Effectiveness of an integrated telehealth service for patients with depression: a pragmatic randomised controlled trial of a complex intervention

Background Many countries are exploring the potential of telehealth interventions to manage the rising number of people with chronic disorders. However, evidence of the effectiveness of telehealth is ambiguous. Based on an evidence-based conceptual framework, we developed an integrated telehealth service (the Healthlines Service) for chronic disorders and assessed its effectiveness in patients with depression. We aimed to compare the Healthlines Depression Service plus usual care with usual care alone. Methods This study was a pragmatic, multicentre, randomised controlled trial with participants recruited from 43 general practices in three areas of England. To be eligible, participants needed to have access to the internet and email, a Patient Health Questionnaire 9 (PHQ-9) score of at least 10, and a confirmed diagnosis of depression. Participants were individually assigned (1:1) to either the Healthlines Depression Service plus usual care or usual care alone. Random assignment was done by use of a web-based automated randomisation system, stratified by site and minimised by practice and PHQ-9 score. Participants were aware of their allocation, but outcomes were analysed masked. The Healthlines Service consisted of regular telephone calls from non-clinical, trained health advisers who followed standardised scripts generated by interactive software. After an initial assessment and goal-setting telephone call, the advisers called each participant on six occasions over 4 months, and then made up to three more calls at intervals of roughly 2 months to provide reinforcement and to detect relapse. Advisers supported participants in the use of online resources (including computerised cognitive behavioural therapy) and sought to encourage healthier lifestyles, optimise medication, and improve treatment adherence. The primary outcome was the proportion of participants responding to the intervention (defined as PHQ-9