Psychological Medicine

Abstract: Background. A 10-question screening scale of psychological distress and a six-question short-form scale embedded within the 10-question scale were developed for the redesigned US National Health Interview Survey (NHIS). Methods. Initial pilot questions were administered in a US national mail survey (N fl 1401). A reduced set of questions was subsequently administered in a US national telephone survey (N fl 1574). The 10-question and six-question scales, which we refer to as the K10 and K6, were constructed from the reduced set of questions based on Item Response Theory models. The scales were subsequently validated in a two-stage clinical reappraisal survey (N fl 1000 telephone screening interviews in the first stage followed by N fl 153 face-to-face clinical interviews in the second stage that oversampled first-stage respondents who screened positive for emotional problems) in a local convenience sample. The second-stage sample was administered the screening scales along with the Structured Clinical Interview for DSM-IV (SCID). The K6 was subsequently included in the 1997 (N fl 36116) and 1998 (N fl 32440) US National Health Interview Survey, while the K10 was included in the 1997 (N fl 10641) Australian National Survey of Mental Health and Well-Being. Results. Both the K10 and K6 have good precision in the 90th‐99th percentile range of the population distribution (standard errors of standardized scores in the range 0‐20‐0‐25) as well as consistent psychometric properties across major sociodemographic subsamples. The scales strongly discriminate between community cases and non-cases of DSM-IV}SCID disorders, with areas under the Receiver Operating Characteristic (ROC) curve of 0‐87‐0‐88 for disorders having Global Assessment of Functioning (GAF) scores of 0‐70 and 0‐95‐0‐96 for disorders having GAF scores of 0‐50. Conclusions. The brevity, strong psychometric properties, and ability to discriminate DSM-IV cases from non-cases make the K10 and K6 attractive for use in general-purpose health surveys. The scales are already being used in annual government health surveys in the US and Canada as well as in the WHO World Mental Health Surveys. Routine inclusion of either the K10 or K6 in clinical studies would create an important, and heretofore missing, crosswalk between community and clinical epidemiology.

Abstract: This is an introductory report for the Brief Symptom Inventory (BSI), a brief psychological self-report symptom scale. The BSI was developed from its longer parent instrument, the SCL-90-R, and psychometric evaluation reveals it to be an acceptable short alternative to the complete scale. Both test--retest and internal consistency reliabilities are shown to be very good for the primary symptom dimensions of the BSI, and its correlations with the comparable dimensions of the SCL-90-R are quite high. In terms of validation, high convergence between BSI scales and like dimensions of the MMPI provide good evidence of convergent validity, and factor analytic studies of the internal structure of the scale contribute evidence of construct validity. Several criterion-oriented validity studies have also been completed with this instrument.

Abstract: This study reports the factor structure of the symptoms comprising the General Health Questionnaire when it is completed in a primary care setting. A shorter, 28-item GHQ is proposed consisting of 4 subscales: somatic symptoms, anxiety and insomnia, social dysfunction and severe depression. Preliminary data concerning the validity of these scales are presented, and the performance of the whole 28-item questionnaire as a screening test is evaluated. The factor structure of the symptomatology is found to be very similar for 3 independent sets of data.

Abstract: Background. The paper reports on the development of the WHOQOL-BREF, an abbreviated version of the WHOQOL-100 quality of life assessment. Method. The WHOQOL-BREF was derived from data collected using the WHOQOL-100. It produces scores for four domains related to quality of life: physical health, psychological, social relationships and environment. It also includes one facet on overall quality of life and general health. Results. Domain scores produced by the WHOQOL-BREF correlate highly (0.89 or above) with WHOQOL-100 domain scores (calculated on a four domain structure). WHOQOL-BREF domain scores demonstrated good discriminant validity, content validity, internal consistency and test-retest reliability. Conclusion. These data suggest that the WHOQOL-BREF provides a valid and reliable alternative to the assessment of domain profiles using the WHOQOL-100. It is envisaged that the WHOQOL-BREF will be most useful in studies that require a brief assessment of quality of life, for example, in large epidemiological studies and clinical trials where quality of life is of interest. In addition, the WHOQOL-BREF may be of use to health professionals in the assessment and evaluation of treatment efficacy. [References: 9]

Abstract: This study reports the factor structure of the symptoms comprising the General Health Questionnaire when it is completed in a primary care setting. A shorter, 28-item GHQ is proposed consisting of 4 subscales: somatic symptoms, anxiety and insomnia, social dysfunction and severe depression. Preliminary data concerning the validity of these scales are presented, and the performance of the whole 28-item questionnaire as a screening test is evaluated. The factor structure of the symptomatology is found to be very similar for 3 independent sets of data.