Table 2.

Summary of selected studies and data extraction process

Study country	Intervention type	Focus of intervention	Sample description	Study design	Measures	Study quality	Detailed description of outcomes
Bigogo et al. (2014) [43] Kenya	Bi-weekly home-based counseling and testing. A team of non-resident HIV counselors provided HIV counseling and testing at residents’ homes.	Cognitive	6366 participants who received HIV testing between January 2008 and February 2009. Age range ≥ 13 years: 1813(28.5%) ≥ 50	One group pre and post analysis of incidence of four syndromes	Healthcare-seeking behaviors using proportions and incidence (expressed as episodes per person-year) of acute respiratory illness (ARI), severe acute respiratory illness (SARI), acute febrile illness (AFI), and diarrhea	Good	Large scale HBCT enabled a large number of newly diagnosed HIV-infected persons to know their HIV status, leading to a change in care-seeking behavior and ultimately a decrease in incidence of common infectious disease syndromes through appropriate treatment and care. No comparisons where done based on age.
Coker et al. (2015) [40] Nigeria	Peer education intervention: the first arm was the standard of care, the second arm received peer education (PE1), and the third arm received peer education plus home visits from peer educators	Cognitive	600 HIV-infected ART naïve patients from Kano Teaching Hospital in Nigeria randomized in the ratio of (1:1:1) into 3 intervention groups. Age range > 18 years: 141(23.5%) > 40 years	Three-arm randomized control trial	-Viral load measurements -Adherence: self-report and cumulative pharmacy refill rates	Fair	There was no significant difference between the groups that received the peer-education intervention and those that did not. This is because adherence improved significantly regardless of whether the patient’s peer-education-based intervention or standard of care services 40+ adults were not likely to achieve viral load suppression compared to the other age categories.
Kunutsor et al. (2012) [41] Uganda	Patient education, health education, involving patient’s family in their treatment, late attendee tracing, short messaging system, educational training for adherence supporters, and systematic monitoring of adherence.	Cognitive affective behavioral	967 participants where included. All adult patients from the age of 18 onwards on ART for at least 3 months from four government facility sites in Uganda. Age range > 18 years: 46–55 years 132 (15.4); > 56 years 34(4%).	One-group pre- and post-intervention design. Patients were monitored for 1 year after intervention implementation. Data were collected using cross-sectional surveys, in-depth interviews, and focus group discussions.	Adherence outcomes -Self-reported adherence through a pill counts at the clinic. -Loss to follow-up: missing more than two consecutive clinic appointments after the date of last attendance -Transfers-out -Death (clinic-confirmed)	Good	Significant differences between the portions of patients with optimal adherence (≥ 95%) and sub-optimal adherence (< 95%) were found. The authors concluded that adherence strategies (including counseling, group education, leaflet, late attendance tracing and attendance diaries) could improve and maintain high levels of adherence in the long-term. There was no significant improvement after the intervention for those who are over 56 years. Those aged 36–55 years did have a significantly greater adherence after the intervention.
Lubega et al. (2015) [44] Uganda	Participants were randomized into 2 groups. One group received the standard care – test results, Cotrimoxazole prophylaxis and post-test counseling on disclosure, positive living and the importance of quarterly pre-ARV attendance. The experimental group, in addition, received visits by community support agents.	Affective cognitive biological	400 newly screened HIV-positive patients, 200 in each arm. Age range > 18 > years 45–70 years 93 (23%)	Randomized control trial with (1:1) parallel group of newly screened (WHO stage 1 or 2) non-ART eligible HIV-positive adult (> 18) in 3 health facilities.	-Attendance of at least 6 of 8 quarterly pre-ART care visits over a period of 24 months. -On attendance, interview on HIV status disclosure, consistency in condom use, and being faithful to 1 sexual partner	Good	The authors found that conducting monthly visits by community support agents for counseling support more than double the likelihood of retaining PLWHA under care for at least 2 years. The visits of community support agents also improve status disclosure and other elements of positive living. The increase was significant for 45–70
Maduka et al. (2013). Nigeria [46]	The experimental group received one adherence counseling session per month for four consecutive months for each patient, each counseling session lasting 45–60 min. In addition, twice a week for the duration of the 4 months, each patient received pre-scripted text messages containing adherence-related information and a reminder to take medication.	Cognitive behavioral	104 were purposefully (via announcement) selected for participation. Selected participants were randomly assigned into two groups. Each group was allocated 52 participants. Age range > 20 years: 50–59 years 9 (8.6%); 60–69 years 3 (2.9)	Randomized control trial using an experimental group and a control group on 1:1 proportion.	-Self-reported adherence -CD4 cell count pre-and post-intervention.	Good	Using the intention to treat analysis, the results showed that 76.9% of those in the intervention group achieved adherence to ARVs compared to 55.8% in the control group. The authors concluded that combining counseling with text message reminders significantly improves drug adherence. No comparisons where done based on age.
Mbuagbaw et al. (2012) [39] Cameroon	Short text motivational with reminder component messages to participants in the intervention group, once a week. The messages also contained a phone number that the participants could call if they needed help. The control group received no messages but standard ART care.	Behavioral	198 participants were recruited by randomization with a 1:1 allocation into the intervention and control arms. Age range > 21 years: no specific age breakdown	Randomized control trial using an experimental group and a control group on 1:1 proportion.	Primary outcome: adherence measured using the following methods -Self-reporting -Visual analogue scale -Refill data Secondary outcomes -Opportunistic infections -Anthropometric measures -Quality of life (assessment form)	Good	At 6 months, the analysis showed no effect on the number of participants achieving 95% adherence by visual analogue scale or reporting missed doses. The authors found that the motivational text messages did not significantly improve adherence to ART among treatment experienced patients after 6 months. No comparisons where done based on age.
Robbins et al. (2015) [42] South Africa	Masivukeni – multimedia technology, computer based, lay counselor delivered intervention – adherence counseling	Cognitive	55 non-adherent (< 90%) patients on ART randomized into two groups. Age range > 18 years: age categories not specified	Randomized control trial with one experimental arm (33) and one control arm (32). Blinded randomization was used to assign participants to various arms.	Primary outcome: adherence -Standard clinic-based pill counting	Fair	The participants who received the Masivukeni counseling reported significant positive attitudes towards disclosure and medication social support. The authors concluded that Masivukeni shows potential to promote optimal adherence. No comparisons where done based on age.
Siedner et al. (2015) [38] Uganda	A combination of short messaging service and transport reimbursement. The short messages were composed in three formats for the three randomized arms: (1) an unprotected SMS indicating abnormal test result and that they should return to the clinic as soon as possible (direct message) (2) a PIN-protected SMS message (PIN message), and (3) the use of a message reading “ABCDEFG” (coded message).	Behavioral	183 participants with abnormal CD4 count. 45 participants in the pre-intervention period and 138 participants in the intervention period randomized into three arms. Age range > 18 years: age categories not specified	Prospective, before-and after clinical trial. After clinical trial, participants were randomized in a 1:1:1 design to receive one of the three SMS message formats.	Primary outcome: -Return to the clinic within 7 days of receiving the SMS of an abnormal result.	Good	All three message formats outperformed the pre-intervention period. A combination of SMS-based laboratory results notification system in combination with transport reimbursements substantially shortened time to return to care and time to ART initiation following abnormal CD4 count results. No comparisons were done based on age.