Olsen 2016a.

Methods	Cluster‐RCT Setting: 16 adapted day‐care centres for home‐dwelling people with dementia in the Norwegian counties of Østfold, Vestfold, Oslo, and Akershus, Norway
Participants	Mean number of people per cluster: 5 (each cluster asked to recruit 5–8 initially)) Number of participants: 80 in total; 42 in intervention group; 38 in control group Inclusion criteria: aged ≥ 65 years, diagnosis of dementia or a cognitive deficit measured as an MMSE score < 25. Exclusion criteria: people with a fear of dogs or with a dog allergy.
Interventions	Intervention: 30‐minute sessions of AAT in groups of 3–7 participants twice per week for 12 weeks led by a qualified dog handler. Protocol was followed to ensure consistency between the intervention sessions held in the day‐care centres. Intervention had a standardised, strict design, despite 1 study objective being to see whether it was possible to measure effects when AAT occurred in a realistic setting with a representative sample of participants and different dog teams. Since the main aim of the study was to see whether interventions with a dog would have an impact on participants' balance, the protocol was designed with that in mind. For each session, the participants were randomly seated in a semi‐circle, and the dog handler moved around the group so that each participant was able to greet the dog and feed it treats. Next, the handler organised different activities such as petting, brushing, or feeding the dog a treat, or throwing a toy for the dog to fetch. No specific mention on formal training of the facilitators on the use of therapy animal. Duration of intervention: 12 weeks. Control: no AAT
Outcomes	Balance (BBS; 0–56, higher score indicates better balance) and quality of life (QUALID; 12–45, higher score indicates poorer quality of life) Measurements at baseline (T0), end of intervention period (T1), and 3 months after the completion of the 12‐week intervention (T2).
Notes	Authors also performed change measure from T0 to T1 and from T1 to T2, and stated that there was statistically significant improvement in BBS from T0 to T1 but not from T1 to T2. We have decided to only report end scores at T1 and T2 as we considered the difference in score at baseline between AAT and control, although statistically significant, was modest (mean difference of 3.76 out of a total score of 56) and not clinically important, with emphasis on end score at T2 after 3 months as the main outcome. The study was supported by university research grant and institute's internal funding, as stated in the finance disclosure: "The project is funded by grant nr. 217516 from the Oslofjordfondet and RFF Hovedstaden, NMBU and Cooperating partners (The Norwegian Centre of Anthrozoology, Buskerud and Vestfold University College, Centre for Development of Institutional and Home Care Services in Vestfold, Nøtterøy municipality). Cooperating partners supported the project with internal financing." Although this study appeared similar to Olsen 2016b, we did not have sufficient evidence to suggest that they were the same study with the same, or overlapping, participants, as the setting of the studies differed (this study enrolled home‐dwelling people attending day‐care centres, while Olsen 2016b enrolled nursing home residents), and they were registered as two separate studies in ClinicalTrial.gov. We have written to the main author for confirmation with no reply. Therefore, we decided to consider these as 2 separate, but possibly related, studies, and made corresponding notes as appropriate in our report of the results and Table 1.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Materials and methods: quote: "After recruitment, each day‐care center was randomized, by computerized random numbers at Uni Helse in Bergen, to either animal‐assisted activity with a dog (AAA) or to a control group."
Allocation concealment (selection bias)	Unclear risk	Although the statement above suggests that randomisation was probably performed centrally, there was no clear statement to confirm the independence of allocation from randomisation. In terms of baseline characteristics, other than a higher proportion of participants in the AAT group who used rollator (14 in AAT group vs 5 in control group) among other types of walking aids, there were no marked differences in the baseline characteristics between groups. We are uncertain on the overall impact of the higher proportion of rollator users in the AAT group on the outcome.
Blinding of participants and personnel (performance bias) All outcomes	High risk	Although not clearly stated, blinding was highly unlikely as 1 group received AAT while the other group did not.
Blinding of outcome assessment (detection bias) All outcomes	High risk	Methods, authors stated that the outcomes were assessed by "pre‐trained health care workers working at the day‐care centres" who most likely knew the allocation status of the participants. This is confirmed in the discussion: "The assessments were not blind, which with QUALID is impossible because of the required profound knowledge of the person."
Incomplete outcome data (attrition bias) All outcomes	High risk	Data from 21/80 (26.3%) participants were missing for BBS, while 2/80 (2.5%) were missing for QUALID score. The number of participants with missing data per group was not stated. Missing data were imputed. Based on the high absolute proportion of missing data for BBS, we accorded the study high risk for this domain.
Selective reporting (reporting bias)	Low risk	The 2 major outcomes prespecified in the trial registration record of this study (NCT02008630), namely balance and quality of life, were reported in sufficient details in the results.
Other bias	Unclear risk	Additional domains for cluster‐RCT. Recruitment bias: low risk, as no new participants were recruited into each cluster after randomisation. Baseline imbalance: unclear risk, although most demographic characteristics were similar between groups, the proportion that used walking aids were significantly different between the groups, with clearly more in control group not needing a walking aid and using walking stick, and clearly more in the intervention group using rollator. Nonetheless, it was not clear which overall direction the differences would bias the results towards. Loss of clusters: low risk, as shown in figure 1, there was no loss of clusters throughout the trial. Incorrect analysis: low risk, the authors took clustering into account in their analyses, as shown in the statements below. Materials and methods, Analyses of effects, paragraph 2: "A mixed model was used to investigate changes over time (T1 and T2) and differences between the groups (intervention and control group) … 'Groups' was included as fixed effect, and day‐care center within group was included as random effect." Comparability with individually randomised trials: unclear risk, as it was unclear whether there was any 'herd effect' in the use of AAT to improve the outcomes collectively in a day‐care centre, hence the difference in the effects of the AAT intervention when applied to all residents in a day‐care centre vs when some in the centre receive AAT while others did not. Overall, due to the unclear risks in 2 domains in the risk of bias area of cluster‐RCT, the study was rated at unclear risk in the domains specific to cluster‐RCT.