Studies eligible for meta-analysis of CWP and mortality
| Study (location) | Sampling frame | Pain phenotype | Pain phenotype prevalence (%) | Deaths (n)/Study (n) | Follow-up (years) |
| Andersson15 | Random sample in two municipalities | >4 pain locations representing both the upper and lower body and including axial pain | 9.4 | 189/1609 | 14 |
| Åsberg et al11 | All inhabitants of one county | CWP modified* definition in ACR 1990 criteria of FM | 23.1 | 12 521/65 026 | 14 |
| Macfarlane et al1 | Persons registered with GP in two areas | WP according to definition in ACR 1990 criteria of FM | 15.3 | 654/6569 | 8 |
| Macfarlane et al (current study) | Persons aged 40–69 registered with GP in 22 areas | ‘Pain all over the body’ lasting ≥3 months | 1.4 | 12 799/288 848 | 7 |
| McBeth et al3 | Age-stratified and sex-stratified sample from 3 GPs in one region | WP definition in ACR 1990 criteria of FM | 16.9 | 1017/4344 | 8 |
| Nitter and Forseth14 | Women born in 1940–1969 in one town | Pain in muscles and joints and back, or pain in whole body, lasting ≥3 months | 12.9 | 89/2038 | 18 |
*There was no requirement to have pain on both sides of the body.
ACR, American College of Rheumatology; CWP, chronic widespread pain; GP, general practitioner; FM,fibromyalgia; WP, widespread pain.