How to evaluate effects of occupational therapy - lessons learned from an exploratory randomized controlled trial

Although occupational therapy (OT) is frequently prescribed in clinical practice, there is still insufficient evidence regarding its efficacy to improve Parkinson's Disease (PD)-related activity limitations.

To evaluate the efficacy of OT and the validity of different outcome-parameters to reflect efficacy, including gold-standard clinical rating scales and quantitative motor assessments.

40 patients were included in an exploratory, randomized-controlled, single-blinded trial, receiving either (I) ten weeks of OT, with a main focus on motor aspects of activity limitations and a ten-week follow-up assessment or (II) no intervention. Inclusion criteria were diagnosis of PD and Hoehn & Yahr stage 2-3. Patients with major depression, other neurological or orthopedic diseases or OT beforehand were excluded from the study. To monitor treatment effects the MDS-UPDRS part II and III were used for patient- and clinician-based assessment. Objective Pegboard as well as Q-Motor "tremormotography" and "digitomotography" were applied.

The interventional group reported a subjective amelioration of activity limitations, with a significant improvement of MDS-UPDRS part II at the end of the study (p = 0.030). However, clinician's rating and quantitative motor assessment failed to detect a significant improvement of motor impairment and fine motor control.

This study goes in line with previous trials, showing an individual improvement of activity limitations from the patients' point of view. The discrepancy between self-perception, focusing on activity limitation, and clinician-based rating, focusing on motor impairment, challenges the current gold standard assessments as valid outcome parameters for occupational therapy trials aiming for an individualized improvement of disease burden.