Acute viral bronchiolitis: Physician perspectives on definition and clinically important outcomes

Two key limitations hamper intervention research in bronchiolitis: the absence of a clear definition of disease, and the heterogeneous choice of outcome measures in current clinical trials. We assessed how paediatricians and general practitioners (GPs) perceived definition and clinically important outcomes in bronchiolitis.

A nationwide online survey (ABBA study) was conducted through the Portuguese Society of Paediatrics and GPs' mailing lists. We assessed agreement with statements on bronchiolitis definition, and participants were asked to score the relative importance of several outcomes. Principal component analysis (PCA) explored dimensions underlying disease definition. Outcomes were ranked by mean score and proportion given highest score.

We included 514 paediatricians and 165 GPs (overall 59% were board-certified). Most paediatricians (76.5%) agreed with a definition based on coryza, wheezing and/or crackles/rales, compared to 38.1% GPs (P < 0.001). Less than 5% physicians agreed with a definition commonly used in clinical trials (<12 months, first episode of wheeze). We retained three dimensions on PCA: one based on coryza, rales/crepitations and no sudden onset; another on number of episodes and age; and a third on wheeze. Dimensions varied by physician specialization and training (P < 0.01). Hospital admission and respiratory distress were top rated outcomes by both groups of physicians.

Physician definitions of bronchiolitis have considerable variability and often mismatch those of clinical trials. Rating of important outcomes was consistent. Our results highlight the need for a robust standardized definition of acute bronchiolitis in infants and support the development of a core outcome set for future clinical trials. Pediatr Pulmonol. 2016;51:724-732. © 2015 Wiley Periodicals, Inc.