Risk Factors for Death After Hospital Discharge for Cardiac Surgery
Background: Little is known regarding the risk factors for early and late death after hospital discharge among pediatric patients undergoing cardiac surgery.
Methods: Statewide hospital discharge data from California in 1989 to 1999 were used to study outcomes of children <18 years old who had a procedure code (by International Classification of Diseases, Ninth Revision, Clinical Modification) indicating cardiac surgery. The outcome variable was death occurring after hospital discharge. Postdischarge deaths were identified by linking hospital discharge data to statewide death registry data. Cardiac surgical procedures were grouped into 23 categories to adjust for risk involved with the procedures. We used logistic regression to evaluate risk factors for postdischarge mortality, including variables age, sex, race and ethnicity, type of insurance, home income, date and month of surgery, type of admission, hospitals case volume, and the various types of procedures.
Results: There were 25402 cardiac surgery cases with 1505 inhospital deaths. Of 23897 hospital discharges, 148 deaths (0.62%) occurred within 365 days after discharge, including 37 deaths within 30 days; 44 deaths at 31 to 90 days; and 67 deaths at 91 to 365 days. Logistic regression showed young age was an important risk factor for postdischarge death with an odds ratio of 4.8 for neonates and 3.5 for infants, compared with children >1 year old. Another significant risk factor was the type of procedure. For death <30 days after discharge, Norwood operation (odds ratio 8.4 compared with closure of ventricular septal defect) was a risk factor. For death that occurred between 31 and 365 days, significant risk factors were truncus arteriosus repair, total anomalous pulmonary vein repair, aortopulmonary shunt, and open valvotomy. Sex, race/ethnicity, home income, and hospital case volume were not significant predictors of postdischarge deaths.
Conclusions: Many demographic and socioeconomic variables affecting inhospital death were not significant predictors for postdischarge death. Important risk factors for postdischarge death were young age and the type of surgery performed.
Outcomes of pediatric cardiac surgery have improved dramatically over the past 20 years. The surgical mortality for congenital heart disease in the current era is in the range of 5% to 6% in most large reported series. Most studies, however, define surgical outcome as "inhospital" mortality or the status of patient at the time of hospital discharge. A more appropriate measure of immediate outcome after surgery would be "30-day mortality"; however, it is generally more difficult to ascertain this information because many centers do not track mortality after hospital discharge. Very limited information has been reported on deaths occurring after hospital discharge in children undergoing cardiac surgery.
Deaths occurring in the community setting among patients with congenital heart disease (CHD) have been examined by some investigators. Most of the postdischarge deaths in these patients are characterized as "sudden death." In a population-based study evaluating patients <19 years old who underwent surgical treatment of CHD in Oregon from 1958 to 1996, Silka et al reported that most deaths occurred in patients with aortic stenosis, coarctation, transposition of the great arteries, and tetralogy of Fallot. The common causes of death are arrhythmia and circulatory (embolic or aneurysm rupture) and acute heart failure.
Although it has been known to clinicians that some deaths after pediatric cardiac surgery occur after hospital discharge, the incidence and characteristics of these occurrences are unknown. Identifying children who are at risk for postdischarge death after CHD surgery will allow clinicians to arrange proper surveillance and follow-up, which have the potential to improve outcomes of these patients. Therefore, we conducted this study with 2 objectives: to characterize the epidemiology of postdischarge death among infants and children undergoing cardiac surgery and (2) to identify risk factors for early and late postdischarge death after pediatric cardiac surgery.
Abstract and Introduction
Abstract
Background: Little is known regarding the risk factors for early and late death after hospital discharge among pediatric patients undergoing cardiac surgery.
Methods: Statewide hospital discharge data from California in 1989 to 1999 were used to study outcomes of children <18 years old who had a procedure code (by International Classification of Diseases, Ninth Revision, Clinical Modification) indicating cardiac surgery. The outcome variable was death occurring after hospital discharge. Postdischarge deaths were identified by linking hospital discharge data to statewide death registry data. Cardiac surgical procedures were grouped into 23 categories to adjust for risk involved with the procedures. We used logistic regression to evaluate risk factors for postdischarge mortality, including variables age, sex, race and ethnicity, type of insurance, home income, date and month of surgery, type of admission, hospitals case volume, and the various types of procedures.
Results: There were 25402 cardiac surgery cases with 1505 inhospital deaths. Of 23897 hospital discharges, 148 deaths (0.62%) occurred within 365 days after discharge, including 37 deaths within 30 days; 44 deaths at 31 to 90 days; and 67 deaths at 91 to 365 days. Logistic regression showed young age was an important risk factor for postdischarge death with an odds ratio of 4.8 for neonates and 3.5 for infants, compared with children >1 year old. Another significant risk factor was the type of procedure. For death <30 days after discharge, Norwood operation (odds ratio 8.4 compared with closure of ventricular septal defect) was a risk factor. For death that occurred between 31 and 365 days, significant risk factors were truncus arteriosus repair, total anomalous pulmonary vein repair, aortopulmonary shunt, and open valvotomy. Sex, race/ethnicity, home income, and hospital case volume were not significant predictors of postdischarge deaths.
Conclusions: Many demographic and socioeconomic variables affecting inhospital death were not significant predictors for postdischarge death. Important risk factors for postdischarge death were young age and the type of surgery performed.
Introduction
Outcomes of pediatric cardiac surgery have improved dramatically over the past 20 years. The surgical mortality for congenital heart disease in the current era is in the range of 5% to 6% in most large reported series. Most studies, however, define surgical outcome as "inhospital" mortality or the status of patient at the time of hospital discharge. A more appropriate measure of immediate outcome after surgery would be "30-day mortality"; however, it is generally more difficult to ascertain this information because many centers do not track mortality after hospital discharge. Very limited information has been reported on deaths occurring after hospital discharge in children undergoing cardiac surgery.
Deaths occurring in the community setting among patients with congenital heart disease (CHD) have been examined by some investigators. Most of the postdischarge deaths in these patients are characterized as "sudden death." In a population-based study evaluating patients <19 years old who underwent surgical treatment of CHD in Oregon from 1958 to 1996, Silka et al reported that most deaths occurred in patients with aortic stenosis, coarctation, transposition of the great arteries, and tetralogy of Fallot. The common causes of death are arrhythmia and circulatory (embolic or aneurysm rupture) and acute heart failure.
Although it has been known to clinicians that some deaths after pediatric cardiac surgery occur after hospital discharge, the incidence and characteristics of these occurrences are unknown. Identifying children who are at risk for postdischarge death after CHD surgery will allow clinicians to arrange proper surveillance and follow-up, which have the potential to improve outcomes of these patients. Therefore, we conducted this study with 2 objectives: to characterize the epidemiology of postdischarge death among infants and children undergoing cardiac surgery and (2) to identify risk factors for early and late postdischarge death after pediatric cardiac surgery.
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