Peretz 2011.

Methods	Design: 2‐arm RCT with factorial design Recruitment period: not reported No. of centres involved: 1 Unit of randomisation: individuals No. randomised: 155 Number of arms considered in this review: 2 Maximum trial duration: 3 months Funding by non‐profit organisation: none reported Funding by commercial organisation: NexSig Cognifit Publication status: full‐text report
Participants	Patient flow: 84 randomised, 84 described at baseline in experimental group; 71 randomized, 71 described at baseline in control group Number of females: 56 of 84 (67%) in experimental group 1; 40 of 71 (56%) in control group 1 Average age (SD): 68 (8.3) years in experimental group 1; 67 (7.2) years in control group 1 Average (SD) education: 14.6 (2.8) years in experimental group; 15.1 (3.6) years in control group Baseline cognitive function: MMSE 29.0 (SD 1.2) Selection criteria on cognition overall: healthy Ethnicity: not reported APOE: number of participants positive for APOE not reported
Interventions	Type of experimental intervention: computerised CT, individualised; treatment duration of 12 weeks; intervention provided as individual training, without supervision Details of experimental intervention: the personalised cognitive training programme selected for this study was the CogniFit Personal Coach. This programme’s training regimen is based on the results of a baseline cognitive evaluation called the Neuropsychological Examination–CogniFit Personal Coach Session duration: 20 to 30 minutes in experimental group Number of treatment sessions: 36 in experimental group Treatment frequency: 3/week in experimental group Maximum treatment duration in weeks: 12 in experimental group Type of control intervention: active computer; treatment duration of 12 weeks; intervention provided as individual training, without supervision Details of control intervention: "twelve classic computer games that significantly engage cognitive processing were selected to create the computer games program. This program shared several features with the personalized cognitive training program, including the baseline cognitive evaluation, a total of 24 sessions comprising 3 different tasks, and a similar graphic design (Appendix 2). However, it did not have the adaptive training features of the personalized cognitive training program" Session duration: 25 minutes in control group Number of treatment sessions: 36 in control group Treatment frequency: 3/week in control group Maximum treatment duration in weeks: 12 in control group
Outcomes	Cognitive functioning outcomes considered Global cognitive functioning measured with Overall score: NexAde battery at 3 months, on a scale from not reported to not reported with higher values indicating benefit Episodic memory measured with Memory recall at 3 months, on a scale from not reported to not reported with higher values indicating benefit Executive functioning measured with Executive functions at 3 months, on a scale from not reported to not reported with higher values indicating benefit Working memory measured with Visuospatial working memory at 3 months, on a scale from not reported to not reported with higher values indicating benefit Physical functioning outcome considered: none reported Quality of life outcome considered: none reported Safety outcome considered: none reported Depression outcome considered: none reported Other outcome data on cognitive functioning, not considered in our meta‐analyses Episodic memory measured with Memory recognition at 3 months, on a scale from not reported to not reported with higher values indicating benefit Episodic memory measured with Visuospatial learning at 3 months, on a scale from not reported to not reported with higher values indicating benefit Executive functioning measured with Focused attention at 3 months, on a scale from not reported to not reported with higher values indicating benefit Executive functioning measured with Mental flexibility at 3 months, on a scale from not reported to not reported with higher values indicating benefit Working memory measured with Sustained attention at 3 months, on a scale from not reported to not reported with higher values indicating benefit
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Judgement: adequate random sequence generation Quote(s): "random number generator"
Allocation concealment (selection bias)	Low risk	Judgement: adequate method of allocation concealment Quote(s): "encrypted codes"
Blinding of participants (performance bias)	High risk	Judgement: a large number of participants correctly identified their group assignment; this is assumed to be an indication of poor blinding of participants Quote(s): "..with investigators and participants being blind to group assignment. Participants received a CD containing either the cognitive training program or the computer games program. To preserve blindness, all CDs were labelled and packaged identically, and all graphics, fonts, opening screens, baseline evaluations and post‐training evaluations were identical on both CDs. Personnel were kept unaware of the participants’ group assignment, which was encrypted in the code number labels on the CDs"; ""Thirty‐six percent of the subjects correctly identified their group assignment (21% personalized cognitive training, 15% games)"
Blinding of personnel (performance bias)	Low risk	Judgement: adequate method of therapist blinding Quote(s): "..with investigators and participants being blind to group assignment. Participants received a CD containing either the cognitive training program or the computer games program. To preserve blindness, all CDs were labelled and packaged identically, and all graphics, fonts, opening screens, baseline evaluations and post‐training evaluations were identical on both CDs. Personnel were kept unaware of the participants’ group assignment, which was encrypted in the code number labels on the CDs"
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Judgement: not clearly reported if outcome assessors were blinded, but all personnel were likely kept blinded to treatment assignment Quote(s): "personnel were kept unaware of the participants’ group assignment, which was encrypted in the code number labels on the CDs"
Incomplete outcome data (attrition bias) All outcomes	High risk	Judgement: for the outcome episodic memory, 66 out of 84 (79%) randomised were analysed in experimental group, and 55 out of 71 (77%) randomised were analysed in control group. Statistical analyses were reported to be done according to the intent‐to‐treat principle. Although study authors state that they used an ITT, 18 participants in experimental group and 16 in control group did not complete the training and had no data available at baseline, follow‐up, or both Quote(s): "a total of 34 (22%) participants (18 in the cognitive training group and 16 in the computer games group) did not complete the training; the majority of those (n = 29) never began the home training"
Selective reporting (reporting bias)	Low risk	Judgement: all outcomes indicated in the methods section are reported in the results section
Other bias	Low risk	Judgement: no other apparent risks of bias