The Effect of Written Posted Instructions on Collection of Clean-Catch Urine Specimens in the Emergency Department

Background

Urinalysis testing is frequently ordered in the emergency department (ED), but contamination of urine specimens limits the interpretation of results. The mid-stream, clean-catch (MSCC) procedure for urine specimen collection is recommended to decrease contamination rates, but without instructions this procedure has poor compliance.

Objective

To evaluate the effectiveness of written instructions alone, we analyzed the rate of specimen contamination, defined by presence of squamous epithelial cells (SECs) and culture results, in the ED after posting information on the MSCC procedure.

Methods

Instructions in simple English for the MSCC procedure were posted in all patient-accessible restrooms in the ED. Frequency of contamination, defined microscopically as > 5 SECs per high-powered field or through growth of mixed or non-pathologic flora on urine culture, was determined over a 3-month period for comparison to historical controls from the previous year.

Results

During the intervention period, 754 urinalyses were sent, with 392 contaminated specimens (51.98%), and 193 urine cultures were sent, with 77 contaminated results (39.8%). Historical controls from the previous year yielded 827 urinalyses sent, with 430 contaminated (51.99%), and 251 urine cultures, with 125 contaminated results (49.8%). The difference between groups was not significant for urinalysis (p = 0.99) or urine culture (p = 0.13).

Conclusions

A poster-based educational intervention with instructions on MSCC procedure failed to decrease contamination rates in this ED-based study. Possible explanations include poor compliance with MSCC technique in the ED, or poor efficacy of this technique at decreasing contamination rates. These results may indicate that other efforts are necessary to improve urine collection methods.