Reliability and validity of the pain threshold measurement with the Dolorímetro Electrónico Portátil® (Portable Electronic Dolorimeter) in healthy individuals and patients with musculoskeletal pain

摘要

Aims: The objective of this study was to establish the reliability and validity of the measurement of the pressure pain threshold using the Dolorímetro Electrónico Portátil (Portable Electronic Dolorimeter) (DEP®) in persons without pain (12 men and 18 women) and in patients with chronic pain (16 women with systemic lupus erythematosus, 16 women with fibromyalgia and 15 women with rheumatoid arthritis).Methods: The assessment of the pressure pain threshold using the DEP® was done over three sessions with a 15 minute interval between the first and second session, and a 7 day interval between the second and third session. Each session comprised two trials in which 24 pressure points were evaluated.Results: Regarding reliability, high correlation coefficients were obtained in the three temporal conditions (within sessions without interval: ρ = 0.922, p < 0.001; inmediate, or brief interval between sessions (15 min): ρ = 0.932, p < 0.001; demorated, or long interval between sessions (7 days): ρ = 0.896, p < 0.001), indicating excellent reliability for the measurement with the DEP®, and also when discriminating between the groups with and without pain. To test validity, criterion instruments such as a pain sensitivity selfreport administered before and after assessment with the DEP® (Pre and Post conditions, respectively) and a medical report about the sensitivity of the patients were used. Healthy persons showed higher correlation coefficients between the Post condition self-report and assessment with the DEP®. Participants with pain showed significant correlations between the Pre condition self-report and the medical report.Conclusions: The study results show as a whole the appropiate psychometric properties of the DEP®.