Rationale: Infant pulmonary function testing has a great value in the diagnosis of post-infectious bronchiolitis obliterans (BOs), because of characteristic patterns of severe and fixed airway obstruction. Unfortunately, infant pulmonary function testing is not available in most pediatric pulmonary centers.
Objective: To develop and validate a clinical prediction rule (BO-Score) to diagnose children under 2 years of age with BOs, using multiple objectively measured parameters readily available in most medical centers.
Methods: Study subjects, children under 2 years old with a chronic pulmonary disease assisted at R. Gutierrez Children's Hospital of Buenos Aires. Patients were randomly divided into a derivation (66%) and a validation (34%) set. ROC analyses and multivariable logistic regression included significant clinical, radiological, and laboratory predictors. The main outcome measure was a diagnosis of BOs. The performance of the BO-Score was tested on the validation set.
Results: Hundred twenty-five patients were included, 83 in the derivation set and 42 in the validation set. The BO-Score (area under ROC curve = 0.96; 95% CI, 0.9-1.0%) was developed by assigning points to the following variables: typical clinical history (four points), adenovirus infection (three points), and high-resolution computed tomography with mosaic perfusion (four points). A Score > or =7 predicted the diagnosis of BOs with a specificity of 100% (95% CI, 79-100%) and a sensitivity of 67% (95% CI, 47-80%).
Conclusions: The BO-Score is a simple-to-use clinical prediction rule, based on variables that are readily available. A BO-Score of 7 or more predicts a diagnosis of post-infectious BOs with high accuracy.