Children who suffer from persistent¹ or recurring² chronic³ pain may miss school, withdraw from social activities, and are at risk of developing internalizing symptoms such as anxiety, in response to their pain. In the first comprehensive review of chronic pain in children and adolescents in 20 years, a group of researchers found that more children now are suffering from chronic pain and that girls suffer more frequently from chronic pain than boys. "We found that persistent and recurrent chronic pain is overwhelmingly prevalent in children and adolescents, with girls generally experiencing more pain than boys and prevalence rates increasing with age," said lead investigator⁴ Sara King, PhD, currently Assistant Professor, Mount Saint Vincent University, Halifax, Nova Scotia. "Findings such as these argue that researchers and clinicians should be aware of the problem and the long-term consequences of chronic pain in children."

Researchers from Dalhousie University and the IWK Health Centre, Halifax, systematically⁵ examined epidemiological studies of pain to evaluate progress made since the first comprehensive review of pain in children and adolescents, published by Goodman and McGrath in PAIN®in 1991. Additionally, they identified a set of criteria⁶ to assess the quality of the studies included in the review. They looked at 32 studies and categorized them according to the type of pain investigated: headache, abdominal⁷（腹部的） pain, back pain, musculoskeletal（肌骨骼的） pain, combined pain, and general pain.

Their findings indicate that most types of pain are more prevalent in girls than in boys, but the factors that influence this gender⁸ difference are not entirely⁹ clear. Pain prevalence rates tend to increase with age. Psychosocial variables impacting pain prevalence included anxiety, depression, low self-esteem, and low socioeconomic status. Headache was found to be the most common studied pain type in youth, with an estimated prevalence rate of 23%. Other types of pain, ie, abdominal pain, back pain, musculoskeletal pain, and pain combinations, were less frequently studied than headache, and prevalence rates were variable because of differences in reporting. However, the overall results indicated that these pain types are highly prevalent in children and adolescents, with median prevalence rates ranging from 11% to 38%. "These rates are of great concern, but what is even more concerning is that research suggests that the prevalence rates of childhood pain have increased over the last several decades," stated Dr. King.

Researchers also found that many studies did not meet quality criteria and there was great variability in prevalence rates across studies due to time periods over which pain was reported. The authors suggest that future epidemiological（流行病学的） studies in this area are in need of better operational definitions of pain and better measures of pain intensity¹⁰, frequency, and duration. Such quality criteria across studies would allow for direct comparison.

The review identified several demographic and psychosocial factors associated with high prevalence rates of specific pain types. "By shifting focus to factors associated with chronic and recurrent pain, it may be possible to identify the most salient risk factors, leading to early and intensive interventions¹¹ for the most at-risk groups," concluded Dr. King.