Discordance Between Clinical Suspicion and Spirometry-Defined Reversible Airflow Obstruction in Children with Sickle...

Background: Asthma is an important respiratory comorbidity in children with sickle cell disease (SCD), but respiratory symptoms overlap with SCD-related pulmonary manifestations. Methods: We analyzed prospectively recorded routine-care data from 140 children aged 5-17 years who were offered a standardized respiratory assessment during clinically stable follow-up. During revision, we applied a post hoc operational spirometric comparator: reversible airflow obstruction required FEV₁/FVC < 80% plus an FEV₁ increase ≥12% after salbutamol. Participants with normal spirometry formed the negative comparator; incomplete or intermediate objective patterns remained unclassified. Results: Reversible obstruction was identified in 43 children, normal spirometry in 25, and 72 remained unclassified. Previous clinical suspicion was present in 10/43 (23.3%), 3/25 (12.0%), and 22/72 (30.6%), respectively. In the deliberately contrastive classified-only analysis (n = 68), sensitivity was 23.3% (95% CI 11.8-38.6), specificity 88.0% (68.8-97.5), LR+ 1.94 (0.59-6.39), LR- 0.87 (0.70-1.09), and κ = 0.090 (95% CI -0.059 to 0.239). The likelihood-ratio intervals were wide and included 1.0, indicating substantial imprecision rather than proof of no discrimination. Conclusions: Prior clinical suspicion showed low sensitivity and slight agreement with spirometry-defined reversible obstruction. Interpretation is limited by the post hoc two-gate comparison and by the large, non-randomly distributed unclassified group.