Table 1.
Characteristics of selected studies included in the systematic review (N = 14).
| NO. | Study | Country | Age (years) | Intervention | Control | Definition of compliance | Compliance measure | Follow-up years | Sample size | No. compliant (%) |
|---|---|---|---|---|---|---|---|---|---|---|
| 1 | Ethan et al. (24) | America | None | Free spectacle and teacher incentive | Spectacles only at the end of the study | Wearing | Direct observation in the classroom | None | Treatment group: 121 Control group: 127 |
41 (33.88%) |
| 2 | Du et al. (19) | China | 10.46 ± 1.08 | Free spectacle | Spectacle voucher | Wearing | Unannounced visits | 7 | Treatment group: 1,055 Control group: 771 |
439 (41.6%) |
| 3 | Thapa et al. (16) | Nepal | 13 ± 4 | Free spectacle | Eye screening only | Wearing | Unannounced visits | 6 | Treatment group: 109 Control group: 145 |
62 (57%) |
| 4 | Holguin et al. (6) | Mexico | 10.4 ± 2.6 | Free spectacle | None | Wearing | Direct inspection | 18 | Treatment group: 493 Control group: None |
66 (13.9%) |
| 5 | Yi et al. (17) | China | 10.9 | Free spectacle, education on their use, and teacher incentive | Spectacle prescriptions only | Wearing | Unannounced visits and children self-reported | 6 | Treatment group: 341 Control group: 352 |
233 (68.3%) |
| 6 | Guan et al. (20) | China | 10.53 | A voucher that can be redeemed for free spectacles | Spectacle prescriptions only | Wearing | unannounced visits | 7 | Treatment group: 971 Control group: 1,018 |
825 (85%) |
| 7 | Nie et al. (22) | China | 13.56 ± 1.14 | Free spectacles | Spectacles only at the end of the study | Wearing | Children self-reported | 3 | Treatment group: 476 Control group: 434 |
343 (72%) |
| 8 | Keay et al. (13) | China | 14.1 ± 0.9 | Free spectacles | None | Wearing | Unannounced visit | 1 | Treatment group: 415 Control group: NONE |
193 (46.5%) |
| 9 | Wedner et al. (15) | Tanzania | 14.4 | Free spectacles | Spectacle prescriptions only | Wearing | Unannounced visit | 3 | Treatment group: 58 Control group: 50 |
27 (46.55%) |
| 10 | Wang et al. (18) | China | 10.6 ± 1.0 | A: Free spectacles B: Free spectacles + offer of $15 Upgrade spectacles C: Free spectacles + offer of $30 Upgrade spectacles |
Spectacle prescriptions only | Spectacle purchase and wearing | Unannounced visits and children self-reported | 6 | Treatment group: 252M Control group: 250 |
80 (31.75%) |
| 11 | Ma et al. (5) | China | 10.5 ± 1.1 | Vouchers for free spectacles at a local facility, or free spectacles provided in class | Spectacle prescriptions only | Wearing | Unannounced direct examinations | 8 | Treatment group: 1,104 Control group: 1,033 |
453 (41.03%) |
| 12 | Ma et al. (21) | China | 13.56 | Free spectacles | Spectacle prescriptions only | Wearing | Unannounced visit | 9 | Treatment group: 476 Control group: 434 |
209 (43.91%) |
| 13 | Ma et al. (23) | China | 10–12 | Early referral to the vision center for refraction and free spectacles | Late referral for the identical intervention | Wearing | Children self-reported | 6 | Treatment group: 1,461 Control group: 1,252 |
806 (55.17%) |
| 14 | Ma et al. (14) | China | None | Free vision care and glasses | Spectacles only at the end of the study | Eyeglasses ownership and wearing | Children self-reported | 3 | Treatment group: 433 Control group: 516 |
347 (80.14%) |