Abstract 151 Poster Session III, Monday, 5/3 (poster 138)

Objective: Outcome assessment for patients with congenital heart disease (CHD) has been hampered by a paucity of methods for measuring disease severity and health-related quality of life (HRQoL). The objectives of this study were to develop and validate a severity of illness index for CHD and to examine the impact of disease severity on a generic measure of HRQoL.

Methods: The Child Health Questionnaire, Parent and Child Forms, was mailed to a consecutive sample of teens (ages 11 to 19 years) and their parents who had recent follow-up evaluation in the cardiology clinic. Physiologic variables were obtained from chart review. We developed a disease severity index based on number of invasive cardiovascular procedures to date, presence of persistent cyanosis, and presence of single ventricle physiology: low severity (<1 invasive cardiovascular procedure), moderate severity (>1 invasive cardiovascular procedure), and high severity (cyanosis or single ventricle physiology).

Results: Overall, 18 distinct CHD lesions were represented with the following classification: 40 low severity, 36 moderate severity, and 10 high severity (N = 78 parent-teen pairs plus 8 parent-only responses). Increasing disease severity was associated with worse left ventricular function (p<0.001), greater use of cardiac medications (p<0.01), greater mean heart rate (p=0.04), higher complexity of interventions (p<0.001), and poorer HRQoL in the specific areas of physical functioning (p=0.0001) and general health perceptions (p=0.02). From the parent's perspective, disease severity was also associated with greater parental emotional impact (p=0.02) and less teen participation in developmentally appropriate activities (p=0.0001). No significant differences were found in HRQoL scales dealing with emotional health, bodily pain, self-esteem, and parental time impact.

Conclusions: Our severity of illness index for CHD demonstrates validity by distinguishing patients on physiologic characteristics, medication use, complexity categorization of interventions, and HRQoL. Furthermore, CHD severity appears to affect physical functioning and perceived well-being more than other aspects of HRQoL. Our severity of illness index is easy to understand and simple to apply. To establish the index as a risk adjustment tool for evaluation of health care quality, additional validation is needed with respect to ability to predict future health outcomes.