Table 3.

Association between adherence measures and virologic failure at least 1000 copies/ml among adults in selected antiretroviral treatment programmes in Tanzania, Uganda and Zambia, 2011.

	Patients with virologic failure ≥1000 copies/ml
	n/N ^a	OR (95% CI)^b	P ^*
Self-reported adherence measures^c
% ARV drugs missed – last 3 days
<93%	12/107 (11.2%)	1.28 (0.68–2.42)	0.450
≥93%	132/1363 (9.7%)
% ARV drugs missed – last 30 days
<99%	22/237 (9.3%)	1.04 (0.63–1.69)	0.888
≥99%	122/1223 (10.0%)
% ARV drugs missed – visual analogue scale – last 30 days
<99%	68/633 (10.7%)	0.86 (0.57–1.30)	0.479
≥99%	80/851 (9.4%)
CASE Adherence Index
<11	33/304 (10.9%)	1.30 (0.84–2.01)	0.233
≥11	115/1189 (9.7%)
Missed ≥48 consecutive hours of ARV drugs in past 3 months
≥48 h	16/64 (25.0%)	2.86 (1.56–5.26)	0.001
<48 h	128/1407 (9.1%)
Other adherence measures
Healthcare provider report
<98%	82/628 (13.1%)	1.57 (1.02–2.41)	0.042
≥98%	60/835 (7.2%)
Pharmacy medication possession ratio (MPR)
<90%	72/659 (10.9%)	1.48 (1.02–2.15)	0.037
≥90%	67/791 (8.5%)

ARV, antiretroviral; CI, confidence interval; OR, odds ratio.

N, number of patients in subgroup; n, number of failures in subgroup.

OR of failure among incomplete-adherent versus adherent patients from logistic regression.

Cut-off points determined by receiver operator curve (ROC) analysis.

P for association between adherence measure and failure, adjusted for ART study site.