in patients with atrial fibrillation, but the predictors of LAAO use in routine care are unclear. We aimed to assess the utilization trends of LAAO and compare the change in characteristics of LAAO users versus OACs since its marketing. METHODS: Using the US Medicare claims database (March 15, 2015, to December 31, 2020), we identified patients with atrial fibrillation, ≥65 years, and CHA2DS2-VASc score ≥2 (men) or ≥3 (women), with either first implantation of an LAAO device or initiation of OACs, including apixaban, dabigatran, rivaroxaban, edoxaban, or warfarin. Patient characteristics, measured 365 days before the first LAAO or OAC use date, were compared using logistic regression. RESULTS: There were 30 058 LAAO recipients (mean age, 77.74 years; female, 42.1%) and 792 600 OAC initiators (mean age, 78.48; female, 53.3%). In 2020, patients had higher odds of initiating LAAO use than in 2015 (0.52 versus 9.32%; adjusted odds ratio [aOR], 13.64 [95% CI, 12.56-14.81]). Old age (ie, >85 versus 65-75 years; aOR, 0.84 [95% CI, 0.80-0.88]), female sex (aOR, 0.74 [95% CI, 0.71-0.76]), Black race (aOR, 0.63 [95% CI, 0.58-0.68]) versus White race, and Medicaid eligibility (aOR, 0.61 [95% CI, 0.58-0.64]) were associated with lower odds of receiving LAAO. Among clinical characteristics, frailty, cancer, fractures, and venous thromboembolism were associated with lower odds of LAAO use, while history of intracranial and extracranial bleeding, coagulopathy, and falls were associated with higher odds of receiving LAAO. CONCLUSIONS: Among patients with atrial fibrillation receiving stroke-preventive therapy, LAAO use increased rapidly from 2015 to 2020 and was positively associated with the risk factors for OAC complications but negatively associated with old age, advanced frailty, and cancer. Black race and female sex were associated with a lower likelihood of receiving LAAO.

Effectiveness and safety of empagliflozin: final results from the EMPRISE study.

AIMS/HYPOTHESIS: Limited evidence exists on the comparative safety and effectiveness of empagliflozin against alternative glucose-lowering medications in individuals with type 2 diabetes with the broad spectrum of cardiovascular risk. The EMPagliflozin compaRative effectIveness and SafEty (EMPRISE) cohort study was designed to monitor the safety and effectiveness of empagliflozin periodically for a period of 5 years with data collection from electronic healthcare databases. METHODS: We identified individuals ≥18 years old with type 2 diabetes who initiated empagliflozin or dipeptidyl peptidase-4 inhibitors (DPP-4i) from 2014 to 2019 using US Medicare and commercial claims databases. After 1:1 propensity score matching using 143 baseline characteristics, we identified four a priori-defined effectiveness outcomes: (1) myocardial infarction (MI) or stroke; (2) hospitalisation for heart failure (HHF); (3) major adverse cardiovascular events (MACE); and (4) cardiovascular mortality or HHF. Safety outcomes included lower-limb amputations, non-vertebral fractures, diabetic ketoacidosis (DKA), acute kidney injury (AKI), severe hypoglycaemia, retinopathy progression, and short-term kidney and bladder cancers. We estimated HRs and rate differences (RDs) per 1000 person-years, overall and stratified by age, sex, baseline atherosclerotic cardiovascular disease (ASCVD) and heart failure. RESULTS: We identified 115,116 matched pairs. Compared with DPP-4i, empagliflozin was associated with lower risks of MI/stroke (HR 0.88 [95% CI 0.81, 0.96]; RD -2.08 [95% CI (-3.26, -0.90]), HHF (HR 0.50 [0.44, 0.56]; RD -5.35 [-6.22, -4.49]), MACE (HR 0.73 [0.62, 0.86]; RD -6.37 [-8.98, -3.77]) and cardiovascular mortality/HHF (HR 0.57 [0.47, 0.69]; RD -10.36 [-12.63, -8.12]). Absolute benefits were larger in older individuals and in those with ASCVD/heart failure. Empagliflozin was associated with an increased risk of DKA (HR 1.78 [1.44, 2.19]; RD 1.59 [1.08, 2.09]); decreased risks of AKI (HR 0.62 [0.54, 0.72]; RD -2.39 [-3.08, -1.71]), hypoglycaemia (HR 0.75 [0.67, 0.84]; RD -2.46 [-3.32, -1.60]) and retinopathy progression (HR 0.78 [0.63, 0.96)]; RD -9.49 [-16.97, -2.10]); and similar risks of other safety events. CONCLUSIONS/INTERPRETATION: Empagliflozin relative to DPP-4i was associated with risk reductions of MI or stroke, HHF, MACE and the composite of cardiovascular mortality or HHF. Absolute risk reductions were larger in older individuals and in those who had history of ASCVD or heart failure. Regarding the safety outcomes, empagliflozin was associated with an increased risk of DKA and lower risks of AKI, hypoglycaemia and progression to proliferative retinopathy, with no difference in the short-term risks of lower-extremity amputation, non-vertebral fractures, kidney and renal pelvis cancer, and bladder cancer.

Design differences and variation in results between randomised trials and non-randomised emulations: meta-analysis of RCT-DUPLICATE data.

Objective: To explore how design emulation and population differences relate to variation in results between randomised controlled trials (RCT) and non-randomised real world evidence (RWE) studies, based on the RCT-DUPLICATE initiative (Randomised, Controlled Trials Duplicated Using Prospective Longitudinal Insurance Claims: Applying Techniques of Epidemiology). Design: Meta-analysis of RCT-DUPLICATE data. Data sources: Trials included in RCT-DUPLICATE, a demonstration project that emulated 32 randomised controlled trials using three real world data sources: Optum Clinformatics Data Mart, 2004-19; IBM MarketScan, 2003-17; and subsets of Medicare parts A, B, and D, 2009-17. Eligibility criteria for selecting studies: Trials where the primary analysis resulted in a hazard ratio; 29 RCT-RWE study pairs from RCT-DUPLICATE. Results: Differences and variation in effect sizes between the results from randomised controlled trials and real world evidence studies were investigated. Most of the heterogeneity in effect estimates between the RCT-RWE study pairs in this sample could be explained by three emulation differences in the meta-regression model: treatment started in hospital (which does not appear in health insurance claims data), discontinuation of some baseline treatments at randomisation (which would have been an unusual care decision in clinical practice), and delayed onset of drug effects (which would be under-reported in real world clinical practice because of the relatively short persistence of the treatment). Adding the three emulation differences to the meta-regression reduced heterogeneity from 1.9 to almost 1 (absence of heterogeneity). Conclusions: This analysis suggests that a substantial proportion of the observed variation between results from randomised controlled trials and real world evidence studies can be attributed to differences in design emulation.

Cardiorenal effectiveness of empagliflozin vs. glucagon-like peptide-1 receptor agonists: final-year results from the EMPRISE study.

BACKGROUND: No randomized clinical trials have directly compared the cardiorenal effectiveness of empagliflozin and GLP-1RA agents with demonstrated cardioprotective effects in patients with a broad spectrum of cardiovascular risk. We reported the final-year results of the EMPRISE study, a monitoring program designed to evaluate the cardiorenal effectiveness of empagliflozin across broad patient subgroups. METHODS: We identified patients ≥ 18 years old with type 2 diabetes who initiated empagliflozin or GLP-1RA from 2014 to 2019 using US Medicare and commercial claims databases. After 1:1 propensity score matching using 143 baseline characteristics, we evaluated risks of outcomes including myocardial infarction (MI) or stroke, hospitalization for heart failure (HHF), major adverse cardiovascular events (MACE - MI, stroke, or cardiovascular mortality), a composite of HHF or cardiovascular mortality, and progression to end-stage kidney disease (ESKD) (in patients with chronic kidney disease stages 3-4). We estimated hazard ratios (HR) and rate differences (RD) per 1,000 person-years, overall and within subgroups of age, sex, baseline atherosclerotic cardiovascular disease (ASCVD), and heart failure (HF). RESULTS: We identified 141,541 matched pairs. Compared with GLP-1RA, empagliflozin was associated with similar risks of MI or stroke [HR: 0.99 (0.92, 1.07); RD: -0.23 (-1.25, 0.79)], and lower risks of HHF [HR: 0.50 (0.44, 0.56); RD: -2.28 (-2.98, -1.59)], MACE [HR: 0.90 (0.82, 0.99); RD: -2.54 (-4.76, -0.32)], cardiovascular mortality or HHF [HR: 0.77 (0.69, 0.86); RD: -4.11 (-5.95, -2.29)], and ESKD [0.75 (0.60, 0.94); RD: -6.77 (-11.97, -1.61)]. Absolute risk reductions were larger in older patients and in those with baseline ASCVD/HF. They did not differ by sex. CONCLUSIONS: The cardiovascular benefits of empagliflozin vs. cardioprotective GLP-1RA agents were larger in older patients and in patients with history of ASCVD or HF, while they did not differ by sex. In patients with advanced CKD, empagliflozin was associated with risk reductions of progression to ESKD.

Prevalence of Pretreatment Testing Recommended for Patients With Chronic Inflammatory Skin Diseases.

Importance: Laboratory testing for the presence of tuberculosis, hepatitis, and other conditions before starting most systemic immunomodulatory agents is recommended in patients with chronic inflammatory skin diseases (CISD) but current testing patterns in the US are unclear. Objective: To determine the prevalence of pretreatment testing that is recommended for patients with CISD (psoriasis, hidradenitis suppurativa, or atopic dermatitis). Design, Setting, and Participants: This descriptive analysis of US commercial insurance claims databases from December 31, 2002, to December 31, 2020, included adult patients with CISD (psoriasis, hidradenitis suppurativa, or atopic dermatitis) who started an immunomodulatory agent, including methotrexate, tumor necrosis factor α inhibitors, interleukin (IL)-17Ai, ustekinumab, IL-23i, dupilumab, or apremilast. Main Outcomes and Measures: The proportion of patients who underwent the screening tests as suggested by professional societies-including for tuberculosis, hepatitis, and liver function; complete blood cell counts; and lipid panels-were determined within 6 months before and during 2 years after treatment start. Results: A total of 122 308 patients with CISDs (median [IQR] age, 49 [38-58] years; 63 663 [52.1%] male) starting systemic immunomodulatory treatment in the US were included. Treatment for patients with CISDs comprised methotrexate (28 684), tumor necrosis factor α inhibitors (40 965), ustekinumab (12 841), IL-23i (6116), IL-17Ai (9799), dupilumab (7787), or apremilast (16 116). Complete blood cell count was the most common test, performed in 41% (3161/7787) to 69% (19 659/28 684) of individuals before initiation across treatments. Between 11% (889/7787) and 59% (3613/6116) of patients had tuberculosis screening within 6 months before treatment, and 3% (149/4577) to 26% (1559/6097) had updated tests 1 year later. Between 13% (1006/7787) and 41% (16 728/40 965) had hepatitis panels before treatment. Low pretreatment testing levels before apremilast (15% [2331/16 116] to 45% [7253/16 116]) persisted a year into treatment (9% [816/8496] to 36% [2999/8496]) and were similar to dupilumab (11% [850/7787] to 41% [3161/7787] vs 3% [149/4577] to 25% [1160/4577]). Conclusions and Relevance: In this descriptive analysis of patients with CISDs starting systemic immunomodulatory treatment in the US, less than 60% received the recommended pretreatment testing. Additional research is required to understand whether variations in testing affect patient outcomes.

High-Dose vs. Standard-Dose Influenza Vaccine and Cardiopulmonary Hospitalization or Mortality: Emulating the INVESTED Trial Using Insurance Claims Data.

The INVESTED trial did not show benefits of high-dose (HD) vaccine vs. standard-dose (SD) for a primary composite outcome of cardiopulmonary hospitalization or all-cause mortality (hazard ratio (HR) = 1.05, 95% confidence interval (CI) = 0.96-1.15) and its components (all-cause mortality HR = 1.01, 95% CI = 0.84-1.21, cardiopulmonary hospitalization HR = 1.05, 95% CI = 0.96-1.16) during three influenza seasons (2016-2019) among participants with recent myocardial infarction or hospitalization for heart failure (HHF). We emulated INVESTED using Medicare claims data to assess whether the real-world evidence (RWE) study reached similar conclusions. We identified 1:1 propensity score (PS)-matched trial-eligible Medicare beneficiaries aged > 65 years and with prior HHF who received an HD or SD vaccine for the 2016-2019 seasons. We also re-analyzed the INVESTED trial data restricting to participants > 65 years with prior HHF to align eligibility criteria more closely with the RWE study. We compared HRs from the trial and RWE study for the main outcomes. Among 53,393 pairs of PS-matched Medicare beneficiaries, the HD vaccine group showed lower risk of the primary composite outcome (HR = 0.96, 95% CI = 0.95-0.98) and all-cause mortality (HR = 0.93, 95% CI = 0.91-0.95), and similar risk of cardiopulmonary hospitalization (HR = 0.98, 95% CI = 0.96-1.00), compared with SD. The RWE and trial results were closely concordant after the trial population was limited to participants > 65 years with prior HHF: trial-based results for the primary composite outcome (HR = 1.02, 95% CI = 0.89-1.17), all-cause mortality (HR = 0.92, 95% CI = 0.72-1.16), and cardiopulmonary hospitalization (HR = 1.02, 95% CI = 0.88-1.18). Although similar to the main trial results, the RWE was closer to the results from trial participants with aligned eligibility criteria. This study affirms the importance of considering different distributions of baseline patient characteristics when comparing trial findings to RWE.

Stratified analysis in comparative effectiveness studies that emulate randomized trials.

PURPOSE: For observational cohort studies that employ matching by propensity scores (PS), preliminary stratification by consequential predictors of outcome better emulates stratified randomization and potentially reduces variance and bias through relaxed dependence on modeling assumptions. We assessed the impact of pre-stratification in two real-life examples. For both, prior evidence from placebo-controlled randomized clinical trials (RCTs) suggested small or no risk reduction, but observational analysis suggested protection, presumably the result of confounding bias. STUDY DESIGN AND SETTING: The study populations consisted of Medicare beneficiaries (2014-18) with type 2 diabetes initiating either (i) empagliflozin versus dipeptidyl peptidase-4 inhibitors (DPP-4i) or (ii) empagliflozin versus glucagon-like peptide-1 receptor agonists (GLP-1RA). The outcome was myocardial infarction or stroke. We estimated hazard ratios (HR) and rate differences (RD) after controlling for 143 pre-exposure covariates via 1:1 PS matching after (1) PS estimation in the total cohort (total-cohort PS-matching) and (2) PS estimation separately by baseline cardiovascular disease (stratified PS matching). RESULTS: Stratified PS matching resulted in HRs that exceeded those from total-cohort PS-matching by 13% and 9%, respectively, for the comparisons of empagliflozin to DPP-4i and GLP-1RA. Against both comparators, HRs and RDs after stratified PS matching were closer to the null, with slightly higher variances (2%-3%) than those after total-cohort PS matching. CONCLUSION: Stratified PS matching produced effect estimates closer to the expected trial findings than total-cohort PS matching. The price paid in increased variance was minimal.

Concepts of Designing and Implementing Pharmacoepidemiology Studies on the Safety of Systemic Treatments in Dermatology Practice.

The U.S. Food and Drug Administration and clinical guidelines use evidence from pharmacoepidemiology studies to inform prescribing decisions and fill evidence gaps left by randomized controlled trials (RCTs). The long-term safety and infrequent adverse reactions are not well-understood when RCTs are short and involve few patients, as is the case for most systemic immunomodulating drugs in dermatology. A better understanding of the design and implementation of pharmacoepidemiology studies will help practitioners assess the accuracy of etiologic findings and use them with confidence in clinical practice. Conducting pharmacoepidemiology studies follows a structured approach, which we discuss in this article: (i) a design layer connects the research question with the appropriate study design, and considering which hypothetical RCT one ideally would want to conduct reduces inadvertent investigator errors; (ii) a measurement layer transforms longitudinal patient-level data into variables that identify the study population, patient characteristics, treatment, and outcomes; and (iii) the analysis focuses on the causal treatment effect estimation. The review and interpretation of pharmacoepidemiology studies should consider issues beyond a typical review of RCTs, chiefly the lack of baseline randomization and the use of secondary data. Well-designed and well-conducted pharmacoepidemiologic studies complement dermatology practice with critical information on prescribing systemic medications.

Reporting of Observational Studies Explicitly Aiming to Emulate Randomized Trials: A Systematic Review.

Importance: Observational (nonexperimental) studies that aim to emulate a randomized trial (ie, the target trial) are increasingly informing medical and policy decision-making, but it is unclear how these studies are reported in the literature. Consistent reporting is essential for quality appraisal, evidence synthesis, and translation of evidence to policy and practice. Objective: To assess the reporting of observational studies that explicitly aimed to emulate a target trial. Evidence Review: We searched Medline, Embase, PsycINFO, and Web of Science for observational studies published between March 2012 and October 2022 that explicitly aimed to emulate a target trial of a health or medical intervention. Two reviewers double-screened and -extracted data on study characteristics, key predefined components of the target trial protocol and its emulation (eligibility criteria, treatment strategies, treatment assignment, outcome[s], follow-up, causal contrast[s], and analysis plan), and other items related to the target trial emulation. Findings: A total of 200 studies that explicitly aimed to emulate a target trial were included. These studies included 26 subfields of medicine, and 168 (84%) were published from January 2020 to October 2022. The aim to emulate a target trial was explicit in 70 study titles (35%). Forty-three studies (22%) reported use of a published reporting guideline (eg, Strengthening the Reporting of Observational Studies in Epidemiology). Eighty-five studies (43%) did not describe all key items of how the target trial was emulated and 113 (57%) did not describe the protocol of the target trial and its emulation. Conclusion and Relevance: In this systematic review of 200 studies that explicitly aimed to emulate a target trial, reporting of how the target trial was emulated was inconsistent. A reporting guideline for studies explicitly aiming to emulate a target trial may improve the reporting of the target trial protocols and other aspects of these emulation attempts.

The IMPACT of the COVID-19 Pandemic on Prescription Drug Use in Patients with Psoriasis Vulgaris in Germany.

INTRODUCTION: Real-world evidence (RWE) data is increasingly important to generate rapid insights to effectively manage patient populations. Disruptions like the coronavirus disease 2019 (COVID-19) pandemic may negatively impact the choice of medications used for managing chronic diseases such as psoriasis (PSO). Here, we explored the effect of the COVID-19 pandemic on the sales volumes of treatment guideline-based PSO medication in Germany. METHODS: Patient-level pharmacy dispensing data from the Permea platform, covering approximately 44% of all community pharmacy dispensing in Germany, were analysed from 2019 through to 2021. Patient demographics and PSO indicated medication sales were assessed specifically before and during the pandemic in Germany. RESULTS: We included 6,865,852 sold PSO related drugs from April 2019 to March 2021. Medication sales increased during the pandemic compared with before the pandemic for treatment classes of first-line biological and second-line drugs. The increase was observed across all age groups, but monthly variations could not be detected. Furthermore, we observed increased sales in first-line biological and second-line medications when comparing low to high COVID-19 incidence state. CONCLUSION: Throughout the COVID-19 pandemic the PSO indicated medication sales increased for first-line biological and second-line treatment. This shows that despite the pandemic impact, there continues to be an increase in sales volume for biologics. Only German federal states with intermittently very high COVID-19 incidences show a stagnation in sales volume. The reasons for this need to be investigated in further studies to possibly gain a better understanding of the concerns and uncertainties of patients with PSO.

Comparative Cardiovascular Effectiveness and Safety of SGLT-2 Inhibitors, GLP-1 Receptor Agonists, and DPP-4 Inhibitors According to Frailty in Type 2 Diabetes.

OBJECTIVE: To evaluate the comparative cardiovascular effectiveness and safety of sodium-glucose cotransporter 2 inhibitors (SGLT-2is), glucagon-like peptide 1 receptor agonists (GLP-1RAs), and dipeptidyl peptidase 4 inhibitors (DPP-4is) in older adults with type 2 diabetes (T2D) across different frailty strata. RESEARCH DESIGN AND METHODS: We performed three 1:1 propensity score-matched cohort studies, each stratified by three frailty strata, using data from Medicare beneficiaries (2013-2019) with T2D who initiated SGLT-2is, GLP-1RAs, or DPP-4is. In time-to-event analyses, we assessed the primary cardiovascular effectiveness composite outcome of acute myocardial infarction, ischemic stroke, hospitalization for heart failure, and all-cause mortality. The primary safety outcome was a composite of severe adverse events that have been linked to SGLT-2i or GLP-1RA use. RESULTS: Compared with DPP-4is, the overall hazard ratio (HR) for the primary effectiveness outcome associated with SGLT-2is (n = 120,202 matched pairs) was 0.72 (95% CI 0.69-0.75), corresponding to an incidence rate difference (IRD) of -13.35 (95% CI -15.06 to -11.64). IRD ranged from -6.74 (95% CI -8.61 to -4.87) in nonfrail to -27.24 (95% CI -41.64 to -12.84) in frail people (P for interaction < 0.01). Consistent benefits were observed for GLP-1RAs compared with DPP-4is (n = 113,864), with an overall HR of 0.74 (95% CI 0.71-0.77) and an IRD of -15.49 (95% CI -17.46 to -13.52). IRD in the lowest frailty stratum was -7.02 (95% CI -9.23 to -4.81) and -25.88 (95% CI -38.30 to -13.46) in the highest (P for interaction < 0.01). Results for SGLT-2is versus GLP-1RAs (n = 89,865) were comparable. Severe adverse events were not more frequent with SGLT-2is or GLP-1RAs than DPP-4is. CONCLUSIONS: SGLT-2is and GLP-1RAs safely improved cardiovascular outcomes and all-cause mortality, with the largest absolute benefits among frail people.

Development of the TrAnsparent ReportinG of observational studies Emulating a Target trial (TARGET) guideline.

BACKGROUND: Observational studies are increasingly used to inform health decision-making when randomised trials are not feasible, ethical or timely. The target trial approach provides a framework to help minimise common biases in observational studies that aim to estimate the causal effect of interventions. Incomplete reporting of studies using the target trial framework limits the ability for clinicians, researchers, patients and other decision-makers to appraise, synthesise and interpret findings to inform clinical and public health practice and policy. This paper describes the methods that we will use to develop the TrAnsparent ReportinG of observational studies Emulating a Target trial (TARGET) reporting guideline. METHODS/DESIGN: The TARGET reporting guideline will be developed in five stages following recommended guidance. The first stage will identify target trial reporting practices by systematically reviewing published studies that explicitly emulated a target trial. The second stage will identify and refine items to be considered for inclusion in the TARGET guideline by consulting content experts using sequential online surveys. The third stage will prioritise and consolidate key items to be included in the TARGET guideline at an in-person consensus meeting of TARGET investigators. The fourth stage will produce and pilot-test both the TARGET guideline and explanation and elaboration document with relevant stakeholders. The fifth stage will disseminate the TARGET guideline and resources via journals, conferences and courses. ETHICS AND DISSEMINATION: Ethical approval for the survey has been attained (HC220536). The TARGET guideline will be disseminated widely in partnership with stakeholders to maximise adoption and improve reporting of these studies.