Collection devices to reduce contamination in urine samples provided for diagnosis of uncomplicated urinary tract infection: a single blind randomised controlled trial.
Hayward G., Mort S., Yu L-M., Voysey M., Glogowska M., Croxson C., Yang Y., Allen J., Cook J., Tearne S., Blakey N., Tonner S., Sharma V., Patil M., Kelly S., Butler CC.
BACKGROUND: Urine collection devices (UCD) are being marketed and used in clinical settings to reduce urine sample contamination, despite inadequate supporting evidence. AIM: To determine whether UCDs, compared to standardised instructions for urine sample collection, reduce the proportion of contaminated samples. Design, Setting: Single blind randomised controlled trial in UK Primary care. METHOD: Women aged ≥ 18 years presenting to with symptoms attributable to urinary tract infection (UTI) were randomised (1:1:1) to use either a Peezy UCD, a Whizaway Midstream UCD, or standardised verbal instructions (SVI) for midstream sample collection. The primary outcome was the proportion of urine samples reported as contaminated by microbiology laboratory analysis. RESULTS: 1264 women (Peezy n=424; Whizaway n=421; SVI n=419) were randomised between 5/10/16 and 20/8/18. 90 women were excluded from the primary analysis due to ineligibility or lack of primary outcome data, leaving 1174 (n=381; n=390; n=403) for intention-to-treat analysis. The proportion of contaminated samples was 26.5% with the Peezy, 28.2% Whizaway, and 29% SVI (relative risk (RR) Peezy v SVI 0.91 [95% Confidence Interval (CI) 0.76 to 1.09] (P = 0.32); Whizaway v SI 0.98 [95% CI 0.97 to 1.20] (P = 0.82)). There were 100 (25.3%) device failures with Peezy and 35 (8.8%) with Whizaway UCDs; the proportion of contaminated samples was similar after device failure samples were excluded. CONCLUSION: Neither Peezy nor Whizaway UCDs reduced sample contamination when used by women presenting to primary care with suspected UTI. Their use cannot be recommended for this purpose in this setting.