Validity reliability, and insights from applying the McGill quality of life questionnaire to people living with Parkinson's disease (MQoL-PD)

Existing quality-of-life instruments foi Parkins on's disease (PD) may not fully assess quality of life (Q0L) for people with PD in a holistic and multidimens ional manner. This study examines the subscale struct ure, validity, and internal-consistency reliability of the McGill Quality of Life (MQoL) Questionnaire in a sample of people with PD. This cross-sectional study evaluates the MQoL-PD by using Cronbach's alpha and principal components analysis. A total of 81 consenting people with PD from a tertiary care outpatient clinic were studied. Scores were tabulated for the motor Unified Parkinson's Disease Rating Scale (mUPDRS), the Short Form Health Survey (SF-36). the Parkinson's Disease Questionnaire (PDQ-39), the MQoL Single-Item Scale (MQoL-SIS), and the MQoL Questionnaire (MOoL). Cronbach's alpha for the MQoL-PD was: physical symptoms, 0.83; psychological symptoms, 0.59; and existential/support symptoms, 0.76. Important contribu tors to QoL in PD Include mobility, bowel and bladder function, fatigue, and pain. The MQoL Questionnaire is a valid and reliable measure of physical, psychological, and existential/support symptoms for people with PD.