Longevity of patients with cystic fibrosis in 2000 to 2010 and beyond: survival analysis of the Cystic Fibrosis Foundation patient registry

Abstract

Background: Advances in treatments for cystic fibrosis (CF) continue to extend survival. An updated estimate of survival is needed for better prognostication and to anticipate evolving adult care needs.

Objective: To characterize trends in CF survival between 2000 and 2010 and to project survival for children born and diagnosed with the disease in 2010.

Design: Registry-based study.

Setting: 110 Cystic Fibrosis Foundation-accredited care centers in the United States.

Patients: All patients represented in the Cystic Fibrosis Foundation Patient Registry (CFFPR) between 2000 and 2010.

Measurements: Survival was modeled with respect to age, age at diagnosis, gender, race or ethnicity, F508del mutation status, and symptoms at diagnosis.

Results: Between 2000 and 2010, the number of patients in the CFFPR increased from 21,000 to 26,000, median age increased from 14.3 to 16.7 years, and adjusted mortality decreased by 1.8% per year (95% CI, 0.5% to 2.7%). Males had a 19% (CI, 13% to 24%) lower adjusted risk for death than females. Median survival of children born and diagnosed with CF in 2010 is projected to be 37 years (CI, 35 to 39 years) for females and 40 years (CI, 39 to 42 years) for males if mortality remains at 2010 levels and more than 50 years if mortality continues to decrease at the rate observed between 2000 and 2010.

Limitations: The CFFPR does not include all patients with CF in the United States, and loss to follow-up and missing data were observed. Additional analyses to address these limitations suggest that the survival projections are conservative.

Conclusion: Children born and diagnosed with CF in the United States in 2010 are expected to live longer than those born earlier. This has important implications for prognostic discussions and suggests that the health care system should anticipate greater numbers of adults with CF.

Primary funding source: Cystic Fibrosis Foundation.

Appendix Figure

Rate of reduction in mortality per year, by patient characteristics, calculated by using hazard ratios from a Cox proportional hazards model and adjusted for age, gender, F508del mutation status, and age and presentation at diagnosis.

Figure 1

Mortality from 2001 to 2010 relative to 2000. The graph depicts changes in mortality between 2000 and 2010 using mortality hazard ratios (estimated using a Cox proportional hazards model) with 2000 as the referent year and adjusted for age (the time scale), age at diagnosis, race/ethnicity, presentation at diagnosis, gender, and F508del mutation status. The rate of decrease in mortality was 1.8% per year (95% CI, 0.7% to 2.8%).

Figure 2

Annual mortality and 95% CIs, by age, gender, and F508del mutation status, estimated by using a triangular kernel with a radius of 5 y.

Figure 3

Projected survival curves for children born and diagnosed with cystic fibrosis in 2010, overall and by gender and genotype. The most optimistic projection (dotted line) assumes that mortality will continue to decrease indefinitely at the rate observed between 2000 and 2010 (1.8% per year). The solid line represents survival if mortality does not decrease further (i.e., stays at 2010 levels). The other projection (dashed line) assumes that mortality decreases at half the rate seen from 2000 to 2010 (0.9% per year). Further details are provided in Table 3.