Table 2.

Distribution of included articles by reporting quality category

Reporting Quality Category	STROBE Score Range (0–22)	No. Articles [Refs.] (%)
Excellent These articles had no missing elements and accounted for potential biases and confounding factors	22 21 if only missing declaration of funding source	16 [26–29, 34–38, 42, 43, 47, 49, 50, 52, 56] (51.6%)
Good These articles had only a few missing elements	19–21	4 [33, 44, 45, 51] (12.9%)
Fair These articles had many missing elements	18–14	0 (0.0%)
Low These articles had limited reporting. Meeting abstracts generally fall in this category	0–13	11 [30–32, 39–41, 46, 48, 53–55] (35.5%)

STROBE Strengthening the Reporting of Observational Studies in Epidemiology

Reference: von Elm E, et al. The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement: guidelines for reporting observational studies. J Clin Epidemiol. Apr 2008;61(4):344–9