Table 3.

Sensitivity analysis for the association between serum IGF-1 concentrations and COVID-19 mortality after excluding 267 participants with baseline cancer or cardiovascular disease

	Quartile of log-transformed IGF-1 levels, OR (95% CI)a				P-trendb	OR per 1-SD incrementc	Adjusted OR per 1-SD incrementd
	Q1	Q2	Q3	Q4
No. of cases	113	84	83	44
Model 1	Ref	0.73 (0.51–1.06)	0.85 (0.58–1.23)	0.46 (0.30–0.70)	0.002	0.80 (0.69–0.92)	0.75 (0.62–0.90)
Model 2	Ref	0.77 (0.53–1.12)	0.94 (0.64–1.38)	0.51 (0.33–0.80)	0.02	0.85 (0.73–0.98)	0.81 (0.67–0.98)
Model 2 plus other factorse	Ref	0.71 (0.47–1.08)	1.03 (0.68–1.57)	0.57 (0.35–0.91)	0.09	0.86 (0.73–1.01)	0.82 (0.66–1.01)

OR, odds ratio; CI, confidence interval; ref, reference

^aModel 1: adjusted for age at infection, sex, ethnicity. Model 2: additionally adjusted for Townsend deprivation index, body mass index, smoking status, alcohol drinking, physical activity, and prevalent diabetes

^bP-trend was based on the median value of each quartile of log-transformed IGF-1 levels as a continuous variable in the models

^cSD was the standard deviation of log-transformed IGF-1 levels, which was 0.30

^dORs per SD increment were additionally corrected for the intraclass correlation coefficient (0.78) obtained from the subsample of participants with repeat IGF-1 measurements

^eModel 2 plus additional adjustment for serum glucose, cardiovascular risk factors (serum lipids, blood pressure, cholesterol lowering and antihypertensive medication), and C-reactive protein. A total of 195 participants had missing data on serum glucose, lipids, or C-reactive protein