Pain a Part of Daily Life for One in Four

By Crystal Phend
PRINCETON, N.J., 04 may 2008-- More than a quarter of all Americans are in pain at any given time during the day, particularly those with lower income and less education, researchers said.In a population-based survey, 28.8% of men and 26.6% of women reported some level of pain during everyday activities at randomly sampled times through the day, according to Alan B. Kruger, Ph.D., of Princeton University, and Arthur A. Stone, Ph.D., of Stony Brook University in Stony Brook, N.Y.Activities associated with the highest average levels of pain were lawn care and caregiving as well as medical care among women and sports and exercise among men, they reported in the May 3 issue of The Lancet.
"If the relation with pain is causal, palliative care could increase the quality of life and range of activities in which people participate," the researchers said.
Even changing the mix of activities could lower a person's level of pain, they added.
So when doing a pain assessment, clinicians might consider asking for information about daily activities, Drs. Kruger and Stone suggested.
Previous studies have found that 17% to 29% of the general population suffers chronic pain, commented Juha H.O. Turunen, Ph.D., of the University of Kuopio in Kuopio, Finland, in an accompanying editorial.
Because little is known about pain prevalence other than chronic or condition-specific pain, such as arthritis, the researchers conducted the Princeton Affect and Time Survey (PATS). The Gallup Organization administered the community-based telephone survey to a nationally representative sample of households.
The 3,982 respondents provided a pain diary for one 24-hour period during which they rated pain on a seven-point scale. The researchers randomly selected three 15-minute intervals during waking hours for each participant.
Overall, respondents averaged 17.8 episodes of any degree of pain during the day before the survey.
Reports were similar from men and women. Race and ethnic origin were likewise not significant predictors of pain.
Pain ratings generally rose with age, although scores tended to plateau from the mid-40s to the mid-70s.
Along with age, education was a strong predictor of pain. Participants with less than a high school diploma had an average pain rating twice that of college graduates (1.21 versus 0.69, P<0.001).
Likewise, average pain ratings were about twice as high for men and women in households with yearly income below $30,000 as for those with an annual income of more than $100,000 (1.27 versus 0.67, P<0.001).
Individuals in the lowest income category spent 34.2% of their time in some degree of pain and 18.5% of their time in more severe pain (pain scores of three or higher on the seven-point scale). Those proportions were 22.9% and 7.7% for those in the highest income category.
The reason for these disparities, the authors suggested, was at least partly related to occupational status. Blue-collar workers had higher average pain ratings both during and outside of work than did white-collar workers (1.00 and 0.84 versus 0.61 and 0.61, respectively).
"Such a disparity emphasizes the need for pain-prevention measures, such as better ergonomics and better availability of occupational health services, in jobs with high physical strains," Dr. Turunen said in his editorial.
Drs. Kruger and Stone also found that disability and lack of satisfaction with life and health status were associated with the highest pain levels (all P<0.001).
Those participants who reported significant pain during much of the day reported spending 24.1% of their time watching television, whereas others spent 16% of the day in front of the TV.
Those individuals also spent more time relaxing and less time working and traveling than others, even when controlling for age and other demographic factors.
However, the researchers cautioned that the survey response rate was low (37%) and noted that the study lacked information on causes, location, and duration of pain, as well as medical conditions and treatments.
Further study is needed to identify groups of patients needing help with pain, Dr. Turunen said, "for example, to enable pain sufferers to obtain quicker and easier access to multidisciplinary pain clinics."
The study was supported by the National Institute of Aging and the Hewlett Foundation. Drs. Kruger and Stone reported being consulting senior scientists to the Gallup Organization. Dr. Stone also reported being associate chair of the scientific advisory board for Invivodata. Dr. Turunen reported no conflicts of interest.

Primary source: The LancetSource reference:Krueger AB, Stone AA "Assessment of pain: A community-based diary survey in the USA" Lancet 2008; 371: 1519-25. Additional source: The LancetSource reference: Turunen JHO "Depicting the pain profile with the diary-day method" Lancet 2008; 371: 1482-83.