Seven studies (1,841 women) were included in the review.
Six studies were prospective in design, four of which included consecutive patient samples. Four studies reported blinding of the test results. Follow-up was greater than 90% in all studies. There was significant heterogeneity across the studies (P<0.001). A funnel plot showed no significant heterogeneity.
Visual dipstick urinalysis was evaluated in 6 studies. The positive LRs ranged from 0.54 to 50.12 and the negative LRs from 0.45 to 5.49. For predicting 300 mg/24-hour proteinuria at the 1+ or greater threshold, the pooled positive LR was 3.48 (95% confidence interval, CI: 1.66, 7.27) and the pooled negative LR was 0.6 (95% CI: 0.45, 0.80).
Automated urinalysis (1+, 2+ and 3+ thresholds), other visual dipstick thresholds (2+ or 3+), and a reference standard based on 300 mg/L proteinuria were each evaluated in one or two studies. The results for these studies, which were given in the article, generally showed poor accuracy of the dipstick tests.
A univariate subgroup analysis stratified for items of study quality did not provide an explanation for the observed variation in diagnostic performance.