The THumb Osteoarthritis Exercise TriAl (THETA); a Multicenter, Randomized Controlled Trial on Exercise Therapy with an Orthosis Compared to an Orthosis Alone in Patients with Thumb Base Osteoarthritis

THIS TRIAL WAS PROSPECTIVELY REGISTERED ON FEBRUARY 27, 2020 IN THE DUTCH TRIAL REGISTRY (www.trialregister.nl), BUT THIS TRIAL REGISTRY WAS TERMINATED. THE DATA ON OUR TRIAL WERE TRANSFERED BY THE DUTCH TRIAL REGISTRY TO WHO'S CLINICAL TRIALS SEARCH PORTAL (REFERENCE NUMBER: NL-OMON54664). WE ALSO REGISTERED THE TRIAL HERE AT CLINICALTRIALS.GOV TO BE ABLE TO ADD MORE DETAILS ON OUR STUDY.

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