Study participation and nonresponse in a population of adolescents and adults with operated congenital heart disease (GUCH patients).
A group of patients after surgery of congenital heart defects was examined as to whether participants and nonparticipants (refusers, nonresponders, moved away, and deceased subjects) differed in terms of the type of congenital heart disease, the type of surgery (curative, reparative, and palliative), age and gender. A group of 698 subjects between 15 and 45 years were invited to participate in a study where a standardized interview was combined with a series of medical examinations. Finally, 361 patients participated, 121 explicitly refused, 92 did not respond, 91 had moved away, and 33 had died. Comparing participants and nonparticipants at the level of bivariate analyses using type of surgery, type of congenital malformation, gender, and age did not yield statistically significant differences. The final analysis using multivariate logistic regression revealed that individuals who underwent palliative treatment, the most severe type of surgery, had the same likelihood of not participating than patients with curative treatment. Classifying patients by the type of heart defect did not reveal group differences in the likelihood to participate. No differences for gender and age emerged. The analyses have shown that a worse health status may not lead to nonparticipation. As a consequence, we may conclude that selective nonparticipation because of the measures considered may not have occurred, and the likelihood for obtaining biased results can be considered as low.