Objectives: A randomized trial to compare two levels of an intervention (full versus brief) for use by primary health-care professionals with family members affected by the problematic drug or alcohol use of a close relative.
Design: A prospective cluster randomized comparative trial of the two interventions.
Setting: A total of 136 primary care practices in two study areas within the West Midlands and the South West regions of England.
Participants: A total of 143 family members affected by the alcohol or drug problem of a relative were recruited into the study by primary health-care professionals. All recruited family members were seen on at least one occasion by the professional delivering the intervention and 129 (90 %) were followed-up at 12 weeks.
Main outcome measures: Two validated and standardized self-completion questionnaires measuring physical and psychological symptoms of stress (Symptom Rating Test) and behavioural coping (Coping Questionnaire) experienced by the family members. It was predicted that the full intervention would show increased reduction in both symptoms and coping when compared to the brief intervention.
Results: The primary analysis adjusted for clustering, baseline symptoms and stratifying variables (location and professional group) showed that there were no significant differences between the two trial arms. The symptom score at follow-up was 0.23 [95% confidence interval (CI): -3.65, +4.06] higher in the full intervention arm than in the brief intervention arm, and the coping score at follow-up was 0.12 (95% CI: -5.12, +5.36) higher in the full intervention arm than in the brief intervention arm.
Conclusions: A well-constructed self-help manual delivered by a primary care professional may be as effective for family members as several face-to-face sessions with the professional.