Table 3.

Results of univariate and multivariate logistic regression of sociodemographic factors and psychosocial factors associated with COVID-19–related post-traumatic stress disorder risk group

	Univariate		Multivariate
	OR (95% CI)	p-value	Model 1*		Model 2†
			OR (95% CI)	p-value	OR (95% CI)	p-value
Sociodemographic factors
Gender
Men	1.46 (0.57–3.76)	0.430
Women	1
Age (yr)	0.77 (0.63–0.95)	0.014			0.68 (0.53–0.88)	0.004
Grade
Premed Y1	6.36 (1.35–29.96)	0.019	6.82 (1.43–32.42)	0.016
Med Y1	8.58 (1.91–38.45)	0.005	8.23 (1.83–37.12)	0.006
Med Y3	1		1
Living arrangement
Living alone	0.49 (0.18–1.34)	0.168
Not living alone	1
Smoking
Current smoker	2.89 (1.12–7.48)	0.028	2.85 (1.05–7.70)	0.039	3.04 (1.08–8.93)	0.045
Non-smoker (including ex-smoker)	1		1		1
Drinking
At-risk drinking	0.98 (0.32–3.01)	0.980
Normal	1
COVID-19 exposure
Indirect exposure
Yes	3.15 (1.39–7.13)	0.006			2.47 (0.99–6.15)	0.051
No	1				1
Direct exposure
Yes	0.72 (0.32–1.61)	0.426
No	1
Total exposure
Yes	1.52 (0.51–4.59)	0.455
No	1
Psychosocial factors
CD-RISC	0.87 (0.85–0.89)	0.010
MSPSS	0.86 (0.83–0.89)	0.016
RSS	0.81 (0.75–0.87)	0.003
Psychological variables
PSS	1.11 (1.05–1.18)	<0.001			1.15 (1.08–1.23)	<0.001
BDI-II	1.09 (1.04–1.14)	<0.001
BAI	1.13 (1.06–1.21)	<0.001

^*after controlling for sociodemographic factors in multiple logistic regression analyses with a backward stepwise method;

^†after controlling for sociodemographic factors, COVID-19 exposure, psychosocial factors, and psychological variables in multiple logistic regression analyses with a backward stepwise method.

Premed Y1, premedical first-year; Med Y1, medical first-year; Med Y3, medical third-year; CD-RISC, Connor-Davidson Resilience Scale; MSPSS, Multidimensional Scale of Perceived Social Support; RSS, Rosenberg Self-esteem Scale; PSS, Perceived Stress Scale; BDI-II, Beck Depression Inventory-II; BAI, Beck Anxiety Inventory; OR, odds ratio; CI, confidence interval