Table 2.

Associations of gender and country of affiliation with authorship position

Comparison/authorship position	Univariable models		Multivariable model
	OR (95% CI)	P value	aOR (95% CI)	P value
Gender: woman versus man
0 percentile (first)	1.90 (1.15 to 3.13)	0.01	1.78 (1.09 to 2.92)	0.02
1–33	1.11 (0.69 to 1.78)	0.68	1.07 (0.66 to 1.73)	0.78
34–66	1		1
67–99	1.00 (0.66 to 1.52)	0.99	0.96 (0.64 to 1.46)	0.86
100 percentile (last)	0.69 (0.44 to 1.09)	0.11	0.59 (0.37 to 0.94)	0.02
Country of affiliation
Lower versus high income
0 percentile (first)	0.27 (0.14 to 0.52)	<0.001	0.30 (0.16 to 0.57)	<0.001
1–33	0.60 (0.36 to 1.01)	0.06	0.61 (0.36 to 1.03)	0.06
34–66	1		1
67–99	0.61 (0.39 to 0.98)	0.04	0.61 (0.38 to 0.98)	0.04
100 percentile (last)	0.16 (0.07 to 0.37)	<0.001	0.15 (0.06 to 0.34)	<0.001
Upper middle versus high income
0 percentile (first)	0.53 (0.31 to 0.92)	0.02	0.50 (0.29 to 0.86)	0.01
1–33	0.74 (0.44 to 1.24)	0.25	0.73 (0.43 to 1.24)	0.25
34–66	1		1
67–99	0.79 (0.50 to 1.25)	0.31	0.79 (0.50 to 1.26)	0.33
100 percentile (last)	0.67 (0.42 to 1.08)	0.10	0.69 (0.43 to 1.11)	0.12

Results from generalised multinomial regression model with random intercept for authors. Multivariable model is adjusted for gender and income level of the country of affiliation. Lower-income countries include World Bank lower middle-income countries and low-income countries.

aOR, adjusted OR.