DISC Study 2011.

Study characteristics
Methods	Study design: parallel‐group RCT Study centre: 1 (Hong Kong Polytechnic University) Number randomised: 221 children Study follow‐up: 2 years Exclusions and losses to follow‐up: 38 (34.2 %) in BFSCL group and 36 (32.7%) in SVSCL group were excluded; 8 (7.2 %) in BFSCL group and 11 (10.0%) in SVSCL group were lost to follow‐up
Participants	Age: mean = 11 years (range 8‐13 years) Gender: 85 boys, 136 girls Culture: Hong Kong, China Inclusion criteria:  age 8‐13 years spherical equivalent −1.00 to −5.00 D  astigmatism ≤ 1.00 D anisometropia ≤ 1.25 D spectacle‐corrected monocular VA 0.0 logMAR or better contact lens–corrected monocular VA 0.1 logMAR or better willingness to wear contact lenses regularly and parents' understanding and acceptance of random allocation of intervention Exclusion criteria:  ocular or systemic abnormalities affecting visual function or refractive development prior use of PALs or BF contact lenses contraindication for contact lens wear
Interventions	BFSCL group (n = 111): dual‐focus incorporated soft contact (DISC) lenses, which were custom‐made BFSCLs with distance correction in the centre and alternating rings of defocusing (+2.50 D addition) and distance correction zones SVSCL group (n = 110): SVSCLs Note: children were instructed to wear lenses for 5‐10 h/day and to wear spectacles with full prescription when not wearing contact lenses
Outcomes	Primary outcomes Refractive error (cycloplegic autorefraction) AL Secondary outcome Corneal curvature Measurements taken every 6 months over 2 years Unit of analysis: individual (right eye used for analysis)
Notes	Study dates: September 2007‐ October 2009 Trial registration: NCT00919334 Funding source: "the study was supported by grants of RGC GRF (B‐Q04G) and Niche Areas Fund (J‐BB7P) from The Hong Kong Polytechnic University" Conflict of interest: reported "none"