Lambdin BH, Micek MA, Sherr K, Gimbel S, Karagianis M, Lara J, Gloyd SS, Pfeiffer J. Integration of HIV care and treatment in primary health care centers and patient retention in central Mozambique: A retrospective cohort study. J Acquir Immune Defic Syndr. 2013 Jan 2. [Epub ahead of print]
To examine the impact of an integrated service delivery model in public sector clinics providing antiretroviral therapy (ART) on retention in HIV care.
Seventeen clinics in Manica and Sofala provinces, Mozambique.
Retrospective cohort study.
Adult (age ≥15 years) HIV-infected, non-pregnant patients initiating ART between January 2006 and June 2008.
The primary outcome assessed was attrition from care, defined as all-cause mortality or loss to follow-up. The date of attrition was defined as the last pharmacy refill date for those who were lost to follow-up and the date of death for those who died. Data were also gathered on patient transfers to treatment at a different facility and on patients who suspended HIV treatment per clinicians' recommendation but remained in care.
Two service delivery models were evaluated: vertical (HIV/AIDS services operated within a clinic separate from clinics providing other primary care services, which were not integrated in physical structure or human resources), and integrated (HIV/AIDS services were co-located with other primary care services, with human resources shared between services). Eligible clinics had operational electronic databases of patient medical records. Investigators utilized these databases, which contained patients' socio-demographic characteristics, pharmacy and clinical data, and other relevant data. Eligible patients initiated ART between January 1, 2006, and June 30, 2008. Cross-checks were incorporated within the databases to minimize data errors, and database managers performed queries to monitor data quality. Investigators began analysis of the databases in May 2009, 11 months after the study's end, so that peer counselors would have had sufficient time to trace patients missing from care. To assess data validity, investigators compared data from the databases to a randomly selected sample of 520 paper-based patient medical records from the study clinics. K scores and concordance correlation coefficients for sex, pre-ART CD4 value and patient retention were very high, ranging from 0.91 to 0.97, and there was >92% agreement in the dates of CD4 blood draw, ART initiation and outcome.
Cox proportional hazards models were used to analyze time until attrition. Individuals who were categorized as transferred or suspended from care (discontinued ART) were treated as censored observations at the time of transfer or suspension. Follow-up time began at each p's primary analysis tested the association of clinic model and time-to-attrition; a secondary analysis tested the association between clinic location and clinic experience with time-to-attrition. Investigators evaluated the associations of these characteristics with attrition in both early patient follow-up, defined as a patient's first six months of follow-up, and late patient follow-up, defined as a patient's follow-up beginning six months after initiating treatment. Using backward stepwise regression with a criterion p value of <0.2 for inclusion in the final model, each of these analyses considered a range of pre-specified potential confounders, including pre-ART CD4 count, pre-ART World Health Organization (WHO) clinical stage, age at enrollment in the ART clinic, education level, sex, year of ART initiation and pharmacy staff burden.
A total of 11,775 patients was included in the study. Patients attending the two different types of clinics (vertical vs. integrated) were similar with regard to sex and age, but patients did have statistically-significant differences in education, CD4 count and WHO clinical stage. Thirteen (76%) of the 17 clinics provided integrated services. Six (46%) of the integrated clinics were in urban settings, as were two (50%) of the vertical clinics.
A total of 6,190 patients initiated ART at vertical facilities, while 5,585 initiated ART at integrated facilities. An average of 61 patients per clinic-month initiated ART at vertical facilities, while 19 per clinic-month initiated ART at integrated facilities (p<0.01). Four clinics provided person-time for vertical clinics and 14 provided person-time for integrated facilities. One clinic shifted from a vertical to an integrated model during the study period, providing person-time for both categories. Among patients initiating treatment, the average number of days between enrolling at the facility and initiating treatment was 180 days for vertical clinics and 93 days for integrated clinics (p<0.01).
The proportion of patients retained in care at 24 months was 60.7% (95% CI, 59.0% to 62.3%) among those attending vertical facilities and 54.9% (95% CI, 52.3% to 57.4%) among those attending integrated facilities. Patients attending integrated clinics had a higher hazard of attrition in late follow-up (HR=1.75, 95% CI 1.04 to 2.94, p=0.03), but did not have a significantly higher hazard of attrition in early follow-up (HR=0.97, 95% CI 0.71 to 1.33, p=0.87). Patients attending urban clinics had a significantly lower hazard of attrition in late follow-up compared to those attending rural clinics (HR=0.57, 95% CI 0.35 to 0.91, p=0.02), but did not have a significantly lower hazard in early follow-up (HR=0.84, 95% CI 0.61-1.17, p=0.30).
The authors conclude that there was a significantly higher hazard of late attrition for patients attending integrated clinics and clinics in rural settings.
With its observational design and retrospective analysis, the risk of bias in this study is high. Among other potential confounders, the vertical clinics in these provinces were better resourced than were the integrated clinics, with generally stronger clinical skills, higher staffing levels, more training opportunities etc.
The retention estimates in this study were similar to those of another a recent Mozambican study,(1) but were lower than those from a recent systematic review of HIV treatment cohorts in sub-Saharan Africa.(2) As ART becomes more widely available, with the potential for patients to live for many years, new approaches to service delivery are needed. In Mozambique and other resource-limited settings, it will be difficult if not impossible for vertical models of HIV service delivery to meet demand. The integration of HIV care and treatment into primary health care clinics is an important strategy to increase ART coverage. Although attrition was higher in the rural integrated clinics, the integration of services made it possible for many more people to enter care. More rigorous research is needed to understand the areas in which improvements can be made in integrated service delivery.
Funding agencies should consider supporting large-scale, multi-country cluster-randomized trials comparing the efficacy and cost effectiveness of standard ART delivery models with models integrating ART delivery into primary care.
- Lahuerta M, Lima J, Elul B, Okamura M, Alvim MF, Nuwagaba-Biribonwoha H, et al. Patients enrolled in HIV care in Mozambique: baseline characteristics and follow-up outcomes. J Acquir Immune Defic Syndr. 2011 Nov 1;58(3):e75-86.
- Fox MP, Rosen S. Patient retention in antiretroviral therapy programs up to three years on treatment in sub-Saharan Africa, 2007-2009: systematic review. Trop Med Int Health. 2010 Jun;15 Suppl 1:1-15.