Background: Urinary tract infections (UTI) are among the most common reasons for antibiotic prescriptions. Due to increasing resistance rates, antibiotic therapy should be targeted and based on evidence-based recommendations. Test results and recommendations by medical laboratories have a relevant impact on the choice of antibiotics. The extent to which medical laboratories consider antibiotics recommended by evidence-based treatment guidelines in microbiological testing is unclear.
Objectives: The aim of the present study is to assess whether guideline recommendations for antibiotic therapy of UTI are taken into account by medical laboratories in northern Germany.
Materials and methods: A standardized and piloted questionnaire was used in our telephone survey. All microbiological laboratories in northern Germany (Hamburg, Bremen, Lower Saxony, Schleswig-Holstein, and Mecklenburg-Western Pomerania; n = 82) were asked about their standards in diagnosing and microbiological testing of urine cultures.
Results: A total of 71 of the 82 contacted laboratories perform microbiological tests, whereby 40 of these participated (56 %). Most of the laboratories (43 %) routinely perform microbiological testing when bacterial counts were ≥ 10(4) colony forming units per ml (CFU/ml), 15 % ≥ 10(5) CFU/ml, 17 % ≥ 10(3) CFU/ml, and 8 % ≥ 10(2) CFU/ml. Antibiotic testing includes ciprofloxacin (95 %), cotrimoxazole (87.5 %), trimethoprim (57 %), fosfomycin (85 %), and nitrofurantoin (72 %).
Conclusions: The diagnostic threshold recommended in evidence-based guidelines (10(3) CFU/ml) is used only by a few laboratories. Antibiotics recommended as a first line therapy are only partly taken into account in microbiological testing. This variance in different diagnostic thresholds and microbiological testing is a barrier to guideline implementation.
Keywords: Antibiotics; Diagnostics, microbiological; Drug resistance, bacterial; Health services research; Medicine, evidence-based.