Effectiveness of a Psychoeducational Intervention on Myositis Patients' Quality of Life and Well-Being: A Randomized Controlled Trial

Materials and methods The Medical Research Ethics Committee and Research Projects Commission of the Vall d'Hebron University Hospital approved the project [number PR(AG)398/2022]. Attending to circumstances of the intervention and to enhance methodological quality, the study is designed as a randomized controlled trial with a control group and an experimental group, with two measurement time points. The CONSORT statement is followed to conduct the study.

Participants Patients are eligible for enrolment based on the following inclusion criteria.

1. a definite diagnosis of myositis according to the International Myositis Classification Criteria (score > 90) and
2. the ability to understand the purpose and procedures of the study, and motivation and agreement to participate.

A large cohort of adult myositis patients attending our outpatient clinic (Systemic Autoimmune Diseases Unit of Vall d'Hebron General Hospital, Barcelona, Spain) are potential candidates for the study. Vall d'Hebron General Hospital is a 700-bed referral and teaching hospital for a catchment population of nearly 450,000 inhabitants. Virtually all patients from the area with suspected myositis are referred to Vall d'Hebron, where they are diagnosed, treated, and followed up, whether the disease is severe or not.

All candidate patients are contacted by telephone and invited to participate in the study during a 2-month period. Patients are excluded from the study if they do not meet the diagnostic criteria or are hospitalized for an extremely severe illness, declined to participate, required excessive convincing for participation, deemed likely to play a disruptive role in the group, are younger than 18 years, had severe psychiatric conditions, or had an unfavourable short-term prognosis.