Substantial Loss to Follow-Up and Missing Data in National Arthroscopy Registries: A Systematic Review

Purpose: To report follow-up methodologies, compliance, and existing strategies for handling missing data in national arthroscopy registries collecting patient-reported outcome measures (PROMs). Methods: Annual reports, EMBASE, and MEDLINE were queried following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines to identify national arthroscopy registries reporting follow-up with a validated PROM and sample size greater than 500. Extracted data included weighted compliance in peer-reviewed publications, cumulative compliance throughout the time span of data collection, and missing-data methodologies. Results: Nine national arthroscopy registries currently collect PROMs, with cumulative rates of follow-up ranging from less than 10% to more than 70%. We identified 36 publications from 5 national registries reporting hip and knee arthroscopies. The weighted mean compliance with PROMs in national registry publications was 56% at 0.5 years, 44% to 59% at 1 year, 40% to 61% at 2 years, 35% to 54% at 5 years, and 40% at 10 years. A missing-data analysis was reported or referenced in 58% of publications. Conclusions: In national arthroscopy registries, compliance with 2-year PROMs does not meet traditional follow-up thresholds of 60% or 80% and reporting of missing-data methodologies is inconsistent. Level of Evidence: Level IV, systematic review of Level II through IV studies.