Abstract
The aim of this study was to evaluate the relative socioeconomic costs of benign cranial base tumors treated with open surgery and gamma knife radiosurgery.
In a retrospective study, we studied 174 patients with benign cranial base tumors, less than 3 cm in diameter (or volume less than 30 ml), admitted in the past 5 years. Group A (n = 94) underwent open surgery for removal of the tumors, whereas Group B (n = 80) underwent gamma knife radiosurgery. The socioeconomic costs were evaluated by both direct and indirect cost. The direct costs comprised intensive care unit cost, ward cost, operating room cost, and outpatient visiting cost. The indirect costs included loss of workdays and mortality. The length of hospital stay, the number of lost workdays, surgical complications, mortality, and cost-effectiveness analysis were calculated as well. Student t test and χ2 test were used for statistical analysis.
The mean length of hospital stay for open surgery was 18.2 ± 30.4 days including 5.0 ± 14.7 days of intensive care unit stay and 13.0 ± 15.2 days of ward stay, P<0.01. The mean hospital stay for gamma knife was 2.2 ± 0.9 days with no need of intensive care unit stay, P<0.01. The mean loss of workdays for open surgery was 160 ± 158 days and 8.0 ± 9.0 days for gamma knife, P<0.01. The gamma knife cost per hour (US $1435) is higher than the open surgery cost per hour (US $450), P<0.01. The direct cost for gamma knife (US $9677 ± $6700) is higher than that for open surgery (US $5837 ± $6587), P<0.01. Open surgery had more complication rates (31.2%) than gamma knife (3.8%). Open surgery had a mortality rate of 5.3%; there was no mortality for gamma knife. The indirect costs, including loss of workdays and mortality, were significantly higher for open surgery than for gamma knife, P<0.01. Finally, the socioeconomic cost (US $34,453 ± $97,277) is higher for open surgery than for gamma knife (US $10,044 ± $7481), P<0.01. The CEA is significantly higher in gamma knife (US $3762/quality-adjusted life year) than in open surgery (US $8996/quality-adjusted life year), P<0.01.
Most of the socioeconomic loss with open surgery for benign cranial base tumors comes from the indirect costs of workdays lost and mortality. Gamma knife radiosurgery is a worthwhile treatment to our patients and to our society because it may shorten hospital stays and workdays lost and reduce complications, mortality, socioeconomic loss, and achieve better cost-effectiveness.
Radiosurgery is an innovative and minimally invasive technique (4,7,18,19,22,23,26,32,33). Current indications for radiosurgery include deep and small-sized brain tumors (less than 3 cm in diameter or a volume less than 30 ml). The benign cranial base tumors, including acoustic neuroma, trigeminal neuroma, meningioma, pituitary tumor, and craniopharyngioma, are the typical candidates for radiosurgery. Brain tumors are second only to stroke as the leading cause of death from neurological disease (15). Benign cranial base tumors make up 20 to 30% of intracranial tumors (5,22,25). Recent studies have reported that untreated tumors enlarge progressively over the course of 1 or 2 years (14). Although historically benign, untreated cranial base benign tumors lead to serious morbidity and even death when they compress adjacent cranial nerves and brainstem as they grow (3). Pollock et al. (23) reported that stereotactic radiosurgery was an effective and less costly treatment for unilateral neuroma. In addition, for patients eligible for radiosurgery, the general health rating was better for radiosurgery than for open surgery in treatment of acoustic neuroma (23,26).
Most of the previous studies have focused on comparison of open surgery and radiosurgery for acoustic neuroma. The calculated costs in these studies have been based primarily on direct medical costs (31), as opposed to indirect costs. In addition to direct costs, the indirect costs can be a heavy burden on families as well as on society and the economy in general (16,24). In the series by Roijen et al. (26), the calculated indirect costs of gamma knife treatment for acoustic neuroma comprised only the value of production losses (morbidity cost), including an inability to perform paid or unpaid work; it did not include mortality. From the socioeconomic viewpoint, both the direct and indirect costs of disease control are very crucial issues for social affairs expenditure (16,29). Especially in Taiwan, our insurance (National Health Insurance) is a compulsive and unique public insurance: the insurance fee accounts for only 5.6% of gross domestic product (8,12,27). Over 97% of Taiwan's population is covered under this insurance (12). Compared with the percentage of the gross domestic product devoted to health care expenditures in the United States (14.2%), Japan (7.8%), and other countries, our public insurance budget is the lowest (27), as seen in Figure 1. Unfortunately, since the start of National Health Insurance, health care expenditure has increased by more than 10% per year (12). To control the increasing financial burden of Bureau of National Health Insurance, the global budget system began to oversee this expenditure 2 years ago. Gamma knife radiosurgery is a high-cost technique with a high investment necessary (approximately US $3,000,000). Initially, the direct cost-effectiveness is higher for gamma knife than for open surgery when treating acoustic neuromas. Is this true for indirect and socioeconomic costs, and is this true for other benign cranial base tumors? If other brain tumors are eligible for both open surgery and gamma knife radiosurgery, which one is the most cost-effective, in terms of socioeconomic costs? The goal of our study was to compare the socioeconomic costs of open surgery and gamma knife radiosurgery for treatment of benign cranial base tumors.
Algorithm of socioeconomic costs, including direct, indirect, hospital stay, outpatient visiting, workdays lost, and mortality costs.
Algorithm of socioeconomic costs, including direct, indirect, hospital stay, outpatient visiting, workdays lost, and mortality costs.
MATERIALS AND METHODS
This is a retrospective study. In the past 5 years, 174 patients with benign cranial base tumors were admitted. Group A (n = 94) underwent open surgery before we had a gamma knife facility (2000–2001). Group B (n = 80) underwent gamma knife radiosurgery after our hospital had begun to use gamma knife treatment (2002–2003). The criteria for patient selection included five kinds of cranial base tumors, all less than 3 cm in diameter (or having a volume less than 30 ml): pituitary tumor, meningioma, trigeminal and acoustic neuroma, and craniopharyngioma. Patients younger than 20 years and older than 65 years were excluded. Demographic data for the two groups is shown in Table 1.
The socioeconomic costs comprised both direct and indirect costs. The direct costs included the costs of hospital stays and outpatient visiting costs. The costs of hospital stays comprised intensive care unit (ICU) stay costs, ward stay costs, and operating room (OR) costs. The cost of anesthesia was included and averaged into the OR cost per hour. The imaging cost or blood working cost were included and averaged into daily hospital stay cost and out-patient visiting cost. The indirect costs comprised workdays lost and mortality. The algorithm of cost evaluation is shown in Figure 2. The lost workdays were evaluated by the cost of absence of work because of postoperative rest or surgical morbidity. The mortality cost was evaluated by the loss of work before age of 65 because of surgical mortality (16). The unemployment rate was 4.99% in Taiwan (11); on the contrary, the employed rate was 95.01%. The average inflation rate (r) or money discounting rate in Taiwan from 1960 to 2003 was 4.86% (9). The quality-adjusted life analysis was multiplied by 1.0 if the patient had a normal activity, was multiplied by 0.8 if the patient had minor disability, was multiplied by 0.5 if the patient had moderate disability, was multiplied by 0.2 if the patient had severe disability, and was multiplied by 0 if the patient was in a vegetative state or died (28). The wage was reported by the patient him or herself. If patient had no occupation before operation, such as a housewife, we assumed the average wage of a Taiwanese citizen (from 2000–2003) as their wage (US $13,582) (9).
Taiwan's healthcare spending is low. Healthcare spending as a share (%) of gross domestic product.
Taiwan's healthcare spending is low. Healthcare spending as a share (%) of gross domestic product.
Cost Evaluation Formulas
ICU cost = cost of ICU/day × ICU days
Ward stay cost = cost of ward/day × ward stay days
OR cost = cost of OR/hour × operation hours
Cost of outpatient visiting = cost of outpatient visiting/time × outpatient visiting times
Cost of workless = Σ cost of loss of work (wage/yr/person) × workless days × (1 + r) years of loss of work × 95.01% (employment rate in Taiwan) (12). r, average inflation rate or money discounting rate/year in Taiwan (4.86%)
Cost of mortality = Σ(wage/yr/person) × 95.01% (employment rate in Taiwan) × (1 + r) (65 - age of mortality). R, average inflation rate or money discounting rate/year in Taiwan (4.86%)
Direct cost/person = (total mortality cost and total workless cost)/no. of patients in group
Indirect cost/person = (hospital stay cost + outpatient cost)/person
Socioeconomic cost/person = (direct cost + indirect cost)/person
Quality-adjusted life years (QALY) added: normal life or normal activity × 1, minor disability × 0.8, moderate disability × 0.5, severe disability × 0.2, vegetation or death × 0
CEA = Socioeconomic cost/QALY added (28)
RESULTS
The total hospital cost, including the costs of ICU and ward stays and OR costs (surgery or gamma knife), is analyzed in Table 2. Nursing costs account for 17.2% of ward stay costs and 32.4% of ICU stay costs. Medicine administration and instrument applications are the major costs (55%) in open surgery, whereas gamma knife installation is the major cost (81%) in the gamma knife room at our hospital. Our cost calculation for the gamma knife facility includes depreciation of gamma knife, construction, renovation, interest, start-up, reloading, operating cost, tax, etc., as shown in Table 3. In contrast, the physician fee is only 4.9 to 22% of the hospital costs for each type of treatment. The mean costs of ICU stay/day, ward stay/day, OR/hour, outpatient visiting/time, and wage/year/person are shown in Table 4. The OR cost/hr for open surgery is US $450 and $1435 for gamma knife. The ICU stay/day costs US $365/day. The ward costs are US $85/day. The outpatient visiting cost/time is US $54/time. The GNP/year/person in Taiwan is US $17,350 (6,17).
Cost analyses for operating room, gamma knife, intensive care unit stay, and ward stay
Cost analyses for operating room, gamma knife, intensive care unit stay, and ward stay
Costs of operating room, intensive care unit, ward, outpatient visiting, and wages for both groups
Costs of operating room, intensive care unit, ward, outpatient visiting, and wages for both groups
Open surgery may increase the length of ICU stays (open surgery 5.0 ± 14.7 d; gamma knife 0 d, P<0.01) and ward stays (open surgery 13.2 ± 20.3 d; gamma knife 2.2 ± 0.3 d, P<0.01). In addition, open surgery is associated with a higher frequency of outpatient visits (18.6 ± 21.3 times versus 8.1 ± 3.8 times, P<0.01) and a higher number of workless days (160 ± 58 d versus 8.0 ± 9.0 d, P<0.01), as shown in Table 5.
Operation time, blood loss, mortality, complications, hospital stays, and workdays lost for both groups
Operation time, blood loss, mortality, complications, hospital stays, and workdays lost for both groups
The operating time was similar for both groups (5.67 h for open surgery versus 5.27 h for gamma knife). However, open surgery has a higher amount of blood loss (270 ml, P<0.01) and higher complications (31.9%) and mortality rates (5.3%), P<0.01. In gamma knife radiosurgery, there was a complication rate of only 3.8% and no mortality. The respective complications and mortality rates of the two groups are shown in Table 6. The most common complications occurred with visual impairment, diabetes insipidus, cerebrospinal fluid leakage, hydrocephalus, central nervous system infection, facial palsy, and hearing impairment. Five patients in open surgery died. One died of central nervous system infection, one of acute hydrocephalus, one of delayed intracerebral hematoma, one of direct brain injury, and one of vascular injury.
On the basis of our calculations of direct cost, the mean hospital stay cost for open surgery is US $4930 ± $4915, far less than for gamma knife (US $9240 ± $3352), P<0.01. The mean outpatient visiting cost for open surgery is US $907 ± $775, less than for gamma knife (US $437 ± $135). In total, the direct cost of open surgery (US $5837 ± $5687) is still statistically lower than that of gamma knife (US $9677 ± $6700), P<0.01, as seen in Table 7.
On the basis of our calculations of indirect cost, the workless cost for open surgery is higher (US $4936 ± $9884) than for gamma knife (US $367 ± $290), P<0.01. On the other hand, the mortality cost was high for open surgery (US $23,680 ± $83,873), whereas there was no mortality for gamma knife. In total, the indirect costs of open surgery are much higher (US $28,616 ± $89,775) than for gamma knife (US $367 ± $290), P<0.01. Although the direct cost of open surgery is lower than that of gamma knife, the indirect cost of open surgery is much higher than that of gamma knife. In total, the socioeconomic cost (direct plus indirect costs) of open surgery (US $34,453 ± $97,277) was statistically higher than that of gamma knife (US $10,044 ± $7481), P<0.01, as seen in Table 7. The cost-effectiveness analysis was better for radiosurgery (3762/QALY) than for open surgery (8996/QALY), P<0.01 (Table 8).
DISCUSSION
This study was based on a retrospective analysis in a single hospital before (2000–2001) and after (2002–2003) a gamma facility was available. Before the gamma knife was available, all of the benign cranial base tumors underwent open surgery and therefore served as a study control group. After the gamma knife was available, we tried to use the gamma knife facility for all benign cranial base tumors (less than 3 cm in diameter or 30 ml in volume). Only a few patients with pituitary tumor, tightly compressing adjacent optic chiasm, underwent open surgery. For comparison, the follow-up for each group ranged from 3 to 5 years, with a mean of 3.5 years in group A and 2.3 years in Group B. Patient selection bias are not absolutely avoided by this two-stage chronology selection, but we wanted to reduce this bias as much as possible. From analysis of the demographic data of patients, it was seen that there are no statistical differences between the two groups.
Unger et al. (30) reported that radiosurgery was a minimally invasive alternative microsurgery for acoustic neuroma. In their study, control of tumor growth was achieved in all but three (3/56) cases in a 4-year follow-up, without fatal complications. Useful hearing was preserved in 62% of patients, and neurological status improved in 54% of patients. Irradiation-associated adverse effects (18%) comprised incomplete facial palsy (4/56), from which two patients recovered. Pollock et al. (23) reported similar results. In gamma knife radiosurgery for acoustic neuromas, functional outcomes and patient satisfaction were greater than in the microsurgical group. In the radiosurgery group, patients returned to independent functioning sooner. The length of the hospital stays and total management charges were less in the radiosurgical group. Before the start of our study, we supposed that the same findings would extend to all benign cranial base tumors. In our study, because of the lower rate of morbidity and the lower degree of invasiveness in gamma knife radiosurgery, the lengths of both ward and hospital stays were shorter. In previous reports about treatment of acoustic neuroma, the number of days of absence from work was approximately 60 for open surgery and 5 for radiosurgery (30). In our study, the mean number of workdays lost after open surgery was 160, which seems to be longer than in the previous studies. Five kinds of benign cranial base tumors were included in our study, as opposed to other studies, in which only one kind of tumor, the acoustic neuroma, was included (23,30).
Roijen et al. (26) reported that 23.3% of patients experienced short-term complications and 10% experienced long-term complications in treatment of acoustic neuroma with microsurgery. These results are similar to ours. In our study, most of the complications associated with open surgery were small and temporary, such as cerebrospinal fluid leakage, hydrocephalus, temporary facial palsy, and diabetes insipidus, but a few patients had severe complications, including central nervous system infection, delayed intracranial hemorrhage, and direct brain and vascular injury, which may cause mortality. The length of ICU, ward, and hospital stays need to be prolonged when the morbidity occurs. The frequency of outpatient visiting also increases as a result of surgical sufferings. In our study, open surgery for cranial brain tumors is more invasive than gamma knife radiosurgery, and therefore, the number of workdays lost is higher for open surgery.
For cost analysis, in our study, the direct cost of gamma knife radiosurgery is higher than that of open surgery. This result is quite different from those of previous studies (21,23,26). The ward, ICU, and hospital stay costs are lower in our country than in other reported series (18,19,26,31). However, the cost of gamma knife investment is the same as in other countries (1,2). The gamma knife facility accounts for 81% of total operating costs in our hospital. At the present time, approximately 180 patients per year (2004) undergo gamma knife radiosurgery at our hospital. With use of this operational number, our mean gamma knife cost per hour is similar to that noted in other reports (1,10,13). However, if the annual number of gamma knife treatments increases, we may further reduce the cost of the gamma knife facility (26). On the basis of the data of gamma knife facility cost, the cost of each case is equal to US $1171/hr × 5.27 hours = $6171/case, slightly higher than the data of Rutigliano (27) (US $5012/case) because the patient number (120 case/yr, 2002–2003) in our hospital is slightly lower than in Rutigliano's series (150 case/yr). If including the operating cost, our total cost of gamma knife for each patient (US $1435/h × 5.27 h = $7562/case) is still lower than Rutigliano's series (US $9787/case). On the other hand, the insurance reimbursements for open surgery and gamma knife are nearly equal in our country. In Asia, Germany, and the United States, gamma knife reimbursements typically range from US $6000 to $12,000. Taiwan offers the lowest (US $4500) (21,31). National Health Insurance pays the cost of a gamma knife or of an open surgery procedure with a fixed payment but not a capital expense. Although the fixed insurance payment is irrelevant to the cost of treatment, it may influence the physician profit fee, which will be relevant to the hospital cost. As seen in Table 2, the physician cost/hour accounts for US $71.00 (4.9%) of gamma knife cost/hour, but it accounts for US $39.10 (8.7%) of OR cost/hour. However, in our study, the physician cost is not included as a fixed cost (facility cost) of the gamma knife, or OR room, as shown in Tables 2 and 3.
In our study, gamma knife for benign cranial base tumors offers the most advantages with respect to indirect and socioeconomic costs. The cost-effectiveness analysis of gamma knife is better than open surgery, similar to the comparison of metastatic brain tumor treatment as reported by Rutigliano (27). Because of the lower rate of morbidity and the absence of mortality in gamma knife treatment, the lost workdays and mortality costs are much lower than those for open surgery. For socioeconomic cost evaluation, we do not include the opportunity costs in our study because the opportunity costs are complicated and not easily quantified.
In their experiences with gamma knife radiosurgery for acoustic neuroma, Noren et al. (20) described health-related quality of life in the 10 years after both open surgery and radiosurgery treatment and reported that radiosurgery was better for tumor control. For benign cranial base tumors, the long-term outcomes of both treatments may be similar but short-term postoperative complications or morbidity may be higher for open surgery. The symptomatic progress of benign cranial base tumors is not rapid, especially in a tumor size less than 3 cm in diameter. The only differences between treatments are focused on how to control and to reduce the treatment complications. The role of gamma knife for treatment of small benign cranial base tumor has the advantage of minimizing morbidity, as it was reported in the literature (22,23,30,31).
Health-related quality of life is evaluated by QALY in our study. The findings of previous reported studies suggest that the indirect cost is usually closely related to quality of life (26). If patients can perform paid work and return to their original work quickly, then they can be considered to have recovered their quality of life after the operation. Cost-effectiveness analysis is a good method to evaluate the relationship of life quality and socioeconomic costs. From the indirect costs and cost-effectiveness analysis results, we may prove the concept that the gamma knife is better than open surgery for quality life maintenance.
CONCLUSION
Most socioeconomic loss associated with open surgery for treatment of benign cranial base tumor is caused by increases in workless and mortality costs. Gamma knife treatment is worthwhile for our patients as well as for our society because it may reduce both the length of hospital stays and the number of lost workdays and, therefore, may reduce complications, mortality, and socioeconomic loss and achieve better cost-effectiveness value.
REFERENCES
Acknowledgments
We thank Ms. Meilan Tsao, B.A. and Chia-Eng Lee, B.A. for their statistics analysis and Ms. Pei-Yei Lin, B.A. for her hospital cost analysis.
COMMENTS
The aim of this study was to evaluate the relative socioeconomic costs of benign cranial base tumors treated with resection or gamma knife radiosurgery. Although cost-finding studies are legitimate exercises, in this case, it is of little value unless a cost-effectiveness study is performed. The issue at hand is the value of the procedure, and, for a benign tumor, the outcome assessment really requires long-term follow-up. Such an assessment is a major limitation of this study.
Are the results of this study surprising? Radiosurgery should have a shorter length of stay, more rapid return to work, and have a lower complication cost. These authors concluded that radiosurgery was more expensive as a procedure because of amortization of purchase costs. A cost-effectiveness analysis helps the reader understand how one gets the best “bang for their buck” and is of value not only for clinicians, but also for health systems evaluating investment in new technologies.
As noted, outcomes are best stated in dollars and quality adjusted life years. This is the accepted standard across most of the medical economic literature. This method takes into account the increased morbidity from open surgery and the rapid return to work from the gamma knife arm. The numerator reflects the increased indirect costs (lost productivity) from open surgery and the denominator the reduced morbidity from radiosurgery. A real assessment of societal cost requires consideration of not only direct and indirect costs of each approach, but also an assessment of opportunity costs. In a societal context, money spent on such treatments is not available to be spent on other needs. Although this is difficult to quantify, it should be understood.
In this study, National Public Insurance (NPI) seems to be a reasonable proxy for a societal cost perspective, given that it includes 97% of the Taiwanese. If this is used as the cost basis, then it is important to determine how capital expenses are paid for by the hospitals. If the NPI pays only for procedures performed, then the fixed cost of the gamma knife is irrelevant in this study. It would be relevant from the hospital's perspective, but not from the perspective of NPI because they are only paying a bill for a procedure. If the NPI participates in funding fixed costs for capital expenditures, then the authors need to determine the fixed costs involved with the surgical arm, including operating room construction (usually amortized), the cost of the microscope, etc.
The cost of “workless days” needs to take into account the time value of money by calculating everything back to present value terms. This is especially important when determining the cost of mortality and long-term disability because future dollars are not as valuable as those today. This is not the same as taking inflation into account. The “cost of working day” alluded to in the results is actually a measure of productivity (gross national product/365 days) rather than a cost. Furthermore, costs associated with lost work are generally measured in wages lost rather than a fraction of gross national product.
The authors have tackled a difficult project. Different readers in different countries and health care systems may draw different conclusions from the data. In some environments, gamma knife radiosurgery or resection may have different costs associated with them, as well as different morbidity rates and other expenditures. Thus, the conclusions reached by additional cost-effectiveness analyses may show further variation.
Michael Rutigliano
Douglas S. Kondziolka
Pittsburgh, Pennsylvania
I think this is a thoughtful and detailed analysis of the costs associated with radiosurgery and open surgery for cranial base tumors in the circumstance of practice in Taiwan. I am sure that extrapolation in general to other economies has merit and value. I think the outcome could have been easily predicted. The interest lies in the figures themselves. However, this will be different depending upon the locale and all of the various factors that make each locale unique. This study adds to the data regarding the overall value of stereotactic radiosurgery to societies in general. Unfortunately, not all cases can be treated by gamma knife alone. This should be brought to the attention of public policymakers who may use such studies as instruments to deny or otherwise limit payment for certain services.
John D. Day
Englewood, Colorado
This study by Cho et al. compares the socioeconomic costs associated with treating benign cranial base tumors using either microsurgery or radiosurgery. A broad range of direct and indirect measures have been included in this quantitative analysis. The ultimate conclusion is unambiguous: radiosurgery is the much more cost effective treatment. However, a range of assumptions were required to reduce a variety of inputs and costs to dollar values. Furthermore, some critical variables, such as gamma knife use factors, institutional experience with microsurgery, the admission of radiosurgical patients to the hospital, etc., apply only to this particular institution. For example, if the number of patients treated annually were double current values, which is not unrealistic, the cost of radiosurgery per patient would decline appreciably. Although the overall conclusion (i.e., the cost effectiveness of radiosurgery) is not surprising (to me at least), the highly quantitative character of the current study precludes too broad an extrapolation and are strictly applicable only to one particular hospital in Taiwan.
Although the authors make a compelling case for the relative cost effectiveness of radiosurgery in their native Taiwan, it is worth noting that their country seems to have the lowest reimbursement rate for radiosurgery in the developed world. Perhaps after reading the current study, the Taiwanese officials who oversee payment for medical procedures will come to more fully appreciate the value of radiosurgery and reimburse more generously.
John R. Adler, Jr.
Stanford, California
This study compares the direct and indirect costs of surgical resection and radiosurgery for patients with benign cranial base tumors managed under the Taiwanese health care system. As expected, the length of hospital stay, complication rates, and time away from work were less with radiosurgery. Interestingly, the direct cost of radiosurgery was greater in this system than surgical resection. I completely agree with the conclusion that radiosurgery should be considered the primary treatment for the majority of patients with small- to moderated-sized cranial base tumors and congratulate the authors for this interesting article.
Bruce E. Pollock
Rochester, Minnesota
