Mortality and treatment costs of hospitalized chronic kidney disease patients between the three major health insurance schemes in Thailand

Background Thailand has reformed its healthcare to ensure fairness and universality. Previous reports comparing the fairness among the 3 main healthcare schemes, including the Universal Coverage Scheme (UCS), the Civil Servant Medical Benefit Scheme (CSMBS) and the Social Health Insurance (SHI) have been published. They focused mainly on provision of medication for cancers and human immunodeficiency virus infection. Since chronic kidney disease (CKD) patients have a high rate of hospitalization and high risk of death, they also require special care and need more than access to medicine. We, therefore, performed a 1-year, nationwide, evaluation on the clinical outcomes (i.e., mortality rates and complication rates) and treatment costs for hospitalized CKD patients across the 3 main health insurance schemes. Methods All adult in-patient CKD medical expense forms in fiscal 2010 were analyzed. The outcomes focused on were clinical outcomes, access to special care and equipment (especially dialysis), and expenses on CKD patients. Factors influencing mortality rates were evaluated by multiple logistic regression. Results There were 128,338 CKD patients, accounting for 236,439 admissions. The CSMBS group was older on average, had the most severe co-morbidities, and had the highest hospital charges, while the UCS group had the highest rate of complications. The mortality rates differed among the 3 insurance schemes; the crude odds ratio (OR) for mortality was highest in the CSMBS scheme. After adjustment for biological, economic, and geographic variables, the UCS group had the highest risk of in-hospital death (OR 1.13;95 % confidence interval (CI) 1.07–1.20; p < 0.001) while the SHI group had lowest mortality (OR 0.87; 95 % CI 0.76–0.99; p = 0.038). The circumscribed healthcare benefits and limited access to specialists and dialysis care in the UCS may account for less favorable comparison with the CSMBS and SHI groups. Conclusions Significant differences are observed in mortality rates among CKD patients from among the 3 main healthcare schemes. Improvements in equity of care might minimize the differences. Electronic supplementary material The online version of this article (doi:10.1186/s12913-016-1792-9) contains supplementary material, which is available to authorized users.


Background
Thailand implemented healthcare reforms in 2002 to ensure universal healthcare provision [1]. The 4 national healthcare insurance schemes include: (i) the Universal Coverage Scheme (UCS) provides free medical care for persons without any other insurance (i.e., > 70 % of the population: the majority of farmers, low-income persons, and the unemployed); (ii) the Civil Servant Medical Benefit Scheme (CSMBS) provides free medical care for government employees and their dependents; (iii) the Social Health Insurance (SHI) scheme for private sector employees; and, (iv) private insurance. The first 3 schemes cover > 96 % of the population [2].
The level of healthcare in Thailand depends on the particular hospital type and location. Community hospitals principally provide primary care and have limited resources for treating complex illnesses. Patients from the latter are sent to general (secondary) and tertiary hospitals, as appropriate. The distribution of hospitals in turn depends on economics and geography. The central region-where the capital is located-has the highest gross domestic product (GDP) per capita (~158 % of national GDP). By comparison, the respective proportion of national GDP of the Northeast and North is 34 and 45 % [3].
Previous reports-comparing the fairness of healthcare provision among the 3 main healthcare schemes-were mainly on the provision of medication for cancers and HIV/AIDS [4][5][6][7][8]. To our knowledge, there has been no report comparing the different healthcare schemes vis-àvis chronic diseases (i.e., chronic kidney diseases -CKD) that require medicine, special care teams, special medical equipment, and hospitalization.
Since CKD patients have an increased rate of hospitalization and a high risk for death [9,10], we evaluated the nationwide healthcare data of hospitalized CKD patients in fiscal year 2010 for practice outcomes of healthcare among the 3 main health insurance schemes. Our particular focus was on differences in (i) clinical outcomes, (ii) access to special care and equipment (notably dialysis), and (iii) budgeting.

Methods
The data analyzed were from (i) the in-patients total medical expense forms from the UCS fiscal year 2010 from the National Health Security Office; (ii) the inpatient data from the CSMBS from the Comptroller General's Department; and, (iii) the in-patient data from the SHI from the Social Security Office. The variables included: sex, age, occupation, address, type of hospital, health insurance scheme, co-morbidities, length of hospital stay (days), complications, treatment, clinical outcomes, and medical expenses (costs charged). Additional information obtained from the Nephrology Society of Thailand, the National Statistical Office, and the Office of the National Economic and Social Development Board, Office of the Prime Minister included: ratio of nephrologists to dialysis units/regional population and end-stage renal disease (ESRD) patients, and the reimbursement of renal replacement therapies among the different healthcare schemes.
The in-patient data were first checked for accuracy by examining for (i) overlapping information (ii) visit dates (iii) missing items (iv) incorrect coding and (v) the correct fiscal year. CKD patients were identified in either the primary diagnosis (CKD-primary) or secondary diagnosis (CKD-secondary) as code N18 of the International Statistical Classification of Diseases and Related Health Problems, 10th revision (ICD-10) [11]. Hemodialysis and peritoneal dialysis were identified as code 39.95 and 54.98, respectively (ICD-9-CM 2010 classification of procedures) [12]. The data were analyzed not only on the basis of health insurance scheme but also on the level of care provided (i.e., community/primary, general/secondary or tertiary hospital or private hospital) in order to assess accessibility to appropriate care.

Outcome measures
The differences across the 3 health insurance schemes vis-à-vis in-hospital mortality and high treatment cost were examined. Demographic data, comorbidities and complications were analyzed as to whether they affected the two measures. In addition, policies involving the CKD treatment of the three schemes, budget allocation were explored to facilitate the explanation of the differences of the outcome measures (if any).

Statistical analysis
STATA version 14 was used for the statistical analyses. The means ± SD or medians (25th-75th percentile) and percentages were used to present the continuous and categorical data, respectively. The generalized estimating equation (GEE) and multiple logistic regression analysis (MLRA) were performed to adjust the odds ratios for factors influencing the (i) high cost accounting for multiple admissions within an individual and (ii) mortality rate at individual level.

Demographic data of the patients
In fiscal 2010, the population over 19 years of age numbered 47,966,734-or 74 % of Thailand's total population of 64.7 million. Approximately 96 % of the adult population (46,208,964 persons) was covered by one of the 3 health insurance systems. The total number of adult inpatients was 3,876,792 (admitted 4,863,935 times), accounting for 71 % of all in-patients. According to the 23 major disease groups in the ICD 10, among the respective causes of hospitalization and mortality, diseases of the genitourinary system ranked 7th among hospitalized patients (298,258 persons, 7.7 % of all adults in-patients and 392,498 admissions) and the 7th cause of mortality [13].
CKD was the most common diagnosis of the genitourinary system. The total number of CKD patients was 128,338 (generating 236,439 admissions), and accounting for 4.9 % of all adult in-patient admissions (268 persons or 493 visits per 100,000 adult population). Of these, 98,727 persons (185,161 admissions), 24,767 (42,348 admissions) and 4844 (8930 admissions) were covered in the UCS, CSMBS, and SHI groups, respectively.
Characteristics of hospitalized CKD patients under different healthcare schemes Table 1 presents the characteristics of CKD patients in the UCS, CSMBS, and SHI schemes. The age of subjects in the CSMBS were the oldest while those in the SHI scheme were the youngest. Most of participants in the UCS, CSMBS and SHI scheme were admitted in a community, tertiary and private hospital, respectively. The patients in the CSMBS and SHI scheme comprised the majority from the central region while those in the UCS were from the Northeast region. Highest proportion of CKD patients in the CSMBS group was diagnosed as CKD-secondary. The respective proportion of ESRD among in-patients under the SHI, CSMBS and UCS was 52.1, 31.6, and 24.2 %.  Note: CKD chronic kidney disease, ESRD end stage renal disease, N northern region, NE northeastern region, C central region, S southern region, SD standard deviation and stroke (7.4 %). Patients in the CSMBS had the greatest proportion of co-morbidities (Table 1).

Complications
Complications for all CKD patients comprised significant anemia requiring blood transfusion (30.2 %), hyperkalemia (14.9 %), volume overload (11.9 %), and metabolic acidosis (8.2 %). The rate of complications was highest in the UCS (Table 1). The characteristics of CKD patients defined as CKDprimary or CKD-secondary and admitted in different hospital levels are presented in the Additional file 1: Table S1 and Additional file 2: Table S2. Subjects in the CKD-secondary group were older, stayed in hospital longer, were more likely from the central region and were admitted to a tertiary hospital. The CKD-secondary group also had more co-morbidities, incurred a higher hospital cost, and had higher mortality rate than the CKD-primary group. In contrast, the rate of complications was higher in the CKD-primary group. Patients treated in tertiary hospitals had more comorbidities; particularly cardiovascular disease, pneumonia, acute on  top CKD, and sepsis. By region, hospitals admitting the greatest proportion of CKD patients were in the North and Northeast in community hospitals. By comparison, patients in the central region were admitted to tertiary hospitals. Most of the private hospitals are also located in the central region, where a significant number of patients in the SHI group were admitted.

Length of hospital stay
The longest hospital stay among CKD patients was in the central region at tertiary hospitals under the CSMBS ( Table 2).

Factors influencing the high treatment cost of in-patient
Hospital charges for CKD patients were highest in (i) the central region compared with other regions (ii) at private hospitals compared with community, general and tertiary hospitals, and (iii) covered by CSMBS compared with UCS and SHI (Table 2). Comparing hospital charges of the 3 health schemes with the same hospital levels revealed that hospital charge of the SHI was significantly highest at community hospitals while the CSMBS was the highest at general and tertiary hospitals. No significant differences in hospital charges between the 3 health schemes treated at private hospitals were observed ( Table 2). After adjustment with the factors affecting high hospital charges (>50,000 baht or~1470 USD per admission)-sex, hospital level, region, co-morbidities, complications, and dialysis treatment-the UCS and SHI groups had a respective 62 and 55 % lower hospital charges than the CSMBS (Table 3). Table 4 presents patient characteristics. After adjustment for age, sex, region, hospital level, hospital charge, comorbidities, complications, and mode of dialysis, the multiple logistic regression analysis revealed that the highest mortality rate was for patients under the UCS while the lowest was for those under the SHI. Patients under the SHI and CSMBS had a respective 23.0 and 11.5 % reduction of mortality rates compared to the UCS group.
In addition to the factors associated with mortality, health policies among the health schemes differed ( Table 6). Patients in the UCS trended to have fewer benefits than patients in the other healthcare schemes. Patients under the UCS were not able to choose the hospitals with full-scale CKD care. They had to be referred by a primary care hospital. The limited distribution of nephrologists and dialysis units outside major urban centres might be a barrier for patients under the UCS who live mainly in the North and Northeast (Table 7).

Discussion
CKD is defined as abnormalities in the kidney structure or function and/or a decreased glomerular filtration rate for more than 3 months (GFR < 60 ml/min/1.73 m 2 ) [14]. Code N18 in the ICD-10 represents an older nomenclature for chronic renal failure as a decrease in GFR comparable to stage 3a-5 CKD patients (estimated GFR < 60 ml/min/1.73 m 2 ). Our study revealed that 45-60 % of admitted CKD patients also had hypertension and diabetes. The co-morbidities associated with mortality and high hospital charges were sepsis, pneumonia, respiratory failure followed by cardiovascular diseases and AKI on pre-existing CKD. This finding agrees with previous studies that demonstrated the severity of CKD increased in-hospital mortality among patients with acute coronary syndrome [15][16][17][18][19][20], heart failure [21][22][23], cardiac surgery [24], and stroke [25]. Early optimum therapeutic interventions and appropriate medications After the Thai healthcare reforms were implemented in 2002, the poor indeed had wider access to medical services. Equity of health financing, health workers and healthcare infrastructure have been studied and an improving trend in equity was reported [26][27][28][29]. Notwithstanding, differences in access to hospital types persist among the 3 insurance schemes. The population under UCS must be registered at a community hospital near home. When necessary, there is a line of referrals. Any patient who does not follow the referral process and attempts to go directly to a tertiary care center will have to pay all costs by themselves. By comparison, under the CSMBS, a government employee can register at any public hospital according to their preference [2] while an employee covered by SHI must register at the contracted public or private hospital [30]. If a referral is required, the employee must go to one of the hospitals in the designated network. Only in an emergency may persons covered by SHI or UCS be exempted from paying; however, they must be transferred to their registered hospital as soon as possible. These vagaries in regulations provide an explanation as to why those on UCS go to community hospitals and government employees go to tertiary care hospitals [2]. Since the UCS group comprises a higher proportion of low socio-economic patients, mainly located in rural region, they experience delayed hospital accessibility. Furthermore, our study revealed differences in clinical outcomes of hospitalized CKD patients that might represent residual inequality that needs addressing.
Mortality rates of hospitalized CKD patients differed among the 3 insurance schemes: the crude odd ratios revealed the highest mortality under the CSMBS. Patients admitted under the CSMBS had more severe or complicated disease than the other schemes; as indicated by the highest (i) percentage of life-threatening co-morbidities, (ii) length of stay, and (iii) hospital charges. After adjusting for biological and economic geographic variables, the multivariable analysis demonstrated that the UCS group had the highest risk of in-hospital death while the SHI group had the lowest mortality. The explanation may be related to the limited health care benefits under the UCS compared to the CSMBS and SHI. Table 6 presents a comparison of the health policies among the 3 schemes. The CSMBS appears     -Hemodyalysis Not more than 1,500 bahts (44 USD)/ session and not more than 4,500 bahts (132USD)/week.
Hemodialysis was allowed only CAPD was contraindication or having complications. Not more than 1,500-1,700 bahts (44-50 USD)/session and not more than 3,000-3,400 bahts (88-100 USD)/week. Improving CKD care might be achieved by implementing policies that ensure fairness by providing a comparable budget allocation among the healthcare schemes. The "PD First" policy in Thailand launched in 2008 initiated CAPD as renal replacement therapy for ESRD patients under the UCS [33]. This policy represents an effective strategy for correcting the inadequate distribution of hemodialysis machines and insufficient numbers of nephrologists in rural areas and to underprivileged groups.

As the actual expenses
Anemia is one of the complications seen in CKD patients, and this can be corrected by injection of erythropoiesis stimulating agent (ESA). ESA is relatively costly and is only reimbursed during the pre-dialysis period under the CSMBS scheme. Our data revealed that there was a lower proportion of patients with anemia requiring blood transfusion under the CSMBS than the UCS or SHI groups. More intensive, high-cost medication support by the 3 main health schemes might reduce morbidity and hospitalization.
The strength of this study is that almost all of the subjects were hospitalized adult, Thai, CKD patients. The results, therefore, provide a clear overview of the situation vis-à-vis these adult patients; however, some limitations existed. Lack of a registered nationwide laboratory system means that there is no standardized staging of CKD patients, which might influence the clinical outcomes. The present study analyzed the administrative claim data, therefore socio-economic status of patients was not available. In addition, we are not able to generate an area locator as a proxy for socioeconomic status of individual patients due to lack of data. Insufficient data of these demand-side characteristics observed at the individual level made some limitations in comparison of equity among the three health insurance schemes. The record of charges for each group represents an average and this might not wholly characterize the severity of individual patients nor include details of the procedures and medical instruments needed for each patient. Moreover, the mortality focused in this study was outcome at discharge which may be different with mortality after discharge because some patients died at home.