The patient perspective workshops at the Outcome Measures in Rheumatology Clinical Trials have included daily measures of health status (patient diary) and use of electronic tools for data collection in the research agenda. The objective of this study was to compare daily and weekly registrations of self-reported health status measures between personal digital assistant (PDA) and paper-pencil (PP) format regarding scores, variation, and feasibility.
Thirty-eight patients with stable rheumatoid arthritis recorded their health status during 84 days in a repeated crossover design, using PDA or PP format during four 21-day periods. Visual analog scales (VAS) for pain, fatigue, and global disease and the Rheumatoid Arthritis Disease Activity Index were scored daily; the Short Form 36 and Modified Health Assessment Questionnaire were scored weekly.
The average scores and measures of variation of the 4 daily health status measures over 21 days did not differ significantly between PDA and PP formats in either of the 2 crossover periods. The values for the average range between the maximum and minimum values for daily measures were similar between the 2 formats, but showed considerable variation (e.g., range for pain VAS was 19-28 mm over each 21-day period). The time to complete the instruments was similar between the 2 formats. Missing daily data entries were generally low for both periods and somewhat higher for PDA. The majority of patients (82.9%) preferred using PDA.
Daily assessments with PDA may be efficiently used for frequent data collection because this format performs similarly to the traditional PP format.