The Association Between Pain and Depression and Some Determinants of Depression for the General Population of the United States

ABSTRACT

Pain and depression are major reasons for pharmacotherapy, making the relationship between these two complaints important in defining optimal pharmacotherapy for both. Although the association between the two has been documented in the literature, most of the available work only focused on specific disease group or patients with certain type of pain. Whether the association exists for the general population is still an unsettled issue. The goal of this study was to examine the association between pain and depression and explore the some determinants of depression using national representative survey data for the general population in the United States. This work employed data from Medical Expenditure Panel Survey (MEPS) 2009, with people older than 18 were included in the study. Ordered logistic regression and generalized ordered logistic regression were performed while incorporating complex survey features. Estimation results suggested that depression and physical pain were positively associated. In addition, individuals with better perceived health, older age, male gender, higher family income, and employed were less depressed. Divorced or separated marital status was associated with higher depression level. This work fills the gap in the literature by using nationally representative survey data set to examine the association between physical pain and depression. Levels of physical pain and many socioeconomic factors were found significantly associated with depression.

KEYWORDS :

• complex sampling survey
• general population
• generalized ordered logistic model
• Medical Expenditure Panel Survey (MEPS)
• pain and depression

Notes

* Survey sampling strata and primary sampling units (PSUs) were incorporated into our calculation of weighted mean and standard deviations. In addition, all individual statistics were computed based on person weight, whereas family level statistics were computed using family weight (10)

† SAS 9.2 has a ready-to-use program for generalized ordered logistic model while incorporating survey features. The user-written program gologit2 in STATA 12 is also capable of performing the generalized ordered logistic regression with complex sampling survey features. The choice of statistical software is solely due to authors’ preference and convenience.

‡ Instrument variable (2SLS) is often used in econometrics to deal with endogeneity caused by reversed causality. The validity of regression analysis relies on selection of instruments variables, which should measure exogenous changes of the endogeneous variable but have no effect on the dependent variable. The causality analysis between pain and depression will be studied in our future work.