WS12.1 Evidence of diminished FEV1 in CF 6-year-olds followed in the European CF registry, 2007–2009

Abstract

Objectives: Studies have demonstrated that CF infants without respiratory signs and symptoms commonly have lung disease markers including inflammation, bronchial wall thickening, reduced flow, and ventilation inhomogeneity. However, a majority of CF 6-year-olds have an FEV1 >90% predicted, which might be considered ‘normal’ and suggest that only a minority of these children have diminished FEV1. Methods: Stanojevic FEV1 % predicted and Z-score distributions were determined for 686 6-year olds (362 males) from Austria, Belgium, Czech Republic, Germany, Denmark, France, Greece, Hungary, Israel, Italy, The Netherlands, Portugal, and Slovenia followed in the ECFS Registry. Observed Z-scores were plotted against theoretical values based on the Normal distribution. Conclusions: The population FEV1 % predicted was 91.6% (SD = 17.9). More than twice as many children had FEV1 Z-scores −1. Quantile-quantile plots revealed that FEV1 Z-scores were consistently lower than expected, suggesting that most, if not all, CF children have diminished lung function by age 6, including those patients with apparently ‘normal’ FEV1 % predicted values (Z-scores >−1). Strategies emphasizing treatment of the minority of CF infants with respiratory signs and symptoms may be inadequate to reduce lung disease progression in the population. Quantile-quantile plots may prove useful for evaluating future population changes in CF lung disease progression.