Urine analysis and decision-making on cystitis in general practice.

Area of Science:

• General Practice
• Urology
• Diagnostic Medicine

Background:

• Urinary tract infections (UTIs) are common in primary care.
• Accurate diagnosis of cystitis in general practice is crucial for appropriate treatment.
• Test strips are widely used for initial UTI screening.

Purpose of the Study:

• To evaluate how general practitioners (GPs) use test strips in diagnosing cystitis.
• To assess the impact of test strip results on GPs' diagnostic probability and treatment decisions.
• To determine the diagnostic power of test strips in a general practice setting.

Main Methods:

• Survey of 1171 GPs with a case history and test strip results (leucocyte esterase and nitrite).
• Analysis of estimated pre- and post-test probabilities of UTI.
• Calculation of likelihood ratios to assess diagnostic power.
• Examination of treatment decisions and further investigations.

Main Results:

• Test strip results significantly altered GPs' estimated probability of UTI.
• Nitrite-positive results increased estimated UTI probability to 90%, while nitrite-negative results had less impact (50%).
• Median likelihood ratios indicated diagnostic utility, particularly for nitrite-positive results (4.75).
• Treatment decisions varied, with a high proportion prescribing antibiotics (90% probability) or awaiting further examination (50% probability).
• Microscopy was performed more frequently than recommended in some guidelines.

Conclusions:

• Test strip results are influential in GPs' diagnostic and management decisions for cystitis.
• The diagnostic power of test strips, especially nitrite results, impacts clinical actions.
• Further investigations and antibiotic prescriptions are guided by post-test probabilities, highlighting the importance of accurate initial testing.