Diagnosis and testing in bronchiolitis: a systematic review.

BACKGROUND The diagnosis of bronchiolitis is based on typical history and results of a physical examination. The indications for and utility of diagnostic and supportive laboratory testing (eg, chest x-ray films, complete blood cell counts, and respiratory syncytial virus testing) are unclear. OBJECTIVES To review systematically the data on diagnostic and supportive testing in the management of bronchiolitis and to assess the utility of such testing. DESIGN In conjunction with an expert panel, we generated admissibility criteria and derived relevant terms to search the literature published from 1980 to November 2002 in MEDLINE and the Cochrane Collaboration Database of Controlled Clinical Trials. Trained abstractors completed detailed data collection forms for each article. We summarized the data in tables after performing data integrity checks. RESULTS Of the 797 abstracts identified, we present evidence from 82 trials that met our inclusion criteria (17 are primary articles on diagnosis of bronchiolitis and 65are reports of treatment or prevention trials). Numerous studies demonstrate that rapid respiratory syncytial virus tests have acceptable sensitivity and specificity, but no data show that respiratory syncytial virus testing affects clinical outcomes in typical cases of the disease. Seventeen studies presented chest x-ray film data. Abnormalities on chest x-ray films ranged from 20% to 96%. Insufficient data exist to show that chest x-ray films reliably distinguish between viral and bacterial disease or predict severity of disease. Ten studies included complete blood cell counts, but most did not present specific results. In one study, white blood cell counts correlated with radiologically defined disease categories of bronchiolitis. CONCLUSIONS A large number of studies include diagnostic and supportive testing data. However, these studies do not define clear indications for such testing or the impact of testing on relevant patient outcomes. Given the high prevalence of this disease, prospective studies of the utility of such testing are needed and feasible.