"Ideally, SPA should be used for microbiological assessment of urine in young children," states the abstract conclusion for this article from Australia.
Looking retrospectively at urine samples from 599 children with an average age of 7 months, these authors conclude that suprapubic aspiration is superior to all other methods of obtaining urine samples for contamination rates. Contamination rates were 46% with bag urine, 26% for clean catch, 12% for catheterization, and 1% for suprapubic aspiration.
We generally rely on catheterized urine samples in our Emergency Departments - and we even have difficulty convincing some parents that this is required, let alone a suprapubic aspiration. In fact, I'm rather surprised they had 84 patients (14%) in their cohort receiving suprapubic aspiration, considering I have never seen it performed.
While I have no issue with their conclusion from a microbiologic accuracy standpoint, I'm not so sure such an invasive and painful procedure has a place in routine practice.
"Contamination rates of different urine collection methods for the diagnosis of urinary tract infections in young children: An observational cohort study."