Objective: To generate and examine evidence in support of diagnosing cystic fibrosis (CF) early through newborn screening (NBS).
Study design: Using a randomized controlled trial with unique unblinding/surveillance, we evaluated patients with CF receiving similar treatment after assignment to an early diagnosis (screened) group or to a control group. Outcomes studied at diagnosis and longitudinally included measures of nutritional status and lung disease.
Results: Assessment of patients with CF without meconium ileus who had pancreatic insufficiency revealed marked differences in age and condition at diagnosis--screened patients had significantly better length/height, weight, and head circumference. Follow-up evaluation for 16 years showed that height and weight differences persisted long term. Although screened patients had better chest x-ray scores at diagnosis, our trial suggests that the effects of confounders such as Pseudomonas aeruginosa infections led to deterioration of their scores after 10 years, but there were no significant differences between the 2 CF/pancreatic insufficiency subgroups.
Conclusions: Early diagnosis of CF and aggressive nutritional management can prevent malnutrition and growth failure. Although CF NBS provides a potential opportunity for better pulmonary outcomes, it appears that other factors can predominate over time in pulmonary prognosis. Overall, the Wisconsin trial is positive and provides enough evidence for routine CF NBS.