We have a “no clinical details-no test” policy at my lab, so in general, we get accompanying clinical details with the vast majority of samples received for microbiology testing. After all, at the end of the day, clinicians just want their requests processed…

This is great, but it always irritates me slightly when we get a urine sample into the laboratory from a young adult female with symptoms of a straightforward cystitis with no supporting clinical information to suggest that a “complicated UTI” is being queried.

My first reaction when seeing this is “Why are you sending this urine sample to the lab? Do you think this is going to help your patient?”

In New Zealand, and I suspect most of the rest of the world, uncomplicated UTIs are treated empirically according to local antibiograms, usually with a short course of nitrofurantoin or trimethoprim. In most cases, this settles things down, and no further medical input is required.

We receive approximately 400 urine samples for microbiology processing into our lab each day. My rough estimate is that 5-10% of these urines have clinical details that suggest an uncomplicated UTI. It doesn’t sound much, but it certainly adds up over the course of a year, and the total cost of processing all these would likely cover a scientist’s salary.

...And if we received urine cultures into the lab on every uncomplicated UTI diagnosis, then we would be completely overwhelmed!

During the early stages of the COVID pandemic, when we were getting hammered by SARS-CoV-2 PCR requests, we urged clinicians to send us critical samples only. This certainly reduced the number of requests where the clinical details suggested uncomplicated UTI. But old habits die hard, and now we are more or less back to baseline.

I have often wondered whether we should only accept urines where the clinical details are suggestive of a complicated UTI, but we have not gone there yet. Some might wonder if such an approach is too “hardline”, but it remains an option and I think a very reasonable one at that.

People sometimes think diagnostic stewardship is all about optimising the use of very expensive laboratory tests, e.g multiplex PCR assays, but in actual fact, looking after less costly but higher volume tests such as urine culture is every bit as important…

Michael