Systematic review with meta-analysis of childhood and adolescent risk and prognostic factors for musculoskeletal pain :

A clear majority of patients with chronic pain are women; however, it has been surprisingly difficult to determine whether this sex bias corresponds to actual sex differences in pain sensitivity. A survey of the currently available epidemiological and laboratory data indicates that the evidence for clinical and experimental sex differences in pain is overwhelming. Various explanations for this phenomenon have been given, ranging from experiential and sociocultural differences in pain experience between men and women to hormonally and genetically driven sex differences in brain neurochemistry.

Prospective study with 8-year follow-up. To describe the evolution of low back pain from adolescence into adulthood. High prevalence rates of low back pain among children and adolescents have been demonstrated in several studies, and it has been theorized that low back pain in childhood may have important consequences for future low back pain. It is important to understand the nature of such a link if effective preventive programs are to be established. Almost 10,000 Danish twins born between 1972 and 1982 were surveyed by means of postal questionnaires in 1994 and again in 2002. The questionnaires dealt with various aspects of general health, including the prevalence of low back pain, classified according to number of days affected (0, 1-7, 8-30, >30). Low back pain in adolescence was found to be a significant risk factor for low back pain in adulthood with odds ratios as high as four. We also demonstrated a dose-response association: the more days with low back pain at baseline, the higher the risk of future low back pain. Twenty-six percent of those with low back pain for more than 30 days during the baseline year also had more than 30 days with low back pain during the follow-up year. This was true for only 9% of the rest of the sample. Our study clearly demonstrates correlations between low back pain in childhood/adolescence and low back pain in adulthood. This should lead to a change in focus from the adult to the young population in relation to research, prevention, and treatment.

Recurrent pains are a complex set of conditions that cause great discomfort and impairment in children and adults. The objectives of this study were to (a) describe the frequency of headache, stomachache, and backache in a representative Canadian adolescent sample and (b) determine whether a set of psychosocial factors, including background factors (i.e., sex, pubertal status, parent chronic pain), external events (i.e., injury, illness/hospitalization, stressful-life events), and emotional factors (i.e., anxiety/depression, self-esteem) were predictive of these types of recurrent pain. Statistics Canada's National Longitudinal Survey of Children and Youth was used to assess a cohort of 2488 10- to 11-year-old adolescents up to five times, every 2 years. Results showed that, across 12-19 years of age, weekly or more frequent rates ranged from 26.1%-31.8% for headache, 13.5-22.2% for stomachache, and 17.6-25.8% for backache. Chi-square tests indicated that girls had higher rates of pain than boys for all types of pain, at all time points. Structural equation modeling using latent growth curves showed that sex and anxiety/depression at age 10-11 years was predictive of the start- and end-point intercepts (i.e., trajectories that indicated high levels of pain across time) and/or slopes (i.e., trajectories of pain that increased over time) for all three types of pain. Although there were also other factors that predicted only certain pain types or certain trajectory types, overall the results of this study suggest that adolescent recurrent pain is very common and that psychosocial factors can predict trajectories of recurrent pain over time across adolescence.