Urine tests for diagnosis of infection are unique in that test accuracy is thought to depend on how the specimen is collected, yet often the specimen is collected by the patient with no direct supervision. Meanwhile, diagnostic testing is increasingly initiated at the point of triage, where there is minimal regard for pre-test probabilities and not enough time or personnel to provide careful patient instructions.
To our knowledge, this is the first study addressing the issue of instructions for urine specimen collection in the ED. We found that female patients with indications for MSPC urine collection often did not recall being instructed on, or performing, the important steps in MSPC. The results suggest that nursing difficulties were more to blame than patient issues, such as poor understanding or an inability or unwillingness to carry out MSPC. While the study’s generalizability may be limited and the survey methodology unstable, we suspect our findings reflect the reality in most EDs.
In the broadest sense, this study illustrates the inherent difficulty implementing a seemingly simple ED process of care by way of a nursing protocol. We discovered that communicating carefully and consistently with patients about how to collect a diagnostic sample, based on a particular physician order, in the midst of the ED nursing environment, is a complex process. Nursing-related challenges that were likely at play include difficulty successfully training all nurses about the MSPC policy, competing nursing priorities that led to rushed or omitted instructions, and the need to collect urine shortly after triage before the specific indication (e.g., UTI testing, STI testing, pregnancy testing) was known. While our survey data cannot pinpoint the reason for the low rate of successful MSPC urine instructions, the findings nonetheless suggest areas for practice improvement and future research.
Practice improvements might include ongoing nursing education that emphasizes the important components of MSPC for UTI testing. If possible, nurses should ascertain or anticipate the indication for urine testing before they give collection instructions. Written MSPC instructions using simple language and illustrations could be posted in female patient bathrooms.
Alternatively, given the myriad potential barriers to successful MSPC urine collection, it might be easier to adopt diagnostic strategies that simply eliminate MSPC specimens. In reproductive-age women with cystitis symptoms who have no signs of pyelonephritis or vaginal symptoms, urine testing for UTI is generally not needed, since pretest probability is so high.7
Physicians could be taught to base treatment decisions in such cases on the history and physical alone, without urinalysis. In the remainder of women with suspected UTI, particularly those unlikely to understand or properly carry out MSPC instructions, a catheterized specimen could be obtained.
Our findings should spur further pragmatic ED studies on the impact of urine collection instructions on urine test performance. The two best studies examining the impact of urine collection technique on urine culture contamination enrolled only university or nursing students, and the investigators themselves gave the collection instructions. These studies came to different conclusions about the importance of collection technique.4,8
Dipstick urinalysis of midstream specimens, on the other hand, has been studied in a real world outpatient setting, and shown to somewhat improve UTI diagnosis.9
However, it is still not known whether varying specimen collection instructions, or eliminating instructions, would have an impact on dipstick test accuracy. The study we would like to see would compare the difference in urine dipstick accuracy and the rate of urine culture contamination, among female ED patients randomized to written MSPC instructions versus no instructions.
Further complicating the issue of urine specimen collection in sexually active women is the increasing use of urine nucleic acid amplification tests (NAAT) for STI screening.10
In contrast to testing for UTI, urine specimens for NAAT should be maximally contaminated with vaginal material. A first void sample, collected without parting the labia, is therefore recommended.11
Thus far there has been almost no discussion in the emergency medicine (EM) literature about this dramatic difference in optimal urine collection technique between UTI and STI testing, and how it should affect testing strategies. One non-EM report suggested that women be instructed to collect a first void specimen in one cup, stop, then collect a MSPC specimen in a separate cup.12
This approach would certainly depend on detailed urine collection instructions, and our results suggest it is therefore unrealistic for the ED. Another solution is to use self-administered vaginal swabs for NAAT,13
which would obviate the need for anything other than MSPC specimens. To the extent that urine NAAT for STI do become more widespread in EDs, it strengthens the case for abandoning MSPC altogether and basing UTI treatment decisions on history and physical alone, or on catheterized specimens.