Measuring depression in South Korea: validity and reliability of a brief questionnaire in the Korean Cancer Prevention Study

J Affect Disord. 2013 Sep 25;150(3):760-5. doi: 10.1016/j.jad.2013.02.035. Epub 2013 Mar 28.


Objective: To examine the validity and reliability of a new questionnaire for measuring depression in a South Korean population, and then to estimate the prevalence of depression in that country using this tool.

Methods: In total, 742,600 individuals (123,725 women), aged 30-64 years at entry into the Korean Cancer Prevention Study, completed a depression symptom in 1992 (baseline enrollment) and again in 1994. We examined the concurrent validity of the depression questionnaire by relating data from it to known socio-demographic and behavioral correlates of depression; its predictive capacity by relating scores from the questionnaire to the occurrence of future hospitalization for depression; and the test-retest reliability by comparing scores from its administration in 1992 to those in 1994.

Results: The prevalence of major depression was 7.5% in men and 10.0% in women. Factors significantly related to major depression were being younger (men), being female, not being married, of lower socioeconomic status, being a smoker, a heavy drinker, and not exercising regularly. Men (hazard ratio; 95% confidence interval: 2.0; 1.8, 2.2) and women (1.6; 1.3, 1.9) with questionnaire-ascertained depression experienced an elevated risk of hospitalization for the disorder during follow-up. The rates of agreement between responses to 1992 and 1994 surveys were 91.3% in men and 88.3% in women.

Conclusions: These findings imply validity of the instrument and support its use in future studies directed at links of depression with somatic disease endpoints.

Limitation: The questions do not have a specified time frame of reference.

Keywords: Depression; Epidemiology; Prevalence; Questionnaire.

Publication types

  • Research Support, Non-U.S. Gov't
  • Validation Study

MeSH terms

  • Adult
  • Asians
  • Depression / epidemiology*
  • Depressive Disorder / epidemiology*
  • Depressive Disorder, Major / epidemiology
  • Female
  • Humans
  • Male
  • Middle Aged
  • Prevalence
  • Reproducibility of Results
  • Republic of Korea / epidemiology
  • Surveys and Questionnaires*