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Integration of antiretroviral therapy services into antenatal care increases treatment initiation during pregnancy: a cohort study
Global Health Sciences Literature Digest
Published June 17, 2013
Journal Article

Stinson K, Jennings K, Myer L. Integration of antiretroviral therapy services into antenatal care increases treatment initiation during pregnancy: a cohort study. PLoS One. 2013 May 16; 8(5):e63328.

Objective

To compare three service models for initiating antiretroviral therapy (ART) in pregnant women.

Setting

Cape Town, South Africa

Study Design

Retrospective triple cohort study.

Population

Pregnant women presenting at three public sector antenatal clinics (ANC).

Intervention (Predictor Variable)

"Integrated" service model, with ART provided within the ANC; a "proximal" service model, with ART delivered at a separate ART service on the same premises, but outside the ANC; or a "distal" service model, with ART delivered at a separate primary care clinic in another part of the city.

Main Outcome Measures

ART initiation before delivery.

Methods

At the site providing "integrated" services (Site 1), women initiated ART on one day each week when an obstetrician specialized in HIV care was present. At the "proximal" care site (Site 2), women were referred by letter to a separate service on the same premises as the maternity unit but 100 meters away. At the site with the "distal" service model (Site 3), women were referred by letter to a primary care clinic located three kilometers away. At each site, clinical services were delivered according to standard Western Cape Province ART protocols, including same-day CD4 cell count testing (with results available to the ANC within one week).

Investigators reviewed clinical and laboratory records of all pregnant women presenting for care at each site during the 2008 calendar year. Records included routinely collected data such as women's names, dates of birth, whether or not they had received HIV counseling and testing, HIV status, CD4 cell counts, and obstetric data. When data were missing, investigators accessed electronic medical records systems for laboratory and obstetric information. To ascertain ART initiation and coverage among eligible women, investigators examined the electronic and paper records of Cape Town's 31 ART clinics. Investigators estimated the proportions of women completing each step of the PMTCT cascade, according to the respective model of service delivery.

Results

During the study period, 14,617 women presented for antenatal care, with 4,879 at Site 1, 4,990 at Site 2, and 4,748 at Site 3. The median age at presentation was 25 years (interquartile range [IQR]: 22 to 30 years). Women tended to be slightly older at Site 1 (p<0.001).

All sites had very high uptake of HIV counseling and testing (89% to 99%, p<0.001). Site 1 with 32% had the highest proportion of women testing HIV-positive (among those who tested), while Site 3 with 18% had the lowest (p<0.001). Across all sites, the median CD4 cell count in HIV-infected women was 373 cells/µL (IQR 240 cells/µL to 542 cells/µL).

Six hundred fifty-eight (17%) HIV-infected women overall had CD4 cell count ≤200 cells/µL and were thus ART-eligible. Of these 81 (11.6%) were already on ART when they presented for antenatal care. Twenty-seven percent of HIV-infected women overall had CD4 counts of 200-350 cells/µL. There were 617 ART-eligible women in total, with 215 (85.3%) at Site 1, 247 (89.2%) at Site 2 and 155 (91.7%) at Site 3.

Apart from the women already on ART at presentation, 365 (52.3%) women were on ART by delivery. Site 1 had the highest proportion, with 120 women (55.8%). Site 3 had 70 women (45.2%), and Site 2 had 94 women (38.1%) (p=0.003). Two hundred fifty-six (41.5%) ART-eligible women, overall, did not begin ART during pregnancy. Because of missing patient folders, it was unknown whether 77 (12.5%) ART-eligible women had initiated ART during pregnancy. Some ART-eligible women were known to have initiated ART after delivery (Site 1, n=46, 21.4%; Site 2, n=50, 20.2%; Site 3, n=29, 18.7%; p=0.228).

In ART-eligible women, the estimated median gestational age at first presentation was 26 weeks (95% CI, IQR 21 weeks to 31 weeks). Women tended to be several weeks earlier in gestation at Site 3 (p=0.001). Overall, women who began ART presented earlier in gestation than those who did not begin ART (23 weeks vs. 29 weeks, p=0.001). At 31 weeks, the median gestational age at ART initiation was not different across sites (IQR 28 weeks to 34 weeks, p=0.946).

In a Poisson regression model (see table), after adjusting for maternal age and gestational age at first presentation, women attending Site 1 were more likely to begin ART during pregnancy, compared to those attending Site 3 (rate ratio [RR] 1.33, 95% confidence interval [CI] 1.09 to 1.64, p=0.005). There was no difference between Site 2 and Site 3 in the probability of beginning ART during pregnancy (p=0.704). Women presenting for care later in gestation had a lower probability of initiating ART during pregnancy. Compared to women presenting at or before 20 weeks' gestational age, women presenting at 25-28, 29-32, 33-36 and after 36 weeks' gestational age were 28%, 38%, 78% and 82% respectively less likely to start ART during the antenatal period (see table). Older women also had a slightly higher probability of beginning ART (for each one-year increase in age, RR 1.02, 95% CI 1.00 to 1.03).

Table (from article). Poisson regression predicting the probability of antenatal ART initiation among eligible pregnant women.

Table (from article). Poisson regression predicting the probability of antenatal ART initiation among eligible pregnant women.

Conclusions

The authors conclude that integrating ART into routine antenatal care services can lead to significant improvements in ART initiation during pregnancy, increasing both the proportion of eligible women who start ART and the duration of ART received before delivery.

Risk of Bias

As a non-randomized, retrospective cohort study, the risk of bias in this study is moderate to high. The authors also point out that they did not assess whether the time required for ART-eligible women's clinical and psychosocial assessments prior to ART initiation varied between the models and within the sites, depending on service provider. Such variation would have had the greatest impact on late presenters, as there would be little time in which these assessments could be accomplished. This study was conducted in an urban setting, with high antenatal HIV prevalence as well as high volume in the number of patients accessing ANC and HIV services. Its findings may not be generalizable to other contexts.

In Context

This study was conducted when World Health Organization (WHO) guidelines recommended ART initiation in pregnant women at CD4 cell count ≤200 cells/µL.(1) Since the release and implementation of WHO's 2010 PMTCT guidelines,(2) one recommendation of which was to initiate ART at CD4 ≤350 cells/µL, far more pregnant women are beginning ART. Even so, very few HIV-infected pregnant women in sub-Saharan Africa begin ART before delivery.(3, 4) One of the main reasons for this is that health systems in the region are often suboptimal in design.(5) HIV-infected women are often identified through PMTCT programs, but ART initiation and follow-up usually are done separately from PMTCT clinics. HIV-infected pregnant women have needs that often not met by adult care and treatment services.(6) Colocating ART within ANC services is a way to optimize care for pregnant women with HIV.(7, 8)

Programmatic Implications

This research focuses on ART initiation. ART adherence and retention in care among HIV-infected pregnant women pose separate challenges,(7) and will need to be taken into account in designing and implementing integrated service models.

References

  1. World Health Organization. Antiretroviral drugs for treating pregnant women and preventing HIV infection in infants: towards universal access: Recommendations for a public health approach (2006 revision). [accessed 13 June 2013]
  2. World Health Organization. Antiretroviral drugs for treating pregnant women and preventing HIV infection in infants: Recommendations for a public health approach (2010 revision). [accessed 13 June 2013]
  3. Stinson K, Boulle A, Coetzee D, Abrams EJ, Myer L (2010) Initiation of highly active antiretroviral therapy among pregnant women in Cape Town, South Africa. Tropical Medicine and International Health 15: 825-832.
  4. Ferguson L, Lewis J, Grant AD, Watson-Jones D, Vusha S, et al. (2012) Patient Attrition Between Diagnosis With HIV in Pregnancy-Related Services and Long-Term HIV Care and Treatment Services in Kenya: A Retrospective Study. Journal of Acquired Immune Deficiency Syndromes 60: e90-e97.
  5. Ferguson L, Grant AD, Watson-Jones D, Kahawita T, Ong'ech JO, et al. (2012) Linking women who test HIV-positive in pregnancy-related services to long-term HIV care and treatment services: a systematic review. Tropical Medicine and International Health 17: 564-580.
  6. Abrams E, Myer L, Rosenfield A, El-Sadr W (2007) Prevention of Mother-to-Child Transmission services as a gateway to family-based HIV care and treatment in resource-limited settings: rationale and international experiences. American Journal of Obstetrics and Gynecology 197: S101-S106.
  7. Myer L, Rabkin M, Abrams E, Rosenfield A, El-Sadr W (2005) Focus on women: Linking HIV care and treatment with reproductive health services in the MTCT-Plus initiative. Reproductive Health Matters 13: 136-146.
  8. Rosenfield A, Figdor E (2001) Where is the M in MTCT? The broader issues in mother-to-child transmission of HIV. American Journal of Public Health 91:703-704.
  9. Myer L, Rabkin M, Abrams E, Rosenfield A, El-Sadr W (2005) Focus on women: Linking HIV care and treatment with reproductive health services in the MTCT-Plus initiative. Reproductive Health Matters 13: 136-146.