[Strategies for occult urinary blood in annual health examination]

Although occult urinary blood in health examinations is common in healthy employees, in the majority with occult urinary blood usually no further examination or treatment is necessary, but occult urinary blood could be an early symptom in urinary tract malignancy. In this study the data on health examinations of male employees with occult urinary blood were analyzed from 1999 to 2002 and strategies for them were discussed. The subjects were male employees working in a steel company, 1,135 ('99), 1,077 ('00), 994 ('01) and 945 ('02). The positive ratios of occult urinary blood were 8.6% in '99, 7.6% in '00, 7.8% in '01, 8.3% in '02, respectively. Multiple logistic regression analysis showed that age and urinary protein were significant factors associated positively with occult urinary blood. In general, a man who had urinary tract malignancy would have macroscopic hematuria in the course of the disease. Therefore, in people with recurrent occult urinary blood the risk of urinary malignancy is considered to be rare. The follow-up protocol was set up for employees with occult urinary blood. For four years 6 employees were referred to specialists (5 to a urologist and 1 to a nephrologist). No significant disease, including urinary tract malignancy, was detected.