Wolfe F, Ablin J, Baker JF, et al. - Given the presence of differences in studies assessing the relation of fibromyalgia (FM) and widespread pain (WSP) to mortality concerning the presence or absence of an association and the extent of cause-specific mortality and lack of inquiry in these studies concerning either the definitions of FM and WSP that associate with mortality or FM mortality in other diseases, researchers here focussed on these issues and the meaning of mortality in patients with FM. They studied 35,248 rheumatic disease patients using Cox regression with up to 16 years of mortality follow-up in all patients and separately in those with diagnoses of rheumatoid arthritis (RA) (N = 26,458), non-inflammatory rheumatic disorders (NIRMD) (N = 5,167) and clinically diagnosed FM (N = 3,659). In models adjusted for age and gender as well as in models that included a full range of covariates, including comorbid disease and functional status, 2016 FM criteria and other FM and WSP criteria were applied. The degree of explained of variance was determined as a measure of predictive ability. Positive correlations were observed between al`l definitions of FM and WSP and all-cause mortality; relative risks (RR)s varied from 1.19 (95%CI 1.15–1.24) for American College of Rheumatology (ACR) 1990 WSP to 1.38 (1.31–1.46) in age and gender adjusted revised 2016 criteria (FM 2016). Outcomes suggest a weak correlation of FM with mortality within all criteria definitions of FM and WSP examined (3.4% of explained variance), and across all diseases (RA, NIRMD, clinical FM) equally. Mortality outcomes differed with clinical and criteria-defined FM. No evidence was gained supporting a positive correlation of cancer and FM or WSP.