Identifying a long-term/chronic, non-cancer pain population using a one-dimensional verbal pain rating scale: an epidemiological study.

The usefulness of the verbal pain rating scale (VRS) included in the Short Form 36 (SF-36) in identifying characteristics of long-term pain conditions, was analyzed using data from the 1994 Danish Health and Morbidity Survey. Based on the rating of pain intensity during a 4-week recall period the respondents were categorized into three groups: a high pain group (HPG) consisting of persons reporting moderate to severe pain (VRS 4-6), a low pain group (LPG) who rated their pain as very mild or mild (VRS 2-3), and a control group (CG) with no pain (VRS 1). The investigated sample comprised 3992 persons (HPG=563 persons, LPG=1714, and CG=1715 persons). Older age, educational level (< 10 years of schooling), cohabitation status (divorce/separation), and moderate to severe physical job strain were found to be significant risk factors for reporting high pain intensity (HPG). Only minor differences were observed between the LPG and CG. The proportion of respondents with good perceived health was significantly lower in the HPG compared with LPG and CG. The dominant complaints in the HPG were related to the musculoskeletal system. During a 14-day period prior to the interview persons in the HPG had a mean of 1.19 working days lost due to illness compared with a mean of 0.2 for the LPG and CG. Analyzing the use of medical services during the year before the interview, persons belonging to the HPG had an average number of nine contacts to general practitioners and specialized doctors in the primary sector as compared to six for the LPG and four for the CG. Mean numbers of hospital admissions were 0.29 for the HPG, 0.15 for the LPG and 0.10 for the CG. Mean numbers of in-hospital days were 1.60, 0.80, and 0.43 for the HPG, LPG, and CG, respectively. Our study suggest that one-dimensional pain intensity scoring using a simple VRS-scoring is useful as a screening instrument for identifying persons suffering from pain of a more complex nature. High intensity scores on a pain intensity scale should indicate to the investigator that she/he might be facing a person whose pain complaints and behavior are not only based on a pure biological background, but in whom also severe psychological and social problems might be present.