Toward A Simple Diagnostic Index for Acute Uncomplicated Urinary Tract Infections

PURPOSE Whereas a diagnosis of acute uncomplicated urinary tract infection (UTI) in clinical practice comprises a battery of several diagnostic tests, these tests are often studied separately (in isolation from other test results). We wanted to determine the value of history and urine tests for diagnosis of uncomplicated UTIs, taking into account their mutual dependencies and information from pre-ceding tests. METHODS Women with painful and/or frequent micturition answered questions about their signs and symptoms (history) of UTIs and underwent urine tests. A culture was the reference standard (103 colony-forming units per milliliter). A diag-nostic index was derived using logistic regression with bootstrapped backward selection and parameter-wise shrinkage. Risk thresholds for UTI of 30 % and 70% were used to analyze discriminative properties. Six models were compared: (1) history only, (2) history + urine dipstick, (3) history + urine dipstick + urinary sedi-ment, (4) history + urine dipstick + dipslide, and (5) history + urine dipstick + uri