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Adherence support workers: A way to address human resource constraints in antiretroviral treatment programs in the public health setting in Zambia
Global Health Sciences Literature Digest
Published February 10, 2009
Journal Article

Torpey K, Mushota E, Mutale LN, et al. Adherence support workers: A way to address human resource constraints in antiretroviral treatment programs in the public health setting in Zambia. PLoS ONE 2008;3(5):e2204.


To assess the effectiveness of adherence support workers (ASWs) in adherence counseling, treatment retention, and addressing inadequate human resources at health facilities

Study Design

Mixed quantitative and qualitative methods. The quantitative component included a cross-sectional study of 500 antiretroviral treatment (ART) patients and a retrospective electronic records review of all new patients on ART for 12 months before and 12 months after the introduction of ASWs in five clinics. The qualitative component included key informant interviews and two focus groups at each of the five study clinics, one with health care workers (HCWs) and one with ASWs.


The study was performed from 1 March to 4 April 2007 at five public health facilities in Zambia selected from the 49 Family Health International's Zambia Prevention Care and Treatment Partnership (ZPTC)-supported sites offering ART services. The five were selected because they had captured treatment data with an electronic ARV-dispensing tool at least 12 months before and 12 months after the deployment of the ASWs. Zambia is among the countries hardest hit by the HIV/AIDS epidemic in Africa, with an estimated 1.2 million of the total Zambian population of 10 million infected with HIV by 2005. Zambia is rapidly scaling up services that provide ART to people with HIV.


Patients 18 years of age or older who had commenced ART from January 2006 onwards were approached consecutively at the ART clinics until the required sample size of 500 for the cross-sectional survey was reached. The 500 clients included 295 women (59.0%) and 205 men (41.0%) of whom 42.8% were 35-49 years old and 38.8% were 25-34 years. The mean and median age was 36 and 35 years, respectively. Almost half of respondents (48.0%) were married and in a monogamous relationship;, 2.0% were in polygamous relationships; and 35.0% were divorced, separated, or widowed. Of the 500 participants, 47.4% attended school through the secondary level, 30.2% received only primary education, and 3.6% had no formal education. Two hundred seventy-six clients (55.2%) started ART before the introduction of the ASW program, and 224 (44.8%) started after.

For the retrospective record review, 3903 and 4972 electronic patient records of all new patients on ART were analyzed for the period 12 months before and 12 months after the introduction of ASWs, respectively. The focus groups with HCWs included those who were providing ART services at least twice a week and had been working at the site for at least 12 months. All ASWs at the study sites were eligible to take part in the focus groups. Key informants were facility managers or people in charge of the ART clinics.


In July 2006, ZPCT developed a curriculum to train community volunteers as ASWs. The volunteers mostly were persons living with HIV/AIDS who also were on ART. The curriculum was a longer version of adherence counseling training for HCWs but was a simplified version designed for lay providers. It was implemented after an initial pilot study in two provinces. Apart from technical information on ART and adherence, additional modules on techniques for relationship-building, counseling skills, and documentation were included. The training modules involve didactic sessions, role plays, group and individual exercises, and two days of practicum. Participants were observed and assessed by HCWs who are trainers or who were trained in HIV/AIDS care and ART management. Adherence counseling was done mostly by HCWs before introduction of ASWs. Other untrained staff, such as registration officers and data entry clerks helped during staff shortages. Since July 2006, ZPCT has deployed ASWs to provide adherence counseling to patients, in conjunction with HCWs, as part of the ART team in health facilities. They work alongside nurses and doctors in the ART clinic and are supervised by the ART Adherence Counselor, who is an HCW. The ASWs also conduct community visits to locate patients who have missed their clinic appointments and provide support to improve adherence.

Primary Outcomes

Quality of adherence counseling was measured during the cross-sectional study and was compared at two levels. The ART patients who initiated therapy before and after the ASW scheme were compared. Second, ART patients counseled by ASWs were compared to those counseled by HCWs after the introduction of ASWs in the facilities.

Quality of adherence counseling was measured by (1) duration of the counseling sessions, scored as too short, too long, or about the right amount of time); (2) counseling procedures; (3) counselors' responsiveness to clients' questions; and (4) coverage of key questions and information, including the advantages of ART, drug-specific information, and safe sex practices.

Adherence was measured by patient self-report during the cross-sectional study, using the same two comparison levels described above. Using a 3-day recall, ART patients were asked if they took their medicines regularly without missing any pills during that period.

Loss to follow-up was measured using the electronic patient-record review. The electronic database is used to track dispensing of ARVs, appointments, loss to follow-up, and treatment retention rates. Loss to follow-up was defined as missing three consecutive pharmacy appointments.

Qualitative outcomes included strengths and weaknesses of the ASW scheme; recommendations, such as on the role of ASWs in addressing the human resource shortage problem; quality of adherence counseling; and patient waiting times.


Quality of adherence counseling:

  1. Duration of the counseling sessions: The percentage of ART patients who thought that the time spent on adherence counseling was just right was 77.1% among those receiving counseling from a HCW and initiating therapy prior to the ASW program. This percentage was slightly higher, 81.1% among those initiating after the ASW program began but also receiving counseling from an HCW, and was nearly identical (82.1%) among those receiving counseling from an ASW. There was no statistically significant difference in the perception of counseling duration provided by ASWs versus HCWs (p>0.05).
  2. Counseling procedures: 89.1% of patients received pre-treatment adherence counseling before the ASW program was initiated, compared to 90.2% after the program was initiated (p>0.05). The pattern was similar for follow-up adherence counseling. The responsibility for pre-treatment adherence counseling shifted from HCWs to ASWs; 72.4% of ART clients received counseling by HCWs before the ASW program, which declined to 52.0% after the ASW program was initiated. Similar results were seen when the analysis was disaggregated by ART site (p<0.05). The number of untrained non-health care workers (e.g. data entry clerks, registration officers) who conducted adherence counseling to support HCWs declined from 37.0% to 2.4% after the introduction of ASWs (p<0.05).
  3. Counselors' responsiveness to clients' questions: There was no difference in the counseling received before and after the introduction of ASWs (p>0.05).
  4. Coverage of key questions and information: There was no difference in the accuracy of the responses provided before and after the introduction of ASWs across all the elements. Quality of adherence counseling provided by ASWs was similar to HCWs, except responding to questions, particularly on advantages of ART, where the ASWs fared better.

Adherence: There was no statistically significant difference in self-reported adherence before and after the introduction of ASWs (p>0.05). Self-reported adherence between clients counseled by HCWs compared to ASW after the ASW intervention was similar and not statistically significant (p>0.05).

Loss to follow-up: Of the 3903 electronic records of all new ART patients who commenced treatment 12 months prior to the introduction of ASWs, 3332 patients (85.4%) were retained in the ART program and 571 patients (14.7%) were lost to follow-up over a 12-month period. Of the 4972 electronic records of all new ART patients who commenced treatment after the introduction of ASWs, 4972 (100.0%) of the patients had been retained in the ART program over 12 months.

Qualitative results: The focus groups revealed the following recurring themes regarding the effect of ASWs on human resources: reduced patient waiting times; reduced workload for HCWs; and streamlining patient flow by quickly identifying patients, leading to a greater number of clients being seen. Furthermore, quality of adherence counseling was seen to improve due to ASWs motivating and educating patients on ART adherence; acting as role models, as many of the ASWs were HIV positive; and providing and assuring the availability of specialized adherence counseling services. All interviewed facility managers and ART clinic people in charge confirmed that ASWs were conducting adherence counseling in their facilities and contributing to the reduction of the workload of HCWs. In addition, the time to prepare a patient before the initiation of ART was reduced. Three of the five facility managers rated the quality of adherence counseling provided by ASWs to be very good and two said that it was good.


The authors conclude that ASWs were effective in providing quality adherence counseling, improving patient retention, and reducing the loss to follow-up rates as well as addressing the human resource problem at selected hospitals in Zambia. Furthermore, the shifting of tasks from more skilled HCWs to ASWs does not compromise the quality of counseling provided.

Quality Rating

There is no system for rating the quality of mixed method studies such as this one. Although informative, the study had several limitations. Interviewing ART patients within a clinic setting is likely to introduce a selection bias, as clients who are interviewed are more likely to be retained in care and treatment. Analysis of the ARV dispensing tool, however, which tracks all patients on ART, showed an 85.0% retention rate among all new clients before the introduction of ASWs compared to 100.0% 12 months later. Furthermore, selection of sites could have introduced a bias, as of the 49 ZPCT ART sites, only five were selected because they had backed up electronic information for over 12 months before the introduction of ASWs. The cross-sectional survey relied on recall of adherence counseling that for some was over a year in the past. The assignment of ASWs or HCWs was not random, and no information was provided on how the assignments were made, which is a source of possible bias. The adherence measurement was based on patient self-reports, which may be affected by desirability and recall bias. Finally, this study only assessed the performance of ASWs when they were working under the supervision of HCWs. The findings of both the quantitative and qualitative research, however, support the conclusion that the quality of adherence counseling does not differ by personnel. Further research is required as lay providers are mainstreamed into service provision in health facilities.

In Context

Adherence is closely associated with improved viral suppression, prevention of resistance, delay in disease progression, and decreased mortality. The existing, human resource capacity in Zambia is far below the WHO-recommended cadre-to-population ratios, and with the rapid expansion of access to ART, the increasing patient load will put a strain on the existing fragile human resource base. ART programs using community workers and treatment supporters to implement HAART using the Directly Observed Therapy approach have reported some success.(1,2,3) Although the predictors and biologic consequences of non-adherence to ART are well documented, there is a general lack of information comparing the quality of adherence counseling provided by lay providers, such as ASWs with HCWs.(1,4,5) There also is a paucity of information on the impact of using lay providers like ASWs in both the health facility and community settings, even though these can be vital strategies in ART program implementation.

Programmatic Implications

Training lay providers like ASWs is necessary to help address issues of inadequate human resource associated with ART scale-up. The relatively low training cost and the important contribution that ASWs offer in complementing the efforts of HCWs make it a viable option in addressing human resource constraints in ART programs. The average cost of training one ASW in this study was approximately $320 (range $266 to $380) including meals, accommodation, and transportation. After training, each ASW received a monthly stipend of $25 while volunteering 20 hours per week, making this potentially a cost-effective approach to expanding the workforce needed to scale-up provision of ART. ASWs were quite stable and had a relatively low attrition rate. Out of the 248 ASWs trained by the time of the study, only 22 were not at post due to ill heath or loss to follow-up after 18 months. The fact that quality of adherence counseling did not change counters the perception that lay providers provide inferior quality of service. In a resource-limited setting, where staff shortages are common, ASWs provide the much needed support for an overburdened workforce. In addition, ASWs, who are mostly people living with HIV, may be in a better position to provide empathic and emotional support to patients as well providing community follow-up, which remains a challenge for HCWs.


  1. Farmer P, Leandre F, Mukherjee J, et al. Community based treatment of advanced HIV disease: Introducing DOT-HAART. Lancet 2001;358:404-9.
  2. Nachega JB, Knowlton AR, Deluca A, et al. Treatment supporter to improve adherence to antiretroviral therapy in HIV-infected South Africans: A qualitative study. J Acqu Immune Defic Syndr 2006;43:S127-33.
  3. Pearson C, Micek M, Simoni J, et al. Modified directly observed therapy to facilitate highly active antiretroviral therapy adherence in Beria, Mozambique: Development and implementation. J Acqu Immune Defic Syndr 2006;43:S134-40.
  4. Berg KM, Arnsten JH. Practical and conceptual challenges in measuring antiretroviral adherence. J Acquir Immune Defic Syndr 2006;43:S79-87.
  5. Kober K, Damme WV. Scaling up access to antiretroviral treatment in southern Africa: Who will do the job? Lancet 2006;364:103-7.