Objectives: An increasing percentage of cystic fibrosis (CF) diagnoses are occurring in adulthood. The purpose of this study was to explore how age at diagnosis may be associated with selected disease and sociodemographic characteristics.
Design: The 1996 Cystic Fibrosis Foundation (CFF) Patient Registry data were analyzed to test for associations between age at diagnosis and selected variables. All cases involved individuals > or = 18 years who were represented in the CFF Patient Registry for 1996. Patients were assigned to one of two groups: those diagnosed with CF after age 18 years (n = 786) and those diagnosed before 18 years (n = 6,641).
Results: In 1996, the incidence of late diagnosis was 7.8%, and the prevalence was 10.9%. The mean age of late diagnosis was 27 years. Respiratory symptoms most frequently led to late diagnosis. Patients receiving a late CF diagnosis were less likely to have alleles for Delta F508. There was no correlation between age at diagnosis and percent predicted FEV(1), although patients in the late-diagnosis group were an average of 10 years older than those in the early-diagnosis group. Late diagnosis was associated with fewer complications, fewer hospitalizations, less oxygen use, fewer courses of home IV treatment, and less enzyme use. Women were most often diagnosed late. Men displayed more diversity in conditions leading to diagnosis. Psychosocially, those patients receiving late diagnoses were more likely to be college graduates, married, and employed full time. For those adults who died in 1996, there was a positive association between their age at diagnosis and age at death.
Conclusion: Those patients diagnosed with CF as adults differ, both medically and psychosocially, from those diagnosed at a younger age; these differences have implications for diagnosis, treatment, and education.