Quality of Life and Economic Impacts of Retinitis Pigmentosa on Japanese Patients: A Non-interventional Cross-sectional Study

Introduction Retinitis pigmentosa (RP) is an inherited progressive disease, characterized by a loss of photoreceptors, and is the second leading cause of visual impairment in Japan. RP is currently incurable and can result in complete blindness, with affected patients typically experiencing a gradual loss of light sensitivity, visual field, and visual acuity. Identification of any unmet medical needs of patients with this condition requires an understanding of the impacts of RP; in this study, we surveyed Japanese patients with RP to investigate the quality of life and economic impacts of visual impairment. Methods This non-interventional, cross-sectional study surveyed Japanese patients with RP. Economic impact was measured using an original questionnaire that assessed out-of-pocket cost (e.g., vision aids and medical services), salary gap with the general public, and the cost of depression and anxiety. Worker productivity was assessed using the Work Productivity and Activity Impairment Questionnaire (WPAI). Quality of life was evaluated using the Health Utilities Index Mark 3 (HUI3), the National Eye Institute Visual Function Questionnaire-25 (VFQ-25), and the 5-level EQ-5D version (EQ-5D-5L). The primary outcome was direct and indirect costs of visual impairment or blindness during the lifetime of patients with RP. Results Among 122 surveyed patients with RP, the estimated annual cost per patient was 218,520 yen (2176 USD), and the estimated lifetime cost per patient was 18,523,909 yen (184,501 USD). Additional robustness testing increased the estimated annual cost and lifetime cost per patient to 783,176 yen (7801 USD) and 66,389,827 yen (661,253 USD), respectively. In working patients, work productivity loss was 26.2% per person and impairment of daily activities was 31.6% per person. The mean VFQ-25, HUI3, and EQ-5D-5L scores were 42.0, 0.393, and 0.833, respectively. Conclusion RP imposed a heavy economic burden and negative quality of life impacts in Japanese patients.