Objectives: To assess requests for microbiological analysis made by Primary Care doctors and to evaluate the quality of the procedure by the indicator: proportion of contaminated urine samples.
Design: A retrospective crossover study of requests to the Microbiology Laboratory in the University Hospital of Salamanca during 1995.
Setting: The study covered the Salamanca Health Area, which consists of 35 Health Centres and a catchment population of 358,408.
Patients and other participants: The requests for microbiological diagnosis and results of the 43,317 samples processed were analysed.
Interventions: The data was distributed according to care level and the Area's Health Centres.
Measurements and results: 9,574 (22%) of the total number of samples received turned out positive, 27.4% of the requests originated in Primary Care (PC). The overall request rate from PC was 33 per 1,000 inhabitants.
Conclusions: The microbiological analysis most frequently requested from PC is urine culture. Relationship between request and positives is 4 to 1.