Number of pain sites is associated with demographic, lifestyle, and health-related factors in the general population.

Research on widespread pain often relies upon case definitions bounded by duration limits or "cut-offs." In clinical reality, however, there are no natural cut-off points between localized and widespread pain. Rather, pain is best represented by a continuum of "widespreadness" from localized pain to pain spread across the body. The objective of this paper was to describe the number of pain sites (NPS) reported in a population study and its association with demographic, lifestyle, and health-related factors. Using a cross-sectional design, the Standardized Nordic Questionnaire was used to measure musculoskeletal pain among seven age groups in Ullensaker, Norway (n=2926). Results showed that women reported a higher mean NPS than men. A higher NPS was also found for individuals who were separated or divorced, undergoing rehabilitation, or who had a disability pension. Additionally, greater NPS was reported by smokers, individuals with less physical activity, and a higher BMI. A strong linear relationship was found between NPS and reduction in overall health, sleep quality, and psychological health. Results from a multivariate linear regression analysis showed that overall health, sleep quality, and gender demonstrated the strongest associations with increasing NPS, accounting for 31.4% of the variance. Our study indicates that the straightforward and simple method of counting the NPS could be important in managing the complex problem of musculoskeletal pain.