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Assessing the costs of chronic obstructive pulmonary disease: The state medicaid perspective

Open ArchivePublished:November 14, 2005DOI:https://doi.org/10.1016/j.rmed.2005.10.001

      Summary

      Background: State Medicaid programs provide insurance coverage to over 40 million Americans. However, estimates of the annual cost of chronic obstructive pulmonary disease (COPD) from the Medicaid perspective are lacking.
      Methods: This retrospective cohort study used Medicaid administrative claims data from California and Florida to estimate COPD expenditures using two alternative methods: (1) excess costs (comparing a COPD cohort to a matched comparison cohort); and (2) attributable costs (COPD-related expenditures within a COPD cohort, inclusive of respiratory medications). The COPD cohort in each state included Medicaid recipients not dually eligible for Medicare who were 40+ years of age with at least one medical claim for COPD during 2001. The comparison cohort consisted of patients with medical claims during 2001 for conditions other than chronic respiratory disease, matched by age, sex, and race to the COPD cohort.
      Results: A total of 6738 Medicaid recipients in California and 18,017 in Florida were included in the COPD cohort, with mean ages of 56 and 60 years, respectively. Comorbidities, especially congestive heart failure and vascular disease, were more common in the COPD cohort than among matched controls. The mean excess cost of COPD per-patient was estimated to be approximately $6500 in California Medicaid and $5200 in Florida Medicaid. Mean attributable costs of COPD were similar in the two Medicaid programs (approximately $2200 and $2300 per patient, respectively).
      Conclusions: COPD places a substantial financial burden on State Medicaid programs. These findings may be of interest to clinicians and policy-makers involved in preventing or managing this chronic disease.

      Keywords

      Introduction

      Chronic obstructive pulmonary disease (COPD) is an important cause of morbidity and mortality in the US, and a major source of healthcare costs.
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      COPD currently ranks as the fourth leading cause of death in the US after heart disease, cancer, and cerebrovascular disease, with about 120,000 annual deaths.
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      National Heart, Lung, and Blood Institute. Data Fact Sheet: Chronic Obstructive Pulmonary Disease (COPD) [Web Page]. Available at http://www.nhlbi.nih.gov/health/public/lung/other/copd_fact.htm (Accessed 2003 Dec).

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      The prevalence, morbidity, and mortality of COPD have increased over time, and are expected to increase with the aging of the US population.

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      COPD is a slowly progressive disease of the airways characterized by airflow limitation and gradual loss of lung function that is not fully reversible.

      National Heart, Lung, and Blood Institute. Data Fact Sheet: Chronic Obstructive Pulmonary Disease (COPD) [Web Page]. Available at http://www.nhlbi.nih.gov/health/public/lung/other/copd_fact.htm (Accessed 2003 Dec).

      National Heart, Lung, and Blood Institute/World Health Organization. Global Strategy for the Diagnosis, Management, and Prevention of Chronic Obstructive Pulmonary Disease: NHLBI/WHO Workshop [Web Page]. 1998 April; Available at www.goldcopd.com (Accessed 2003 Dec).

      It is considered “a preventable and treatable disease state”.
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      In the US, the term COPD includes chronic bronchitis, chronic obstructive bronchitis, emphysema, and combinations of these conditions.

      National Heart, Lung, and Blood Institute. Data Fact Sheet: Chronic Obstructive Pulmonary Disease (COPD) [Web Page]. Available at http://www.nhlbi.nih.gov/health/public/lung/other/copd_fact.htm (Accessed 2003 Dec).

      Symptoms of COPD include wheezing, cough, sputum production, and dyspnea, with the latter the most prominent and disabling symptom and the most common reason for patients to seek medical care.
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      Diagnosis is usually made on the basis of medical history, physical examination, and results from pulmonary function testing.

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      Treatment options for COPD are aimed largely at symptom control; these include inhaled and oral bronchodilators, anti-inflammatory drugs, and supplemental oxygen.

      American Lung Association®. Fact Sheet: Chronic Obstructive Pulmonary Disease (COPD) [Web Page]. 2003 October; Available at http://www.lungsusa.org/diseases/copd_factsheet.html (Accessed 2003 Dec).

      However, cessation of smoking is the only intervention that has successfully proven to reduce rate of decline in lung function.
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      Surgical treatment, such as bullectomy, lung volume reduction surgery, and lung transplantation, is not an option for most patients.

      American Lung Association®. Fact Sheet: Chronic Obstructive Pulmonary Disease (COPD) [Web Page]. 2003 October; Available at http://www.lungsusa.org/diseases/copd_factsheet.html (Accessed 2003 Dec).

      • Benditt J.O.
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      The direct and indirect costs of COPD have been estimated at $32.1 billion in 2003.

      National Heart, Lung, and Blood Institute. Data Fact Sheet: Chronic Obstructive Pulmonary Disease (COPD) [Web Page]. Available at http://www.nhlbi.nih.gov/health/public/lung/other/copd_fact.htm (Accessed 2003 Dec).

      American Lung Association®. Fact Sheet: Chronic Obstructive Pulmonary Disease (COPD) [Web Page]. 2003 October; Available at http://www.lungsusa.org/diseases/copd_factsheet.html (Accessed 2003 Dec).

      Direct costs (i.e., those related to hospital care, physician and other professional services, home care, nursing home care, and pharmacy) accounted for $18 billion, while indirect costs (lost earnings due to illness and lost future earnings resulting from death) comprised $14.1 billion.

      National Heart, Lung, and Blood Institute. Data Fact Sheet: Chronic Obstructive Pulmonary Disease (COPD) [Web Page]. Available at http://www.nhlbi.nih.gov/health/public/lung/other/copd_fact.htm (Accessed 2003 Dec).

      American Lung Association®. Fact Sheet: Chronic Obstructive Pulmonary Disease (COPD) [Web Page]. 2003 October; Available at http://www.lungsusa.org/diseases/copd_factsheet.html (Accessed 2003 Dec).

      Most US COPD cost analyses are limited to Medicare or private insurers, or have used fairly outdated national survey data.
      • Ward M.M.
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      Direct medical cost of chronic obstructive pulmonary disease in the USA.
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      The Medicaid program, financed by the US Federal Government and individual states, covers more than 40 million poor or medically needy persons, or about 14% of the population. Each state organizes its own services under Medicaid and finances up to 50% of the program costs. The economic burden of COPD is an important issue from the Medicaid perspective given that smoking, the most important risk factor for this disease, has a 50–100% higher prevalence among Medicaid recipients versus the general population.
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      • et al.
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      Centers for Disease Control and Prevention CDC
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      In addition, adults eligible for Medicaid assistance have poorer health status than other adults.
      • Holahan J.
      Health status and the cost of expanding insurance coverage.
      The objective of the present study was to use data from two large state Medicaid programs to estimate the direct costs of COPD.

      Methods

      Data sources

      California Medicaid

      California Medicaid (“Medi-Cal”) is the largest state Medicaid program in the US, with over 8 million recipients.

      Centers for Medicare & Medicaid Services. MSIS Statistical Report for Federal Fiscal Year 2001 for the State of California [Web Page]. Available at http://www.cms.hhs.gov/medicaid/msis/01ca.pdf (Accessed 2004 Jun).

      Total program expenditures exceeded $19.8 billion in 2001,

      Centers for Medicare & Medicaid Services. MSIS Statistical Report for Federal Fiscal Year 2001 for the State of California [Web Page]. Available at http://www.cms.hhs.gov/medicaid/msis/01ca.pdf (Accessed 2004 Jun).

      of which $4.3 billion represented capitated payments to managed care organizations. The major components of expenditures for non-capitated care included hospitalization and nursing homes ($6.1 billion), prescription medications ($2.8 billion), personal support ($2.8 billion), hospital outpatient and clinics ($1.1 billion), and physician and laboratory services ($1.1 billion).
      The database used in this study consisted of administrative claims and eligibility information for a 20% random sample of Medi-Cal recipients. The Medi-Cal eligibility file included recipient age, sex, race, whether or not the recipient was eligible for Medi-Cal services in each month, and dual (i.e., Medicaid and Medicare) coverage status. The claims files included details on prescriptions filled (National Drug Code, dispense date, quantity of medication prescribed, and therapy days supplied), outpatient services (date of service, type of service, and one ICD-9-CM diagnosis code), and institutional services (type of facility, admission and discharge dates, primary and secondary ICD-9-CM diagnosis code, and procedures performed).
      A total of approximately 1.04 million California Medicaid recipients were eligible for full benefits in the 20% file as of the start of our study period, 419,000 of whom were eligible for fee-for-service coverage (see Cohort Selection below).

      Florida Medicaid

      The Florida Medicaid program is the fourth largest in the US with 2.5 million recipients.

      Centers for Medicare & Medicaid Services. MSIS Statistical Report for Federal Fiscal Year 2001 for the State of Florida [Web Page]. Available at http://www.cms.hhs.gov/medicaid/msis/01fl.pdf (Accessed 2004 Jun).

      Total program expenditures exceeded $8.4 billion in 2001,

      Centers for Medicare & Medicaid Services. MSIS Statistical Report for Federal Fiscal Year 2001 for the State of Florida [Web Page]. Available at http://www.cms.hhs.gov/medicaid/msis/01fl.pdf (Accessed 2004 Jun).

      of which $0.9 billion represented capitated payments to managed care organizations. The major components of expenditures for non-capitated care included hospitalization and nursing homes ($3.5 billion), prescription medications ($1.5 billion), personal support ($0.3 billion), hospital outpatient and clinics ($0.6 billion), and physician and laboratory services ($0.5 billion).
      The database used for analysis consisted of administrative claims and eligibility information for Florida Medicaid recipients drawn from the entire population of recipients. The Florida Medicaid database, which is similar in structure to the Medi-Cal database, included eligibility information and claims for institutional medical services, outpatient medical services, and prescription drugs.
      A total of approximately 1.96 million Florida Medicaid recipients were eligible for benefits as of the start of our study period, of whom 1.44 million were eligible for fee-for-service coverage.

      Cohort selection

      The initial study population included all Medicaid recipients in the state of Florida and a 20% random sample of Medicaid recipients in California. These recipients were required to have fee-for-service coverage (i.e., non-capitated prescription drug and medical benefits) as of the beginning of the study period (i.e., January 1, 2001 through December 31, 2001 for California, and July 1, 2000 through June 30, 2001 for Florida). Recipients who were eligible for both Medicaid and Medicare (primarily those 65 years of age and older) were excluded from the analysis since complete claims details often are lacking for this population. We also excluded Medicaid recipients under 40 years of age, since COPD would be expected to be uncommon in this age group.
      From each database, Medicaid recipients with a diagnosis of COPD (“COPD cohort”), and those with no respiratory disease diagnoses (“comparison cohort”), were selected from the initial population, as follows:
      COPD cohort: All recipients having one or more medical claims with a primary or secondary diagnosis of chronic bronchitis (ICD-9-CM diagnosis codes 491.xx), emphysema (ICD-9-CM 492.xx), or chronic airway obstruction not elsewhere classified (ICD-9-CM 496.xx) during the study period were included in the COPD cohort.
      Comparison cohort: All recipients who had no claims with a primary or secondary diagnosis for respiratory disease (ICD-9-CM codes 491.xx through 496.xx) but had one or more claims for other medical services with a valid ICD-9-CM diagnosis during the study period were candidates for inclusion in the comparison cohort. Patients from this pool were selected at random and matched, on a one-to-one basis, with patients in the COPD cohort by age (exact year), sex, and race/ethnicity.

      Study measures

      Healthcare utilization and excess cost of COPD. We evaluated the use of healthcare services and medications among the COPD and comparison cohorts in each Medicaid program. In addition, the excess cost of COPD was estimated as the mean of the per-patient differences in overall medical and pharmacy expenditures between the COPD and matched comparison cohorts. Resource utilization and expenditures also were evaluated by category of service (i.e., inpatient, outpatient, home healthcare, physician, drugs).
      Attributable cost of COPD. The attributable cost of COPD was assessed by accumulating all Medicaid payments for medical claims that had a listed diagnosis (primary or secondary) of COPD and adding the cost of respiratory medications. The latter included beta-agonists, anticholinergics, methylxanthines, glucocorticoids, and combinations of these therapies.
      Our assessment focused on direct medical costs only. Indirect costs (e.g., from lost productivity due to illness) were not included since this information is not recorded in Medicaid databases.

      Data analyses

      Descriptive analyses of patient characteristics were performed for the COPD and comparison cohorts, including demographics, comorbidities, and duration of Medicaid eligibility. To assess the prevalence of comorbidities, medical claims from 2001 were reviewed. A total of 17 binary variables were created, each corresponding to a chronic disease contained in the comorbidity scale developed by Charlson and colleagues.
      • Charlson M.E.
      • Pompei P.
      • Ales K.L.
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      The method of Deyo et al.,
      • Deyo R.A.
      • Cherkin D.C.
      • Ciol M.A.
      Adapting a clinical comorbidity index for use with ICD-9-CM administrative databases.
      which established ICD-9-CM codes for each of these 17 conditions, was used to create the binary comorbidity variables from the claims database. Finally, these conditions were weighted to create a single comorbidity score.
      • Charlson M.E.
      • Pompei P.
      • Ales K.L.
      • MacKenzie C.R.
      A new method of classifying prognostic comorbidity in longitudinal studies: development and validation.
      The Charlson comorbidity classification scheme was employed because it has been validated in several other studies using administrative claims data.
      • Charlson M.E.
      • Pompei P.
      • Ales K.L.
      • MacKenzie C.R.
      A new method of classifying prognostic comorbidity in longitudinal studies: development and validation.
      • Deyo R.A.
      • Cherkin D.C.
      • Ciol M.A.
      Adapting a clinical comorbidity index for use with ICD-9-CM administrative databases.
      • Romano P.S.
      • Roos L.L.
      • Jollis J.G.
      Adapting a clinical comorbidity index for use with ICD-9-CD administrative data: differing perspectives.
      • D’Hoore W.
      • Bouckaert A.
      • Tilquin C.
      Practical Considerations on the use of Charlson comorbidity index with administrative data bases.
      Because of potential overlap with COPD, chronic pulmonary disease was excluded from calculations of the comorbidity score. In addition, we documented whether patients in the COPD cohort had asthma (ICD-9-CM 493.xx) as a primary or secondary diagnosis during the study period.
      Healthcare resource utilization and costs—both excess and attributable—also were analyzed descriptively. The contribution of comorbidity to excess cost, calculated as the paired difference in costs for the COPD cohort and matched controls, was assessed through multivariate modeling based on analysis-of-covariance (least-squares means), which included the Charlson comorbidity score, the presence of concomitant asthma (in the COPD cohort), and controlled for length of follow-up. An alternative model that included all of the available comorbidities individually also was estimated, but yielded similar findings and therefore is not reported herein. For cost measures, standard errors also were calculated.
      All data analyses were conducted using the Statistical Analysis System (SAS) software package.
      SAS Institute Inc
      SAS/STAT® User's Guide, Version 8.

      Results

      Patient characteristics

      A total of 24,755 Medicaid recipients with COPD (and an equal number of matched controls) met cohort selection criteria: 6738 in California and 18,017 in Florida. These patients were identified as follows. In the Medi-Cal program, using the 20% data file, 16,752 recipients were found to have at least one medical claim with a COPD diagnosis. From this group, 8871 were excluded due to dual Medicare–Medicaid eligibility, 79% of whom were 65 years of age or older. An additional 1143 patients were excluded because they were under 40 years of age. In Florida Medicaid, 42,495 recipients had a COPD diagnosis. From this group, 17,758 were excluded due to dual Medicare–Medicaid eligibility, 78% of whom were 65 years of age or older. Another 6720 were excluded because they were under 40 years of age.
      The mean age of study patients was 56 years in California and 60 years in Florida, with 53% and 58% female, respectively. Twenty-eight percent and 21% of patients in the COPD cohort had a concomitant asthma diagnosis. Comorbidities, especially congestive heart failure and vascular disease, were more common in the COPD cohorts than among matched controls. This pattern of comorbidities was found in both the California and Florida Medicaid programs (Table 1).
      Table 1Characteristics of COPD and matched comparison cohorts, by state Medicaid program, 2001.
      MeasureCalifornia MedicaidFlorida Medicaid
      COPD cohort (n=6738)Comparison cohort (n=6738)COPD cohort (n=18,017)Comparison cohort (n=18,017)
      Age
      This calculation excludes chronic pulmonary disease.
       40–54 years45.1%45.1%35.6%35.6%
       55–64 years40.3%40.3%37.2%37.2%
       65+ years14.6%14.6%27.2%27.2%
      Mean±SD56.1±9.656.1±9.659.5±11.859.5±11.8
      Percent male
      This calculation excludes chronic pulmonary disease.
      47.1%47.1%42.2%42.2%
      Race
      This calculation excludes chronic pulmonary disease.
       White55.6%55.6%52.6%52.6%
       Black21.2%21.2%13.9%13.9%
       Asian19.1%19.1%0.2%0.2%
       Hispanic4.1%4.1%6.8%6.8%
       Other0.0%0.0%26.6%26.6%
      Charlson comorbidity index (Mean±SD)
      This calculation excludes chronic pulmonary disease.
      1.5±2.20.9±1.71.5±2.11.0±1.8
      Selected Charlson comorbidities (%):
       Myocardial infarction4.6%2.1%5.3%2.0%
       Congestive heart failure17.9%5.5%17.9%4.9%
       Peripheral vascular disease8.0%2.7%7.7%3.5%
       Cerebrovascular disease14.1%6.8%12.2%6.7%
       Rheumatologic disease7.3%3.6%2.9%2.3%
       Peptic ulcer disease7.1%3.7%3.7%1.7%
       Diabetes31.2%24.7%25.7%19.4%
       Liver disease4.1%3.0%3.6%2.2%
       Any malignancy7.9%5.5%9.2%6.4%
       Metastatic solid tumor2.3%1.1%2.7%1.6%
      Asthma (%)28.1%0.0%20.6%0.0%
      Other selected comorbidities (%):
       Depression9.9%6.7%17.8%11.2%
       Hip fracture1.9%1.0%1.9%1.2%
      Number of months of eligibility (Mean±SD)11.5±1.811.1±2.511.2±2.110.8±2.7
      low asterisk This calculation excludes chronic pulmonary disease.

      Healthcare utilization

      The proportion of patients hospitalized was higher in the COPD cohorts in both programs (Table 2). As a result, COPD patients spent, on average, an additional 3.2 and 4.2 days in the hospital in California and Florida, respectively, during the study year. The proportions of patients using hospital outpatient services, home health-care services or durable medical equipment, and physician services also were higher in the COPD cohorts in both state Medicaid systems. The only exception was for nursing facility admissions, which were higher in the COPD cohort in California, but lower in Florida. For the COPD cohort, 32% and 16% underwent spirometry during 2001 in California and Florida, respectively.
      Table 2Healthcare utilization for COPD and matched comparison cohorts, by state Medicaid program and component, 2001.
      MeasureCalifornia MedicaidFlorida Medicaid
      COPD cohort (n=6738)Comparison cohort (n=6738)COPD cohort (n=18,017)Comparison cohort (n=18,017)
      Inpatient
       Acute hospital care
       Percent hospitalized32.3%13.3%46.6%18.5%
       Mean (± SD) hospital days per patient4.9±14.01.7±8.95.6±10.81.4±5.2
       Nursing facility admissions
       Percent with NF admissions7.4%4.7%9.3%11.4%
       Mean (± SD) NF days per patient13.1±61.811.6±62.318.0±71.631.1±97.5
      Outpatient
       Percent with hospital outpatient services67.7%56.5%72.1%62.5%
       Percent with durable medical equipment38.1%14.5%47.1%9.4%
      Physician
       Percent with physician visits96.5%82.0%92.8%87.9%
      The use of all types of medications, both respiratory and non-respiratory, was higher in the COPD cohort (Table 3). Nearly three-quarters of patients in the COPD cohort used antibiotics versus 50% in the comparison cohort. Approximately one-half of patients in the COPD group used short-acting beta-agonists, while about 20% used anticholinergics, inhaled steroids, or systemic steroids, and 10% used long acting bronchodilators or xanthines (Table 4). These usage patterns were similar in both state Medicaid programs.
      Table 3Drug utilization for COPD and matched comparison cohorts, by state Medicaid program, 2001.
      MeasureCalifornia MedicaidFlorida Medicaid
      COPD cohort (n=6738)Comparison cohort (n=6738)COPD cohort (n=18,017)Comparison cohort (n=18,017)
      Respiratory-related
       Percent with prescription
      Percent of patients with any prescription in category.
      57.6%11.7%65.7%17.1%
       Mean (±SD) number of prescriptions per patient
      Number of prescriptions for unique drugs, excluding refills.
      1.4±1.70.2±0.51.7±1.70.3±0.7
      Antibiotics
       Percent with prescription
      Percent of patients with any prescription in category.
      73.5%46.9%74.1%52.1%
       Mean (±SD) number of prescriptions per patient
      Number of prescriptions for unique drugs, excluding refills.
      1.5±1.40.8±1.01.7±1.61.0±1.2
      Other
       Percent with prescription
      Percent of patients with any prescription in category.
      97.7%88.8%94.8%90.2%
       Mean (±SD) number of prescriptions per patient
      Number of prescriptions for unique drugs, excluding refills.
      13.4±9.28.2±7.213.4±8.49.2±7.0
      Overall
       Percent with prescription
      Percent of patients with any prescription in category.
      98.4%89.7%95.3%90.9%
       Mean (±SD) number of prescriptions per patient
      Number of prescriptions for unique drugs, excluding refills.
      16.3±10.29.2±7.816.7±9.710.4±7.9
      low asterisk Percent of patients with any prescription in category.
      Number of prescriptions for unique drugs, excluding refills.
      Table 4Respiratory drug utilization for COPD patients, by slate Medicaid program, 2001.
      MeasureCalifornia MedicaidFlorida Medicaid
      Short acting beta agonists
       Percent with prescription
      Percent of patients with any prescription in category.
      49.3%55.2%
       Mean (±SD) number of medications dispensed per user
      Number of medications dispensed, including refills.
      5.4±6.26.5±6.3
      Long acting beta agonists
       Percent with prescription
      Percent of patients with any prescription in category.
      9.7%10.7%
       Mean (±SD) number of medications dispensed per user
      Number of medications dispensed, including refills.
      3.2±2.93.6±3.1
      Anticholinergics
       Percent with prescription
      Percent of patients with any prescription in category.
      20.8%21.9%
       Mean (±SD) number of medications dispensed per user
      Number of medications dispensed, including refills.
      4.3±4.84.8±4.5
      Methylxanthines
       Percent with prescription
      Percent of patients with any prescription in category.
      8.9%15.4%
       Mean (±SD) number of medications dispensed per user
      Number of medications dispensed, including refills.
      4.7±3.86.3±4.2
      Inhaled glucocorticosteroids
       Percent with prescription
      Percent of patients with any prescription in category.
      19.1%22.0%
       Mean (±SD) number of medications dispensed per user
      Number of medications dispensed, including refills.
      3.1±2.93.8±3.3
      Systemic glucocorticosteroids
       Percent with prescription
      Percent of patients with any prescription in category.
      18.6%28.1%
       Mean (±SD) number of medications dispensed per user
      Number of medications dispensed, including refills.
      2.7±2.83.3±3.4
      Combination long acting beta agonists and glucocorticosteroids
       Percent with prescription
      Percent of patients with any prescription in category.
      1.7%2.0%
       Mean (±SD) number of medications dispensed per user
      Number of medications dispensed, including refills.
      1.7±1.01.3±0.6
      low asterisk Percent of patients with any prescription in category.
      Number of medications dispensed, including refills.

      Medicaid expenditures

      Excess costs of COPD. The mean (± standard error) excess costs of COPD per-patient in the California and Florida Medicaid programs were estimated at $6468± $319 and $5242±$188, respectively (Table 5). Approximately one-half of these costs were associated with inpatient treatment. Additional expenditures associated with prescription drugs and physician visits accounted for most of the remaining differences in each state. Based on multivariate analyses, asthma and other comorbidity in the COPD cohort accounted for 47% and 43% of the excess cost in California and Florida, respectively. Median excess costs were estimated to be $2952 in California and $3711 in Florida.
      Table 5Mean healthcare costs (2001 US dollars) for COPD and matched comparison cohorts, by state Medicaid program and component, 2001.
      MeasureCalifornia MedicaidFlorida Medicaid
      COPD cohort (n=6738)Comparison cohort (n=6738)COPD cost (COPD − comparison cohort) (Mean±SE)COPD cohort (n=18,017)Comparison cohort (n=18,017)COPD cost (COPD − comparison cohort) (Mean±SE)
      Inpatient
       Acute hospitalization$5007$1701$3306±$207$5526$1477$4049±$88
       Nursing facility$1509$1445$64±$154$1894$3203−$1309±$95
      Subtotal$6516$3146$3370±$258$7421$4680$2741±$131
      Outpatient
       Hospital$278$178$100±$12$715$476$240±$17
       Durable medical equipment$230$89$141±$20$686$106$581±$16
      Subtotal$508$268$241±$23$1402$581$820±$23
      Physician$1446$527$919±$33$1513$614$899±$23
      Pharmacy$3683$2008$1675±$71$4284$2802$1482±$61
      Other healthcare cost$749$535$213±$41$1883$2584−$701±$89
      Total healthcare cost$12,952$6484$6468±$319$16,503$11,261$5242±$188
      Attributable costs of COPD. The mean (± standard error) attributable costs of COPD per patient in the California and Florida Medicaid programs were similar ($2160±$97 and $2337±$35, respectively), of which approximately one-half was associated with hospitalization.
      Relative costs of COPD. The mean per-patient cost for a COPD patient was estimated to be $12,952 in California, which is about five times average per-capita spending ($2405) in the state for the same year (2001).
      Centers for Medicare & Medicaid Services
      Health Care Financing Review. Statistical Supplement, 2003.
      Corresponding figures for the Florida Medicaid program are $16,503 and $3528.
      Centers for Medicare & Medicaid Services
      Health Care Financing Review. Statistical Supplement, 2003.

      Discussion

      This retrospective study used data from two large state Medicaid programs to estimate the annual direct medical costs of COPD from the Medicaid system perspective. Using two different estimation methodologies, our findings suggest that the costs of COPD, on a per-recipient basis, range from approximately $2200 to $6500 in California, and $2300 to $5200 in Florida. There have been numerous published studies on the economic burden of COPD, but we believe this is the first to focus specifically on state Medicaid programs. Our estimate of excess cost is comparable to those from other claims-based studies that examined different payer perspectives. For example, Mapel and colleagues, using administrative claims data from a US managed-care organization, estimated mean costs of COPD at $6039 per patient (1997 US dollars),
      • Mapel D.W.
      • Hurley J.S.
      • Frost F.J.
      • et al.
      Health care utilization in chronic obstructive pulmonary disease. A case–control study in a health maintenance organization.
      or $7023 adjusted to 2001 dollars. Grasso and colleagues, using Medicare claims, estimated per-patient COPD costs at $4971 (1992 US dollars),
      • Grasso M.E.
      • Weller W.E.
      • Shaffer T.J.
      • Diette G.B.
      • Anderson G.F.
      Capitation, managed care, and chronic obstructive pulmonary disease.
      or $7133 in 2001 dollars. Two studies based on survey data derived somewhat lower estimates. Halpern and colleagues,
      • Halpern M.T.
      • Stanford R.H.
      • Borker R.
      The burden of COPD in the USA: results from the Confronting COPD survey.
      using data derived from the US sample of the international COPD survey, Confronting COPD in North America and Europe, estimated costs at $4120 (2000 US dollars). Miller et al. derived an estimate of excess costs of $4932 (2000 US dollars) using data from the Medical Expenditure Panel Survey (MEPS), with an attributable cost estimate of $2507; the latter figure compares favorably with our estimate.

      Miller JD, Foster T, Boulanger L, et al. Costs of chronic obstructive pulmonary disease (COPD) in the US: an analysis of Medical Expenditure Panel Survey (MEPS) Data. American Thoracic Society International Conference, Orlando, FL, May 21–26, 2004.

      Our findings have several implications with respect to the Medicaid population. First, the excess cost of COPD for Medicaid recipients is notable since it appears to be comparable to that estimated for Medicare
      • Grasso M.E.
      • Weller W.E.
      • Shaffer T.J.
      • Diette G.B.
      • Anderson G.F.
      Capitation, managed care, and chronic obstructive pulmonary disease.
      and private insurance
      • Mapel D.W.
      • Hurley J.S.
      • Frost F.J.
      • et al.
      Health care utilization in chronic obstructive pulmonary disease. A case–control study in a health maintenance organization.
      populations despite the fact that the average age of patients in our study was at least 10 years younger. Second, the high prevalence of smoking in the Medicaid population relative to the general US population
      • Carr R.M.
      • Christiansen B.
      • Jehn L.
      • Matitz D.
      Meeting the challenge of tobacco use within the Medicaid population.
      • Frazier L.M.
      • Molgaard C.A.
      • Fredrickson D.D.
      • et al.
      Barriers to smoking cessation initiatives for Medicaid clients in managed care.
      Centers for Disease Control and Prevention CDC
      State medicaid coverage for tobacco-dependence treatments—United States, 1994–2002.
      means that counseling regarding smoking cessation and financial coverage for smoking cessation aids are worthy of consideration. However, as of 2002, 15 Medicaid programs still did not provide coverage for tobacco-dependence treatment, which falls short of the 2010 national health objective of providing such coverage in all states.
      Centers for Disease Control and Prevention CDC
      State medicaid coverage for tobacco-dependence treatments—United States, 1994–2002.
      Moreover, Medicaid recipients and the uninsured have been shown to be less likely to receive smoking cessation counseling in their physicians’ office when compared to persons with private insurance coverage.
      • Parnes B.
      • Main D.S.
      • Holcomb S.
      • Pace W.
      Tobacco cessation counseling among underserved patients: a report from CaReNet.
      A strength of this study is that we employed two alternative costing approaches. The attributable cost approach only counts medical services that list a diagnosis of COPD. Since COPD patients have multiple comorbidities, in some cases those conditions may be coded rather than COPD, resulting in an underestimation of costs. This may be especially problematic for physician services, as only one diagnosis is coded in many claims databases. The excess cost method measures the overall difference in expenditures, regardless of specific diagnoses, between patients with COPD and a non-respiratory disease comparison group matched on sociodemographic factors. Some of the estimated excess costs may reflect other, related medical conditions. For example, we found a higher prevalence of other illnesses in the COPD cohort that are linked to smoking, such as cardiovascular disease, stroke, and cancer. These comorbidities were estimated to account for 35–38% of the excess cost of COPD. Asthma as a concomitant diagnosis was found to contribute an additional 8–9% to excess costs. Because both of the costing approaches have merit, we elected to report both here.
      There are several limitations to our study. First, Medicaid claims for persons with dual Medicaid and Medicare coverage were not complete. These patients, representing more than 40% of the overall number with COPD, were therefore excluded from the analyses. Future studies that take a broader government perspective (e.g., both Medicare and Medicaid) would be of interest, especially given the recent passage of a new Medicare prescription drug benefit. Second, the study used data from only two state Medicaid programs. While California and Florida comprise about 20% of the entire US Medicaid population, additional state-specific studies in other regions of the US would be valuable. Finally, health insurance claims data have known limitations. For instance, the use of ICD-9-CM codes (e.g., the specific diagnosis codes or the number of times they occur during the one-year study period) to assess prevalent cases of COPD has not, to our knowledge, been validated against objective clinical data, such as spirometry results.
      In summary, results from this study suggest that the costs of COPD from the Medicaid perspective are substantial and consistent in the two states evaluated. These findings may be of interest to clinicians and policy-makers involved in preventing or managing this chronic disease.

      Acknowledgments

      The authors wish to thank Rick deFriesse, M.S. for his expert programming assistance, and Rebecca Audette, B.Sc. for her help with preparing this manuscript.
      Research support was provided by Pfizer Inc., New York, NY.

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