Income and health-related quality of life among prostate cancer patients over a one-year period after radical prostatectomy: a linear mixed model Analysis: a linear mixed model analysis

PURPOSE: To examine income-related disparities in health-related quality of life (HRQOL) over a one-year period after surgery (radical prostatectomy) and its contributory factors in a longitudinal perspective. Evidence of associations between income and HRQOL among patients with prostate cancer (PCa) is sparse and their explanations still remain unclear.

METHODS: 246 males of two German hospitals filled out a questionnaire at the time of acute treatment, 6 and 12 months later. Age, partnership status, baseline disease and treatment factors, physical and psychological comorbidities, as well as treatment factors and adverse effects at follow-up were additionally included in the analyses to explain potential disparities. HRQOL was assessed with the EORTC (European Organisation for Research and Treatment of Cancer) QLQ-C30 core questionnaire and the prostate-specific QLQ-PR25. A linear mixed model for repeated measures was calculated.

RESULTS: The fixed effects showed highly significant income-related inequalities regarding the majority of HRQOL scales. Less affluent PCa patients reported lower HRQOL in terms of global quality of life, all functional scales and urinary symptoms. After introducing relevant covariates, some associations became insignificant (physical, cognitive and sexual function), while others only showed reduced estimates (global quality of life, urinary symptoms, role, emotional and social function). In particular, mental disorders/psychological comorbidity played a relevant role in the explanation of income-related disparities.

CONCLUSIONS: One year after surgery, income-related disparities in various dimensions of HRQOL persist. With respect to economically disadvantaged PCa patients, the findings emphasize the importance of continuous psychosocial screening and tailored interventions, of patients' empowerment and improved access to supportive care.