Table 3 Data extraction of findings (except where specified, results are presented as Int. group vs. Cont. group)

Gross et al. (2019) [23]

Immediately post-intervention at week 48

100%: Using self-reported adherence n (%):

[Int. 174(73) vs. Cont. 173(69)]; p = 0·89

Ruan et al. (2017) [20]

Immediately post-intervention at month 6

100%: Using CPCRA adherence n (%):

[Int. 42(89.3) vs. Cont. 34(72.3)]; Z = 2.208; p = 0.027

80%-99% Using CPCRA adherence n (%):

[Int. 3(6.4) vs. Cont. 3(6.4)]; Z = 2.208; p = 0.027

 < 79% Using CPCRA adherence n (%):

[Int. 2(4.3) vs. Cont. 10(21.3)]; Z = 2.208; p = 0.027

Using Visual Analogue Scale (VAS) mean ± SD:

[Int. (98.72 ± 2.35) vs. Cont. (93.11 ± 6.51)]; Z = 2.735; p = 0.006

Nsagha et al. (2016) [26]

Immediately post-intervention at week 4

Using the interviewer-administered self-report questionnaire %:

[Int. 64.4% vs. Cont. 44.2%] Z = NR; p = 0.05

Sabin et al. (2015) [27]

Immediately post-intervention at month 9 following 3 months of pre-intervention

Using wise-pill device mean ± SD:

[Int. (96.2 ± 6.4) vs. Cont. (89.1 ± 15.9)]; Z = NR; p = 0.003

Moore et al. (2015) [24]

Immediately post-intervention at day 30

Using MEMS mean ± SD::

[Int. (86.2 ± 12.7) vs. Cont. (84.8 ± 18.1)]; cliff’s d = 0.01; p = 0.95

Using self-reported VAS mean ± SD:

[Int. (95.8 ± 6.6) vs. Cont. (92.4 ± 13.0)]; Z = NR; p = 0.44

Maduka and Tobin-West., (2013) [22]

Immediately post-intervention at month 4

Using self-reported adherence questionnaire n (%):

[Int. 40(76.9) vs. Cont. 29(55.8)]; Z = 0.224; p = 0.022

Mbuagbaw et al. (2012) [21]

Immediately post-intervention at month 6

Using Visual Analogue Scale (VAS) n (%):

[Int. 72(71.3) vs. Cont. 66(66.7)]; Z = NR; p = 0.542

Using self-report n (%):

[Int. 80(79.2) vs. Cont. 78(79.0)]; Z = NR; p =  > 0.999

Using pharmacy refill data mean ± SD:

[Int. (3.8 ± 1.48) vs. Cont. (3.7 ± 1.34)]; Z = NR; p = 0.617

Using SF-12 scale score Quality of life assessment form:

[Int. (3.79 ± 0.585) vs. Cont. (3.75 ± 0.583)]; Z = NR; p = 0.629

da Costa et al. (2012) [18]

Immediately post-intervention at month 4

Using self-reported adherence n (%):

[Int. 8(100.00) vs. Cont. 12(92.31)]; Z = 0.8038; p = 0.4215

Using pill counting n (%):

[Int. 5(62.50) vs. Cont. 6(46.15)]; Z = 0.7284; p = 0.4664

Using micro-electronic monitoring systems (MEMS) n (%):

[Int. 6(75.00) vs. Cont. 7(53.85)]; Z = 0.9694; p = 0.3324

Pop-eleches et al. (2011) [25]

Immediately post-intervention at week 48

Using the medication event monitoring system (MEMS) n/N:

4 intervention groups (daily short messages, weekly short messages, daily long messages and weekly long messages) with the control group

Summary group (All daily reminder groups, irrespective of message length):

[Int. 0.41 vs. Cont. 0.40]; Z = NR; p = 0.92

Summary group (All weekly reminder groups, irrespective of message length):

[Int. 0.53 vs. Cont. 0.40]; Z = NR; p = 0.03

Summary group (All short reminder groups, irrespective of message frequency):

[Int. 0.47 vs. Cont. 0.40]; Z = NR; p = 0.27

Summary group (All long reminder groups, irrespective of message frequency):

[Int. 0.47 vs. Cont. 0.40]; Z = NR; p = 0.24

Subgroups

Subgroup 1 (daily short messages):

[Int. 0.40 vs. Cont. 0.40]; Z = NR; p = 0.97

Subgroup2 (weekly short messages):

[Int. 0.53 vs. Cont. 0.40]; Z = NR; p = 0.07

Subgroup3 (daily long messages):

[Int. 0.42 vs. Cont. 0.40]; Z = NR; p = 0.85

Subroup4 (weekly long messages):

[Int. 0.53 vs. Cont. 0.40]; Z = NR; p = 0.08

Lester et al. (2010) [19]

Immediately post-intervention

Using self-reported questionnaire n (%):

[Int. 168(62) vs. Cont. 132(50)]; Z = NR; p = 0.006