Impact of changes in medical aid status on health care utilization

Abstract

Background: Provision of appropriate levels of health care services to required individuals is a pursuit of every health care system. In accordance, the government of South Korea operates a Medical Aid (MA) program targeting selected low income individuals in the aim of ensuring medical service delivery to the disadvantaged while enhancing self-sufficiency of work capable beneficiaries to reduce welfare dependency in the long run. However, as reasons behind welfare exits are diverse and do not always infer poverty relief, a need exists to investigate the impact of changes in MA status on health care utilization, with consideration of unmet need and catastrophic health expenditure (CHE). This study investigated the association between changes in MA status and health care utilization, unmet need, and CHE. Materials and Methods: Health care utilization was investigated using the 2006 to 2015 National Health Insurance (NHI) claims data and the 2010 to 2014 Korea Health Panel (KHP) data. The impact of changes in annual MA status (‘MA to MA,’ ‘MA to MA Exit,’ ‘MA Exit to MA,’ and ‘MA Exit to MA Exit’) on health care utilization [yearly number of outpatient visits, inpatient visits, length of stay, and emergency department (ED) visits] were investigated in individuals receiving MA benefits at baseline using the generalized estimating equation (GEE) model. Analysis was separated for individuals aged 20 to 64 and 65 or above in the NHI data analysis. Similarly, health care utilization was studied separately for MA type I and II individuals in the KHP data analysis. In addition, the relationship between MA status change and unmet need (all-cause and financial) and CHE were examined using the KHP data. Results: Changes in health care utilization were measured using the NHI and KHP data. In the NHI data analysis, of 117,943 adult subjects aged 20 to 64, 76,908 (65.2%) subjects were in the ‘MA to MA,’ 7,561 (6.4%) in the ‘MA to MA Exit,’ 849 (0.7%) in the ‘MA Exit to MA,’ and 32,625 (27.7%) in the ‘MA Exit to MA Exit’ groups. Compared to the ‘MA to MA’ group, the ‘MA to MA Exit’ group showed general decreases in utilization [outpatient visits: β -3.93, P<0.0001; hospital admissions: Relative Risk (RR) 0.87, 95% Confidence Interval (CI) 0.83-0.91; length of stay: β -3.64, P<0.0001; ED visits: RR 0.83, 95% CI 0.77-0.90]. Similar patterns were found in the ‘MA Exit to MA Exit’ group (outpatient visits: β -5.72, P<0.0001; hospital admissions: RR 0.91, 95% CI 0.87-0.94; length of stay: β -5.87, P<0.0001; ED visits: RR 0.81, 95% CI 0.75-0.88). Of 74,747 older adult subjects aged 65 or above, 60,614 (81.1%) subjects were in the ‘MA to MA,’ 2,783 (3.7%) in the ‘MA to MA Exit,’ 378 (0.5%) in the ‘MA Exit to MA,’ and 10,972 (14.7%) in the’ MA Exit to MA Exit’ groups. Compared to the ‘MA to MA’ group, the ‘MA to MA Exit’ group showed reduced levels of utilization (outpatient visits: β -1.51, P=0.0020), as well as the ‘MA Exit to MA Exit’ group (hospital admissions: RR 0.92, 95% CI 0.89-0.95; length of stay: β -5.45, P<0.0001; ED visits: RR 0.90, 95% CI 0.83-0.97). In the KHP data analysis, utilization patterns remained generally similar for both type I and II subjects. Regarding unmet need, 1,164 Medical Aid type I subjects were analyzed, in which 1,049 (90.1%) were in the ‘MA to MA,’ 53 (4.6%) in the ‘MA to MA Exit,’ 9 (0.8%) in the ‘MA Exit to MA,’ and 53 (4.6%) in the ‘MA Exit to MA Exit’ groups. A total of 305 (26.2%) subjects reported unmet need and 188 (16.2%) unmet need due to financial reasons. Compared to the ‘MA to MA’ group, the ‘MA to MA Exit’ group showed increased likelihoods of unmet need [Odds Ratio (OR) 2.43, 95% CI 1.21-4.85] and financial unmet need (OR 2.26, 95% CI 1.29-3.99). Similarly, 852 type II subjects were analyzed, in which 564 (66.2%) were in the ‘MA to MA,’ 116 (13.6%) in the ‘MA to MA Exit,’ 12 (1.4%) in the ‘MA Exit to MA,’ and 160 (18.8%) in the ‘MA Exit to MA Exit’ groups. A total of 217 (25.5%) subjects reported unmet need and 154 (18.1%) unmet need due to financial reasons. Lastly, with regard to CHE, 284 (24.4%) type I subjects reported CHE at the 10% and 58 (5.0%) at the 40% household capacity to pay standards. Compared to the ‘MA to MA’ group, the ‘MA to MA Exit’ group showed higher likelihoods of CHE at the 10% standard (OR 1.22, 95% CI 1.07-1.40). The ‘MA Exit to MA Exit’ group showed increased likelihoods of CHE at the 10% (OR 1.33, 95% CI 1.13-1.57) and 40% standards (OR 1.13, 95% CI 1.02-1.26). Similarly, 188 (22.1%) type II subjects reported CHE at the 10% and 35 (4.1%) at 40% standards. The ‘MA to MA Exit’ group showed an increased likelihood of CHE at the 10% standard (OR 1.14, 95% CI 1.05-1.24). Conclusion: Medical Aid exit was associated with general decreases in health care utilization. Higher likelihoods of all-cause and financial unmet need were also found in the MA exit group in type I beneficiaries, in addition to escalated risks of mild levels of CHE in both type I and II individuals. Decreased health care utilization were likely a result of enhanced optimization of health care resources impacted by reduced levels of moral hazard and occurrences of unmet need. Therefore, utilization patterns of individuals with experiences of receiving Medical Aid benefits should be monitored to promote ideal use of health care services while preventing potential financial barriers present in accessing medical care.