The Whole Systems Demonstrator (WSD) trial found that telehealth was associated with lower rates of emergency hospital admissions than usual care amongst patients with long-term health conditions. However, admission rates increased amongst the control group shortly after recruitment, leading to concerns about whether the estimated treatment effect reflected telehealth, or was an artefact of the trial. We have conducted further analyses of this issue, and summarise these below as they have implications for the generalisability of the WSD trial. Attention to generalisability is important because trials typically estimate treatment effects for the sample of individuals recruited, rather than for the whole target population. The two might differ due to differences in the patients, centres or treatments.
