Clinical decision making with transbronchial lung biopsies. The value of nonspecific histologic examination.

To investigate the importance of fiberoptic bronchoscopy with transbronchial biopsy (TBB) in clinical decision making, we reviewed 242 consecutive TBB procedures with respect to clinical presentation, roentgenographic pattern of disease, bronchoscopy result, and patient outcome. The specific yield of TBB was greatest in patients with multilobar disease and suspected sarcoidosis, metastatic neoplasm, or opportunistic infection. The value of a nonspecific TBB was estimated from its influence in changing clinically-derived suspicions of disease. Using pretest probabilities based on prebronchoscopic suspicions and likelihood ratios derived from our TBB results, Bayes's theorem was applied to estimate posttest probabilities. Nonspecific TBB reduced the probability of granulomatous pneumonitis. However, only small differences in posttest probabilities were associated with this bronchoscopy result in other patients with multilobar infiltrates, and no differences were observed in those with localized disease.