Table 2 –

Summary of findings.

h-index	Standard mean difference (95% CI)	Number of participants (number of studies)	Comments
Overall	0.547 (0.360 to 0.734)	8369 (11)	All academic ranks
Assistant professor	0.12 (0.01 to 0.24)	2372 (5)	N/A
Associate professor	0.14 (−0.06 to 0.33)	920 (5)	N/A
Full professor	0.12, (−0.08 to 0.31)	1606 (5)	N/A
Study	Selection	Assessment of outcome	Comparability	Overall quality assessment
Khan et al. 2013		*		Low
Lopez et al. 2014	*	*	**	Moderate
Tomei et al. 2014	*	*	**	High
Paik et al. 2014	*	*		Low
Hill et al. 2015		*	**	Moderate
Martinez et al. 2015	*	*	**	High
Ence et al. 2016		*	**	Moderate
Theratti et al. 2016	*	*	*	Moderate
Geltzeiler et al. 2017	*	*	*	Moderate
Mayer et al. 2017	*	*	*	Moderate
Mueller et al. 2017		*	*	Moderate
Bastian et al. 2017	*	*		Low

Selection, assessment of outcome, and comparability are parameters considered as part of the quality assessment. Each parameter can receive 0–2 asterisks depending on degree to which the parameter was addressed.

Population: Surgeons.

Intervention: Research productivity as measured by Hirsch index (h-index).

Comparison: Men and Women.

Setting: Academic institutions (i.e., affiliated with residency, fellowship, and medical schools).