Did Expanded Dental Insurance Reduce Out-of-Pocket Expenditures on Dental Care among Older Adults in Korea? Interrupted Time-Series Analysis
Abstract
:1. Introduction
2. Materials and Methods
2.1. Study Design and Data Resource
2.2. Study Population and Main Variable
2.3. Statistical Analysis
2.4. Ethics Approval and Consent to Participate
3. Results
4. Discussion
5. Conclusions
Supplementary Materials
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Acknowledgments
Conflicts of Interest
References
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Aged 65 and Older b | Income Quintile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
Lowest Income (1st Quintile) | Highest Income (5th Quintile) | |||||||||||
Year | n | Mean a | 95% CI c | n | Mean | 95% CI | n | Mean | 95% CI | |||
Lower | Upper | Lower | Upper | Lower | Upper | |||||||
2008 | 2826 | 533,419 | 396,727 | 670,111 | 1159 | 351,243 | 229,066 | 473,420 | 199 | 543,440 | 265,229 | 821,651 |
2009 | 2829 | 457,749 | 356,623 | 558,876 | 1112 | 340,571 | 231,185 | 449,957 | 218 | 959,568 | 243,232 | 1,675,905 |
2010 | 2876 | 552,945 | 451,359 | 654,531 | 1127 | 418,162 | 259,423 | 576,900 | 232 | 674,084 | 395,857 | 952,311 |
2011 | 2967 | 538,179 | 440,376 | 635,982 | 1181 | 457,466 | 299,049 | 615,884 | 201 | 753,351 | 331,709 | 1,174,994 |
2012 | 2979 | 516,566 | 440,857 | 592,276 | 1168 | 422,420 | 322,145 | 522,696 | 200 | 520,553 | 291,492 | 749,615 |
2013 | 3003 | 515,598 | 444,563 | 586,633 | 1128 | 393,791 | 289,891 | 497,692 | 206 | 623,622 | 405,143 | 842,100 |
2014 | 4061 | 546,371 | 454,968 | 637,774 | 1665 | 413,100 | 333,199 | 493,001 | 270 | 786,488 | 52,650 | 1,520,326 |
2015 | 4047 | 571,270 | 496,892 | 645,648 | 1704 | 487,369 | 400,756 | 573,981 | 277 | 577,704 | 405,373 | 750,035 |
2016 | 4052 | 600,972 | 526,261 | 675,684 | 1620 | 477,076 | 395,055 | 559,097 | 284 | 612,729 | 424,484 | 800,974 |
2017 | 4158 | 532,489 | 476,690 | 588,288 | 1650 | 476,449 | 396,838 | 556,060 | 264 | 383,789 | 219,802 | 547,777 |
Measure of Interest | Model Parameter | 2012 b | 2014 c | ||||
---|---|---|---|---|---|---|---|
Point Estimate | p-Value | 95% CI | Point Estimate | p-Value | 95% CI | ||
Within-group comparison a | |||||||
Pre-intervention trend: control | β1 | 34,426 | 0.53 | −81,194 to 150,044 | −23,911 | 0.50 | −98,843 to 51,022 |
Pre-intervention trend: treatment | β5 + β1 | 39,626 | 0.001 | 23,939 to 55,313 | 142,17 | 0.13 | −4684 to 33,117 |
Difference pre-intervention: treatment versus control | β5 | 5201 | 0.92 | −111,477 to 121,880 | 38,127 | 0.30 | −39,152 to 115,406 |
Difference immediately following the intervention: treatment versus control | β6 | 80,095 | 0.61 | −249,356 to 409,546 | −181,221 | 0.11 | −412,852 to 50,409 |
Post-intervention trend: control | β1 + β3 | −26,400 | 0.44 | −98,800 to 46,000 | −117,000 | 0.001 | −155,000 to −79,800 |
Post-intervention trend: treatment | β1 + β3 + β5 + β7 | 17,000 | 0.001 | 6987 to 27,000 | 18,000 | 0.08 | −2220 to 38,200 |
Difference post-intervention: treatment versus control | β5 + β7 | 43,400 | 0.22 | −2.9700 to 117,000 | 135,000 | 0.001 | 92,700 to 178,000 |
Difference pre- versus post-intervention: control | β3 | −60,862 | 0.37 | −202,176 to 80,453 | −93,397 | 0.03 | −177,347 to −9447 |
Difference pre- versus post-intervention: treatment | β3 + β7 | −22,647 | 0.03 | −42,329 to −2964 | 3759 | 0.81 | −29,035 to 36,552 |
Difference pre- versus post-intervention: treatment versus control | β7 | 38,215 | 0.57 | −104,464 to 180,893 | 97,155 | 0.04 | 7028 to 187,283 |
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Kim, N.-H.; Jung, S.-H.; Kawachi, I. Did Expanded Dental Insurance Reduce Out-of-Pocket Expenditures on Dental Care among Older Adults in Korea? Interrupted Time-Series Analysis. Int. J. Environ. Res. Public Health 2021, 18, 3003. https://doi.org/10.3390/ijerph18063003
Kim N-H, Jung S-H, Kawachi I. Did Expanded Dental Insurance Reduce Out-of-Pocket Expenditures on Dental Care among Older Adults in Korea? Interrupted Time-Series Analysis. International Journal of Environmental Research and Public Health. 2021; 18(6):3003. https://doi.org/10.3390/ijerph18063003
Chicago/Turabian StyleKim, Nam-Hee, Se-Hwan Jung, and Ichiro Kawachi. 2021. "Did Expanded Dental Insurance Reduce Out-of-Pocket Expenditures on Dental Care among Older Adults in Korea? Interrupted Time-Series Analysis" International Journal of Environmental Research and Public Health 18, no. 6: 3003. https://doi.org/10.3390/ijerph18063003