Nancy A. Melville

September 26, 2012

September 26, 2012 (Phoenix, Arizona) — Traumatic experiences, such as serious accidents or assault, play a significant role in chronic pain that is severe enough to interfere with daily activities, new research suggests.

Researchers surveyed patients about the degree to which pain interfered with their normal work and found that the strongest predictors of high interference of pain with work life was a history of trauma relating to a bad accident, physical assault, or abuse.

"Our results suggest a direct relationship between trauma and pain interference; [however] none of the trauma-depression interactions were significant," lead author Mark G. Haviland, PhD, of the Loma Linda School of Medicine, in California, told Medscape Medical News.

"The strongest trauma predictors were having been in a bad accident and physical assault and abuse, suggesting a progression from acute to chronic pain/pain interference," he said.

Their results were presented here at the American Academy of Pain Management (AAPM) 23rd Annual Meeting.

Factors in Chronic Pain

With some previous studies linking traumatic experiences with pain severity in patients with fibromyalgia and irritable bowel syndrome, researchers sought to determine whether the same factors applied to patients with chronic pain in general.

For the study, the research team evaluated the responses of 9506 people surveyed for the Biopsychosocial Religion and Health Study. The study is the fourth in a series evaluating the data set for factors that play a role in chronic pain.

Of the patients, 66.8% were female; 61.5% were white; 33.1% were black; 2.8% were Hispanic; and 1.8% were Asian.

Patient responses to the question of how much pain interfered with their normal work over the past 4 weeks were evaluated, along with rates of pain on a 5-point scale, ranging from 1 (not at all) to 5 (severe pain interference).

The results showed that 3585 (37.7%) reported moderate pain interference and 1338 (14.1%) had severe interference, with the remaining 48.2% reporting no pain-related interference.

The variables that were the strongest predictors of greater pain (odds ratios [ORs] > 1) were trauma relating to a bad accident and trauma relating to physical assault/abuse (respective ORs = 1.311 and 1.234).

The strongest predictors of having less pain (OR < 1) included being black (0.763), having a college degree (0.849), and being male (0.865).

Other independent variables that were all statistically significant included age, sex, race/ethnicity, education, financial strain, general health, body mass index, sleep difficulties, and depressive symptoms.

Trauma related to emotional abuse/neglect and depression was not a predictor of pain.

Dr. Haviland noted that the results were not changed when those with fibromyalgia and irritable bowel syndrome were excluded.

"Given the relatively modest effect sizes (the odd ratios/confidence intervals), we needed to verify that the findings were not due only to the 'pull' of those with fibromyalgia or irritable bowel syndrome," he said.

The findings may not give the full picture, but they shed important light on the complex relationship between chronic pain and psychological factors, particularly trauma, Dr. Haviland said.

"Trauma is tricky. In general, at least in our studies, traumatic experiences, such as sexual abuse/assault and physical abuse/assault and having been in a bad accident, are associated with fibromyalgia prevalence and pain interference among women with fibromyalgia and in people in general," he said.

In understanding the key factors associated with pain that interferes with daily activities, clinicians can better guide patients to manage chronic pain, Dr. Haviland said.

"Our data suggest that chronic pain/pain interference may improve with better patient education, better access to care, and attending to patients' general and mental health issues, including sleep difficulties (better diet/more exercise) and not ignoring patients' traumatic experiences."

Complex Characteristics

According to Lawrence D. Robbins, MD, of the Robbins Headache Clinic in Northbrook, Illinois, the findings highlight the complex characteristics that can be associated with chronic pain.

"This was a very interesting survey study, with about half of older adults reporting mood or severe pain interference," he told Medscape Medical News.

"It is interesting in terms of predictors of less pain — being black, college-educated, and male. Previous trauma and/or abuse were higher predictors of pain."

Whereas previous studies have suggested that males may have less chronic pain, previous headache studies have indicated that those with lower socioeconomic status have more headaches. The new study meanwhile looked at education and less pain with more highly educated individuals, Dr. Robbins noted.

"Studies such as this are interesting and hopefully will lead to more studies as to causation, such as why, for instance, blacks have less pain interference as adults."

The study received funding from the National Institute on Aging (Biopsychosocial Religion and Health Study) and from the National Cancer Institute for the parent study (Adventist Health Study 2). The authors and Dr. Robbins have disclosed no relevant financial relationships.

American Academy of Pain Management (AAPM) 23rd Annual Meeting. Poster abstract 33. Presented September 22, 2012.