Accuracy of reagent strip testing for urinary tract infection in the elderly

The accuracy of reagent strip testing for urinary tract infection (UTI) was assessed in 100 elderly patients (50 acute patients admitted to hospital and 50 attending the day hospital). Reagent strip sensitivities were: acute patients-urinary nitrite 83%, blood 67%, protein 72% and leucocytes 72%, and day hospital patients-urinary nitrite 90%, blood 65%, protein 30% and leucocytes 60%. Urinary nitrite specificities were 100% for both groups of patients. Only 28% of patients with a UTI had specific symptoms of the infection; pyrexia and a raised WBC also proved poor indicators. Urinary nitrite was thus the most accurate immediate indicator of UTI.