The American Journal of Managed Care March 2010
Inpatient Rehabilitation Utilization for Acute Stroke Under a Universal Health Insurance System
Based on claims data from a universal health insurance system, inpatient stroke rehabilitation use was 34.0% and mainly related to stroke type and stroke severity.
Objective: To explore the population-level utilization and factors associated with the use of inpatient stroke rehabilitation services under a single-payer government-based National Health Insurance (NHI) program in Taiwan.
Study Design: Retrospective cohort study based on claims data.
Methods: Inpatients with stroke were sampled from a nationally representative cohort of 200,000 NHI program enrollees. Multiple inpatient claims for individuals were merged to create a patientlevel file; the first-ever admission was considered the index stroke. Proxy indicators to represent stroke severity, comorbidity, and complications were constructed. Predisposing, need, and enabling characteristics associated with rehabilitation use were explored.
Results: Among 2639 identified patients with stroke from January 1, 1997, to December 31, 2002, the overall inpatient rehabilitation utilization was 34.0% (33.0% for physical therapy, 19.6% for occupational therapy, and 5.3% for speech therapy). Stroke type and stroke severity were immediate causes of rehabilitation use. Except in neurology wards, rehabilitation use was unaffected by physician or facility characteristics. Among 898 patients receiving rehabilitation services, the median number of treatment sessions was 8 (interquartile range, 4-19), and the total rehabilitation costs were US $114.00 (interquartile range, $47.80-$258.30), with a mean (SD) length of stay of 22.2 (21.8) days.
Conclusions: In a setting in which ability to pay is neutralized, inpatient stroke rehabilitation service in this universal NHI program was equitable but inadequate relative to use elsewhere or estimated need. Less severe case mix and financial or human resources constraints might partially account for the low utilization. Further studies measuring stroke severity and functional status are needed to clarify the actual utilization, requirements, and cost-effectiveness of inpatient stroke rehabilitation services.
(Am J Manag Care. 2010;16(3):e67-e74)
This study explored inpatient stroke rehabilitation use based on claims data from a nationally representative cohort under a single-payer universal health insurance system.
- Considered equitable but inadequate, rehabilitation use was 34.0%, mainly related to stroke type and severity.
- On average, patients received 8 treatment sessions at a total cost of US $114.00 for rehabilitation, initiated approximately 7 to 14 days after acute stroke admission, with a mean (SD) length of stay of 22.2 (21.8) days.
- Less severe case mix and financial or human resource constraints may partially account or the low utilization.
- Measurement of stroke severity and functional status is needed to clarify the utilization and cost-effectiveness of inpatient stroke rehabilitation services.
Taiwan has a population of 23 million people, with a 2008 gross national product (GNP) of US $17,941 per capita.13 In 1995, a universal National Health Insurance (NHI) program, financed in roughly equal shares by the government, employers, and households in a complex scheme that includes payroll taxes, subsidies, and individual premiums, commenced in Taiwan.14,15 The NHI program extended existing insurance coverage from 57% of the population to 98%, particularly to the most vulnerable populations (eg, children, older persons, and nonworking adults). Healthcare is delivered by a mixed system that includes private clinics, private nonprofit hospitals, and public hospitals, among which patients have full freedom of choice. Almost all medical institutions are contracted with the NHI program.
The benefits of the NHI program are comprehensive, including inpatient care, ambulatory care, laboratory tests, diagnostic imaging, prescriptions, certain over-the-counter drugs, dental care, alternative medicine, and other services. National health expenditure accounts for 6.2% of the GNP in Taiwan compared with 16% in the United States.16 Copayments (10% for inpatient care and 20% for outpatient care within 30 days of onset) are waived for patients experiencing acute stroke.14,15 Inpatient rehabilitation services are provided to patients with acute stroke in acute wards through coordination of rehabilitation physicians on request of the treating physicians. The NHI program sets its own fee schedule and pays hospitals for rehabilitation claims on a fee-for-service basis.
This study aimed to explore the utilization and factors associated with the use of inpatient stroke rehabilitation services by a nationally representative cohort under a single-payer government-based universal health insurance program in Taiwan. The NHI program in Taiwan has weathered the challenges of a decade, and its stable costs and short wait times for healthcare have garnered worldwide attention.16,17 Analyses of service utilization from this program may be relevant to countries pursuing implementation of more equitable and efficient healthcare systems.
A longitudinal NHI claims cohort data set, constructed by the National Health Research Institute in Taiwan, was used to identify our stroke sample. The cohort data set consists of all inpatient and outpatient medical claims and the registration files of 200,000 NHI program enrollees from 1996 to 2006 and was developed to follow up a representative group of the population longitudinally. The cohort was randomly sampled from 23,753,407 persons insured by the NHI program from March 1, 1995, to December 31, 2000, using the sampling technique function (linear congruential random number generation) of Sun WorkShop C 5.0 (Sun Microsystems, Inc, Santa Clara, CA).18 The distributions of age, sex, and health services utilization among the cohort are representative of the entire population in Taiwan.18 For this study, admissions were extracted from January 1, 1997, to December 31, 2002, with a principal discharge diagnosis of acute cerebrovascular disease (International Classification of Diseases, Ninth Revision, Clinical Modification [ICD-9-CM] codes 430-437). Multiple inpatient claims for individuals were merged to create a patient-level file; the first-ever admission was considered the index stroke.
A total of 2639 patients (2092 with ischemic stroke and 547 with hemorrhagic stroke) comprised the study sample. Ischemic stroke denoted cerebral infarction (ICD-9-CM codes 433, 434, and 436) or transient ischemic attack or other unspecified cerebrovascular diseases (codes 435 and 437) as the primary discharge diagnosis. Hemorrhagic stroke denoted subarachnoid hemorrhage (code 430) or intracerebral hemorrhage (codes 431 and 432) as the primary discharge diagnosis.
Key Variables of Interest
The dependent variable was whether the patient received rehabilitation services during acute hospitalization after stroke. Use of rehabilitation services was defined as reimbursement claims for physical therapy, occupational therapy, speech therapy, or a combination of these therapies. Factors associated with the use and amount of rehabilitation services were stratified into categories of predisposing (age and sex), need (stroke type, stroke severity, comorbidity, and complications), and enabling (onset year and hospital characteristics) characteristics according to a behavioral model of healthcare use.19,20
The following 4 proxy indicators to represent stroke severity were constructed based on secondary diagnoses or Current Procedural Terminology (CPT) codes21: (1) surgical operation (any surgical procedures reimbursed by the NHI program such as craniotomy, ventriculostomy with shunting for hemorrhagic disease, and tracheostomy for patients with ventilation failure); (2) use of mechanical ventilation (CPT codes 94656 and 94657 and ICD-9-CM code 96.7x); (3) hemiplegia or hemiparesis (ICD-9-CM code 342.xx); and (4) residual neurologic deficits (ICD-9-CM codes 345.40-345.51 and 345.80-345.91 for epilepsy, 348.1 for anoxic brain damage, 348.3x for encephalopathy, 780.3x for convulsions, and 784.3 for aphasia).
Charlson Comorbidity Index (CCI) with hemiplegia and paraplegia excluded was used to quantify patients’ preexisting or concurrent comorbidities.22 Clinical Classifications System software (ICD-9-CM [http://www.hcup-us.ahrq.gov/toolssoftware/ccs/ccs.jsp]) and the categorization system by Smith et al21 were used to identify infection or aspiration pneumonia. The identification of enrollees in the NHI research database was encrypted for privacy. Therefore, death status was based on “coded as dead at discharge” plus no additional healthcare utilization record after discharge.
Hospital characteristics included admission ward, hospital accreditation level, hospital ownership, and hospital location. Admission wards included neurology, general medicine, neurosurgery, rehabilitation, and miscellaneous. Based on the hospital bed size, sophistication of medical services, and teaching status, hospitals are classified into the following 3 accreditation levels: medical center, regional hospital, and district hospital. In Taiwan, there are more than 10 medical centers with thousands of beds, hundreds of physicians, and specialized stroke rehabilitation teams; more than 200 regional hospitals with hundreds of beds and tens to a hundred physicians offering general rehabilitation programs; and hundreds of district hospitals of smaller bed size with basic rehabilitation services. Hospitals are broadly classified in the following 3 ownership categories: public hospitals (managed by the government, public enterprise, or universities), nonprofit hospitals (established by private universities or donations for the purposes of charity or medical research), and private hospitals (proprietary hospitals owned by physicians).23 Hospital location was determined based on the NHI bureau to which the hospital belonged and was categorized as Taipei, Northern, Central, Southern, Kao-Ping (the most southern part of Taiwan), or Eastern regions.
The length of stay (LOS) per stroke episode was combined if a patient was transferred to other wards or hospitals for consecutive hospitalization or if the data were divided for administrative reasons. For patients who ever transferred to other wards or hospitals, the ward and hospital responsible for the care of index stroke admission and the main diagnostic category were adjudicated by 2 of us (H-CL and K-CC).
SAS for Windows (version 8.2, SAS Institute, Cary, NC) and SPSS 11.0 for Windows (SPSS Inc, Chicago, IL) were used for data management and analysis. A multiple logistic regression analysis with all variables entered was performed to examine the factors associated with inpatient rehabilitation use simultaneously; the adjusted odds ratio (aOR) (95% confidence interval [CI]) was computed for each variable. One hundred forty patients ever admitted or transferred to the rehabilitation wards were excluded, leaving 2499 patients (1991 with ischemic stroke and 508 with hemorrhagic stroke) in the multivariate analysis. Goodness of fit was checked using Hosmer-Lemeshow test.
Among 2639 subjects with stroke (2092 ischemic and 547 hemorrhagic) with a mean age of 66.7 years, the proportions of subarachnoid hemorrhage, intracerebral hemorrhage, cerebral infarction, and other unspecified stroke were 3.1%, 17.6%, 58.8%, and 20.4%, respectively (Table 1). Mechanical ventilation was used in 5.6% of patients, and surgery was performed in 10.5% of patients. Fifteen percent had secondary hemiplegia or hemiparesis, while 2.0% had residual neurologic deficits such as epilepsy, anoxic brain damage, encephalopathy, convulsions, or aphasia. The rate of infection or aspiration pneumonia during the hospital stay was 16.1%. Almost half (49.1%) had no comorbidity, 29.4% had a CCI of 1, and 21.5% had a CCI of at least 2. The in-hospital mortality was 9.2%. More subjects were admitted to neurology wards (46.5%), regional hospitals (38.7%), nonprofit hospitals (44.8 %), and hospitals in Taipei (26.5%).
The overall utilization of inpatient stroke rehabilitation services was 34.0% (33.0% for physical therapy, 19.6% for occupational therapy, and 5.3% for speech therapy) (Table 1). Utilization was similar irrespective of age, sex, or onset year. Utilization was higher among patients with intracerebral hemorrhage (aOR, 2.93; 95% CI, 1.88-4.55), cerebral infarction (aOR, 3.49; 95% CI, 2.49-4.90), or hemiplegia or hemiparesis (aOR, 3.04; 95% CI, 2.27-4.08) and among patients who survived (aOR, 5.59; 95% CI, 3.25-9.61) (P <.01 for all). Utilization was less among patients with use of mechanical ventilation (aOR, 0.54; 95% CI, 0.31-0.95; P = .05), residual neurologic deficits (aOR, 0.42; 95% CI, 0.21-0.85; P = .05), or infection or aspiration pneumonia (aOR, 0.68; 95% CI, 0.50-0.92; P = .05).
Rehabilitation services were used more among patients treated in neurology wards (aOR, 2.09; 95% CI, 1.56-2.80; P <.01) or in Eastern hospitals (aOR, 2.10; 95% CI, 1.16-3.81; P = .05) (Table 1). Rehabilitation services were less used in public hospitals (aOR, 0.71; 95% CI, 0.51-0.98; P = .05), while no differences were observed in use across hospital accreditation levels.