A new susceptibility index to predict the risk of severe herpes zoster-associated pain: A Japanese regional population-based cohort study, the Shizuoka study.

• Reports of zoster-associated pain risk factors are inconsistent. • We conducted a database cohort study to identify risk factors. • We identified peripheral vascular disease and the onset from October to December as novel risk factors. • We developed azoster-associated pain risk prediction scoring system. Approximately 7–20% of patients with herpes zoster (HZ) develop zoster-associated pain (ZAP). ZAP not only impairs quality of life and psychological well-being, but also can reduce work effectiveness, which has negative economic effects. Reports of ZAP risk factors are inconsistent. To confirm risk factors for the development of severe ZAP in HZ patients in Japan using a large-scale database, the Shizuoka Kokuho Database. A population-based cohort study using the Shizuoka Kokuho Database was conducted. Of 792,647 patients, 7491 (0.95%) experienced "severe ZAP" (as defined in this study). We developed a ZAP risk prediction scoring system by identifying risk factors using logistic regression analysis of several candidate risk factors for severe ZAP: age, sex, seasonality, and presence of comorbidities (using the Charlson comorbidity index), excluding HIV/AIDS. We identified peripheral vascular disease and the onset from October to December as novel risk factors for severe ZAP, in addition to the previously reported risk factors of age and comorbidities (cerebral vascular disease, chronic pulmonary disease, rheumatic disease, peptic ulcer, liver disease, diabetes, and malignant neoplasms with/without metastasis). In contrast, dementia was found to reduce ZAP risk. We developed a susceptibility index to predict the risk of ZAP. We newly demonstrated that peripheral vascular disease and the onset from October to December are ZAP risk factors. Our comorbidity findings support previous observations. The susceptibility index proposed here provides a new approach to the prevention of ZAP using early intervention for high-risk patients. [ABSTRACT FROM AUTHOR]