Table 3. Differences in diabetes prevalence before and during the COVID-19 (weighted % [95% CI]) based on data obtained from the KNHANES

Variables		Overall (1998–2021)		Before the pandemic (1998–2019)		During the pandemic (2020–2021)		Ratio of ORs (95% CI) during the pandemic compared to before the pandemic (reference)
		Weighted OR (95% CI)	P-value	Weighted OR (95% CI)	P-value	Weighted OR (95% CI)	P-value	Weighted ratio of ORs (95% CI)	P-value
Diabetes
Age (years)	30–39	1.00 (ref)		1.00 (ref)		1.00 (ref)
	40–49	3.67 (3.12 to 4.32)	<.001	3.75 (3.17 to 4.43)	<.001	3.14 (1.86 to 5.32)	<.001	0.84 (0.48 to 1.45)	0.528
	50–59	9.76 (8.41 to 11.34)	<.001	10.10 (8.66 to 11.78)	<.001	7.15 (4.42 to 11.56)	<.001	0.71 (0.43 to 1.17)	0.180
	≥60	21.05 (18.21 to 24.34)	<.001	21.77 (18.75 to 25.28)	<.001	14.91 (9.31 to 23.88)	<.001	0.69 (0.42 to 1.12)	0.133
Sex	Female	1.00 (ref)		1.00 (ref)		1.00 (ref)
	Male	1.12 (1.07 to 1.18)	<.001	1.10 (1.05 to 1.16)	<.001	1.25 (1.09 to 1.43)	0.002	1.14 (0.98 to 1.31)	0.083
Region of residence	Urban	1.00 (ref)		1.00 (ref)		1.00 (ref)
	Rural	1.43 (1.33 to 1.53)	<.001	1.42 (1.32 to 1.53)	<.001	1.55 (1.26 to 1.91)	<.001	1.09 (0.88 to 1.36)	0.437
Education level	College or higher education	1.00 (ref)		1.00 (ref)		1.00 (ref)
	High school or lower education	3.03 (2.88 to 3.18)	<.001	3.16 (2.99 to 3.33)	<.001	3.16 (2.71 to 3.68)	<.001	1.00 (0.85 to 1.18)	0.999
Household income	Third and highest quartile income	1.00 (ref)		1.00 (ref)		1.00 (ref)
	Lowest and second quartile income	2.10 (2.00 to 2.21)	<.001	2.12 (2.01 to 2.23)	<.001	2.27 (1.98 to 2.60)	<.001	1.07 (0.93 to 1.24)	0.358
Smoking status	Non-smoker	1.00 (ref)		1.00 (ref)		1.00 (ref)
	Current and ex-smoker	1.97 (1.88 to 2.08)	<.001	1.95 (1.85 to 2.06)	<.001	1.80 (1.56 to 2.07)	<.001	0.92 (0.79 to 1.07)	0.297
BMI group	Underweight or normal	1.00 (ref)		1.00 (ref)		1.00 (ref)
	Overweight or obese	2.75 (2.62 to 2.88)	<.001	2.74 (2.61 to 2.88)	<.001	2.23 (1.91 to 2.61)	<.001	0.82 (0.69 to 0.96)	0.015

Abbreviations: BMI, body mass index; CI, confidence interval; KNHANES, Korea National Health and Nutrition Examination Survey; OR, odds ratio.
The numbers in bold indicate significant differences (p<0.05).