Table 3.

Correlates of DBS specimens genotyping failure

Factor	Genotyping failure n (%)	Odds ratio (95% CI)	p-value	Adjusted OR [aOR (95% CI)]	p-value
Pre-genotyping viral load testing
Not done	1038/1885 (55.1)	1	< 0.0001		0.001
Done	888/1952 (45.5)	0.68 (0.6–0.77)		0.71 (0.16–0.22)
Viral load
1000–10,000 cps/mL	599/897 (66.8)	1	< 0.0001		< 0.0001
> 10,000–50,000 cps/mL	185/497 (37.2)	0.29 (0.23–0.37)		0.3 (0.24–0.38)
> 50,000–200,000 cps/mL	73/344 (21.2)	0.13 (0.11–0.18)		0.14 (0.10–0.18)
> 200,000 cps/mL	31/214 (14.5)	0.08 (0.06–0.13)		0.07 (0.06–0.13)
Specimen source
Research studies	48/137 (35.0)	1	< 0.0001		0.006
Routine clinical diagnosis	1574/3279 (48.0)	1.72 (1.36–2.18)		1.4 (1.11–1.84)

Each denominator represents the number of specimens of that specific category