2. Summary of duration of interventions and timing of assessments.
| Study | Duration (weeks) | Session frequency (per week) | Total number of sessions | Session duration (minutes) | Total direct intervention (minutes) | Total direct intervention (hours) | Session format | Adherence rates | Fidelity measures |
| Beck 1988 | 6 (cognitive training) | 3 | 18 | Approx. 35 | Approx. 630 | Approx. 10.5 | Individual, with a research assistant | Not reported | Not reported |
| NA (control) | NA | NA | NA | NA | NA | NA | NA | NA | |
| Heiss 1993 | 24 (cognitive training) | 2 | 48 | 60 | 2880 | 48 | Individual | Not reported | Not reported |
| 24 (social support) | 1 | 24 | 60 | 1440 | 24 | Individual | Not reported | Not reported | |
| 24 (cognitive training+pyritinol) | 2 | 48 | 60 | 2880 | 48 | Individual | Not reported | Not reported | |
| 24 (cognitive training+phosphatidylserine) | 2 | 48 | 60 | 2880 | 48 | Individual | Not reported | Not reported | |
| Quayhagen 1995 | 12 (cognitive training) | 6 | 72 | 60 | 4320 | 72 | Individual | Not reported | Caregiver and care recipient were trained together in programme implementation techniques. Return demonstrations by caregivers were required to validate training |
| NA (passive control) | NA | NA | NA | NA | NA | NA | NA | NA | |
| 12 (active control) | Not reported | Not reported | Not reported | Not reported | Not reported | Not reported | Not reported | Caregiver and care recipient were trained together in programme implementation techniques. Return demonstrations by caregivers were required to validate training | |
| de Vreese 1998 | NA (cognitive training) | NA | NA | NA | NA | NA | NA | NA | NA |
| 12 (cognitive training+ChE‐I, after 12 weeks on drug) | 2 | 24 | 45 | 1080 | 18 | Individual | Not reported | Not reported | |
| 12 (placebo drug) | NA | NA | NA | NA | NA | NA | Not reported | Not reported | |
| 12 (AChE‐I, after 12 weeks on drug) | NA | NA | NA | NA | NA | NA | Not reported | Not reported | |
| Quayhagen 2000 | 8 (cognitive training) | 1 | 8 | 90 | 720 | 12 | Individual, with help from caregiver | Not reported | Ongoing monitoring of personnel performance to ensure uniformity and consistency of administration of assessments or interventions |
| 8 (dyadic counselling) | 1 | 8 | 90 | 720 | 12 | Dyad | Not reported | Ongoing monitoring of personnel performance to ensure uniformity and consistency of administration of assessments or interventions | |
| 8 (seminar groups) | 1 | 8 | 90 | 720 | 12 | Group | Not reported | Ongoing monitoring of personnel performance to ensure uniformity and consistency of administration of assessments or interventions | |
| 8 (daycare) | 7 | 8 | 240 | 1920 | 32 | Group | Not reported | Ongoing monitoring of personnel performance to ensure uniformity and consistency of administration of assessments or interventions | |
| NA (wait‐list control) | NA | NA | NA | NA | NA | NA | NA | NA | |
| Davis 2001 | 5 (cognitive training) | 1 | 5 | 60 | 300 | 5 | Individual | Not reported | Not reported |
| 5 (control) | 1 | 5 | 60 | 300 | 5 | Individual | Not reported | Not reported | |
| Koltai 2001 | 5 (cognitive training ‐ group) | 1 | 5 | 60 | 300 | 5 | Group | Not reported | Not reported |
| 6 (cognitive training ‐ individual) | 1 | 6 | Not reported | Not reported | Not reported | Individual | Not reported | Not reported | |
| NA (wait‐list control) | NA | NA | NA | NA | NA | NA | NA | NA | |
| Cahn‐Weiner 2003 | 6 (cognitive training) | 1 | 6 | Not reported | Not reported | Not reported | Group, with a clinical neuropsychologist | 1 participant did not complete the first session, and 2 participants did not complete the fourth session | "All sessions were identical for all participants, with the memory group instructor relying on a trainer's manual with scripts for how to present the information" |
| 6 (control) | 1 | 6 | 45 | 270 | 4.5 | Group, with a clinical neuropsychologist | 4 participants missed 1 session, and 1 participant missed 2 sessions | Not reported | |
| Galante 2007 | 4 (cognitive training) | 3 | 12 | 60 | 720 | 12 | Individual, with a neuropsychologist | Not reported | Not reported |
| 4 (control) | 3 | 12 | 60 | 720 | 12 | Individual, with a neuropsychologist | Not reported | Not reported | |
| Neely 2009 | 8 (cognitive training ‐ collaborative intervention) | 1 | 8 | 30 to 40 | Approx. 280 | Approx. 4.5 | Dyads, with a research assistant | Not reported | Not reported |
| 8 (cognitive training ‐ individual intervention) | 1 | 8 | 30 to 40 | Approx. 280 | Approx. 4.5 | Individual, with a research assistant | Not reported | Not reported | |
| NA (control group) | NA | NA | NA | NA | NA | NA | NA | NA | |
| Kawashima 2005 | 24 (cognitive training) | 2 to 6 | 48 to 144 | Approx. 20 | 960 to 2880 | 16 to 48 | Individual, with the possibility to ask staff members for advice | Not reported | Not reported |
| NA (control) | NA | NA | NA | NA | NA | NA | Not reported | Not reported | |
| Boller 2011 | 2 (cognitive training ‐ recollection) | 12 | 24 | 60 | 1440 | 24 | Not reported | Not reported | Not reported |
| 2 (cognitive training ‐ recognition) | 12 | 24 | 60 | 1440 | 24 | Not reported | Not reported | Not reported | |
| NA (control) | NA | NA | NA | NA | NA | NA | NA | NA | |
| Fernández‐Calvo 2011 | 12 (cognitive training ‐ BBA) | 3 | 36 | 60 | 2160 | 36 | Individual, with an OT and a psychologist | Not reported | Not reported |
| 12 (cognitive training ‐ IPP) | 3 | 36 | 60 | 2160 | 36 | Individual, with an OT and a psychologist | Not reported | Not reported | |
| NA (control) | NA | NA | NA | NA | NA | NA | NA | NA | |
| Goudour 2011 | 12 (cognitive training) | 1 | 12 | 50 | 600 | 10 | Individual, with a neuropsychologist. | Not reported | Not reported |
| 12 (control) | 1 | 12 | 50 | 600 | 10 | Individual, with a clinical psychologist. | Not reported | Not reported | |
| Jelcic 2012 | 12 (cognitive training) | 2 | 24 | 60 | 1440 | 24 | Group, provided by a neuropsychologist | Not reported | Not reported |
| 12 (control) | 2 | 24 | 60 | 1440 | 24 | Group, provided by a neuropsychologist | Not reported | Not reported | |
| Bergamaschi 2013 | 20 (cognitive training) | 5 | 100 | 120 | 12000 | 200 | Group, supervised by a neuropsychologist | Not reported | Not reported |
| 20 (control) | Presumed to be 5 | Not reported | Not reported | Not reported | Not reported | Group | Not reported | Not reported | |
| Lee 2013 | 6 (cognitive training ‐ CELP) | 2 | 12 | 30 | 360 | 6 | Individual, with a therapist | Not reported | Not reported |
| 6 (cognitive training ‐ TELP) | 2 | 12 | 30 | 360 | 6 | Individual, with a therapist | Not reported | Not reported | |
| 6 (active control) | 2 | 12 | 30 | 360 | 6 | Not reported | Not reported | Not reported | |
| Mapelli 2013 | 8 (cognitive training) | 5 | 40 | 60 | 2400 | 40 | With a therapist | Not reported | Not reported |
| 8 (control ‐ occupational therapy) | 5 | 40 | 60 | 2400 | 40 | Not reported | Not reported | Not reported | |
| NA (control ‐ usual care) | NA | NA | NA | NA | NA | NA | NA | NA | |
| Jelcic 2014 | 12 (cognitive training ‐ LSS‐tele) | 2 | 24 | 60 | 1440 | 24 | Small groups, provided by a therapist | Not reported | Not reported |
| 12 (cognitive training ‐ LSS‐direct) | 2 | 24 | 60 | 1440 | 24 | Small groups, provided by a therapist | Not reported | Not reported | |
| 12 (control) | 2 | 24 | 60 | 1440 | 24 | Small groups, provided by a therapist | Not reported | Not reported | |
| Quintana Hernandez 2014 | 104 (cognitive training) | 3 (IPP) | 288 | 90 | 25920 | 432 | Group, with a clinical psychologist | Not reported | Not reported |
| 104 (muscular relaxation) | 3 | 288 | 90 | 25920 | 432 | Group, with a clinical psychologist | Not reported | Not reported | |
| 104 (mindfulness) | 3 | 288 | 90 | 25920 | 432 | Group, with a clinical psychologist | Not reported | Not reported | |
| NA (passive control) | NA | NA | NA | NA | NA | NA | Not reported | Not reported | |
| Kim 2015 | 8 (cognitive training) | 1 | 8 | 60 | 480 | 8 | Individual and in a group | Not reported | Not reported |
| 8 (control) | 1 | 8 | 60 | 480 | 8 | Not reported | Not reported | Not reported | |
| Amieva 2016 | 96 (cognitive training) | 1 (during the first 3 months); 1 every 6 weeks (for the next 21 months) | 15 | 90 | 1350 | 22.5 | Groups | Not reported | Manual detailing the guidelines of each intervention was provided. Standardised procedures to guarantee homogeneity. Professional visits to therapists to ensure that interventions were applied in accordance with protocol |
| NA (control ‐ usual care) | NA | NA | NA | NA | NA | NA | NA | NA | |
| 96 (reminiscence therapy) | 1 (during the first 3 months); 1 every 6 weeks (for the next 21 months) | 15 | 90 | 1350 | 22.5 | Groups | Not reported | Manual detailing the guidelines of each intervention was provided. Standardised procedures to guarantee homogeneity. Professional visits to therapists to ensure that interventions were applied in accordance with protocol | |
| 96 (cognitive rehabilitation) | 1 (during the first 3 months); 1 every 6 weeks (for the next 21 months) | 15 | 90 | 1350 | 22.5 | Individual | Not reported | Manual detailing the guidelines of each intervention was provided. Standardised procedures to guarantee homogeneity. Professional visits to therapists to ensure that interventions were applied in accordance with protocol | |
| Cavallo 2016 | 12 (cognitive training) | 3 | 36 | 30 | 1080 | 18 | Individual, with a neuropsychologist | Not reported | Not reported |
| 12 (control) | 3 | 36 | 30 | 1080 | 18 | Individual, with a neuropsychologist | Not reported | Not reported | |
| Kao 2016 | 6 (cognitive training ‐ spaced retrieval) | 5 | 30 | 40 | 1200 | 20 | With a trainer | Not reported | Not reported |
| 6 (cognitive training ‐ spaced retrieval+Montessori activities) | 5 | 30 | 40 | 1200 | 20 | With a trainer | Not reported | Not reported | |
| na (control) | NA | NA | NA | NA | NA | NA | NA | NA | |
| Barban 2016 | 12 (cognitive training) | 2 | 24 | 60 | 1440 | 24 | Small groups, provided by a cognitive therapist | Not reported | Not reported |
| 12 (control) | NA | NA | NA | NA | NA | NA | NA | NA | |
| Giuli 2016 | 10 (cognitive training) | 1 | 10 | 45 | 450 | 7.5 | Individually, with homewrok exercises with support of a caregiver | Not reported | Not reported |
| 10 (control) | 1 | 10 | 45 | 450 | 7.5 | Not reported | Not reported | Not reported | |
| Venturelli 2016 | 12 (cognitive training) | 5 | 60 | 60 | 3600 | 60 | Performed in collaboration with patients’ caregivers | 85±12% in the CT group | Not reported |
| 12 (aerobic exercise) | 5 | 60 | 60 | 3600 | 60 | Performed in collaboration with patients’ caregivers | 78±8% in the AE group | Not reported | |
| 12 (aerobic exercise+cognitive training) | 5 | 60 | 60 | 3600 | 60 | Performed in collaboration with patients’ caregivers | 75±14% in the AE+CT group | Not reported | |
| NA (control) | NA | NA | NA | NA | NA | NA | NA | NA | |
| Tsantali 2017 | 16 (cognitive training) | 3 | 48 | 90 | 4320 | 72 | Individual with licensed psychologist | Not reported | Not reported |
| 16 (cognitive stimulation) | 3 | 48 | 90 | 4320 | 72 | Individual with licensed psychologist | Not reported | Not reported | |
| 16 (control) | NA | NA | NA | NA | NA | NA | Not reported | Not reported | |
| Brueggen 2017 | 12 (cognitive training) | 5 | 60 | Approx. 15 | Approx. 900 | Approx. 15 | Individual homework, with 1 meeting per month | 100% | Not reported |
| 12 (cognitive rehabilitation) | 2 | 24 | 60 | 1440 | 24 | Small group guided by a psychologist and an occupational therapist | 100% (including only the 8 participants who completed the study and were, therefore, analysed) | Intervention was based on the CORDIAL programme, via a manual‐guided approach | |
| Giovagnoli 2017 | 12 (cognitive training) | 2 | 24 | 45 | 1080 | 18 | Small groups of 3 participants, guided by a neuropsychologist | Not reported | CT was co‐ordinated by a neuropsychologist using defined materials and procedures |
| 12 (music therapy) | 2 | 24 | 45 | 1080 | 18 | Small groups of 3 participants, guided by a music therapist | Not reported | Active music therapy was provided by a music therapist. Sessions were videotaped and evaluated via a structured assessment | |
| 12 (neuroeducation) | 2 | 24 | 45 | 1080 | 18 | Small groups of 3 participants, co‐ordinated by a neurologist | Not reported | Not reported | |
| Serino 2017 | 3‐4 (VR group ‐ AD) | 3 | 10 | 20 | 200 | 3.3 | Individual with a neuropsychologist | Not reported | Not reported |
| 3‐4 (VR group ‐ normal ageing) | 3 | 10 | 20 | 200 | 3.3 | Individual with a neuropsychologist | Not reported | Not reported | |
| NA (control) | NA | NA | NA | NA | NA | Underwent traditional cognitive rehabilitative activities with the neuropsychological staff | NA | NA | |
| Trebbastoni 2018 | 24 (cognitive training) | 2 | 48 | 75 | 3600 | 60 | Group | 11% (6 participants) attended less than 80% of sessions of the first period of the study (from T0 to T1). In the second period, 72.9% attended more than 95% of sessions, 10,4% attended 90% to 95%, 4.2% attended 85% to 89%, and 12.5% attended 80% to 84% | Study authors reported high adherence to a strict protocol |
| NA | NA | NA | NA | NA | NA | NA | NA | NA | |
| Kallio 2018 | 12 (cognitive training) | 2 | 24 | 45 | 1080 | 18 | Group/individual when required | Mean attendance at 22 (92%) sessions | CT was administered by trained psychology students under the supervision of an experienced neuropsychologist |
| NA (control) | NA | NA | NA | NA | NA | NA | NA | NA |
AChEI: anti‐cholinesterase inhibitor.
AD: Alzheimer's disease.
BBA: Big Brain Academy.
CELP: computerised errorless learning‐based memory training programme.
ChEI: cholinesterase inhibitor.
CT: cognitive traininng.
IPP: Integrated Psychostimulation Program.
LSS: lexical‐semantic simulation.
NA: not applicable.
TELP: therapist‐led errorless programme.
VR: virtual reality.