Table 4.

Summary of factors investigated for association with HIV testing among internet-using MSM

Factor	Overall assessment and strength of evidence	Testing outcome	Meta-regression findings	Individual studies’ findings (where reported)
Age	Younger age is associated with never testing for HIV (Moderate) but is not clearly associated with testing within the last 12 months (Inconclusive)	Ever tested	Proportion of participants age 30 years or younger was significantly associated with never testing (κ = 15, p = 0.016)	Margolis et al. found men 18–24 years were significantly less likely to have been tested (unadjusted and adjusted) [32] and Rendina et al. found increased age was associated with having ever tested (adjusted) [64]
		Tested past year	Insufficient evidence to support investigation (κ < 10)	Rendina et al. 2013 found a statistically significant association between older age and having tested in the last year (adjusted) [45], and Schnarrs et al. found a similar but non-significant trend (unadjusted) [47]
Self-reported sexual orientation	Self-identification as Homosexual or Gay is associated with ever testing for HIV (Moderate). Inconsistent findings prevent determination of whether it is associated with testing in the past year (Inconclusive)	Ever tested	Ever testing was significantly associated with self-identification as homosexual (κ = 25, p = 0.014)	Margolis et al. and Rendina et al. [32, 45]. both found MSM who self-identified as gay or homosexual were more likely to have ever tested than those who self-identified as straight, heterosexual, or bisexual in both unadjusted and adjusted models
		Tested past year	Testing in the past year was not significantly associated with self-identification as homosexual (κ = 14, P = 0.162)	While Schnarrs et al. 2012 found gay men were more likely to have tested than bisexual men (unadjusted OR) [47] Rendina et al. 2013 found no association (adjusted regression) [45]
Drug use	Drug use is associated with never testing for HIV, but this association does not appear to be independent (Low)	Ever tested	Insufficient evidence to support investigation due to variability in reporting methods	Margolis et al. 2012 and Rendina et al. 2013 [32, 45] found drug use, including noninjection drug use, in the last 2–3 months was significantly associated with never having tested in unadjusted but not adjusted models
Race/ethnicity	Race/ethnicity is not convincingly associated with ever testing or testing within the past year; however, there is insufficient evidence to rule this possibility out (Inconclusive)	Ever tested	No association was found between White/European (κ = 29), Black/African American (κ = 25), or Hispanic (κ = 26) self-identification and testing	Rendina et al. 2013 found MSM who reported being black or multicultural were more likely to have ever tested (adjusted) [45], while Margolis et al. 2012 [32] and Khosropour [38] found no association
		Tested past year	No association was found between White/European American (κ = 14), Black/African American (κ = 14), or Hispanic (κ = 14) self-identification and testing	Neither Rendina et al. [45]. nor Khosropour et al. [38]. found statistically significant associations between race/ethnicity and having tested within the last 12 months, and Rendina et al. reported a non-significant trend toward black race/ethnicity being more likely to have tested in the last 12 months
Condomless anal intercourse (CAI)	The association between CAI and testing is too inconsistent to determine an association; however, the possibility of an association cannot be ruled out (Inconclusive)	Ever tested	Insufficient evidence to support investigation (κ < 10)	NA
		Tested past year	Insufficient evidence to support investigation (κ < 10)	Rendina et al. 2013 found CAI in the last 3 months was significantly associated with testing within the last year (adjusted) [45], while Navejas et al. 2102 found no association between CAI in the past year and testing (unadjusted or adjusted) [54]
Quality assessment items	Methodological sources of potential bias are not convincingly associated with ever testing or associated with testing within the past year; however, there is insufficient evidence to rule this possibility out. (Inconclusive)	Ever tested	No association found for any factor (κ = 30; p > 0.05)	NA
		Tested past year	No association found for any factor (κ = 14; p > 0.05)	NA
Year of study publication	No association identified, but insufficient evidence to conclude there is no association. (Inconclusive)	Ever tested	No association (κ = 30; p > 0.05)	NA
		Tested past year	No association (κ = 14; p > 0.05)	NA
Education	This meta-regression and one study found college education was associated with ever testing; no studies reported contradictory findings (Low)	Ever tested	Completing a 4-year/Bachelor’s degree was significantly associated with having ever tested. (κ = 30; p = 0.002). Insufficient evidence to assess other education levels	Margolis et al. reported the rate of never testing was higher among college graduates (6 %) than those with less education (12 %), OR 1.24 (95 % 1.02–1.51), even after adjusting for confounding factors (OR 2.2 (95 % CI: 1.72–2.37) [32]
	One study among Latino men only found no association between testing in the past year and college graduation, which is an insufficient amount of evidence to support a conclusion. (Inconclusive)	Tested past year	Insufficient evidence to support investigation (κ < 10)	Among a Latino-only population, Schnarrs found no relationship with college graduation and having tested in the past year [47]
Income	One study identified an association with low income and never having tested, but this is an insufficient amount of evidence to draw a conclusion from (Inconclusive)	Ever tested	Insufficient evidence to support investigation (κ < 10)	Horvath (2008) reported that men earning less than $10,000/year were less likely to have ever tested [34]
		Tested past year	Insufficient evidence to support investigation (κ < 10)	NA

NA not applicable