Effectiveness of the dipstick urine test for identifying chronic kidney disease in Japanese male workers over 40 years old

I evaluated the effectiveness of the dipstick urine test for identifying chronic kidney disease (CKD) in Japanese male workers over 40 years old. Our study was conducted in all male workers aged ≥40 years who were employed at Central Japan Railway Company between 2007 and 2010. The urine dipstick test was performed to evaluate albuminuria excretion on a scale of (-), (±), (+), (2+), (3+) and (4+). The estimated glomerular filtration rate (eGFR) was calculated using the equation for Japanese. I calculated the number of participants who fit the definition of CKD in the new guidelines by albuminuria only and a combination of albuminuria and GFR. A total of 32,484 workers were included in the study. A total of 1,705 participants (5.2%) had an albuminuria excretion of (+) or higher and fit the definition of CKD by albuminuria only. A total of 4,844 participants (14.9%) had albuminuria and/or GFR<60 and fit the definition of CKD by a combination of albuminuria and GFR. Accordingly, a total of 3,139 participants (9.7%) did not fit the definition of CKD by albuminuria only. A total of 64.8% of participants who fit the definition of CKD were overlooked using albuminuria excretion only. Therefore, it is not sufficient to identify CKD by dipstick urine test only. Both the urine dipstick test and GFR measurement are required to identify CKD and to prevent end-stage renal disease.