How late is too late? Timeliness to scheduled visits as an antiretroviral therapy adherence measure in Nairobi, Kenya and Lusaka, Zambia.
Collecting self-reported data on adherence to highly active antiretroviral therapy (HAART) can be complicated by patients' reluctance to report poor adherence. The timeliness with which patients attend visits might be a useful alternative to estimate medication adherence. Among Kenyan and Zambian women receiving twice daily HAART, we examined the relationship between self-reported pill taking and timeliness attending scheduled visits. We analyzed data from 566 Kenyan and Zambian women enrolled in a prospective 48-week HAART-response study. At each scheduled clinic visit, women reported doses missed over the preceding week. Self-reported adherence was calculated by summing the total number of doses reported taken and dividing by the total number of doses asked about at the visit attended. A participant's adherence to scheduled study visits was defined as "on time" if she arrived early or within three days, "moderately late" if she was four-seven days late, and "extremely late/missed" if she was more than eight days late or missed the visit altogether. Self-reported adherence was <95% for 29 (10%) of 288 women who were late for at least one study visit vs. 3 (1%) of 278 who were never late for a study visit (odds ratios [OR] 10.3; 95% confidence intervals [95% CI] 2.9, 42.8). Fifty-one (18%) of 285 women who were ever late for a study visit experienced virologic failure vs. 32 (12%) of 278 women who were never late for a study visit (OR 1.7; 95% CI 1.01, 2.8). A multivariate logistic regression model controlling for self-reported adherence found that being extremely late for a visit was associated with virologic failure (OR 2.0; 95% CI 1.2, 3.4). Timeliness to scheduled visits was associated with self-reported adherence to HAART and with risk for virologic failure. Timeliness to scheduled clinic visits can be used as an objective proxy for self-reported adherence and ultimately for risk of virologic failure.
Blacher
Rachel J
RJ
Centers for Disease Control and Prevention, Atlanta, GA, USA. Rachel.J.Blacher@macrointernational.com
Muiruri
Peter
P
Njobvu
Lungowe
L
Mutsotso
Winnie
W
Potter
Dara
D
Ong'ech
John
J
Mwai
Paul
P
Degroot
Alain
A
Zulu
Isaac
I
Bolu
Omotayo
O
Stringer
Jeffrey
J
Kiarie
James
J
Weidle
Paul J
PJ
D019380:Anti-HIV Agents / Q000008:administration & dosage*; D023241:Antiretroviral Therapy, Highly Active; D001071:Appointments and Schedules; D004812:Epidemiologic Methods; D005260:Female; D015658:HIV Infections / Q000188:drug therapy* / Q000821:virology; D006801:Humans; D007630:Kenya; D055118:Medication Adherence; D013997:Time Factors; D019562:Viral Load; D015024:Zambia
D019380:Anti-HIV Agents