Dabelko‐Schoeny 2014.

Methods	Randomised cross‐over trial Setting: ADS centre in Mid‐West metropolitan area of the US
Participants	Number of participants: 16 People with Alzheimer's disease. About 1/3 participants relied on wheelchairs for mobility.
Interventions	Intervention: equine‐assisted therapy, which included grooming and interaction with the horses, followed by painting and washing the horses, and ended by feeding the horses. 4 therapy horses aged 12–22 years were used. The intervention took place 1 day per week for 4 weeks. Control: standard care, which included crafts, rest periods, exercise, or discussion groups. After 4 weeks, the control group received equine‐assisted therapy while the group that received this intervention earlier served as controls with standard care as mentioned. Sessions facilitated by equine‐assisted learning certified and horse‐handler staff from an equine education centre.
Outcomes	Behaviour and Affect (modified Philadelphia Geriatrics Centre Affect Rating Scale), disruptive behaviours (Modified NHBPS; 0–88, higher score indicates worse behaviour), and salivary cortisol concentrations. Outcomes assessed 4 weeks after commencement of intervention or control.
Notes	Among the outcomes reported, only disruptive behaviours (Modified NHBPS) were reported separately for each phase, although no paired data were extractable. We evaluated the impact of excluding this study via sensitivity analyses, as reported in the 'Effects of intervention' under the outcome of 'Behaviour'. Study funded by a personal donation, as stated in the acknowledgement: "This work was supported by a generous donation to The Ohio State University College of Veterinary Medicine by Mr. Duncan Alexander."
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Methods, design: quote: "Participants: once the pool of participants were identified, each individual was randomly assigned to either the first or second intervention period group using a computer‐generated list of random numbers."
Allocation concealment (selection bias)	Unclear risk	Methods, design: quote: "In this design, one randomly selected group received the intervention while the second group served as the comparison group." There was no further information on sequence generation and allocation to enable a meaningful assessment on the relationship between sequence generation and allocation. There were some imbalance in certain baseline characteristics of the allocated group, including a higher proportion of females, a higher score in MMSE and a lower proportion of those with instrumental assistance in daily living in the group that received equine‐assisted therapy first. However, it is unclear whether such differences would affect the outcome and in which direction, especially in view of the cross‐over nature of the study.
Blinding of participants and personnel (performance bias) All outcomes	High risk	Not stated but blinding was highly unlikely as 1 group received equine‐assisted therapy while another group did not.
Blinding of outcome assessment (detection bias) All outcomes	High risk	Not clearly stated, but the day centre staff and researchers who obtained the outcome information were highly unlikely to have been blinded, as the timing of the outcome assessment included the period when participants were receiving either equine‐assisted therapy or standard care.
Incomplete outcome data (attrition bias) All outcomes	Low risk	It appeared that all 16 participants initially recruited completed the study.
Selective reporting (reporting bias)	High risk	It appeared that the prespecified outcomes of behaviours and affect, disruptive behaviours, and salivary cortisol were reported in the results (although there was no study protocol available for confirmation), but only the Modified NHBPS was reported in sufficient detail for meta‐analysis.
Other bias	High risk	Additional domains for cross‐over trials Was the use of cross‐over design appropriate? Low risk, as the intervention evaluated appeared to produce transient change (if any) in the outcomes selected for this study, in a chronic and non‐rapid changing condition such as Alzheimer's disease, we considered the use of cross‐over trials appropriate. Can it be assumed that the trial was not biased from carry‐over effects? Unclear risk, while salivary cortisol level appeared free of major carry‐over effect, we were unclear whether the behavioural aspects evaluated were free from carry‐over effects. Were unbiased data (e.g. data from both periods of the trial, data with removal of dropout from any one period) presented? High risk, only data from NHBPS were reported in separate phases. Based on the risk of bias judgement given in the domains above, we accorded the study an overall high risk of bias in the additional domains specific to cross‐over trials. In accordance with our predefined strategy in handling the unit of analyses issues in cross‐over trials, as detailed under Unit of analysis issues, we would only have used data from the first phase before cross‐over took place if available. However, only NHBPS data, reported in separate phases, were available for meta‐analysis.