title: Development of the Perceived Stress Inventory: A New Questionnaire for Korean Population Surveys.
abstract: BACKGROUND
  Given emerging evidence of the association between stress and disease, practitioners need a tool for measuring stress. Several instruments exist to measure perceived stress; however, none of them are applicable for population surveys because stress conceptualization can differ by population. The aim of this study was to develop and validate the Perceived Stress Inventory (PSI) and its short version for use in population surveys and clinical practice in Korea.
  
  
  METHODS
  From a pool of perceived stress items collected from three widely used instruments, 20 items were selected for the new measurement tool. Nine of these items were selected for the short version. We evaluated the validity of the items using exploratory factor analysis of the preliminary data. To evaluate the convergent validity of the PSI, 387 healthy people were recruited and stratified on the basis of age and sex. Confirmatory analyses and examination of structural stability were also carried out. To evaluate discriminatory validity, the PSI score of a group with depressive symptoms was compared with that of a healthy group. A similar comparison was also done for persons with anxious mood.
  
  
  RESULTS
  Exploratory factor analysis supported a three-factor construct (tension, depression, and anger) for the PSI. Reliability values were satisfactory, ranging from 0.67 to 0.87. Convergent validity was confirmed through correlation with the Perceived Stress Scale, Center for Epidemiologic Studies Depression Scale, and State-Trait Anxiety Inventory. People with depressive or anxious mood had higher scores than the healthy group on the total PSI, all three dimensions, and the short version.
  
  
  CONCLUSIONS
  The long and short versions of the PSI are valid and reliable tools for measuring perceived stress. These instruments offer benefits for stress research using population-based surveys.
authors.affiliation: Department of Family Medicine, Inje University Ilsan Paik Hospital, Inje University College of Medicine, Goyang, Korea.
authors.forename: Eon Sook
authors.initials: ES
authors.lastname: Lee
authors.affiliation: Department of the Family Medicine, Kangbuk Samsung Hospital, SungKyunKwan University School of Medicine, Seoul, Korea.
authors.forename: Ho Cheol
authors.initials: HC
authors.lastname: Shin
authors.affiliation: Department of Family Medicine, Inje University Ilsan Paik Hospital, Inje University College of Medicine, Goyang, Korea.
authors.forename: Jun Hyung
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Department of Family Medicine, Inje University Ilsan Paik Hospital, Inje University College of Medicine, Goyang, Korea.
authors.forename: Yun Jun
authors.initials: YJ
authors.lastname: Yang
authors.affiliation: Department of Family Medicine, Hallym University Dongtan Sacred Heart Hospital, Hallym University College of Medicine, Hwaseong, Korea.
authors.forename: Jung Jin
authors.initials: JJ
authors.lastname: Cho
authors.affiliation: Kangnam University Graduate School of Education, Yongin, Korea.
authors.forename: Gwiyeoroo
authors.initials: G
authors.lastname: Ahn
authors.affiliation: Department of Family Medicine, Inje University Ilsan Paik Hospital, Inje University College of Medicine, Goyang, Korea.
authors.forename: Yeong Sook
authors.initials: YS
authors.lastname: Yoon
authors.affiliation: Department of the Family Medicine, Kangbuk Samsung Hospital, SungKyunKwan University School of Medicine, Seoul, Korea.
authors.forename: Eunju
authors.initials: E
authors.lastname: Sung
keywords: Factor Analysis, Statistical; Measurement; Reliability; Stress; Validity