Predictors of Informal Caregiver Burden in Parkinson's Disease: A Systematic Review.

Background: Caregivers of people with Parkinson's disease are at risk of experiencing caregiver burden. Understanding contributing factors is required to develop appropriate targeted interventions and support for this group. This systematic review provides an updated appraisal and synthesis of quantitative studies assessing predictors of burden among informal caregivers of people with Parkinson's.

Method: Five electronic databases (APA PsycINFO, CINAHL, MEDLINE, Web of Science, and Cochrane Library) were systematically searched (from inception until July 2024), supplemented by hand-searches. Study quality was assessed using the cross-sectional JBI Critical Appraisal Checklist. Results were synthesized narratively.

Results: Forty-one studies were included. Predictors of increased burden included greater impact of motor symptoms on activities of daily living, greater severity of neuropsychiatric symptoms, poorer quality of life of the person with Parkinson's, and poorer caregiver mental health. Demographics, presence of motor symptoms, motor complications, and general cognitive function did not predict burden. Evidence was inconclusive for several variables including disease stage and duration, motor symptom severity, functional ability, overall non-motor symptoms, mental health of the person with Parkinson's, and caregivers' involvement and protective factors.

Conclusion: Several areas for potential future intervention are indicated, although methodological weaknesses within the literature constrain the robustness of conclusions. Key areas for future research include exploring understudied variables (caregiver personality and coping style, relationship quality, and positive aspects of caregiving) that may be important predictors of burden, specifying and utilizing a more consistent definition of "informal caregiver," and recruiting younger and non-spousal caregivers and more diverse samples regarding disease severity.