Diagnostic criteria for urinary tract infection in hospitalized elderly patients over 75 years of age: a multicenter cross-sectional study.

Introduction: Urinary tract infection (UTI) is one of the most frequent infections in geriatric patients. Nevertheless, the diagnosis remains difficult because of the high prevalence of asymptomatic bacteriuria (AB). We studied the diagnosis criteria used by physicians in geriatric patients 75 years of age or more.

Method: A multicenter study was carried out in October 2009 in acute care wards (geriatrics, infectious diseases, internal medicine). During 1 week, the local investigator collected all positive urine microscopy and culture in geriatric patients 75 years of age or more and filled out a questionnaire on the final diagnosis (AB, cystitis, pyelonephritis, prostatitis), symptoms, clinical signs, and other infectious diagnosis.

Results: Two hundred and forty-one questionnaires were filled out in 48 wards. Physicians diagnosed AB in 91 patients (37.8%), cystitis in 72 (29.9%), pyelonephritis in 48 (19.9%), prostatitis in 20 (8.3%). 28.2% of patients were asymptomatic; 35% presented with clinical signs. General signs were significantly associated with invasive infection and the absence of functional signs with AB. Among the patients presenting with an invasive UTI, 27.9% also presented with another infection. This other infection was not statistically associated with AB, cystitis, or invasive UTI.

Conclusion: Too many urine microscopy and culture procedures are not justified, and too many patients are diagnosed with several infections. Usual functional and clinical signs are important for the diagnosis but are infrequent. It seems necessary to review the range of clinical presentations and diagnostic criteria for UTI in geriatric patients.