ABSTRACT
BACKGROUND: The object of this study was to develop an Iranian version of the General Health Questionnaire-28 (GHQ-28) for use with elderly subjects. METHODS: The GHQ-28 Farsi version was evaluated for face validity among 204 elderly subjects aged 59 years or older, chosen randomly from residents of Tehran. The Composite International Diagnostic Interview (CIDI) was used to establish a gold standard diagnosis of mental disorders. RESULTS: The GHQ-28 was an internally consistent measure. Cronbach's alpha, split-half coefficients and test-retest reliability were 0.9, 0.89 and 0.58 respectively. Four factors were extracted using factor analysis: "depression," "psychosocial activity," "anxiety," and "somatic." Using receiver operating curve (ROC) analysis, the optimum cutoff score for the GHQ-28 in this group was 19/20 (sensitivity 0.83, specificity 0.76). Using a loading of 0.6 or greater, a short form of the instrument (GHQ-15) (alpha=0.9) was derived and correlated well with the longer form of the scale (r=0.97). Using ROC analysis, the optimum cutoff score was 10/11 (sensitivity 0.83, specificity 0.69). CONCLUSIONS: The short and long forms of the GHQ-28 are suitable screening instruments for elderly Iranian residents, particularly those living in urban areas.
Subject(s)
Health Status , Mental Disorders/diagnosis , Mental Disorders/ethnology , Surveys and Questionnaires , Aged , Aged, 80 and over , Anxiety Disorders/epidemiology , Depression/epidemiology , Factor Analysis, Statistical , Female , Humans , Iran , Male , Mass Screening , Mental Disorders/epidemiology , Middle Aged , Psychology , ROC Curve , Reproducibility of ResultsABSTRACT
OBJECTIVES: Depressive disorders are a public health problem even in developing countries. Access to valid and reliable screening instruments is needed for conducting community surveys. The main objective of this study is to provide the Iranian version of the Geriatric Depression Scale-15 (GDS). METHODS: The GDS-15 Farsi version was developed by translation and back translation. Two hundred and four subjects aged 59 years or older, who were chosen randomly from residents of the Ekbatan district of Tehran, the capital city of Iran, completed the GDS-15. The Composite International Diagnostic Interview (CIDI) was used to establish a gold standard diagnosis of major depressive disorders. RESULTS: The GDS was found to be an internally consistent measure. Alpha, split-half coefficients and test-retest reliability were 0.9, 0.89 and 0.58 respectively. Two factors were extracted by using factor analysis and the principle component analysis (varimax rotation): 'depression' and 'psychosocial activity'. The Depression factor (omitting items 2, 9, 10, 13), which could be considered as a short form of the scale (alpha = 0.92), has significant correlation with the main scale (r = 0.58). Using receiver operating curve (ROC) analysis, the optimum cutoff score for GDS-15 is 7/8, yielding a sensitivity of 0.9 and a specificity of 0.84. The optimum cutoff score for GDS-11 is 6, yielding a sensitivity of 0.9 and a specificity of 0.83. CONCLUSION: The long and short forms of the GDS have excellent properties as screening instruments for major depression in older dwellers in Iran, particularly in urban areas, as presented in our findings.
