What do the numbers mean? Normative data in chronic pain measures.

Although self-reported measures play a central role in the assessment of pain and its treatment, it has long been recognized that interpretation of these measures is severely limited by the absence of normative data. Despite that, relatively few of the measures used in pain clinics or research studies have normative data for reference. Using a pain centre sample (n=6124), this paper describes the development of a normative dataset on a number of commonly used pain-related measures. The measures cover many of the key dimensions in pain assessment, including pain severity/quality, disability (physical functioning), and mood (emotional functioning). Measures of different cognitive and coping constructs are also included. Mean scores are reported for each measure according to age group, gender, pain site, as well as percentiles for different scores for patients with chronic low back pain. The potential uses for datasets of this type include the assessment and evaluation of individual cases, as well as the interpretation of published clinical trials. It is also argued that future systematic reviews of pain treatments should include consideration of such patient characteristics as pain levels, disability and mood in the studies reviewed rather than pain site and chronicity alone.