Per Bech

Translating Health Status Questionnaires and Evaluating Their Quality : The IQOLA Project Approach

This article describes the methods adopted by the International Quality of Life Assessment (IQOLA) project to translate the SF-36 Health Survey. Translation methods included the production of forward and backward translations, use of difficulty and quality ratings, pilot testing, and cross-cultural comparison of the translation work. Experience to date suggests that the SF-36 can be adapted for use in other countries with relatively minor changes to the content of the form, providing support for the use of these translations in multinational clinical trials and other studies. The most difficult items to translate were physical functioning items, which used examples of activities and distances that are not common outside of the United States; items that used colloquial expressions such as pep or blue; and the social functioning items. Quality ratings were uniformly high across countries. While the IQOLA approach to translation and validation was developed for use with the SF-36, it is applicable to other translation efforts.

The factor structure of the SF-36 Health Survey in 10 countries: Results from the IQOLA Project

Studies of the factor structure of the SF-36 Health Survey are an important step in its construct validation. Its structure is also the psychometric basis for scoring physical and mental health summary scales, which are proving useful in simplifying and interpreting statistical analyses. To test the generalizability of the SF-36 factor structure, product-moment correlations among the eight SF-36 Health Survey scales were estimated for representative samples of general populations in each of 10 countries. Matrices were independently factor analyzed using identical methods to test for hypothesized physical and mental health components, and results were compared with those published for the United States. Following simple orthogonal rotation of two principal components, they were easily interpreted as dimensions of physical and mental health in all countries. These components accounted for 76% to 85% of the reliable variance in scale scores across nine European countries, in comparison with 82% in the United States. Similar patterns of correlations between the eight scales and the components were observed across all countries and across age and gender subgroups within each country. Correlations with the physical component were highest (0.64 to 0.86) for the Physical Functioning, Role Physical, and Bodily Pain scales, whereas the Mental Health, Role Emotional, and Social Functioning scales correlated highest (0.62 to 0.91) with the mental component. Secondary correlations for both clusters of scales were much lower. Scales measuring General Health and Vitality correlated moderately with both physical and mental health components. These results support the construct validity of the SF-36 translations and the scoring of physical and mental health components in all countries studied.

Pain epidemiology and health related quality of life in chronic non-malignant pain patients referred to a Danish multidisciplinary pain center

&NA; This paper presents the results of a detailed study of the pain epidemiology and health related quality of life (HRQL) in 150 chronic non‐malignant pain patients consecutively referred to a Danish multidisciplinary pain center. Mean pain severity was 71.6 (SD=18.5) on the VAS scale. Forty‐two percent reported poor quality of sleep. HRQL was evaluated with the Medical Outcome Study‐Short Form (SF‐36), the Hospital Anxiety and Depression scale (HAD) and the Psychological General Well‐Being Scale (PGWB). Compared with the normal population (NP) both SF‐36 scores and PGWB scores were significantly reduced (P<0.001) indicating that physical, psychological and social well‐being were severely reduced. On the HAD scale 58% were found to have a depressive or anxiety disorder. Statistically significant but modest correlations were found between pain severity and HRQL. Psychological and social well‐being was closely correlated. Sixty‐three percent of the referred patients had neurogenic pain conditions. Of these, only 25% were treated with antidepressants or anticonvulsants at referral. Seventy‐three percent were treated with opioids at referral. Mean opioid consumption was 64 mg of morphine per day (range 1–280 mg). Compared with the NP the chronic pain patients had used the health care system five times more often in the years prior to referral (P<0.001). The study confirms the severe multidimensional impact of chronic pain and demonstrates that HRQL of chronic non‐malignant pain patients is among the lowest observed for any medical condition.

QUANTITATIVE RATING OF DEPRESSIVE STATES

A step‐by‐step analysis of Becks and Hamiltons rating scales showed that both, scales failed to differentiate adequately between moderate and severe depression measured by a global clinical assessment. Each item of the scales was tested for calibration, ascending monotonicity, and dispersion parallel to the clinical assessment. Twelve items of Becks scale and six items of Hamiltons scale were found valid with respect to these criteria. Those items should be taken into account in future research for baseline ratings and for change ratings of depressive states quantitatively.

The factor structure of the SF-36 Health Survey in 10 countries: results from the IQOLA Project. International Quality of Life Assessment.

Studies of the factor structure of the SF-36 Health Survey are an important step in its construct validation. Its structure is also the psychometric basis for scoring physical and mental health summary scales, which are proving useful in simplifying and interpreting statistical analyses. To test the generalizability of the SF-36 factor structure, product-moment correlations among the eight SF-36 Health Survey scales were estimated for representative samples of general populations in each of 10 countries. Matrices were independently factor analyzed using identical methods to test for hypothesized physical and mental health components, and results were compared with those published for the United States. Following simple orthogonal rotation of two principal components, they were easily interpreted as dimensions of physical and mental health in all countries. These components accounted for 76% to 85% of the reliable variance in scale scores across nine European countries, in comparison with 82% in the United States. Similar patterns of correlations between the eight scales and the components were observed across all countries and across age and gender subgroups within each country. Correlations with the physical component were highest (0.64 to 0.86) for the Physical Functioning, Role Physical, and Bodily Pain scales, whereas the Mental Health, Role Emotional, and Social Functioning scales correlated highest (0.62 to 0.91) with the mental component. Secondary correlations for both clusters of scales were much lower. Scales measuring General Health and Vitality correlated moderately with both physical and mental health components. These results support the construct validity of the SF-36 translations and the scoring of physical and mental health components in all countries studied.

The Bech-Rafaelsen Mania Scale and the Hamilton Depression Scale

In a study of 18 patients with manic symptomatology and 31 patients with melancholic symptomatology the Bech‐Rafaelsen Mania Scale (BRMS) and the Hamilton Depression Scale (HDS) have been compared. The results showed that the inter‐observer reliability of the BRMS was adequate compared with the HDS. Both scales are constructed for assessing the severity of manic or melancholic states, and no difference was found in the total BRMS or HDS score between the various diagnostic groups, when the patients were classified by an index of the course and symptomatology of their disorder, using the Multi‐axial Classification System for Affective Disorders (MULTI‐CLAD). The homogeneity of the BRMS seemed more adequate than that of the HDS, when each item was correlated to the corresponding total score. Although the homogeneity of the BRMS needs to be evaluated by other statistical models than correlation analysis, our results seem to indicate that the improvement in assessing manic‐melancholic states quantitatively is a matter of redefining items or incorporating new items in the melancholic rather than the manic part of these rating scales.

The Relation between Work-related Psychosocial Factors and the Development of Depression

This review is based on a literature search made in January 2007 on request by the Danish National Board of Industrial Injuries. The search in PubMed, EMBASE, and PsycINFO resulted in more than 1,000 publications. This was reduced to 14 after the titles, abstracts, and papers were evaluated by using the following criteria: 1) a longitudinal study, 2) exposure to work-related psychosocial factors, 3) the outcome a measure of depression, 4) relevant statistical estimates, and 5) nonduplicated publication. Of the 14 studies, seven used standardized diagnostic instruments as measures of depression, whereas the other seven studies used self-administered questionnaires. The authors found moderate evidence for a relation between the psychological demands of the job and the development of depression, with relative risks of approximately 2.0. However, indication of publication bias weakens the evidence. Social support at work was associated with a decrease in risk for future depression, as all four studies dealing with this exposure showed associations with relative risks of about 0.6. Even if this literature study has identified work-related psychosocial factors that in high-quality epidemiologic studies predict depression, studies are still needed that assess in more detail the duration and intensity of exposure necessary for developing depression.

Translating health status questionnaires and evaluating their quality: the IQOLA Project approach. International Quality of Life Assessment.

This article describes the methods adopted by the International Quality of Life Assessment (IQOLA) project to translate the SF-36 Health Survey. Translation methods included the production of forward and backward translations, use of difficulty and quality ratings, pilot testing, and cross-cultural comparison of the translation work. Experience to date suggests that the SF-36 can be adapted for use in other countries with relatively minor changes to the content of the form, providing support for the use of these translations in multinational clinical trials and other studies. The most difficult items to translate were physical functioning items, which used examples of activities and distances that are not common outside of the United States; items that used colloquial expressions such as pep or blue; and the social functioning items. Quality ratings were uniformly high across countries. While the IQOLA approach to translation and validation was developed for use with the SF-36, it is applicable to other translation efforts.

The internal and external validity of the Major Depression Inventory in measuring severity of depressive states.

BACKGROUND We have developed the Major Depression Inventory (MDI), consisting of 10 items, covering the DSM-IV as well as the ICD-10 symptoms of depressive illness. We aimed to evaluate this as a scale measuring severity of depressive states with reference to both internal and external validity. METHOD Patients representing the score range from no depression to marked depression on the Hamilton Depression Scale (HAM-D) completed the MDI. Both classical and modern psychometric methods were applied for the evaluation of validity, including the Rasch analysis. RESULTS In total, 91 patients were included. The results showed that the MDI had an adequate internal validity in being a unidimensional scale (the total score an appropriate or sufficient statistic). The external validity of the MDI was also confirmed as the total score of the MDI correlated significantly with the HAM-D (Pearsons coefficient 0.86, P < or = 0.01, Spearman 0.80, P < or = 0.01). CONCLUSION When used in a sample of patients with different states of depression the MDI has an adequate internal and external validity.

The Hamilton Depression Scale.: EVALUATION OF OBJECTIVITY USING LOGISTIC MODELS

The consistency of the Hamilton Depression Scale (HDS) as a measure of the severity of depressive states has been examined when the scale was used weekly during a trial with imipramine. By use of logistic models (Rasch) the consistency of the HDS has been considered across patient‐variables as age, sex, plasma levels of imipramine, and diagnosis. The results showed that the original 17‐item HDS was without adequate consistency, i.e. the total score of the sample of items was no one‐dimensional measure of depressive states. However, a melancholia subscale of the HDS contained items the total of which can be used to compare patients quantitatively, although in some part of the analysis one of these items showed ceiling effect. It was concluded that the melancholia sub‐scale (containing the items depressed mood, guilt, work and interests, retardation, psychic anxiety, and general somatic symptoms) can form the basis for further improvements in the field of quantitative rating scales for depressive states.