The impact of comorbidity and other clinical and sociodemographic factors on health-related quality of life in Greek patients with Parkinson's disease

Objectives: This study was designed to evaluate the impact of other common self-reported comorbid disorders (hypertension, dyslipidemia, ischemic heart disease, diabetes mellitus, minor stroke, arthritis, low back pain or osteoporosis and depression) on health-related Quality of Life (HRQoL) of Parkinson's disease (PD) patients and to explore the association of their HRQoL with various sociodemographic and clinical factors. Methods: Data about age, gender, education, occupation, income, marital and residential status, social relations, disease duration, functional status, treatment and concomitant diseases were collected of 139 Greek patients (68 men and 71 women) with PD. Patients were consecutively recruited from the outpatient clinic of the first Neurology Department of Athens National University at Aeginition Hospital. Disease severity was assessed using the unified Parkinson's disease rating scale including Hoehn and Yahr and Schwab and England (S&E) scales. HRQoL was measured by the specific Parkinson's disease questionnaire (PDQ-39). A multivariate multiple regression model with normal errors was used for the statistical analysis. Results: The main determinants of HRQoL were low degree of independence measured by the S&E scale (F = 35.942, p < 0.001), social isolation (F = 20.508, p < 0.001), disease duration (F = 14.983, p < 0.001), sleep (F = 6.507, p = 0.013) and gastrointestinal disturbances (F = 4.643, p = 0.035) and the presence of depression (F = 6.022, p = 0.017). Conclusion: Among the other chronic comorbidities only depression was associated with a poor HRQoL in PD patients. Functional dependence and social isolation contributed most to worse HRQoL. Our findings suggest that adequate social support and management of depression, sleep and gastrointestinal disturbances could reduce the distress and improve HRQoL in patients with PD.