Development of a pictorial scale of pain intensity for patients with communication impairments: initial validation in a general population.

This study evaluated a new six-point ordinal scale for measuring pain intensity. Seventy-two participants aged between 23 and 87 years rated the intensity of 'present pain' as well as remembered episodes of 'severe' and 'mild' pain on the scale of pain intensity (SPIN), a 10 cm visual analogue scale (VAS) and a 0-10 numeric scale, in random order. Retesting followed an intervening assessment. Participants' comments on the scales were analysed thematically. Spearman's correlation between scales all exceeded 0.78 (p<O.O01). Test-retest of the SPIN gave percentage agreements (weighted kappa) of present pain 69% (0.83), severe pain 94% (0.94) and mild pain 83% (0.85). Most participants preferred using an ordinal scale to the continuous VAS. Some found numbers easier to use whereas others found the SPIN more helpful. We conclude that the SPIN provides a valid measure of pain intensity in patients fully able to communicate their views and experiences. Investigation in patients with cognitive or communication impairments is now required.