An internet survey of 2,596 people with fibromyalgia

Over the past 20 years fibromyalgia (FM) has emerged as a leading cause of office visits to rheumatologists, both in its primary form and as an accompaniment of other rheumatic disorders. Epidemiological studies report a FM prevalence of between 2 and 7% in most nations [1–12], with a female to male ratio of approximately 9:1. It is increasingly evident that FM represents a significant challenge in view of its high prevalence, frequent comorbidities, and frustration with current treatment modalities.

Patient self-report is increasingly used to assess the impact of rheumatic diseases and gain insight into their impact and to formulate new questions for investigation [13–16]. Study groups such as OMERACT (Outcome Measures in Rheumatology) use self-reported information as a preliminary step in the development of Delphi-based questionnaires with the eventual aim of defining optimal outcome measures for clinical trials [17].

The major aims of the current study were to conduct a large internet-based national survey of people with FM to determine: (1) demographics and sources of information about FM, (2) symptoms and functionality, (3) perceived aggravating factors, (4) perceived triggering events, (5) diagnosis and health care utilization, (6) management strategies, and (7) medication use.

The questionnaire was posted on the NFA's website on October 12, 2005. The survey was completed in a satisfactory manner by 2,569 people over the course of 3 days. The vast majority of responses were from the United States. There was at least 1 responder from each of the 50 States in the United States. In most States approximately 0.05% of the estimated female FM population responded to the survey -based on a conservative estimate FM prevalence of 3.5% in women and the 2002 National Census figures [19]. In addition, there were 46 responses from 12 other countries (Canada, United Kingdom, Ireland, Australia, New Zealand, Mexico, Germany, Holland, Bermuda, France, Israel, and Hungary).

Over the course of 3 days, over 2500 respondents completed a survey that was posted on the web site of the National Fibromyalgia Association. The demographics of the respondents to this survey revealed no particular surprises when compared to other epidemiologic studies and surveys [1–12]. The household income was similar to a previous survey of 537 FM patients in the San Diego, California [20]. In comparison to United States National Census figures, respondents were moderately overweight. Several other studies have reported obesity in FM [21–23] and weight reduction has been reported to provide improvement [24]. This concordance in demographic variables with other published FM studies suggests that the Questionnaire provided a reasonably representative measure.

It is difficult to make direct comparisons of health care utilization in this survey and other studies, as it is largely derived from patients with internet access in the United States. For example, a Canadian study reported annual visits to health care providers were 11.6, emergency room visits were 0.6, and hospital inpatient days or 2.1 [25]. However, the health care system in Canada is a nationalized service compared to the fee for service system in the United States. It is impossible to disentangle the availability and costs of services from service utilization.

Although a hallmark of FM is pain, the respondents listed morning stiffness, fatigue, and non-restorative sleep before pain, as comparable in severity. While morning stiffness is a common symptom in inflammatory rheumatic disorders [26, 27] it has only been mentioned in the occasional FM study [28, 29]. Morning stiffness is a characteristic feature of inflammatory arthritidies, where it has been defined as "slowness or difficulty moving the joints when getting out of bed or after staying in one position too long, which involves both sides of the body and gets better with movement" [30]. Whether such a precise definition would apply to FM patients would be an interesting topic for future study. Morning stiffness in rheumatoid arthritis has been correlated with elevated serum levels of hyaluronic acid [31]. Raised levels of hyaluronic acid have been reported in one study FM patients [32], but not in several others [33–35]. The 63% prevalence of low back pain is particularly noteworthy, as this has not been previously reported in survey or epidemiological studies of FM. It may be a productive topic for future research, as patients with low back pain have been reported to develop FM in 25% of cases [36] and some patients with LBP have augmented pain processing [37].

Six of the most frequently cited exacerbating factors involved some form of emotional distress (endorsed by 83% of the respondents). These results are in accord with several other studies [38–40]. The perceived adverse effect of weather changes (80% endorsed) is noteworthy. This effect has been previously reported [41] but in 2 studies FM symptoms failed to correlate with meteorological variables [42, 43]. In another study pain was correlated with high atmospheric pressure and low temperature [44]. Concordant with several other reports [45–47] "forgetfulness" and problems with "concentration" were rated as quite common and problematical. The frequency of disability claims in the current survey was about the same as a multicenter study in the United States [48].

One study of the prevalence of sexual abuse in FM suggested that it might be as high as 57% [49]. The 7.8% prevalence of childhood sexual abuse in the current survey is substantially lower and may reflect differences in "candidness" between an Internet based survey population and one-on-one interviews. A recent telephone based study found no association between FM and sexual abuse, but did report a three-fold increase of FM in women who had been raped. Thus, it was hypothesized that chronic stress, in the form of posttraumatic stress disorder, may mediate the relationship between rape and FM [50].

Among the most interesting data to come out of this survey was the use of various management strategies and medications by the participants. An attempt was also made to assess the perceived effectiveness of various therapies (on a 0 to 10 scale, with 10 being most effective). The 3 most commonly used interventions were non-medicinal (rest, heat, and distraction). Interventions with the highest effectiveness ratings were: prescription sleep medications (rating: 6.5), prescription pain medications (rating: 6.3), resting (rating: 6.3), heat (rating: 6.3), and prescription antidepressants (rating: 6.2). Although non-prescription pain medications and nutritional supplements were commonly used they did not appear to be particularly effective (ratings of 3.8 and 2.8 respectively). Conversely, pool therapy, used by a quarter of the respondents, was as effective as many of the more frequently used management strategies.

The most commonly used medications were acetaminophen (94%), ibuprofen (87%), naproxen (66%), cyclobenzaprine (64%), and amitriptyline (55%). Based on the percentage of respondents who rated medications as helpful, the top 10 were: hydrocodone preparations (75%), aprazolam (70%), oxycodone preparations (67%), diazepam (65%), zolpidem (64%), clonazepam (61%), cyclobenzaprine (58%), codeine preparations (55%), propoxyphene preparations (54%), and ibuprofen (51%). Interestingly, there is a discrepancy between the most commonly used and the most effective medications. This, discrepancy may be associated with the heavy use of over-the-counter drugs, which are generally cheaper than prescription drugs. There may also be a reluctance of physicians to provide ongoing prescriptions of opioids and benzodiazepines. The perceived effectiveness of hydrocodone preparations is of some interest as this medication has never been formally tested in FM patients. Future research should examine the profile of health care providers who prescribed this and similar opioids. Aprazolam (reported as being helpful in 70% of respondents) has been noted to be of some benefit when used in conjunction with ibuprofen [51], but has never been formally evaluated as a stand-alone drug in FM.

Another way to consider effectiveness of medications is to examine continuation of treatment. The most commonly reported medications that respondents continuing to use were: hydrocodone preparations (41%), ibuprofen (41%), clonazepam (40%), acetaminophen (37%), gabapentin (36%), trazodone (36%), zolpidem (34%), aprozolam (30%), cyclobenzaprine (30%), and bupropion (29%). As expected, newer medications available at the end of 2005, such as duloxetine, sodium oxybate, and pregabalin, were being used by only a small percentage of respondents (i.e., < 8%). Non-adherence to prescribed medications is reported to be common in FM patients [52], but whether this is a result of lack of efficacy, side effects, cost, or psychosocial factors, is not known.

In interpreting the results of this survey it is important to acknowledge its limitations. The surveyed population was self-selected as people with FM who had Internet access and was familiar with the NFA website. Approximately 70% of the respondents indicated that they obtained information about FM from the NFA (the sponsors of the survey). It is possible that those familiar with NFA differ in important ways from people with FM in general. They were not personally interviewed or formally diagnosed. Thus an unknown proportion of those responding may not have met in 1990 ACR classification criteria for a diagnosis of FM [53]. However, only 1.6% of the responders reported that their diagnosis of FM had not been confirmed by a health care professional. There is some evidence that certain combinations of symptoms are strongly correlated with an ACR based diagnosis of FM. For instance, Katz has reported that a history of widespread regional pain (score ≥ 8.0) plus fatigue (score ≥ 6.0) has a 75% concordance with ACR criteria [54]. This Internet based survey was new and previously untested and there is a need to confirm its psychometric properties in future studies. Preliminary testing suggested good face validity and test-retest reliability. Internet-based surveys are increasingly used to obtain patient data [55] and several studies have reported a good correlation with paper-and- pencil surveys [56, 57].

The information from this survey provides as a glimpse into the FM landscape in the United States at the end of 2005 as perceived by a self-selected group of FM patients with Internet access. These results pose several issues for more in depth research, such as the prescribing habits of FM health care providers, the role of emotional precipitants, the impact of obesity, the significance of low back pain and the nature of FM related stiffness.