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 equivalence of SF-36 summary health scores estimated using standard and country-specific algorithms in 10 countries: results from the IQOLA Project. International Quality of Life Assessment

Open choledochostomy still represents an important step of biliary surgery, even during the era of laparoscopic surgery. Although its application has decreased with the widespread use of endoscopic retrograde cholangiopancreatography (ERCP) and papillotomy, still there are some patients in whom it is necessary to perform open choledochostomy and place a T-tube. The morbidity and mortality rates depend mainly on the presence or absence of an acute suppurative cholangitis, rather than the performance of the choledochostomy. In patients with mild cholangitis or those no cholangitis and less than 60 years of age, the mortality rate is lower than that observed after ERCP. This procedure is still an important technique for surgeons dedicated to biliary surgery, and therefore several technical aspects of common bile duct exploration are important to remember.     

Tests of data quality, scaling assumptions, and reliability of the SF-36 in eleven countries: results from the IQOLA Project. International Quality of Life Assessment

Data from general population samples in 11 countries (n = 1483 to 9151) were used to assess data quality and test the assumptions underlying the construction and scoring of multi-item scales from the SF-36 Health Survey. Across all countries, the rate of item-level missing data generally was low, although slightly higher for items printed in the grid format. In each country, item means generally were clustered as hypothesized within scales. Correlations between items and hypothesized scales were greater than 0.40 with one exception, supporting item internal consistency. Items generally correlated significantly higher with their own scale than with competing scales, supporting item discriminant validity. Scales could be constructed for 93-100% of respondents. Internal consistency reliability of the eight SF-36 scales was above 0.70 for all scales, with two exceptions. Floor effects were low for all except the two role functioning scales; ceiling effects were high for both role functioning scales and also were noteworthy for the Physical Functioning, Bodily Pain, and Social Functioning scales in some countries. These results support the construction and scoring of the SF-36 translations in these 11 countries using the method of summated ratings.     

Use of structural equation modeling to test the construct validity of the SF-36 Health Survey in ten countries: results from the IQOLA Project. International Quality of Life Assessment

A crucial prerequisite to the use of the SF-36 Health Survey in multinational studies is the reproduction of the conceptual model underlying its scoring and interpretation. Structural equation modeling (SEM) was used to test these aspects of the construct validity of the SF-36 in ten IQOLA countries: Denmark, France, Germany, Italy, the Netherlands, Norway, Spain, Sweden, the United Kingdom, and the United States. Data came from general population surveys fielded to gather normative data. Measurement and structural models developed in the United States were cross-validated in random halves of the sample in each country. SEM analyses supported the eight first-order factor model of health that underlies the scoring of SF-36 scales and two second-order factors that are the basis for summary physical and mental health measures. A single third-order factor was also observed in support of the hypothesis that all responses to the SF-36 are generated by a single, underlying construct--health. In addition, a third second-order factors, interpreted as general well-being, was shown to improve the fit of the model. This model (including eight first-order factors, three second-order factors, and one third-order factor) was cross-validated using a holdout sample within the United States and in each of the nine other countries. These results confirm the hypothesized relationships between SF-36 items and scales and justify their scoring in each country using standard algorithms. Results also suggest that SF-36 scales and summary physical and mental health measures will have similar interpretations across countries. The practical implications of a third second-order SF-36 factor (general well-being) warrant further study.     

Testing the equivalence of translations of widely used response choice labels: results from the IQOLA Project. International Quality of Life Assessment

The similarity in meaning assigned to response choice labels from the SF-36 Health Survey (SF-36) was evaluated across countries. Convenience samples of judges (range, 10 to 117; median = 48) from 13 countries rated translations of response choice labels, using a variation of the Thurstone method of equal appearing intervals. Judges marked a point on a 10-cm line-representing the magnitude of a response choice label (e.g., "good" relative to the anchors of "poor" and "excellent"). Ratings were evaluated to determine the ordinal consistency of response choice labels within a response scale; the degree to which differences between adjacent response choice labels were equal interval; and the amount of variance due to response choice label, country, judge, and interaction between response choice label and country. Results confirmed the hypothesized ordering of response choice labels; the percentage of ordinal pairs ranged from 88.7% to 100% (median = 98.2%) across countries and response scales. Examination of the average magnitudes of response choice labels supported the "quasi-interval" nature of the scales. Analysis of variance (ANOVA) results supported the generalizability of response choice magnitudes across countries; labels explained 64% to 77% of the variance in ratings, and country explained 1% to 3%. These results support the equivalence of SF-36 response choice labels across countries. Departures from the assumption of equal intervals, when observed, were similar across countries and were greatest for the two response scales that are recalibrated under standard SF-36 scoring. Results provide justification for scoring translations of individual items using standard SF-36 scoring; whether these items form the same scales in other countries as they do in the United States is evaluated with tests of scaling assumptions.     

Cross-validation of item selection and scoring for the SF-12 Health Survey in nine countries: results from the IQOLA Project. International Quality of Life Assessment

Data from general population surveys (n = 1483 to 9151) in nine European countries (Denmark, France, Germany, Italy, the Netherlands, Norway, Spain, Sweden, and the United Kingdom) were analyzed to cross-validate the selection of questionnaire items for the SF-12 Health Survey and scoring algorithms for 12-item physical and mental component summary measures. In each country, multiple regression methods were used to select 12 SF-36 items that best reproduced the physical and mental health summary scores for the SF-36 Health Survey. Summary scores then were estimated with 12 items in three ways: using standard (U.S.-derived) SF-12 items and scoring algorithms; standard items and country-specific scoring; and country-specific sets of 12 items and scoring. Replication of the 36-item summary measures by the 12-item summary measures was then evaluated through comparison of mean scores and the strength of product-moment correlations. Product-moment correlations between SF-36 summary measures and SF-12 summary measures (standard and country-specific) were very high, ranging from 0.94-0.96 and 0.94-0.97 for the physical and mental summary measures, respectively. Mean 36-item summary measures and comparable 12-item summary measures were within 0.0 to 1.5 points (median = 0.5 points) in each country and were comparable across age groups. Because of the high degree of correspondence between summary physical and mental health measures estimated using the SF-12 and SF-36, it appears that the SF-12 will prove to be a practical alternative to the SF-36 in these countries, for purposes of large group comparisons in which the focus is on overall physical and mental health outcomes.     

Evaluating translations of health status questionnaires. Methods from the IQOLA project. International Quality of Life Assessment

There is growing demand for translations of health status questionnaires for use in multinational drug therapy studies and for population comparisons of health statistics. The International Quality of Life Assessment (IQOLA) Project is conducting a three-stage research program to determine the feasibility of translating the SF-36 Health Survey, widely used in English-speaking countries, into other languages. In stage 1, the conceptual equivalence and acceptability of translated questionnaires are evaluated and improved using qualitative and quantitative methods. In stage 2, assumptions underlying the construction and scoring of questionnaire scales are tested empirically. In stage 3, the equivalence of the interpretation of questionnaire scores across countries is tested using methods that closely approximate their intended use, and empirical results are compared. Data analyses from Sweden and the United Kingdom, as well as other research cited, support the feasibility of cross-cultural health measurement using the SF-36.     

Methods for validating and norming translations of health status questionnaires: the IQOLA Project approach. International Quality of Life Assessment

This article briefly summarizes methods used in the empirical validation of translations of the SF-36 Health Survey. In addition, information about the IQOLA Project norming protocol and 13 general population norming samples analyzed in this supplement is provided.     

The Swedish SF-36 Health Survey III. Evaluation of criterion-based validity: results from normative population

Assumptions of the variation in SF-36 scale scores were tested in relation to external criteria in 8930 respondents comprising the Swedish norming population. Physical health scales were strongly associated with age, while small differences were found for the Mental Health scale across age groups. Females reported poorer health than males, particularly in ages between 30-40 and over 70. Worse health profiles were associated with social risk factors (unemployment, divorce, etc.). The disability pension rate was strongly related to reduced Physical Functioning and increased Bodily Pain. The use of medical care was reflected in general health scores (i.e., the lower the scale score, the higher the care consumption). Self-reported physical and psychological symptoms were selectively related to SF-36 scales. All SF-36 scales, except Mental Health, were more strongly related to ratings of health satisfaction than to global quality of life. Combinations of the SF-36 well-being scales explained a substantial part of the variance of these ratings. In conclusion, the performed criterion-validity tests support the cross-cultural stability of the SF-36.     

Review of Applied Cross-cultural Psychology: Selected papers from the Second International Conference: International Association for Cross-cultural Psychology.

Reviews the book, Applied Cross-cultural Psychology: Selected papers from the Second International Conference: International Association for Cross-cultural Psychology edited by J. W. Berry adn W. J. Lonner (1975). This volume consists of a series of selected papers from the Second International Conference of the International Association for Cross-Cultural Psychology held at Queens University, Kingston, Ontario, during August 1974. The editors note that many of the conference presentations concerned applied social questions and the papers selected for the present volume were chosen to reflect and comment on applications of "social science in cultural areas where cross-cultural psychologists may be of some assistance." The book is divided into the following seven sections: Psychology and National Development, Psychology and Social Change, Cross-Cultural Orientation, Culture and Mental Health, Social Issues, Education Applications, and Comparative Approaches to the Study of Behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The Swedish SF-36 Health Survey II. Evaluation of clinical validity: results from population studies of elderly and women in Gothenborg

The validity of the Swedish SF-36 Health Survey was examined, replicating techniques used in the U.S. validation. Principal components analysis was used to test the internal structure of the eight SF-36 scales in relation to hypothesized associations with the two major dimensions of health--physical and mental. Hypothesized relationships between scales and external criteria were also examined by means of clinical group contrasts. Both the principal components analysis and clinical group contrasts largely replicated U.S. findings, which supported the cross-cultural stability of the SF-36 in Sweden. As expected, the Physical Functioning and Mental Health scales were most sensitive to clinical manifestations of medical and mental health, respectively. The General Health scale was associated more with physical than mental health. However, the Social Functioning scale and particularly the Vitality scale were more related to mental health in Sweden than in the corresponding U.S. study. Cultural differences and variation in study samples and selection criteria were suggested as possible explanatory factors for these differences.     

The MOS 36-item Short-Form Health Survey (SF-36): III. Tests of data quality, scaling assumptions, and reliability across diverse patient groups

The widespread use of standardized health surveys is predicated on the largely untested assumption that scales constructed from those surveys will satisfy minimum psychometric requirements across diverse population groups. Data from the Medical Outcomes Study (MOS) were used to evaluate data completeness and quality, test scaling assumptions, and estimate internal-consistency reliability for the eight scales constructed from the MOS SF-36 Health Survey. Analyses were conducted among 3,445 patients and were replicated across 24 subgroups differing in sociodemographic characteristics, diagnosis, and disease severity. For each scale, item-completion rates were high across all groups (88% to 95%), but tended to be somewhat lower among the elderly, those with less than a high school education, and those in poverty. On average, surveys were complete enough to compute scales scores for more than 96% of the sample. Across patient groups, all scales passed tests for item-internal consistency (97% passed) and item-discriminant validity (92% passed). Reliability coefficients ranged from a low of 0.65 to a high of 0.94 across scales (median = 0.85) and varied somewhat across patient subgroups. Floor effects were negligible except for the two role disability scales. Noteworthy ceiling effects were observed for both role disability scales and the social functioning scale. These findings support the use of the SF-36 survey across the diverse populations studied and identify population groups in which use of standardized health status measures may or may not be problematic.     

Evaluation of the MOS SF-36 Physical Functioning Scale (PF-10): II. Comparison of relative precision using Likert and Rasch scoring methods

Inhibition of NO synthesis represents a new therapeutical approach in the treatment of inflammation. Clinical use of NOS inhibitors will necessitate the design of drugs selective for iNOS, because inhibition of constitutive endothelial NOS may cause adverse cardiovascular side effects. This study examines the effect of ibuprofen and its stereoeisomeric components on the activation of iNOS and cNOS as well as on the NO production by human umbilical vein endothelial cells. At therapeutic concentrations Ibuprofen activated iNOS and inhibited NOS. In endothelial cell culture experiments activation of NO production was seen especially at supratherapeutic ibuprofen concentrations. Both stereoisomeric components of ibuprofen showed comparable effects. This drug can therefore not be used for the selective inhibition of iNOS.     

Social skill as moderator of the conscientiousness-performance relationship: Convergent results across four studies.

The authors conducted 4 studies to test the hypothesis that the relationship between Conscientiousness and job performance reflecting interpersonal effectiveness is more strongly positive among workers who are higher rather than lower in social skill. Results of hierarchical moderated regression analyses supported the hypothesis in all 4 studies. Among workers high in social skill. Conscientiousness was positively related to performance. Among workers low in social skill, the relationship between Conscientiousness and performance was essentially irrelevant in Study 2 but was negative in the other 3 studies. Potential implications of these results are discussed as are directions for future research. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Social Recovery of Monkeys Isolated for the First Year of Life: II. Long-Term Assessment.

Previous research demonstrated that the isolation syndrome in rhesus monkeys could be reversed by exposing isolate-reared monkeys to younger, "therapist" monkeys. However, estimates of social recovery were limited because the isolate monkeys were not tested with age-mates and the observations of these monkeys were restricted to the early juvenile period. The present series of experiments demonstrated that 3-year-old rehabilitated isolates could exhibit appropriate social behaviors to age-mate monkeys, but only after further treatment. Isolates were initially deficient to age-mate controls in their social repertoire and were attacked in social encounters with the normal monkeys. Isolate behavior did not change following 10 weeks of visual exposure to the age-mates, but it did improve substantially after the isolates were housed permanently as a group of four rather than individually. Tests with another group of age-mate controls and with monkey infants confirmed the newly acquired social competency of the isolates and their ability to interact appropriately and nonaggressively with young animals. The significance of these findings for theories of social development is discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cross-cultural differences in the perception of the emotional content of speech: A study of the development of sensitivity in Canadian and Mexican children.

Examined and compared the ability of Canadian and Mexican children to identify the emotional content of vocal expressions. Ss were 10 males from each country at each age 6-11 yrs. 10 male Canadian and 10 male Mexican undergraduates also served as Ss. Canadian and Mexican actresses, speaking any words they wished in their respective languages, simulated the emotions of happiness, sadness, love, and anger. After the initial recording, speech samples were arranged in random order and then rendered unintelligible by means of an electronic filtering device (which removed semantic content while leaving intact the tonal qualities of speech). When the filtered vocal expressions were played to Ss, a progressive increase with age in ability to identify correctly the emotions expressed was found. Further, the Mexican Ss overall were significantly more sensitive than the Canadian Ss. However, Ss from both countries judged the speech samples from Mexican actresses more accurately than those from Canadian actresses. (17 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparable studies of the incidence of stroke and its pathological types: results from an international collaboration. International Stroke Incidence Collaboration

BACKGROUND AND PURPOSE: Comparing stroke rates in different parts of the world may increase our understanding of both etiology and prevention. However, comparisons are meaningful only if studies use standard definitions and methods, with comparably presented data. We compared the incidence of stroke and its pathological types (cerebral infarction, primary intracerebral hemorrhage, and subarachnoid hemorrhage) in recent studies from around the world. METHODS: Studies with a midyear of 1984 or later, fulfilling standard criteria for a comparable, community-based study, provided original data for comparative analyses. RESULTS: By mid-1995, data were available from 11 studies in Europe, Russia, Australasia, and the United States, comprising approximately 3.5 million person-years and 5575 incident strokes. Age- and sex-standardized annual incidence rates for subjects aged 45 to 84 years were similar (between approximately 300/100,000) and 500/100,000) in most places but were significantly lower in Dijon, France (238/100,000), and higher in Novosibirsk, Russia (627/100,000). In subjects aged 75 to 84 years, however, Novosibirsk no longer ranked higher than the other studies. The distribution of pathological types, when these were reliably distinguished, did not differ significantly between studies. CONCLUSIONS: The similarities in stroke incidence and pathological types are perhaps not surprising given that all the populations were westernized and mainly white. The higher rates in Novosibirsk, disappearing in the elderly, and the lower rates in Dijon have several potential explanations. These include methodological artifact and different patterns of population risk factors. Further work is needed to explore these possibilities and to extend our knowledge of stroke incidence to other parts of the world, especially developing countries.     

Earning its place as a pan-human theory: Universality of the big-fish-little-pond effect across 41 culturally and economically diverse countries.

For more than 2 decades, big-fish-little-pond effect (BFLPE) research has demonstrated that students in high-ability classes and schools have lower academic self-concepts than their equally able counterparts in mixed-ability schools. However, cross-cultural BFLPE research has been limited to mostly developed and individualist countries. Using the Program for International Student Assessment database (Organisation for Economic Co-operation and Development, 2005a, 2005b), the present investigation assessed the BFLPE in 41 culturally and economically diverse countries. In support of the BFLPE, the effect of school-average self-concept was negative for the total sample (effect size = ?.49), negative for each of the 41 countries considered separately, and statistically significant in 38 countries. In this large, culturally diverse sample of countries, the BFLPE was evident in both collectivist and individualist cultures and in economically developing and developed nations. Implications for BFLPE theory and educational practice are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparability of the Social Skills Rating System to the Social Skills Improvement System: Content and psychometric comparisons across elementary and secondary age levels.

This study compared the Social Skills Rating System (SSRS; Gresham & Elliott, 1990) with the revision of the SSRS, now called the Social Skills Improvement System-Rating Scales (SSIS-RS; Gresham & Elliott, 2008), across three raters (teacher, parent, and student) for elementary- and secondary-aged students. A detailed comparison of these two instruments' comparability has not been previously reported and was considered important because of the frequent use of the SSRS in many externally funded research studies and school districts across the country. Comparisons between the two instruments focused on key reliability and validity estimates across the rating scales for three raters (teacher, parent, and student) using forms for elementary- and secondary-aged students. As hypothesized, the two instruments had high internal consistency estimates and moderately high validity indices for total scores for both social skills and problem behavior scales. The reliability comparisons revealed the SSIS-RS was superior to the SSRS with regard to internal consistency estimates. The validity estimates revealed expected convergent relationships with the strongest relationships consistently found among the various common subscales across all forms of the two instruments. The authors concluded that the SSIS-RS offers researchers and practitioners assessing social behavior of children and youth a broader conceptualization of key social behaviors and psychometrically superior assessment results when using the SSIS-RS over the SSRS. Future research on the SSIS-RS is also identified and contextualized within a multitiered intervention system. (PsycINFO Database Record (c) 2011 APA, all rights reserved)