Background: While there are many studies estimating the effects of private health insurance on various types of health care utilization, few have examined how such effects change in conjunction with important policy reforms in national health insurance (NHI). This study examined how the effect of private health insurance (supplemental and fixed cash benefit) on high-cost outpatient imaging test utilization changed following the expansion of magnetic resonance imaging (MRI) coverage in 2018, which is a key example of the NHI benefit expansion policy in recent years. Methods: Data from the 2017 and 2019 Korea Health Panel Survey, which contained information about healthcare utilization before and after the expansion of MRI coverage in 2018, were used. The incremental effect of private health insurance on high-cost outpatient imaging test utilization for each period were quantified and compared, with special attention given to the type of private health insurance. Results: While people with supplemental private health insurance were more likely to use high-cost outpatient imaging tests than those without, both before and after the expansion of MRI coverage, the incremental effect increased from 1.6% points in 2017 to 2.5% points in 2019. Conclusion Benefit expansion in NHI does not necessarily reduce disparities in the use of health care between private health insurance subscribers and non-subscribers. The results of our study also suggest that the path through which private health insurance affects healthcare utilization may not be limited to the price mechanism alone but can be more complex.

Objectives: This study examined the effect of out-of-pocket (OOP) payment reduction on the potential utilization of low-value magnetic resonance imaging (MRI) across income groups. Methods: We conducted an experimental vignette survey using a proportional quota-based sample of individuals in Korea (n=1229). In two hypothetical vignettes, participants were asked whether they would be willing to use MRI if they had uncomplicated headache and non-specific low back pain, each before and after OOP payment reduction. To account for the possible role of physician inducement, half of the participants were initially presented with vignettes that included a physician recommendation for low-value care. The predicted probability, slope index of inequality (SII), and relative index of inequality (RII) were calculated using logistic regression. Results: Before OOP payment reduction, the lowest income quintile was least likely to use low-value MRI regardless of physician inducement (36.7-49.6% for low back pain; 30.5-39.3% for headache). After OOP payment reduction, almost all individuals in each income quintile were willing to use low-value MRI (89.8-98.0% for low back pain; 78.1-90.3% for headache). Absolute and relative inequalities concerning potential low-value MRI utilization decreased after OOP payments were reduced, even without physician inducement (SII: from 8.15 to 5.37%, RII: from 1.20 to 1.06 for low back pain; SII: from 6.99 to 0.83%, RII: from 1.20 to 1.01 for headache). Conclusions OOP payment reduction for MRI has the potential to increase low-value care utilization among all income groups while decreasing inequality in low-value care utilization.

BACKGROUND/AIMS: The vascular calcification (VC) score on a plain X-ray is associated with cardiovascular disease and mortality in hemodialysis (HD) patients. This study examined the correlations among the VC scores for the hands and pelvis X-rays, arterial stiffness, inflammation, and nutrition in HD patients. METHODS: VC was evaluated using plain x-rays of the hands and pelvis. Patients were categorized into the VC (+) (VC score > or = 3) or VC (-) (VC score < 3) groups. We measured the pulse wave velocity (PWV), ankle brachial index (ABI), and augmentation index (AI). RESULTS: The mean age of the patients was 55.6 +/- 13.2 years. The prevalence of diabetes mellitus (DM) was significantly higher in the VC (+) group than in the VC (-) group (87.5 vs. 34.2%, p < 0.05). The serum PTH (98.4 +/- 141.9 vs. 183.6 +/- 231.3 pg/mL, p < 0.05) and albumin (3.7 +/- 0.5 vs. 3.9 +/- 0.3 g/dL, p < 0.05) levels were significantly lower and PWV was significantly (p < 0.05) higher in the VC (+) group. In multiple linear regression analysis, only the presence of diabetes mellitus was significantly related to the VC score. CONCLUSIONS: The VC score was associated with the serum PTH and albumin, as well as with vascular stiffness. C-reactive protein did not show any significant association with the VC score.
Ankle Brachial Index ; C-Reactive Protein ; Cardiovascular Diseases ; Diabetes Mellitus ; Hand ; Humans ; Inflammation* ; Linear Models ; Mortality ; Pelvis ; Prevalence ; Pulse Wave Analysis ; Renal Dialysis* ; Vascular Calcification* ; Vascular Stiffness*

This study aimed to analyze the eluted components of syringe-type bis-acryl composites and to evaluate the effect of removing the oxygen-inhibited layer on cytotoxicity. Four different bis-acryl provisional composite materials-Protemp 4 (PT), Structur 2 SC (ST), Luxatemp Automix Plus (LT), and Hexa-Temp (HT)-were evaluated. Gas chromatography/mass spectrometry was used to analyze the composite eluate after 24 h of immersion in methanol. An agar overlay test and a live/dead assay were performed on the polymerized disc-shaped specimens after 24 h. To evaluate the effect of removing the oxygen-inhibited layer, samples were prepared with a surface oxygen-inhibited layer. The surface oxygen-inhibited layer of the disc-shaped specimens was removed with alcohol only (subgroup A) or with polishing and alcohol (subgroup PA), and their cytotoxicities were compared with those of “as received” (subgroup N) specimens using the WST-1 assay. Statistical significance was assessed using analyses of variance, followed by Bonferroni multiple comparison tests (α=0.05). Different components were detected by gas chromatography/mass spectrometry analysis among the groups. The agar overlay assay confirmed severe cytotoxicity in HT, LT, and ST groups, whereas PT showed moderate cytotoxicity. The effect of removing the oxygen-inhibited layer on cell viability was significantly higher in PA than in N in all composite groups. In HT and ST, the cell viability was significantly higher in PA than in A. Syringe-type bis-acryl composites for provisional restorations may elute various components into the oral cavity, which may cause cytotoxicity in adjacent structures. The cytotoxicity of the materials is reduced by the removal of the oxygen-inhibited layer.