"An important message from epidemiologic studies cited by Blyth and colleagues (2010) is 'the universal presence across populations of characteristic subgroups of people with an underlying propensity or increased risk for chronic pain, in the context of a wide range of different precipitating or underlying diseases and injuries' (p. 282). These vulnerable subgroups are most often those of concern to public health.5 Increased vulnerability to pain is associated with the following:
"• having English as a second language,
"• race and ethnicity,
"• income and education,
"• sex and gender,
"• age group,
"• geographic location,
"• military veterans,
"• cognitive impairments,
"• surgical patients,
"• cancer patients, and
"• the end of life.
"Many of these same groups also are at risk of inadequate treatment."

Source

Institute of Medicine, "Relieving Pain in America: A Blueprint for Transforming Prevention, Care, Education, and Research" (Washington, DC: National Academy of Sciences, 2011), pp. 64-65.
http://www.nap.edu/openbook.p…