Hospitalization Costs for Endovascular and Surgical Treatment of Unruptured Cerebral Aneurysms in the United States Are Substantially Higher Than Medicare Payments

Discussion

For uncomplicated treatments, the average Medicare payment in 2008 was $12,599 (MS-DRG 27), which is substantially lower than the median 2008 hospital costs of $23,574 for clipping and $25,734 for coiling. The median hospital costs were $36,188 for clipping and $40,502 for coiling treatments complicated by major morbidity and $68,165 for clipping and $56,020 for coiling treatments complicated by mortality (Table). These costs are also substantially higher than the average Medicare payments for patients with major complications and comorbidities of $22,946 for 2008 (MS-DRG 26). Twenty-four percent of patients undergoing clipping or coiling for unruptured aneurysms in the United States were ≥65 years of age,³ so Medicare patients represent a significant minority of these cases.

Hoh et al⁴ reported the cost of cerebral aneurysm treatment in a previous study using NIS data, showing that clipping was associated with significantly longer stay and significantly higher total hospital charges than coiling for patients with both ruptured and unruptured aneurysms. We sought to delineate further the reasons for cost differentials in unruptured aneurysms by stratifying patients by age and outcome and by evaluating the trend in cost with time. When we separately assessed the hospital charges for patients undergoing clipping and coiling who did not have severe morbidity or mortality, we found that the charges are higher for coiling than for clipping. For these cases without complications, coiling was $2,188 more expensive than clipping. This is likely due, in part, to the high costs of the endovascular devices used in the coiling procedure. In a single-center study from the Netherlands, Halkes et al⁵ found that though clipping of unruptured aneurysms had higher costs related to the need for intensive care facilities and longer length of hospitalization, this difference was more than offset by the higher material cost of coils. Similarly, a single-center study of hospital charges for patients with unruptured cerebral aneurysms treated at the University of Florida found that device costs led to higher median charges for coiling versus clipping.⁶ Hospitalization costs for both coiling and clipping increased from 2001 to 2008, but the costs for the 2 procedures remained similar during that period (Fig 2). Although there were some statistical differences, costs for clipping and coiling were fairly similar, with clipping costing more than coiling in some years and coiling costing more than clipping in others.

Hoh et al⁶ found, in their single-center study, that older age tended to lead to higher hospital charges for both clipping and coiling of unruptured aneurysms, but they did not provide quantitative information about the degree of this association. We did not find an increase in costs related to age for either clipping or coiling.

The hospital costs for patients in the NIS treated for unruptured aneurysms was highly dependent on whether the procedure led to morbidity or mortality. For patients who had complications leading to morbidity and mortality, the cost of critical care overwhelmed the differences in periprocedural charges for coiling and clipping. Certainly, reducing morbidity and mortality would have a big impact on reducing hospital charges.

Later charges for follow-up imaging surveillance for aneurysm recurrence are likely to lead to widening of the difference in costs between coiling and clipping. Also, a higher recurrence rate of coiled aneurysms potentially leading to additional treatment with hospitalization will add further charges in a significant fraction of patients. International Subarachnoid Aneurysm Trial⁷ showed relatively little difference in rerupture rates between coiled and clipped aneurysms. It is reasonable to expect that there would similarly be no significant difference in subsequent rupture rates of unruptured aneurysms, so differences in hospitalization for subsequent rupture of coiled versus clipped aneurysms are not likely to add to differences in hospital charges.

Large aneurysms⁶ and posterior circulation aneurysms might be associated with higher charges for either clipping, coiling, or both. The NIS provides no information on aneurysm size or location, so we could not evaluate these parameters. Another potential limitation of this study is the occurrence of coding errors, which are present in any large administrative data base.² However, errors in data bases of this type are probably randomly distributed because recording is done by clerical and coding staff remote from the study questions. Furthermore, random coding errors are probably diluted in such a large sample and thus not likely to affect overall conclusions. Another limitation is that the hospital charge data are given only as a total, so we are unable to evaluate individual components of those charges.