Among all respondents and women only, two types of traumatic experiences—sexual assault/abuse and physical assault/abuse—were associated with a fibromyalgia diagnosis, whereas life-threatening trauma, emotional abuse/neglect, and major life stress were not. The highest odds ratios in both models were those for sexual and physical assault/abuse. Traumatic stress bore the stronger relationship to fibromyalgia compared to major life stress (as operationalized in the present study), and among the traumatic stressors, the two personal/physical contact types (sexual and physical) had stronger relationships to fibromyalgia. Our data are consistent with studies showing that the consequences of trauma may be expressed as chronic musculoskeletal pain, fatigue as well as sleep and mood disturbances, all cardinal features of fibromyalgia (Crofford, 2007
; Bradley, 2008
; Schweinhardt et al., 2008
; Wolfe and Rasker, 2008
). It is important to note, however, that although the trauma versus major life stress distinction we have made is defensible, and to some extent, conventional, there is not universal agreement on the appropriateness of this distinction (Shalev, 1996
A physician-given fibromyalgia diagnosis was reported by 3.7% of the sample, 4.8% of the women and 1.3% of men. The figures for White individuals, which are more comparable to the widely-cited prevalence estimates (Wolfe et al., 1995
) were 4.4% total, 6.2% women, and 1.5% men, all higher than the Wolfe and colleagues’ (1995)
, 2.0% total, 3.4% women, and 0.5% men. The figures reported herein likely are higher for two reasons: (a) they reflect fibromyalgia in one’s lifetime, not point-in-time and (b) our sample was older (slightly more than three-quarters of our subjects were 50 years and older versus approximately half of Wolfe and colleagues’ normative sample). Also, relatively high percentages of our sample had experienced personal trauma in their lifetime () (which, in turn, was associated with fibromyalgia), but we do not have comparative trauma/stress data for the normative sample.
The bulk of the research on fibromyalgia has evaluated women only. In the present study, with the exception of percentages reporting fibromyalgia, the differences between women and men were unremarkable with respect to fibromyalgia symptoms and comorbidities (). Regarding trauma/major life stressors (), men had experienced more life-threatening trauma, whereas women had experienced more sexual assault/abuse. Among men, however, differences in traumatic and major life stress between those in the fibromyalgia versus no fibromyalgia subgroups were not statistically significant. Given the small number of men with fibromyalgia (43 in the total sample), however, we have only modest confidence in the stability/interpretability of these patterns.
Race/ethnicity generally is not listed as a risk factor for fibromyalgia (Chakrabarty and Zoorob, 2007
). In the present study, however, fibromyalgia rates were considerably lower among non-White respondents. Non-White subjects were on average younger (57.9 versus 63.8 years); specifically, 30.3% of the non-Whites compared to 18.5% of the Whites were under age 50. With respect to education, individuals with master’s or doctoral degrees were much less likely to report fibromyalgia than were those with less education.
In the present sample, the odds of self-reporting a fibromyalgia diagnosis increased until approximately age 63 and declined thereafter, whereas Wolfe and colleagues (1995)
reported rate increases through age 79 as did Branco and colleagues (2009)
. In the latter study, however, with data from France, Portugal, Spain, Germany, and Italy, the authors also reported a curvilinear relationship between age and fibromyalgia. This curvilinear relationship appears quite consistently across studies, although the age that the decrease begins differs. In two studies, for example, the decrease occurred in the 70s (Wolfe et al., 1995
; Branco et al., 2009
), whereas in four studies, the decrease in fibromyalgia reports occurred in the 60s, just after midlife, which is similar to our data (Makela and Heliovaara, 1991
; White et al., 1999
; Carmona et al., 2001
; Senna et al., 2004
). Although the reason for the drop off in fibromyalgia reports with age is unclear (may be decreased incidences or inadequate diagnoses), the curvilinear relationship shown here is consistent with other samples.
4.1 Study limits
Chief among our study limits are fibromyalgia diagnosis, trauma and major life stressor self-reports. Although subjects were asked whether a physician had given them a fibromyalgia diagnosis (life-to-date), we have no data on how these diagnoses were made. Moreover, this is an older sample, and the modern term, fibromyalgia, was not introduced until the mid-1970s, and it was not until the 1980s and 1990s that physicians evaluated fibromyalgia patients more consistently. As such, we cannot be certain that our figures are accurate, and if not, whether in fact they are low. Our data provide, at least, moderate support for the validity of this diagnosis, as the rates that we report are reasonable, given (a) sample age and composition, (b) the rate for women was higher than that of men, and (c) individuals reporting a fibromyalgia diagnosis had more pain, less energy, worse sleep, more/severe depressive symptoms, and life-to-date diagnoses of depression and irritable bowel syndrome.
Also, the trauma/stressor variables all are self-report; none of these experiences were corroborated. Moreover there is the potential for systematic reporting bias; specifically we do not know whether fibromyalgia patients under-report (because they are attending to physical illness causes) or over-report (because they are seeking an illness cause) physical and sexual abuse. The self report bias, however, likely creates an underreporting of a socially unacceptable experience, such as child abuse or violence exposure (Ruiz-Perez et al., 2009
), which may have weakened our associations.
Moreover, we were not able to make a distinction between acute versus chronic stress. Acute versus chronic stress can be a particularly important distinction to make, and it is especially important in studies of the consequences of sexual and physical abuse (Herman, 1992
; Ruiz-Perez, et al., 2009
). Other potentially useful distinctions that we were unable to make were early versus late-life trauma/stress and individual perceptions, such as the degrees of predictability and control for given experiences or the extent to which stressful/traumatic experiences had affected individuals’ lives. We also had no data on whom, if anyone had been diagnosed with PTSD following a traumatic experience.
Finally, our sample is unique. Almost all (99%), for example, were members of the Seventh-day Adventist Church and Blacks were oversampled. How sample uniqueness may have affected our results is not obvious; nevertheless, one must be cautious about generalizing to other groups.
Despite these limits, it seems reasonable to conclude that trauma—particularly physical and sexual assault/abuse—are associated with self-reporting a physician-given fibromyalgia diagnosis. We recommend that researchers continue to invest in trauma/stress-fibromyalgia research. This work, coupled with genetic and biomarker studies (Bradley, 2008
; Dadabhoy et al., 2008
), could lead to a better understanding of fibromyalgia, and importantly, more effective treatment (Abeles et al., 2008
). We recommend, too, that researchers study trauma and stress and fibromyalgia in men and racial/ethnic minority groups.