Pain among women: Associations with socio-economic factors over time and the mediating role of depressive symptoms.

Background and aims Lower socioeconomic status (SES), based on economic situation, education and occupation, has been associated with greater morbidity and mortality in a wide range of diseases, and socioeconomic inequalities have been found in several chronic pain populations. Since women are overrepresented in several clinical pain conditions, there is a need to understand the influence of SES among women with pain. In a previous cross-sectional study, socioeconomic-and work conditions were associated with pain among women from the general population of Sweden. In the present study, based on baseline and follow-up measures from 2300 of the same sample, we examined associations between pain variables, socioeconomic status and work conditions over time by means of multiple logistic/linear regression analyses. Additionally, a possible mediating role of depressive symptoms on the relationship between SES and pain was examined. Methods The study was a prospective panel survey with two measurements 12 months apart among 2300 women with and without pain from the general population in Stockholm (aged 18-64). Logistic and linear regression analyses were used to identify associations between SES and pain outcomes. Results Results revealed that pain is a rather stable condition with large impact on daily functioning among many women. Certain SES variables (educational level, financial strain, occupational level) were related to pain and pain related disability prospectively. Financial strain and to be a blue-collar worker were related to the incidence of pain among all women, while educational level was related to worse pain outcomes among women with pain in terms of pain intensity, pain frequency, number of pain locations and pain-related disability. Symptoms of depression were associated with pain incidence and with pain variables (intensity, number of pain locations and pain-related disability) and with lower SES. Conclusions Financial strain and occupational level were here identified as risk factors for the incidence of pain, and could be interpreted as increasing both physical and psychological stress and thereby work both as predisposing the individual to pain and to perpetuate the development of a pain condition. Educational level was associated with the course of pain in terms of pain duration and pain-related disability which may indicate that once affected by pain, lower educational level may be related to less functional coping strategies in the adaptation to the pain condition. Depressive symptoms could be understood as a mediator of the relationship between SES and pain among women in terms of limiting the individual's strategies to handle pain in a functional manner by increasing passive behavior patterns such as avoidance. Implications The interplay between SES and symptoms of depression should be regarded in preventive interventions and in treatment of pain among women. An overall risk-profile in terms of psychosocial and biological factors needs to be assessed early on within pain treatment for women. Increased knowledge of socioeconomic risk factors for long term pain, e.g. low educational level, is needed on all levels among all professionals within the healthcare system in order to facilitate effective communication in the treatment of women with pain.