Association of dipstick hematuria with all-cause mortality in the general population: results from the specific health check and guidance program in Japan

Background. Dipstick urine tests are used for general health screening in Japan. The effects of this screening on mortality have not been examined, especially with regard to hematuria. Methods. Subjects were those who participated in the 2008 Tokutei-Kenshin (nationwide specific health check and guidance program) in six districts in Japan. Using the national database of death certificates from 2008 to 2012, we identified subjects who might have died. We verified the candidates in collaboration with the regional National Health Insurance agency and public health nurses. Data were released to the research team supported by the Ministry of Health, Labor, and Welfare of Japan. Dipstick results of 1+ and higher were defined as hematuria (+). Hazard ratio (HR) [95% confidence interval (CI)] was calculated using the Cox proportional hazard analysis. Results. Among 112 115 subjects, we identified that 1290 had died by the end of 2012. In hematuria (-) subjects, the crude mortality rates were 1.2% (1.8% in men, 0.7% in women), whereas in hematuria (l) subjects, they were 1.1% (2.9% in men, 0.7% in women). After adjusting for age, body mass index, estimated glomerular filtration rate, proteinuria, comorbid condition (diabetes mellitus, hypertension and dyslipidemia), past history (stroke, heart disease and kidney disease) and lifestyle (smoking, drinking, walking and exercise), the HR (95% CI) for dipstick hematuria (+) in men was 1.464 (1.147-1.846; P = 0.003), whereas that for hematuria (-) was 0.820 (0.617-1.073; P = 0.151). Conclusions. Dipstick hematuria is significantly associated with mortality in men among Japanese community-based screening participants.