The challenge of adherence during pregnancy and after

Data on adherence rates during and after pregnancy are limited. These data are important particularly as international guidance moves towards universal ART in pregnancy and during breastfeeding.

A systematic review and meta-analysis published in the 23 October 2012 edition of AIDS was conducted to estimate adherence rates in pregnancy and postpartum and found that achieving adequate adherence during this period was a challenge particularly after delivery. [1]

Jean Nachega and an international group of researchers performed a literature search, which included all studies from low-, middle-, and high-income countries reporting adherence rates in HIV positive women as a primary or secondary outcome. From the review, 72 articles were selected of which 51 met the inclusion criteria for the analysis.

The majority (74%) of the studies were observational and the remaining ones were RCTs evaluating PMTCT programmes. Most were conducted in the United States (27%), followed by Kenya (12%), South Africa (10%) and Zambia (10%). Almost half (45%) the studies reported adherence rates in women receiving ART, and 29% and 24% in women receiving AZT and single dose nevirapine (NVP) respectively. One study compared adherence rates between women receiving ART and those AZT. Adherence thresholds differed across studies from >80% to 100% and most used self reported questionnaires followed by pill count and pharmacy refills. Most studies (76%) reported adherence during the antepartum period, 8% post partum, and 16% reported rates during both periods.

A pooled analysis of all studies found an estimate of 73.5% (95% CI 69.3 – 77.5%) of women with adequate ART adherence (>80%). The pooled proportion of women who achieved adequate adherence was significantly higher during the antepartum (75.7%, 95% CI 71.5 – 79.7%) than the postpartum period (53%, 95% CI 32.8 – 72.7%, p=0.005).

The pooled adherence of women with good adherence rates was significantly higher in low- and middle-income countries (76.1%, 95% CI 72.2 – 79.7%) than in high-income countries (62%, 95% CI 50.1 – 73.3%, p=0.021). When the investigators excluded single dose NVP studies from the analysis, this difference became non-significant (74.3 vs 62%, p=0.062). When the analyses were limited to adherence thresholds of >90% (74.8 vs 69.7%, p=0.071) and 100% (78.3 vs 74%, p=0.103) the differences between low- and middle-income countries and high-income countries were also non-significant.

The investigators noted that this meta-analysis showed that adherence during pregnancy is significantly below that recommended for virologic suppression. They wrote: “It is crucial to monitor ART adherence, investigate specific barriers for nonadherence, and develop interventions to assist antepartum and postpartum women in adhering to ART and ensure the long-term efficacy of such an approach for both maternal health and PMTCT.”

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The importance of adherence in pregnancy and post partum is a big consideration in discussions about WHO Option B+, ie all women starting lifelong treatment in pregnancy regardless of CD4.

There are many brilliant community models to support adherence. MSF recently launched a toolkit describing their very successful Adherence Clubs in the Western Cape. [2]