Predictors of general and health-related quality of life in Parkinson's disease and related disorders including caregiver perspectives.

Introduction: Our understanding of the determinants of quality of life (QOL) in people living with Parkinson's disease and related disorders (PDRD) has grown remarkably in the past decade. However, several areas remain understudied including determinants of general vs. health-related QOL, determinants in high-need patients, drivers of perceptions of caregivers vs. patients, and exploration of potential determinants outside of the traditional medical model.

Methods: This was a cross-sectional study of 210 PDRD patients and 175 caregivers who completed a battery of measures regarding general QOL (QOL-Alzheimer's disease; QOL-AD), health-related QOL (Parkinson's disease Questionnaire; PDQ-39), cognitive function, mood, grief, spiritual wellbeing, symptom burden, disease severity, disease stage, overall function, socioeconomic status, and healthcare utilization. Elastic net regularization modeling of variables significantly associated with our outcomes of interest were performed to determine predictors of general QOL, compare predictors of general vs. health-related QOL, and compare predictors of patient and caregiver perspectives on patient general QOL.

Results: General QOL was associated with spiritual wellbeing, depression, cognitive function, presence of a caregiver, and recent emergency department visits. In contrast, health-related QOL was associated with grief, symptom burden, income, disease stage, and utilization of counseling services. Caregiver ratings of patient general QOL were associated with patient symptom burden, patient grief, patient global function, caregiver burden, and caregiver spiritual wellbeing.

Conclusions: There are notable differences in the predictors of general QOL, health-related QOL and caregiver perspectives on patient general QOL. These differences have important implications for clinical research and models of clinical care.