Staging and clean room: Constructs designed to facilitate transparency and reduce bias in comparative analyses of real-world data.

PURPOSE: We describe constructs designed to protect the integrity of the results from comparative analyses using real-world data (RWD): staging and clean room. METHODS: Staging involves performing sequential preliminary analyses and evaluating the population size available and potential bias before conducting comparative analyses. A clean room involves restricted access to data and preliminary results, policies governing exploratory analyses and protocol deviations, and audit trail. These constructs are intended to allow decisions about protocol deviations, such as changes to design or model specification, to be made without knowledge of how they might affect subsequent analyses. We describe an example for implementing staging with a clean room. RESULTS: Stage 1 may involve selecting a data source, developing and registering a protocol, establishing a clean room, and applying inclusion/exclusion criteria. Stage 2 may involve attempting to achieve covariate balance, often through propensity score models. Stage 3 may involve evaluating the presence of residual confounding using negative control outcomes. After each stage, check points may be implemented when a team of statisticians, epidemiologists and clinicians masked to how their decisions may affect study outcomes, reviews the results. This review team may be tasked with making recommendations for protocol deviations to address study precision or bias. They may recommend proceeding to the next stage, conducting additional analyses to address bias, or terminating the study. Stage 4 may involve conducting the comparative analyses. CONCLUSIONS: The staging and clean room constructs are intended to protect the integrity and enhance confidence in the results of analyses of RWD.

Death, long-term nursing home placement, and impoverishment after recurrent myocardial infarction.

Study objective: To determine whether recurrent myocardial infarction (MI) is associated with increased risk of mortality, long-term nursing home placement, and impoverishment. Design: Retrospective cohort study. Setting: United States Medicare program. Participants: Individuals age > 65 years with recurrent MI hospitalizations (n = 228,826) between January 1, 2007 and June 30, 2017 and controls with initial but not recurrent MI (n = 915,304). Main outcome measures: Death, nursing home placement, and impoverishment (Medicaid enrollment or subsidies for low-income and -resource individuals) through December 31, 2017. Results: In the recurrent MI and control cohorts, 47% and 41% of individuals were age > 80 years, respectively, and 56% of both cohorts were women. After 1 year, 48% of the recurrent MI cohort and 16% of the control cohort died, 9% and 7% experienced nursing home placement, and 4% and 2% experienced impoverishment. Multivariable-adjusted hazard ratios (95% confidence intervals) comparing the recurrent MI and control cohorts were 2.04 (2.03-2.06) for death, 0.89 (0.88-0.91) for nursing home placement, and 1.32 (1.28-1.36) for impoverishment. Conclusions: Older US adults with recurrent MI had higher risk of death and impoverishment than controls who had experienced an initial MI. Unadjusted, recurrent MI was associated with higher risk of nursing home placement; however, after adjusting for sociodemographic characteristics and comorbidities, individuals with recurrent MI had slightly lower risk of nursing home placement. Preventing recurrent MI may also reduce the risk of death and impoverishment among older US adults.