Paper versus electronic rating scales for pain assessment: a prospective, randomised, cross-over validation study with 200 chronic pain patients.
OBJECTIVE: Following the recent introduction of hand-held computers to be used by patients instead of conventional pencil-and-paper questionnaires, a validation study under 'real-life' conditions was conducted, in order to compare these two clinical instruments when used by chronic pain patients to describe their pain using visual and numerical rating scales. METHOD: Each of 200 chronic pain patients attending a single physician's practice was given two pain questionnaires to complete, one on paper and one on a hand-held computer; completion of these took place directly before and after consultation, in randomised order. The questions asked in the two questionnaires were identical: present pain, average pain, worst pain and those of the painDETECT questionnaire (the latter distinguishes characteristic symptoms of nociceptive pain). In accordance with standard practice, the paper questionnaire used numerical rating scales and the electronic one employed visual analogue scales, with or without a numerical indicator. RESULTS: Nearly all patients (99%) of the study population (58% female; aged 57+/-14 years) completed both questionnaires. In spite of the expected substantial intra-individual scatter, overall results from the two questionnaire types were highly consistent. Only a few differences of potential statistical significance (p<5%) were observed, and none were found that would have led to different interpretations. No difference was seen between results from the electronic visual analogue scales with and without a numerical indicator. CONCLUSION: Under conditions of routine clinical practice, the hand-held computer questionnaire can give results equivalent to those obtained with the conventional paper questionnaire.