Association between Changes in the Regularity of Working Hours and Cognitive Impairment in Middle-Aged and Older Korean Workers: The Korean Longitudinal Study of Aging, 2008–2018
Abstract
:1. Introduction
2. Materials and Methods
2.1. Data and Study Population
2.2. Variables
2.3. Statistical Analysis
3. Results
3.1. Descriptive Statistics
3.2. The GEE Model Analysis
4. Discussion
5. Limitations
6. Conclusions
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Acknowledgments
Conflicts of Interest
References
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Total | Noncognitive Impairment | Cognitive Impairment | p-Value | |
---|---|---|---|---|
(n = 3826) | (n = 3361) | (n = 465) | ||
MMSE | ||||
Mean (SD) | 27.2 (± 3.42) | 28.2 (± 1.83) | 19.9 (± 3.54) | <0.001 |
Work regularity (baseline) | ||||
Regular | 2029 (53.0%) | 1862 (55.4%) | 167 (35.9%) | <0.001 |
Irregular | 1797 (47.0%) | 1499 (44.6%) | 298 (64.1%) | |
Changes in work regularity | ||||
Consistently irregular | 1215 (31.8%) | 979 (29.1%) | 236 (50.8%) | <0.001 |
Regular to irregular | 531 (13.9%) | 462 (13.7%) | 69 (14.8%) | |
Irregular to regular | 582 (15.2%) | 520 (15.5%) | 62 (13.3%) | |
Consistently regular | 1498 (39.2%) | 1400 (41.7%) | 98 (21.1%) | |
Sex | ||||
Male | 2226 (58.2%) | 2031 (60.4%) | 195 (41.9%) | <0.001 |
Female | 1600 (41.8%) | 1330 (39.6%) | 270 (58.1%) | |
Age, years | ||||
45–54 | 1307 (34.2%) | 1246 (37.1%) | 61 (13.1%) | <0.001 |
55–64 | 1464 (38.3%) | 1341 (39.9%) | 123 (26.5%) | |
65–74 | 823 (21.5%) | 644 (19.2%) | 179 (38.5%) | |
75 or above | 232 (6.1%) | 130 (3.9%) | 102 (21.9%) | |
Income | ||||
1Q | 918 (24.0%) | 662 (19.7%) | 256 (55.1%) | <0.001 |
2Q | 985 (25.7%) | 879 (26.2%) | 106 (22.8%) | |
3Q | 963 (25.2%) | 894 (26.6%) | 69 (14.8%) | |
4Q | 960 (25.1%) | 926 (27.6%) | 34 (7.3%) | |
Education level | ||||
Elementary school | 1257 (32.9%) | 925 (27.5%) | 332 (71.4%) | <0.001 |
Middle school | 718 (18.8%) | 652 (19.4%) | 66 (14.2%) | |
High school | 1359 (35.5%) | 1304 (38.8%) | 55 (11.8%) | |
University | 492 (12.9%) | 480 (14.3%) | 12 (2.6%) | |
Residential area | ||||
Urban | 1501 (39.2%) | 1384 (41.2%) | 117 (25.2%) | <0.001 |
Small city | 1223 (32.0%) | 1107 (32.9%) | 116 (24.9%) | |
Rural | 1102 (28.8%) | 870 (25.9%) | 232 (49.9%) | |
Marital status | ||||
Married | 3319 (86.7%) | 2970 (88.4%) | 349 (75.1%) | <0.001 |
Separated/Not married | 507 (13.3%) | 391 (11.6%) | 116 (24.9%) | |
Smoking | ||||
Current smoker | 960 (25.1%) | 882 (26.2%) | 78 (16.8%) | <0.001 |
Ex-smoker | 619 (16.2%) | 561 (16.7%) | 58 (12.5%) | |
Non-smoker | 2247 (58.7%) | 1918 (57.1%) | 329 (70.8%) | |
Drinking | ||||
Current drinker | 1964 (51.3%) | 1783 (53.0%) | 181 (38.9%) | <0.001 |
Ex-drinker | 368 (9.6%) | 320 (9.5%) | 48 (10.3%) | |
Non-smoker | 1494 (39.0%) | 1258 (37.4%) | 236 (50.8%) | |
Working hours | ||||
Long | 1153 (30.1%) | 1044 (31.1%) | 109 (23.4%) | <0.001 |
Normal | 2673 (69.9%) | 2317 (68.9%) | 356 (76.6%) | |
Chronic disease * | ||||
Yes | 1409 (36.8%) | 1194 (35.5%) | 215 (46.2%) | <0.001 |
No | 2417 (63.2%) | 2167 (64.5%) | 250 (53.8%) | |
Social activity | ||||
Active | 3155 (82.5%) | 2862 (85.2%) | 293 (63.0%) | <0.001 |
Inactive | 671 (17.5%) | 499 (14.8%) | 172 (37.0%) |
Variable | ORs * | 95% CI |
---|---|---|
Regularity | ||
Consistently regular | 1.00 | Ref |
Consistently irregular | 1.56 | (1.30–1.88) |
Regular to irregular | 1.46 | (1.20–1.77) |
Irregular to regular | 1.24 | (1.01–1.53) |
Sex | ||
Male | 1.00 | Ref |
Female | 1.39 | (1.11–1.74) |
Age, years | ||
45–54 | 1.00 | Ref |
55–64 | 1.34 | (1.06–1.70) |
65–74 | 2.38 | (1.82–3.11) |
75 or above | 3.9 | (2.84–5.34) |
Income | ||
1Q | 1.36 | (1.07–1.73) |
2Q | 0.95 | (0.75–1.21) |
3Q | 1.06 | (0.84–1.33) |
4Q | 1.00 | Ref |
Education level | ||
Elementary school | 4.17 | (2.96–5.88) |
Middle school | 2.4 | (1.68–3.42) |
High school | 1.51 | (1.08–2.12) |
University | 1.00 | Ref |
Residential area | ||
Urban | 1.00 | Ref |
Small city | 1.22 | (1.00–1.49) |
Rural | 1.36 | (1.12–1.65) |
Marital status | ||
Married | 1.00 | Ref |
Separated/Not married | 1.23 | (1.02–1.48) |
Smoking | ||
Current smoker | 0.96 | (0.75–1.22) |
Ex-smoker | 1.00 | (0.78–1.28) |
Non-smoker | 1.00 | Ref |
Drinking | ||
Current drinker | 1.18 | (0.94–1.47) |
Ex-drinker | 0.99 | (0.83–1.18) |
Non-smoker | 1.00 | Ref |
Working hours | ||
Long | 0.94 | (0.80–1.09) |
Normal | 1.00 | Ref |
Chronic disease | ||
Yes | 1.11 | (0.96–1.28) |
No | 1.00 | Ref |
Social activity | ||
Active | 1.00 | Ref |
Inactive | 1.98 | (1.70–2.30) |
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Lee, W.-T.; Lim, S.-S.; Yoon, J.-H.; Won, J.-U. Association between Changes in the Regularity of Working Hours and Cognitive Impairment in Middle-Aged and Older Korean Workers: The Korean Longitudinal Study of Aging, 2008–2018. Int. J. Environ. Res. Public Health 2022, 19, 4161. https://doi.org/10.3390/ijerph19074161
Lee W-T, Lim S-S, Yoon J-H, Won J-U. Association between Changes in the Regularity of Working Hours and Cognitive Impairment in Middle-Aged and Older Korean Workers: The Korean Longitudinal Study of Aging, 2008–2018. International Journal of Environmental Research and Public Health. 2022; 19(7):4161. https://doi.org/10.3390/ijerph19074161
Chicago/Turabian StyleLee, Won-Tae, Sung-Shil Lim, Jin-Ha Yoon, and Jong-Uk Won. 2022. "Association between Changes in the Regularity of Working Hours and Cognitive Impairment in Middle-Aged and Older Korean Workers: The Korean Longitudinal Study of Aging, 2008–2018" International Journal of Environmental Research and Public Health 19, no. 7: 4161. https://doi.org/10.3390/ijerph19074161