Defining the minimum clinically important difference (MCID) in the Hospital Anxiety and Depression Scale (HADS) in patients undergoing total hip and knee arthroplasty

Introduction: Total hip (THA) and knee (TKA) arthroplasty are effective procedures, but whose success depends on various factors, including patients' genetics, sociocultural environments, and psychological factors. Patient-reported outcome measures (PROMs) provide objective health status outcomes measurements, whose lowest significant variation is detected by the minimum clinically important difference (MCID). Hypothesis: We aimed to find the MCID scores for the Hospital Anxiety and Depression Scale (HADS), HADS-A, and HADS-D in a cohort of individuals undergoing THA or TKA. Patients and methods: We enrolled 88 patients suffering from osteoarthritis (43 undergoing THA, and 45 TKA) by administering HADS, SF-12 and WOMAC at baseline and then with a 12-month prospective follow-up. The MCID for HADS, HADS-A, and HADS-D was calculated using the distribution-based approach, according to various techniques (0.5 standard deviation (0.5 SD), the standard error of measurement (SEM), the effect size (ES), and the minimum detectable change (MDC). Results: The analysis of HADS, HADS-A, and HADS-D scores revealed clinically significant improvements in symptoms in patients who underwent THA and TKA. The MCID range values were determined to be between 2.7-8.5 for the HADS, 1.4-4.4 for the HADS-A, and 1.5-4.8 for the HADS-D in the group of patients undergoing THA, and 2.1-6.7 for the HADS, 1.2-3.8 for the HADS-A, and 1.1-3.6 for the HADS-D in the TKA group. Discussion: The study determined significant improvement in all scores applying MCID analysis, which can aid physicians in interpreting anxiety and depression scores and developing both preoperative and postoperative procedures to enhance outcomes for patients undergoing THA and TKA. Level of evidence: I; well-designed cohort study.