Kwok 2013a

Methods	Design: 2‐arm randomised controlled pilot trial with parallel‐group design Recruitment period: not reported No. of centres involved: 6 Unit of randomisation: individuals No. randomised: 223 Number of arms considered in this review: 2 Maximum trial duration: 9 months Funding by non‐profit organisation: CADENZA, a Jockey Club Initiative for Seniors Funding by commercial organisation: none described Publication status: full‐text report
Participants	Type of MCI: not addressed Patient flow: 111 randomised, 111 described at baseline in experimental group; 112 randomised, 112 described at baseline in control group Number of females: 97 of 111 (87%) in experimental group; 93 of 112 (83%) in control group Average age (SD): 75 (5.8) years in experimental group; 75 (5.8) years in control group Average (SD) education: no formal education 6 (5.4%); below or at primary level 84 (75.7%); secondary or above 21 (18.9%) in experimental group; no formal education 14 (12.5%); below or at primary level 72 (64.3%); secondary or above 26 (23.2%) in control group Baseline cognitive function: measured with CMSS and CMMSE Selection criteria on cognition: subjective memory complaints: score ≥ 3 on Chinese Memory Symptoms Scale (mean 4.2, SD 0.8 in experimental group; mean 4.0, SD 0.8 in control group); no dementia: score ≥ 20 on Chinese version of Mini Mental State Examination (mean 25.6, SD 2.5 in experimental group; mean 25.7, SD 2.5 in control group) Ethnicity: 111 Asian in experimental group; 112 Asian in control group APOE: number of participants positive for APOE not reported
Interventions	Type of experimental intervention: computerised CT, treatment duration 12 weeks; intervention provided as group training, under supervision Details of experimental intervention: CCT based on ACTIVE trial protocol, with focus on attention, memory, and reasoning Type of concomitant treatment provided: none Session duration: 90 minutes in experimental group Number of treatment sessions: 12 in experimental group Treatment frequency: 1/week in experimental group Maximum treatment duration: 12 weeks in experimental group Type of control intervention: other; treatment duration 12 weeks; intervention provided as group training, under supervision Details of control intervention: "series of health‐related educational lectures in small groups on prevention of mood disorder, heart diseases, diabetes, and stroke" Session duration: 90 minutes in control group Number of treatment sessions: 12 in control group Treatment frequency: 1/week in control group Maximum treatment duration: 12 weeks in control group
Outcomes	Cognitive functioning outcome considered Global cognitive functioning measured with total score of the Chinese version of Mattis Dementia Rating Scale (CDRS) at 12 weeks on a scale from 0 to 144, with higher values indicating benefit Physical functioning outcome considered: none Quality of life outcome considered: none Depression outcome considered: none Safety outcome considered: none Available cognitive functioning outcomes not considered in this review CDRS subscale: attention at 12 weeks and 9 months on a scale from 0 to 37 with higher values indicating benefit CDRS subscale: initiation/perseveration at 12 weeks and 9 months on a scale from 0 to 37 with higher values indicating benefit CDRS subscale: construction at 12 weeks and 9 months on a scale from 0 to 6 with higher values indicating benefit CDRS subscale: conceptualisation at 12 weeks and 9 months on a scale from 0 to 39 with higher values indicating benefit CDRS subscale: memory at 12 weeks and 9 months on a scale from 0 to 25 with higher values indicating benefit
Notes	Although Kwok 2013a measured global cognitive function at 9 months of follow‐up, they did not report data for the entire study population
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Judgement: method of allocation not reported Quote(s): "single‐blind randomized placebo‐controlled trial"
Allocation concealment (selection bias)	Unclear risk	Judgement: method of allocation concealment not reported Quote(s): none
Blinding of participants (performance bias)	High risk	Judgement: blinding not feasible Quote(s): none
Blinding of physicians / personnel	High risk	Judgement: blinding not feasible Quote(s): none
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Judgement: outcome assessor explicitly reported to be blind Quote(s): "trained research assistant who was blind to treatment assignment"
Incomplete outcome data (attrition bias) All outcomes	Low risk	Judgement: 103 out of 111 (93%) randomised in experimental group were analysed, and 103 out of 112 (92%) randomised in control group were analysed. Fraction with missing data below 10% Quote(s): none; "the authors did not mention analyses to be in line with intent‐to‐treat principles, neither did they report on imputation techniques"
Selective reporting (reporting bias)	High risk	Judgement: incomplete reporting of non‐significant outcome data for the overall group. For example, outcome data for the CDRS total score were not abstractable for the overall group but were reported for subgroups with low, moderate, or high educational baseline values
Other bias	Low risk	Judgement: none detected