In this multi-center analysis, we found that total hospital costs varied significantly by center for all four congenital heart operations evaluated. These differences persisted even after adjustment for patient characteristics and length of stay, and were most prominent for lower complexity operations.
Congenital heart defects, while relatively rare, consume a large share of health care resources (1
). Children with congenital heart disease often require numerous hospitalizations which may include advanced surgical or interventional therapies, care by a multidisciplinary team of specialists, frequent imaging and other diagnostic testing, drug and device therapy, and life-long outpatient follow-up. Over the past several decades, survival following congenital heart surgery has improved significantly, such that evaluation of other outcomes including resource utilization, quality of life, complications, and neurodevelopmental function has now received greater attention (14
). Previous studies have suggested that inpatient costs account for the majority of resource utilization in terms of direct medical costs for patients undergoing congenital heart surgery, as opposed to outpatient services (15
). Similar to others, we also found that the vast majority of inpatient costs were related to room and board charges and that higher costs were associated with longer length of stay (7
). Differences in length of stay are likely related to both patient pre-operative, operative, and post-operative factors as well as center-related factors.
We are not aware of previous studies evaluating variation in hospital costs between centers caring for patients undergoing congenital heart surgery. In a large study evaluating in-hospital charges in more than 10,000 patients undergoing congenital heart surgery in 2000, Connor et al demonstrated significant variation in hospital charges between the 27 different US states included in the analysis (3
). Variation between centers was not evaluated. Investigators also found that, as expected, higher complexity cases were associated with increased hospital charges (3
In the present study, we chose to perform separate analyses of four common surgeries in order to evaluate variation between institutions, and important factors impacting resource utilization, across varying levels of surgical complexity. We also evaluated hospital costs rather than charges in order to assess the actual cost of the services. Interestingly, we found that while total hospital costs varied significantly by center for all operations evaluated, these differences were most prominent for the lower complexity procedures (atrial septal defect and ventricular septal defect repair). The reasons for this are unclear, however it may be possible that for the higher complexity cases, the complexity of the procedure or patient-specific factors outweigh any center-related factors impacting cost. In addition we found that for the lower complexity surgeries, higher center surgical volume was associated with lower total hospital costs, while this association was not seen for the higher complexity surgeries. In evaluating other center-level factors impacting hospital costs, we did not find that teaching or children’s hospitals were associated with reduced hospital costs, similar to other studies (3
There may be several reasons for the association of center volume with lower hospital costs. It may be that patients at higher volume centers have fewer post-operative complications. While were not able to evaluate post-operative complications specific to congenital heart surgery in this study utilizing administrative data, it has previously been shown that complications following congenital heart surgery are associated with increased resource utilization (4
). In addition, it may also be possible that larger, more experienced centers have greater resources and standardized protocols of care to facilitate post-operative recovery. The implementation of multidisciplinary standardized care protocols has been associated with decreased length of stay and reduced hospital charges for patients undergoing congenital heart surgery (16
). Davis et al. showed that implementation of a standardized care plan for 65 consecutive children undergoing atrial septal defect repair at their institution was associated with significant reductions in intensive care unit and total hospital length of stay, as well as a reduction in total hospital charges (16
). Fernandes et al. evaluated a more diverse population of 175 patients undergoing congenital heart surgery and also found that patients treated according to a standardized recovery protocol vs. conventional care had reduced length of stay and reduced hospital costs (17
). Standardized management has also been shown to improve outcome in high risk cohorts as well, such as single ventricle patients undergoing the Norwood operation (19
). Interestingly, we found that the association of center volume with cost was only significant for the lower complexity surgeries. This may be due to a wider range of center surgical volume for the lower complexity surgeries, compared with the higher complexity surgeries.
The results of this study have several implications in this era of rising health care costs. Our data, along with the previous Connor et al. analysis, suggest significant variation in resource utilization among different US states and different centers caring for patients undergoing congenital heart surgery (3
). Further analysis of factors associated with outcome and cost in this population may elucidate best practices which can both improve outcome and reduce cost across different centers and regions. Our data suggest that while higher complexity operations account for greater relative cost, there is greater variation in cost from center to center for lower complexity operations. In addition, while our data indicate that the estimated cost savings per patient if all centers performed as well as the lower cost quartile is greater for the higher complexity procedures, the total cost savings across the board would likely be greater for the lower complexity surgeries such as atrial septal defect and ventricular septal defect repair which are over two times more common than tetralogy of Fallot repair and the arterial switch operation (20
). Thus,, initial efforts to reduce costs may be best focused on these lower complexity, but common, congenital heart operations.