The THumb Osteoarthritis Exercise TriAl

Summary:

OBJECTIVE(S)/RESEARCH QUESTION(S) Does an orthosis combined with exercise therapy results in less pain and less conversion to surgery than an orthosis alone in patients with first carpometacarpal osteoarthritis (CMC-1 OA), at three months and one year after the start of treatment? HYPOTHESIS The investigators hypothesize that the orthosis + exercise therapy group has less pain and conversion to surgery will be lower than the orthosis group.

STUDY DESIGN Randomized controlled multicenter trial STUDY POPULATION(S)/DATASETS Patients with first carpometacarpal osteoarthritis (CMC-1 OA) seeking treatment INTERVENTION Orthosis + exercise therapy USUAL CARE/COMPARISON Orthosis only OUTCOME MEASURES Primary outcomes: pain and conversion to surgery SAMPLE SIZE CALCULATION/DATA ANALYSIS Two groups of 80 participants; analysis based on repeated measures analysis (for pain) and Chi-square tests (for conversion to surgery). The investigators initially planned to perform a survival analysis (log-rank) and logistic regression for conversion to surgery but decided prior to data analysis on using chi-square tests to determine whether there is a between-group difference in the proportion of conversion to surgery. The investigators made this decision due to low inclusion rates, as chi-square tests require smaller sample sizes. The investigators will use a mixed-effect model analysis for pain.

COST-EFFECTIVENESS ANALYSIS (CEA)/ BUDGET IMPACT ANALYSIS (BIA) Economic evaluation will be done from societal \& healthcare perspectives, according cost-effectiveness analysis (CEA) guidelines. Medical \& non-medical costs and consequences (i.e. productivity loss) will be collected and taken into account. Both CEA and cost-utility analysis will be performed, using conversion to surgery and Quality-adjusted life years (QALYs), respectively TIME SCHEDULE Start preparation: December 2019, inclusion: October 2020- December 2022, final report: December 2023