A major reduction in the price of antiretrovirals in Cameroon was associated with an increased number of HIV-infected patients initiating ART, but did not appear to be associated with retention in care in this setting where most patients had to pay for their own treatment. Retention in the Limbe ART programme decreased substantially over time: less than 50% of patients remained in care at two years and only one-third at three years. The proportions of patients remaining in care did not differ according to when treatment was started (i.e., before or after 1 October 2004).
Though we cannot prove that the reduction in price of ART was the only variable associated with the outcome, the socio-economic conditions of the country did not change appreciably during the period of the study. Paying for ART in our study constituted a major increase in the risk of dropout or death, and our findings are consistent with other studies, which have demonstrated that providing ART in resource-constrained settings where people have to pay for their own treatment was associated with high dropout rates among persons with advanced baseline disease [16
]. Other studies have found self-paid programmes were also associated with failure to achieve viral suppression [18
]; however, we were unable to examine this outcome because viral load testing was not available in Southwest Cameroon at that time.
Affordability of antiretroviral treatment is not the only factor that can influence retention or adherence to treatment. For example, laboratory monitoring required for patients on ART at that time cost US$30 in Cameroon and was not readily affordable. The majority of patients had their CD4 cell counts measured as a requirement for entry into the treatment programme, but very few paid for follow-up CD4 cell count testing. For the few patients who paid for follow-up CD4 cell counts, the increases we observed during follow up were consistent with improved clinical outcome. Most patients presented for care with late-stage disease, possibly due to the expense of treatment and insufficient access to voluntary counselling and testing services. The late entry to care we observed in the present study is consistent with the findings of another Cameroonian report that found patients usually first learn their HIV status late in the course of infection when they have already developed clinical signs and symptoms of AIDS [19
Poor adherence is associated with an increased risk of mortality [20
]. Good adherence, retention in care and survival have been achieved through such interventions as home-based AIDS care [21
] and participant-identified support partners [24
]. Adherence in the present study, measured as attendance to scheduled clinic visits, was generally poor, with only 10% of patients attending 95% or more of their visits. More than 20% of patients were lost to follow up after their initial ART visit, which was due, in part, to early deaths. The magnitude of this effect (i.e., early death after ART initiation) was difficult to quantify since for some patients, the date of death was unknown, and some patients who were classified as lost to follow up may have died.
Expanded access to antiretroviral therapy is feasible in urban sub-Saharan Africa [24
]. Increased distance from the Limbe ART clinic was associated with poor retention in care. This has also been demonstrated by others in the United States [25
]. Patients who traveled to Limbe from Douala, which had at least two ART programmes at that time, were at greater risk of becoming lost to follow up. This might have resulted from differences in the antiretroviral treatment options and the quality of care that were available in Limbe compared with Douala. Regardless, expanding antiretroviral treatment programmes to be closer to more people can overcome the obstacle of distance from clinics that may impede attendance.
Few patients had their antiretroviral drug costs and laboratory tests paid entirely by their employer or an ART programme. Most of these persons were employees of a local oil refining company located in Limbe, and had good access to the clinic.
A reduction in antiretroviral drug price in our study was associated with increasing numbers of patients accessing ART, but was not associated with improved retention in care. However, free treatment, which included payment for laboratory monitoring, was associated with improved retention in care. This further validates the approach of the current era of antiretroviral treatment programmes in Africa that are largely donor supported and provide treatment and care to persons living with HIV disease for minimal or no charge. Requiring persons with limited resources to pay for such care would not have been successful or sustainable in the long term.
A strength of our analysis is its large size; we assessed data from a large ART programme with good record keeping and a considerable length of follow-up time for patients, and we had access to patients' pharmacy and clinical payment records. However, our analysis is subject to some limitations. Data were collected retrospectively and there was a low rate of immunologic follow up since clients had to pay for the test and most could simply not afford it; thus the CD4 cell counts available may not reflect the CD4 cell counts of all clients while on ART.
The extremely high rate of loss to follow up, particularly after only one visit, where the outcomes of these patients are not known, may have contributed to underestimation of mortality in particular. A follow-up tracing study to characterize patients receiving ART who were lost to follow up may be useful to enable us to understand the large proportion of those who were lost only after one visit. There was no virologic monitoring available during that time in this part of Cameroon. To overcome potential bias resulting from exclusion of missing data, we employed multiple imputation to generate estimated values for missing data and the abandoned care analyses found that cohort was a predictive factor only when imputed data was included.