Abstract
OBJECTIVE: To compare the duration of exercise therapy needed to achieve a minimal clinically important difference in mobility, walking endurance and patient-reported global physical health in patients referred for inpatient rehabilitation after knee surgery, hip surgery, or with multiple sclerosis or Parkinson's disease. DESIGN: Retrospective pre-post intervention observational cohort study. SUBJECTS: A total of 388 patients (57% women, mean age 65.6 years (standard deviation 9.5)) with a minimum length of stay 10 days were included between 1 January 2020 and 30 April 2021. METHODS: Outcomes were assessed at the start of, and discharge from, rehabilitation, using the following measures: mobility (Timed Up and Go test), walking endurance (6-minute walk test), patient-reported global physical health (Global Physical Health subscale of the 10-item Patient-Reported Outcomes Measurement Information System). The duration of exercise therapy needed to achieve a minimal clinically important difference was determined using anchor-based and distribution-based methods. RESULTS: The duration of therapy needed to achieve a minimal clinically important difference was longer in patients with multiple sclerosis or Parkinson's disease (18-88 h) than in patients after knee or hip surgery (8-25 h). In all patient groups, the duration of exercise therapy needed, determined using the distribution-based method, was shortest for patient-reported global physical health (knee surgery 9.6 h, hip surgery 6.8 h, multiple sclerosis 38.7 h, Parkinson's disease 18.4 h). CONCLUSION: The duration of active therapies required to achieve a minimal clinically important difference in physical outcomes varies widely (range 8-88 h) among different patient groups and outcomes.