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The cost of transplant graft maintenance following solid organ transplantation
The Cost of Transplant Graft Maintenance Following Solid Organ Transplantation T.I. Shireman, J.E. Martin, and J.F. Whiting
M
OST RECENT economic studies of various solid organ transplant recipients are limited to short-term or acute care costs, cost-effectiveness analyses of antiviral or immunosuppressive regimens, or costs incurred during clinical trials.1–5 For patients who survive their first critical year after transplantation, however, considerable costs continue to accrue. As graft survival rates improve, additional attention must be directed toward clinical and economic issues relating to the maintenance of a functioning graft. Although cost data related to the maintenance of a functioning graft are readily available for renal transplant recipients, little data exists for extrarenal organ recipients.6,7 The purpose of this observational study was to determine the health service utilization and cost patterns among solid organ transplant recipients with functioning grafts and to provide a comparison to renal organ recipients.
METHODS This study was a 12-month (February 1, 1998 to January 31, 1999) retrospective claims data analysis for a population of solid organ transplant patients who received Medicaid benefits for at least 6 months. Adult (⬎18 years) ambulatory cases were identified by screening pharmacy claims for one of the following four combinations of tracer medications: cyclosporine and azathioprine (AZA), cyclosporine and mycophenolate mofetil (MMF), tacrolimus and AZA, or tacrolimus and MMF. All medical, institutional, and pharmacy paid Medicaid claims were extracted for the entire 12-month period. Transplant type was determined by screening medical and institutional claims for ICD9 diagnosis codes: kidney or kidney/pancreas (V42.0 ⫾ V.42.83), liver (V42.7), heart or heart/lung (V42.1 ⫾ V 42.6), lung (V42.6), or unspecified (V42.9). All cases were transplanted prior to February 1998. Institutional and medical visits were separated into the following categories of service: inpatient admissions, outpatient hospital visits, nonhospital-based physician visits, and other ambulatory care visits. Visits were further classified as transplant related if the claim included any of the following ICD9 codes (including all subcode extensions): 996, 997, 998, V03, V04, V07, and V42. Immunosuppressive medications and systemic steroids were considered transplant related. Costs were determined from the payer perspective (what the payer reimbursed the provider). Since transplant recipients are frequently eligible for health benefits through multiple payers, we included non-Medicaid (Medicare and other third-party payers) sources of payment as noted in the Medicaid claim files. When Medicare was the primary payer, Medicaid paid the remaining coinsurance and/or deductible amounts for medical and institutional 0041-1345/01/$–see front matter PII S0041-1345(00)02813-X
claims. Medicaid was the primary payer for prescription medications. We summed across all payer sources to generate costs by category of service as well as total costs. All costs were in 1998 dollars. Total health care costs and prescription drug costs were compared across transplant types using Tamhane’s post hoc comparison tests that adjust for unequal variances and unequal sample sizes.
RESULTS
We identified 372 study subjects through the use of tracer medications: cyclosporine and AZA (n ⫽ 106), cyclosporine and MMF (n ⫽ 197), tacrolimus and AZA (n ⫽ 9), and tacrolimus and MMF (n ⫽ 60). We excluded six cases because there were no transplant-related medical or institutional ICD9 codes, suggesting that they may not have been solid organ transplant recipients. Ten patients received their transplant during the study period (one heart, two liver, seven kidney transplants) and were excluded from this analysis. All descriptive statistics are based upon the remaining 356 recipients. A slight majority of subjects were female (51.4%), and their mean age was 41.4 ⫾ 11.7 years (range 18 to 73). Seventy percent were white, non-Hispanic; 27.0% were black, non-Hispanic; and the remaining 3.1% were Hispanic or other race. The majority of cases were renal organ recipients (n ⫽ 250). Liver and heart transplants each accounted for 30 cases, and there were only six lung transplants. Forty cases were unable to be classified with the claims data. We combined the lung transplant recipients with the unspecified group due to the small number of cases. From the University of Kansas School of Pharmacy (T.I.S.), Lawrence, Kansas and the University of Cincinnati Medical Center Pharmacy (J.E.M.) and Pathology and Laboratory Medicine (J.F.W.), Transplant Division, Cincinnati, Ohio. This work was supported through an interagency agreement between the Ohio Department of Human Services, the Medicaid Technical Assistance and Policy Program, and the University of Cincinnati. The views and opinions expressed herein are not necessarily reflective of the opinions of the associated State agencies. Address reprint requests to Theresa I. Shireman, University of Kansas School of Pharmacy, 2058 Malott Hall, Lawrence, KS 66045 USA. © 2001 by Elsevier Science Inc. 655 Avenue of the Americas, New York, NY 10010
1920
Transplantation Proceedings, 33, 1920–1921 (2001)
COST OF GRAFT MAINTENANCE
1921
Table 1. Total Health Care Costs by Type of Transplant (1998 US$) Kidney
Number of cases Cost category Inpatient hospital Outpatient hospital Physician visits Other ambulatory visits Prescriptions Total
Heart
Liver
Unspecified
250
30
30
46
14,101 7,209 3,123 2,561 11,603
26,271 14,568 4,274 980 12,000
12,022 10,966 3,978 2,810 11,872
3,037 5,199 1,840 2,995 11,281
$38,597
$58,093
$41,648
$24,352
Transplant-related hospital admissions accounted for approximately 60% of their total number of hospital admissions (total admissions averaged 0.77 admits/year for 5.3 days). Recipients had 11 visits to outpatient hospital clinics or services and 4.6 of these were for transplant-related reasons. They had an additional 26.6 visits to physicians during the year, but only six of these could be attributed to the transplant diagnosis. There was less than one visit per recipient for other ambulatory care that was transplant related. Of the 121 prescriptions received per year, 33 were for either an immunosuppressive or a systemic steroid. As for costs, 46% of their total health care costs could be directly attributed to transplant maintenance. The largest single component of transplant-related care was prescription medications, averaging $8228 per year. Inpatient hospitalizations were second, averaging $6121 for transplantrelated events. Medicare bore 55% to 60% of the inpatient hospital, outpatient hospital, and physician visit costs, while Medicaid covered over 75% of the other ambulatory care costs. Medicaid paid nearly all prescription medication costs. Table 1 displays total health care costs by category of service and type of transplant. Costs were significantly different between the kidney group and the unspecified/ lung group (P ⫽ .002) and between the liver group and the unspecified/lung group (P ⫽ .019). Heart transplant recipients had the highest costs that averaged nearly $20,000 per year more than kidney recipients, although this difference was not statistically significant. Liver organ recipients’ costs were closer to kidney recipients. Drug costs were consistent across the types of transplants (F ⫽ 0.163, P ⫽ .921). DISCUSSION
The purpose of this study was to examine graft maintenance costs among solid organ transplant recipients, especially extrarenal organ recipients. Through the use of a secondary database, we identified and followed transplanted individuals for 12 months to capture their health care use and costs. Over 46% of health care costs were directly attributable to transplant. Transplant maintenance costs averaged over $17,700 per year. While the majority of cases were renal organ recipients, we found that costs were no different between kidney and liver recipients. Statistically, the costs
differences were not significant between heart transplants and other types, although heart transplant recipients had on average $20,000 higher costs than kidney recipients. Medication costs were consistent and substantial across organ transplant types with 75% of those costs accounted for by immunosuppressive agents. There are many limitations when using administrative claims data such as inaccuracy of diagnosis coding and the lack of clinical parameters. We also question the completeness of the claims data given that many of our study subjects had multiple payers. There may have been claims never paid in full by one of the primary payer sources or the patient may have paid the coinsurance or copayment so that Medicaid would not have received any balance bill. We have undoubtedly understated the actual utilization and costs this cohort incurred, although our costs were similar to those previously reported for dually eligible recipients.8 Solid organ transplantation requires a heavy investment of health care resources. Further work is needed to identify the optimal use of those resources to ensure optimal patient outcomes. Through concurrent primary data collection for this study sample, we will be able to link this health care utilization with the recipients’ quality of life and functional outcomes. This will allow us to determine the contribution of each component of health care to patient-based outcomes. We will also be able to account for time since transplant and compare patient self-reported health care use with the claims experience. REFERENCES 1. Kim WR, Badley AD, Wiesner RH, et al: Transplantation 69:357, 2000 2. Arbo MD, Snydman DR, Wong JB, et al: Clin Transplant 14:19, 2000 3. Smith CR, Woodward RS, Cohen DS, et al: Transplantation 69:311, 2000 4. Rufat P, Fourquet F, Conti F, et al: Transplantation 68:76, 1999 5. Whiting JF, Martin JE, Zavala E, et al: Surgery 125:217, 1999 6. Schnitzler MA, Hollenbeak CS, Cohen DS, et al: N Engl J Med 341:1440, 1999 7. Douzdjian V, Escobar F, Kupin WL, et al: Clin Transplant 13:51, 1999 8. Thamer M, Chan JK, Ray NF, et al: Am J Kidney Dis 31:283, 1998
M
OST RECENT economic studies of various solid organ transplant recipients are limited to short-term or acute care costs, cost-effectiveness analyses of antiviral or immunosuppressive regimens, or costs incurred during clinical trials.1–5 For patients who survive their first critical year after transplantation, however, considerable costs continue to accrue. As graft survival rates improve, additional attention must be directed toward clinical and economic issues relating to the maintenance of a functioning graft. Although cost data related to the maintenance of a functioning graft are readily available for renal transplant recipients, little data exists for extrarenal organ recipients.6,7 The purpose of this observational study was to determine the health service utilization and cost patterns among solid organ transplant recipients with functioning grafts and to provide a comparison to renal organ recipients.
METHODS This study was a 12-month (February 1, 1998 to January 31, 1999) retrospective claims data analysis for a population of solid organ transplant patients who received Medicaid benefits for at least 6 months. Adult (⬎18 years) ambulatory cases were identified by screening pharmacy claims for one of the following four combinations of tracer medications: cyclosporine and azathioprine (AZA), cyclosporine and mycophenolate mofetil (MMF), tacrolimus and AZA, or tacrolimus and MMF. All medical, institutional, and pharmacy paid Medicaid claims were extracted for the entire 12-month period. Transplant type was determined by screening medical and institutional claims for ICD9 diagnosis codes: kidney or kidney/pancreas (V42.0 ⫾ V.42.83), liver (V42.7), heart or heart/lung (V42.1 ⫾ V 42.6), lung (V42.6), or unspecified (V42.9). All cases were transplanted prior to February 1998. Institutional and medical visits were separated into the following categories of service: inpatient admissions, outpatient hospital visits, nonhospital-based physician visits, and other ambulatory care visits. Visits were further classified as transplant related if the claim included any of the following ICD9 codes (including all subcode extensions): 996, 997, 998, V03, V04, V07, and V42. Immunosuppressive medications and systemic steroids were considered transplant related. Costs were determined from the payer perspective (what the payer reimbursed the provider). Since transplant recipients are frequently eligible for health benefits through multiple payers, we included non-Medicaid (Medicare and other third-party payers) sources of payment as noted in the Medicaid claim files. When Medicare was the primary payer, Medicaid paid the remaining coinsurance and/or deductible amounts for medical and institutional 0041-1345/01/$–see front matter PII S0041-1345(00)02813-X
claims. Medicaid was the primary payer for prescription medications. We summed across all payer sources to generate costs by category of service as well as total costs. All costs were in 1998 dollars. Total health care costs and prescription drug costs were compared across transplant types using Tamhane’s post hoc comparison tests that adjust for unequal variances and unequal sample sizes.
RESULTS
We identified 372 study subjects through the use of tracer medications: cyclosporine and AZA (n ⫽ 106), cyclosporine and MMF (n ⫽ 197), tacrolimus and AZA (n ⫽ 9), and tacrolimus and MMF (n ⫽ 60). We excluded six cases because there were no transplant-related medical or institutional ICD9 codes, suggesting that they may not have been solid organ transplant recipients. Ten patients received their transplant during the study period (one heart, two liver, seven kidney transplants) and were excluded from this analysis. All descriptive statistics are based upon the remaining 356 recipients. A slight majority of subjects were female (51.4%), and their mean age was 41.4 ⫾ 11.7 years (range 18 to 73). Seventy percent were white, non-Hispanic; 27.0% were black, non-Hispanic; and the remaining 3.1% were Hispanic or other race. The majority of cases were renal organ recipients (n ⫽ 250). Liver and heart transplants each accounted for 30 cases, and there were only six lung transplants. Forty cases were unable to be classified with the claims data. We combined the lung transplant recipients with the unspecified group due to the small number of cases. From the University of Kansas School of Pharmacy (T.I.S.), Lawrence, Kansas and the University of Cincinnati Medical Center Pharmacy (J.E.M.) and Pathology and Laboratory Medicine (J.F.W.), Transplant Division, Cincinnati, Ohio. This work was supported through an interagency agreement between the Ohio Department of Human Services, the Medicaid Technical Assistance and Policy Program, and the University of Cincinnati. The views and opinions expressed herein are not necessarily reflective of the opinions of the associated State agencies. Address reprint requests to Theresa I. Shireman, University of Kansas School of Pharmacy, 2058 Malott Hall, Lawrence, KS 66045 USA. © 2001 by Elsevier Science Inc. 655 Avenue of the Americas, New York, NY 10010
1920
Transplantation Proceedings, 33, 1920–1921 (2001)
COST OF GRAFT MAINTENANCE
1921
Table 1. Total Health Care Costs by Type of Transplant (1998 US$) Kidney
Number of cases Cost category Inpatient hospital Outpatient hospital Physician visits Other ambulatory visits Prescriptions Total
Heart
Liver
Unspecified
250
30
30
46
14,101 7,209 3,123 2,561 11,603
26,271 14,568 4,274 980 12,000
12,022 10,966 3,978 2,810 11,872
3,037 5,199 1,840 2,995 11,281
$38,597
$58,093
$41,648
$24,352
Transplant-related hospital admissions accounted for approximately 60% of their total number of hospital admissions (total admissions averaged 0.77 admits/year for 5.3 days). Recipients had 11 visits to outpatient hospital clinics or services and 4.6 of these were for transplant-related reasons. They had an additional 26.6 visits to physicians during the year, but only six of these could be attributed to the transplant diagnosis. There was less than one visit per recipient for other ambulatory care that was transplant related. Of the 121 prescriptions received per year, 33 were for either an immunosuppressive or a systemic steroid. As for costs, 46% of their total health care costs could be directly attributed to transplant maintenance. The largest single component of transplant-related care was prescription medications, averaging $8228 per year. Inpatient hospitalizations were second, averaging $6121 for transplantrelated events. Medicare bore 55% to 60% of the inpatient hospital, outpatient hospital, and physician visit costs, while Medicaid covered over 75% of the other ambulatory care costs. Medicaid paid nearly all prescription medication costs. Table 1 displays total health care costs by category of service and type of transplant. Costs were significantly different between the kidney group and the unspecified/ lung group (P ⫽ .002) and between the liver group and the unspecified/lung group (P ⫽ .019). Heart transplant recipients had the highest costs that averaged nearly $20,000 per year more than kidney recipients, although this difference was not statistically significant. Liver organ recipients’ costs were closer to kidney recipients. Drug costs were consistent across the types of transplants (F ⫽ 0.163, P ⫽ .921). DISCUSSION
The purpose of this study was to examine graft maintenance costs among solid organ transplant recipients, especially extrarenal organ recipients. Through the use of a secondary database, we identified and followed transplanted individuals for 12 months to capture their health care use and costs. Over 46% of health care costs were directly attributable to transplant. Transplant maintenance costs averaged over $17,700 per year. While the majority of cases were renal organ recipients, we found that costs were no different between kidney and liver recipients. Statistically, the costs
differences were not significant between heart transplants and other types, although heart transplant recipients had on average $20,000 higher costs than kidney recipients. Medication costs were consistent and substantial across organ transplant types with 75% of those costs accounted for by immunosuppressive agents. There are many limitations when using administrative claims data such as inaccuracy of diagnosis coding and the lack of clinical parameters. We also question the completeness of the claims data given that many of our study subjects had multiple payers. There may have been claims never paid in full by one of the primary payer sources or the patient may have paid the coinsurance or copayment so that Medicaid would not have received any balance bill. We have undoubtedly understated the actual utilization and costs this cohort incurred, although our costs were similar to those previously reported for dually eligible recipients.8 Solid organ transplantation requires a heavy investment of health care resources. Further work is needed to identify the optimal use of those resources to ensure optimal patient outcomes. Through concurrent primary data collection for this study sample, we will be able to link this health care utilization with the recipients’ quality of life and functional outcomes. This will allow us to determine the contribution of each component of health care to patient-based outcomes. We will also be able to account for time since transplant and compare patient self-reported health care use with the claims experience. REFERENCES 1. Kim WR, Badley AD, Wiesner RH, et al: Transplantation 69:357, 2000 2. Arbo MD, Snydman DR, Wong JB, et al: Clin Transplant 14:19, 2000 3. Smith CR, Woodward RS, Cohen DS, et al: Transplantation 69:311, 2000 4. Rufat P, Fourquet F, Conti F, et al: Transplantation 68:76, 1999 5. Whiting JF, Martin JE, Zavala E, et al: Surgery 125:217, 1999 6. Schnitzler MA, Hollenbeak CS, Cohen DS, et al: N Engl J Med 341:1440, 1999 7. Douzdjian V, Escobar F, Kupin WL, et al: Clin Transplant 13:51, 1999 8. Thamer M, Chan JK, Ray NF, et al: Am J Kidney Dis 31:283, 1998