Performance of health status measures with a pen based personal digital assistant

Background: Increasing use of self reported health status in clinical practice and research, as well as patient appreciation of monitoring fluctuations of health over time, suggest a need for more frequent collection of data. Electronic use of health status measures in the follow up of patients is a possible way to achieve this. Objective: To compare self reported health status measures in a personal digital assistant (PDA) version and a paper/pencil version for test - retest reliability, agreement between scores, and feasibility. Methods: 30 patients with stable rheumatoid arthritis ( mean age 61.6 years, range 49.8 to 70.0; mean disease duration, 16.7 years; 63% female; 67% rheumatoid factor positive; 46.6% on disease modifying antirheumatic drugs) completed self reported health status measures ( pain, fatigue, and global health on visual analogue scales ( VAS), rheumatoid arthritis disease activity index, modified health assessment questionnaire, SF-36) in a conventional paper based questionnaire version and on a PDA ( HP iPAQ, model h5450). Completion was repeated after five to seven days. Results: Test - retest reliability was similar, as evaluated by the Bland - Altman approach, the coefficient of variation, and intraclass correlation coefficients. The scores showed acceptable agreement, but with a slight tendency to higher scores on VAS with the PDA than the paper/pencil version. No significant differences were seen for measures of feasibility ( time to complete, satisfaction score), but 65.5% preferred PDA, 20.7% preferred paper, and 13.8% had no preference. Conclusions: The clinimetric performance of paper/pencil versions of self reported health status measures was similar to an electronic version, using an inexpensive PDA.