Table 1 The suggested GHQ-12's factor structures by the previous studies
Studies | Study population | Age range | Applied model | Estimation methods | The best identified model |
|---|---|---|---|---|---|
Gnambs [14] | A representative sample from the population of the United Kingdom or one of its countries | 13–100 years | SEM | ML, WLS | Unidimensional factor with adjusting wording effects |
Hankins [15] | General population of the UK | Not reported | SEM | ML | Unidimensional factor with adjusting wording effects |
Motamed [16] | Adult population of Northern Iran | > = 18 years | CFA | Not reported | Unidimensional factor with correlated errors on negative items |
Rodrigo [17] | A representative sample of all employees living in Catalonia (Spain) | 17–82 years | CFA | WLS | Unidimensional factor with adjusting wording effects |
Smith [18] | A representative sample of the ageing population of the UK | > 50 years | CFA | ML | Unidimensional factor with adjusting negative wording effect |
del Pilar Sánchez-López [19] | General Spanish population | 25–65 years | EFA | ML | Three-factor structure, including successful coping, self-esteem, and stress |
El-Metwally [20] | Al Kharj adult population of Saudi Arabia | > = 18 years | EFA | ML | Three-factor structure, including social dysfunction, anxiety, and loss of confidence |
Griffith [21] | A representative UK sample | Mean = 45.8, SD = 18.0 | Exploratory SEM | Bayesian estimation and ML | Four-factor structure, including lowered self-worth, social dysfunction, stress, and emotional coping |
Mäkikangas [22] | Finnish working-age subjects | 25–59 years | CFA | WLS | Three-factor structure, including anxiety/depression, social dysfunction, and loss of confidence |
Montazeri [23] | A sample of young Iranian adolescents | 18–25 years | EFA | ML | Two-factor structure, including psychological distress and social dysfunction |
Najarkolaei [24] | Students of University of Tehran, Iran | 18–39 years | EFA and CFA | ML and WLS | Two-factor structure, including social dysfunction and psychological distress |
Namjoo [25] | Iranian elder people | > = 60 years | CFA | WLS | Two-factor structure, including social dysfunction and psychological distress |
Salama-Younes [26] | Elderly French people | 58–72 years | CFA | Not reported | Three-factor structure, including anxiety and depression, social dysfunction and loss of confidence |
Gao [27] | A consecutive sample of outpatients with anxiety disorders and/or depressive disorders in Singapore | Not reported | CFA | ML | Three-factor structure, including anxiety and depression, social dysfunction and loss of confidence |
Liang [28] | Young Chinese civil servants | 20–45 years | EFA and CFA | ML | All one-, two-, and three-dimensional models were well fitted |
Smith [49] | Cancer patients with heterogeneous diagnoses in the UK | Late middle age with mean = 57.42 | IRT, CFA | ML | Unidimensional factor with correlated error terms |
Abubakar [50] | A population of Kenyan adults and adolescents | 12–60 years | CFA | Not reported | Three-factor structure, including anxiety, social dysfunction and loss of confidence |