An open-source, self-explanatory touch screen in routine care. Validity of filling in the Bath measures on Ankylosing Spondylitis Disease Activity Index, Function Index, the Health Assessment Questionnaire and Visual Analogue Scales in comparison with paper versions

Objective. The Danish DANBIO registry has developed open-source software for touch screens in the waiting room. The objective was to assess the validity of outcomes from self-explanatory patient questionnaires on touch screen in comparison with the traditional paper form in routine clinical care. Methods. Fifty-two AS patients and 59 RA patients completed Visual Analogue Scales (VASs) for pain, fatigue and global health, and Bath measures on Ankylosing Spondylitis Disease Activity Index (BASDAI) and Function Index (BASFI) (AS patients) or HAQs (RA patients) on touch screen and paper form in random order with a 1-h interval. Intra-class correlation coefficients (ICCs), 95% CIs and smallest detectable differences (SDDs) were calculated. Results. ICC ranged from 0.922 to 0.988 (P < 0.001). The mean differences (95% CI) were: BASDAI [-0.5 (-14.5, 13.5) mm]; BASFI [-1.1 (-10.6, 8.4) mm]; Item 5 [-1.7 (-23.6, 20.2) mm] and Item 6 [-0.7 (-14.7, 13.3) mm] from BASDAI; HAQ score [0.023 (-0.183, 0.229)]. For VAS -0.4 to -2.8 mm (no significance for all except VAS global and VAS fatigue in RA). SDD for BASDAI was 14.0 mm; BASFI 9.5 mm; Item 5 21.8 mm; Item 6 14.0 mm; HAQ 0.206; VAS 11.1-18.8 mm. Conclusions. Self-explanatory touch screens based on the DANBIO open-source system generates valid results in AS and RA patients on completion of BASDAI, BASFI, HAQ and VAS scores for pain, fatigue and global health when compared with the traditional paper form. Implementation of touch screens in clinical practice is feasible and patients need no instruction.