Paula Dhiman1, Hopin Lee2, Shona Kirtley3, Gary S Collins4. 1. Centre for Statistics in Medicine, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, Botnar Research Centre, University of Oxford, Windmill Road, Oxford, OX3 7LD, United Kingdom; NIHR Oxford Biomedical Research Centre, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom. Electronic address: paula.dhiman@csm.ox.ac.uk. 2. Centre for Statistics in Medicine, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, Botnar Research Centre, University of Oxford, Windmill Road, Oxford, OX3 7LD, United Kingdom; School of Medicine and Public Health, University of Newcastle, New South Wales, Australia. 3. Centre for Statistics in Medicine, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, Botnar Research Centre, University of Oxford, Windmill Road, Oxford, OX3 7LD, United Kingdom. 4. Centre for Statistics in Medicine, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, Botnar Research Centre, University of Oxford, Windmill Road, Oxford, OX3 7LD, United Kingdom; NIHR Oxford Biomedical Research Centre, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom.
Abstract
OBJECTIVE: The objective of this study was to evaluate the methodological conduct, reporting, and risk of bias of nonrandomized studies of interventions (NRSIs) funded by UK National Institute for Health Research Biomedical Research Centres (NIHR-BRCs). STUDY DESIGN AND SETTING: We conducted a systematic review, searching the Medline and Web of Science databases between 2012 and 2018, for NRSIs funded by NIHR-BRCs. Eligible studies were published between April 2012 and December 2017. We selected a contemporary subset of NRSIs published in 2017. We extracted study design, methods for overcoming confounding bias from nonrandomization, analysis methods, and items for assessing risk of bias. Risk of bias was the primary outcome, assessed using Risk Of Bias In Non-randomised Studies-of Interventions (ROBINS-I). RESULTS: Fifty-two NSRI publications were included, of which over half were cohort studies and 29% before-and-after studies. Seventy-seven percent analyzed nonpurposefully collected data. All had serious or critical risk of bias. Regression adjustment was most commonly used to address confounding bias (50%). Few (12%) studies accounted for missing data and 42% reported different numbers of outcomes in their methods and results. CONCLUSION: Most reviewed NRSIs had serious or critical risk of bias. Although NRSIs can evaluate treatment effects when appropriately conducted, this review shows that their design, analysis, and reporting require more consideration. Crown
OBJECTIVE: The objective of this study was to evaluate the methodological conduct, reporting, and risk of bias of nonrandomized studies of interventions (NRSIs) funded by UK National Institute for Health Research Biomedical Research Centres (NIHR-BRCs). STUDY DESIGN AND SETTING: We conducted a systematic review, searching the Medline and Web of Science databases between 2012 and 2018, for NRSIs funded by NIHR-BRCs. Eligible studies were published between April 2012 and December 2017. We selected a contemporary subset of NRSIs published in 2017. We extracted study design, methods for overcoming confounding bias from nonrandomization, analysis methods, and items for assessing risk of bias. Risk of bias was the primary outcome, assessed using Risk Of Bias In Non-randomised Studies-of Interventions (ROBINS-I). RESULTS: Fifty-two NSRI publications were included, of which over half were cohort studies and 29% before-and-after studies. Seventy-seven percent analyzed nonpurposefully collected data. All had serious or critical risk of bias. Regression adjustment was most commonly used to address confounding bias (50%). Few (12%) studies accounted for missing data and 42% reported different numbers of outcomes in their methods and results. CONCLUSION: Most reviewed NRSIs had serious or critical risk of bias. Although NRSIs can evaluate treatment effects when appropriately conducted, this review shows that their design, analysis, and reporting require more consideration. Crown