Determinants of patient reported functional mobility in people with Parkinson's disease. A systematic review.

BACKGROUND: Information on determinants of patient-reported functional mobility is lacking but would inform the planning of healthcare, resources and strategies to promote functional mobility in people with Parkinson’s disease (PD). OBJECTIVE: To identify the determinants of patient-reported functional mobility of people with PD.METHODS: Eligible: Randomized Controlled Trials, cohort, case-control, or cross-sectional analyses in people PD without date or setting restrictions, published in English, German, or French. Excluded: instruments with under 50% of items measuring mobility. On December 3rd 2021 we searched Medline, CINAHL and PsychInfo. We assessed risk of bias using the mixed-methods appraisal tool. Results were synthesized by tabulating the determinants by outcomes and study designs. RESULTS: Ten studies published 2012-2022 were included (most in Swedish outpatient settings). Samples ranged from 9-255 participants. Follow-up varied from 1.5-36 months with attrition of 15 to 42%. Heterogenic study designs complicated results synthesis. However, determinants related to participation and environment seem to associate the strongest with patient-reported functional mobility, although determinants related to body structures and functions were most investigated. We identified the ability to drive, caregiving, sex, age, cognitive impairment, postural instability and social participation as determinants of patient-reported functional mobility. DISCUSSION: Methodological quality of the studies was limited. No study reported an a priori power calculation. Three studies controlled for confounders. The included studies lack representativeness of the population of people living with PD. Standardized sets of outcomes could enable more systematic research synthesis. CONCLUSIONS: Future research should focus on activities, participation and environmental factors and improve methodological quality.