Arthroplasty studies with greater than 1000 participants: analysis of follow-up methods

Background: The use of patient-reported outcome measures (PROMs) has become a mainstay of orthopedic joint arthroplasty research. Large studies with >1000 participants are vital to orthopedic research, as they allow for comprehensive multivariable analysis. Achieving high follow-up rates minimizes potential response bias. Maintaining adequate follow-up rates becomes more challenging as sample size increases. We aimed to systematically review the present literature to determine the follow-up rates of large cohorts/registries of total joint arthroplasty patients and to identify factors associated with successful collection of PROMs. Methods: A comprehensive literature search of PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Inclusion criteria were: ≥1000 participants, ≥6 months of postoperative follow-up, and use of validated PROMs postoperatively. Results: Of 720 abstracts screened, 21 studies met inclusion criteria. Only 2 studies reported achieving a PROM follow-up rate ≥80%, but neither collected PROMs preoperatively. The median rate of follow-up was 70%, and the median number of patients was 2970. Only 38% (8 of 21) of studies collected baseline PROMs prior to surgery. Conclusions: Very few studies in the present literature have collected validated PROMs on ≥1000 patients with ≥80% follow-up; these parameters are conducive to comprehensive multivariable analysis, while maintaining study validity and avoiding follow-up bias. Federal funding and a central coordinating site may be helpful in achieving follow-up in studies of this magnitude. Level of Evidence: Level III, systematic review of studies with Level of Evidence I-III. Keywords: Arthroplasty, Knee, Hip, Patient-reported outcomes