Comparison of one-day versus two-day incubation of urine cultures.

The value of incubating urine cultures for 1 versus 2 days was evaluated prospectively for 1526 consecutive specimens. A total of 507 cultures (33.2%) were positive after 1 day; 41 (2.7%) showed different results after 2 days. Only yeasts and corynebacteria were detected more often with longer incubation. Patient charts were available for review from 27 of 41 late positives; in only three instances (11.1%) was action taken by physicians based on these results.