Cognitive Orientation to Daily Occupational Performance (CO-OP) in Parkinson's: Randomized Trial Findings.

Only 20 people took part, a third of the 60 planned, so this trial cannot show whether CO-OP works. The authors describe it as a feasibility study and say its power limits any broader conclusions about efficacy. Participants were a small, culturally homogeneous group, all living independently, with high education levels and near-top scores on daily activities at the start, so the functional measures had little room to move and the results say little about people with more advanced Parkinson's or more disability. Only the goal attainment rating was made by someone unaware of group allocation. The other two goal measures came from the participants themselves and from the therapist who delivered the treatment and knew who was in which group. The comparison was a waiting list rather than an active treatment, and the waiting list group also improved significantly on the masked goal rating, so some of the apparent benefit may come from goal setting and attention rather than CO-OP itself. The three-month follow-up covered the CO-OP group only; the waiting list had no comparison assessment at that point. The COVID-19 pandemic disrupted recruitment and interrupted some treatment, and the authors suggest it may also explain the general decline in quality of life seen in the study. Some survey data were missing and were filled in by multiple imputation, and the planned analysis had to be replaced with a different statistical approach. The self-efficacy improvement alongside the quality of life decline is described by the authors as paradoxical and interpreted cautiously because of the small numbers.

The authors declared no conflicts of interest. The research was funded by an Australian Government Research Training Program scholarship and by a PhD award from Parkinson's Queensland Incorporated, a consumer organisation for people with Parkinson's. The paper does not say whether either funder had a role in designing the study or writing it up.

Do not conclude that CO-OP improves daily performance in Parkinson's disease. This was a feasibility trial of 20 people, far too small to establish whether the approach works, and the only measure rated by someone who did not know which group a person was in found no difference between CO-OP and the waiting list.