Abstract
Objective: We examined whether a positive result for proteinuria in dipstick urinalysis was affected by the use of first morning void or spot urine specimens.
Methods: The sample population consisted of individuals who received a general health check-up at Kameda Medical Center. Urinalysis was conducted for 2,619 individuals who visited our hospital between June and October 2012 using spot urine specimens and for 2,512 individuals who visited our hospital between June and October 2013 using first morning void specimens. Patients who were menstruating, being treated for diabetes, being treated or observed for nephritis, or had either nephrosis or severe kidney disease were excluded. As a primary endpoint, we examined changes in the proteinuria positivity rate and investigated factors affecting this rate by performing logistic regression analysis. As a secondary endpoint, we examined changes in the occult hematuria positivity rate.
Results: The proteinuria positivity rate with the spot urine test was 3.9% (102/2,619) and that with first morning void urine was 1.8% (45/2,512), and the difference was statistically significant (p<0.001). Logistic regression analysis confirmed that the first morning void was independently associated with the reduced proteinuria positivity rate. The occult hematuria positivity rate with the spot urine test was 6.2% (162/2,619) and that with first morning void urine was 1.8% (45/2,512) and the difference was statistically significant (p<0.001).
Conclusions: Use of first morning void urine can lead to lower proteinuria and occult hematuria positivity rates than for spot urine.
