Urine testing in young febrile children: a risk-benefit analysis.

OBJECTIVE: To assess the relative risks and benefits of 10 potential urine testing strategies (compared with no testing) involving urinalysis and urine culture for children aged 3 to 24 months with fever but no focus of bacterial infection. DESIGN: Decision analysis based on the literature. The 10 testing strategies consist of five pairs; within each pair of strategies, one calls for urinalysis and urine culture of a clean-voided (bag) specimen, and urine culture, and in the other, the urine specimen is sent for culture only if the result of the urinalysis is abnormal. The five pairs differ in selectivity for testing: all children, girls only, temperature > or = 39 degrees C only, fever only (no respiratory or gastrointestinal symptoms), or temperature > or = 40 degrees C only. The results of the decision analysis are expressed as the preventive fraction (the proportion of cases prevented) for end-stage renal disease (ESRD) and hypertension, and as two risk/benefit (RB) ratios: the number of children tested per case of ESRD prevented (RB1), and the number of children with false-positive diagnosis and treatment of urinary tract infection per case of ESRD prevented (RB2). RESULTS: On the basis of the available evidence, none of the testing strategies succeeds in preventing the majority of cases of ESRD and hypertension (preventive fraction = 0.10 to 0.50), and all are associated with high ratios of children tested (RB1 = 4167 to 12,500) and false-positive diagnosis and treatment (RB2 = 563 to 1800) per case of ESRD prevented. A strategy of combined urinalysis and urine culture in children with temperature > or = 39 degrees C is associated with the most favorable RB profile: preventive fraction = 0.45, RB1 = 5556; RB2 = 776. Sensitivity analyses indicate that the relative ranking of the strategies is relatively robust in regard to alterations in the estimates of the sensitivity or specificity of the urinalysis, the relative risk of renal scarring associated with delayed diagnosis and treatment, and the risk of scarring-induced hypertension or ESRD. CONCLUSIONS: Up to 50% of the long-term sequelae of occult urinary tract infections in young febrile children appear preventable by urine testing, but even the most favorable strategies require testing of thousands of children, and unnecessarily treating hundreds, for every case prevented. Our analysis reveals those strategies with more favorable RB profiles and emphasizes the need for rapid and convenient urine tests with much higher sensitivity and specificity or the need for less aggressive management strategies for febrile infants and young children with urinary tract infection.

Parents' versus physicians' values for clinical outcomes in young febrile children.

OBJECTIVE: To compare how parents and physicians value potential clinical outcomes in young children who have a fever but no focus of bacterial infection. METHODS: Cross-sectional study of 100 parents of well children aged 3 to 24 months, 61 parents of febrile children aged 3 to 24 months, and 56 attending staff physicians working in a children's hospital emergency department. A pretested visual analog scale was used to assess values on a 0-to-1 scale (where 0 is the value of the worst possible outcome, and 1 is the value for the best) for 22 scenarios, grouped in three categories according to severity. Based on the three or four common attributes comprising the scenarios in a given group, each respondent's value function was estimated statistically based on multiattribute utility theory. RESULTS: For outcomes in group 1 (rapidly resolving viral infection with one or more diagnostic tests), no significant group differences were observed. For outcomes in groups 2 (acute infections without long-term sequelae) and 3 (long-term sequelae of urinary tract infection or bacterial meningitis), parents of well children and parents of febrile children had values that were similar to each other but significantly lower than physicians' values for pneumonia with delayed diagnosis, false-positive diagnosis of urinary tract infection, viral meningitis, and unilateral hearing loss. For bacterial meningitis with or without delay, however, the reverse pattern was observed; physicians' values were lower than parents'. In arriving at their judgment for group 2 and 3 scenarios, parents gave significantly greater weight to attributes involving the pain and discomfort of diagnostic tests and to diagnostic error, whereas physicians gave significantly greater weight to attributes involving both short- and long-term morbidity and long-term worry and inconvenience. Parents were significantly more likely to be risk-seeking in the way they weighted the attributes comprising group 2 and 3 scenarios than physicians, ie, they were more willing to risk rare but severe morbidity to avoid the short-term adverse effects of testing. CONCLUSIONS: Parents and physicians show fundamental value differences concerning diagnostic testing, diagnostic error, and short- and long-term morbidity; these differences have important implications for diagnostic decision making in the young febrile child.

Therapeutic drug monitoring in pediatrics: a need for improvement.

Therapeutic drug monitoring (TDM) is practiced for a number of frequently used drugs in infants and children. It is believed that monitoring drug levels will increase the probability of a therapeutic response and minimize the probability of adverse drug sequelae. Dose adjustments are based on measured drug levels interpreted relative to published therapeutic ranges which may or may not reflect the true relationship with either therapeutic or adverse effects. Potential errors derive from many sources, some amenable to solutions based on current knowledge, others awaiting improved understanding of the causes and consequences of unreliable therapeutic ranges.

Role of the complete blood count in detecting occult focal bacterial infection in the young febrile child.

Previous studies of the value of the complete blood count (CBC) in distinguishing viral from bacterial infection in young febrile children have failed to exclude children with clinically evident bacterial infection and thus have inflated the positive predictive value of the test for occult focal infection. We prospectively studied 2492 children 3-24 months of age who presented to a children's hospital emergency department between March 1989 and August 1990 with fever (> or = 38.0 degrees C) of acute (< or = 4 days) onset but no evident bacterial focus of infection, 433 (17.4%) of whom received a CBC. We also carried out an 8-year retrospective analysis to estimate prior, or pre-test, probabilities (prevalences) and examine CBC results for rare occult bacterial infections (meningitis, osteomyelitis, and septic arthritis). Estimated prior probabilities for the four most common categories of infection that can be diagnosed at the initial visit were: non-pneumonitic viral infection, 88.6% in boys and 86.0% in girls; pneumonia, 8.5% in both sexes; urinary tract infection (UTI), 3.0% in boys and 5.5% in girls; and bacterial meningitis, 0.0066% in both sexes. The likelihood (sensitivity) of a total white blood cell (WBC) count > or = 15,000/mm3 was 25.5, 64.5, 62.5, and 50.0% for viral infection, pneumonia, UTI, and meningitis, respectively. Among children with a high total white blood cell count, neither a total polymorphonuclear count > or = 10,000/mm3 nor a band count > or = 500/mm3 was associated with significantly elevated likelihoods for occult pneumonia or UTI, a finding confirmed by multiple logistic regression analysis.(ABSTRACT TRUNCATED AT 250 WORDS)