Measuring adherence to antiretroviral treatment in resource-poor settings: The clinical validity of key indicators

Table 5 Estimates from general linear models of indicators of adherence and appointment keeping as predictors of change in CD4 count at time of follow-up CD4 test between 4 and 9 months after ART initiation.

	Parameter estimate	P-value	Confidence interval
Coverage (vs. 100% coverage) *
<80% of days covered	-97.3	0.0156	-176.1, -18.5
80% to <90% of days covered	-28.8	0.2817	-81.2, 23.7
90% to <100% of days covered	-22.1	0.1224	-50.2, 6.0
Gap >30 days (vs. no gap in coverage)	-80.7	0.0212	-149.3, -12.1
Average self-report (vs. all self-reports perfect) ** &
Better than good but less than perfect	-27.0	0.1752	-66.1, 12.1
Good or worse	-67.2	0.0141	-120.8. -13.7
Any self-report less than perfect (vs. all perfect) &	-40.2	0.0186	-73.6, -6.8
<80% of visits on day scheduled	-7.3	0.6759	-41.7, 27.1
<80% of visits within 3 days of schedule	-25.5	0.3605	-80.3, 29.3
<80% of visits before medicines finished	-8.6	0.5091	-34.1, 16.9

Key: All models use variables measured at the time of the follow-up CD4 test. For all models except those involving self-reported adherence, n = 401 cases; in all models involving self-report, n = 296 cases. Models include: gender, age category (30 or younger, 31-40, >40 years), whether married, capital-urban-rural location, baseline CD4 level, WHO stage at ART initiation (stage 1 or 2 vs. stage 3 or 4), time since ART initiation (in nine 30-day categories up to 270 days), evidence of TB at ART initiation, any evidence in medical record of side effect or opportunistic infection since treatment initiation, number of different ART regimens since initiation, ever treated with a protease inhibitor.
* F-test for inclusion of 3 coverage terms in model, p = 0.0465
** F-test for inclusion of 2 self-report terms in model, p = 0.0316
& Models exclude cases from Ethiopia which assessed self-reported adherence differently

ISSN: 1472-6963