The American Joint Replacement Registry (AJRR) is the largest registry of total hip and knee arthroplasty (THA and TKA) procedures performed in the U.S. The National (Nationwide) Inpatient Sample (NIS) is a public database containing demographic estimates based on more than seven million hospitalizations annually. The purpose of this study was to analyze whether AJRR data is representative of the national experience with TJA as represented in NIS Cohen's d effect sizes were computed to ascertain the magnitude of differences in demographics, hospital volume (in 50 patient increments), and geographic characteristics between the AJRR and NIS databases.Introduction
Methods