Reliability, construct and criterion validity of the KIDSCREEN-10 score: a short measure for children and adolescents' well-being and health-related quality of life.

BACKGROUND: To assess the criterion and construct validity of the KIDSCREEN-10 well-being and health-related quality of life (HRQoL) score, a short version of the KIDSCREEN-52 and KIDSCREEN-27 instruments. METHODS: The child self-report and parent report versions of the KIDSCREEN-10 were tested in a sample of 22,830 European children and adolescents aged 8-18 and their parents (n = 16,237). Correlation with the KIDSCREEN-52 and associations with other generic HRQoL measures, physical and mental health, and socioeconomic status were examined. Score differences by age, gender, and country were investigated. RESULTS: Correlations between the 10-item KIDSCREEN score and KIDSCREEN-52 scales ranged from r = 0.24 to 0.72 (r = 0.27-0.72) for the self-report version (proxy-report version). Coefficients below r = 0.5 were observed for the KIDSCREEN-52 dimensions Financial Resources and Being Bullied only. Cronbach alpha was 0.82 (0.78), test-retest reliability was ICC = 0.70 (0.67) for the self- (proxy-)report version. Correlations between other children self-completed HRQoL questionnaires and KIDSCREEN-10 ranged from r = 0.43 to r = 0.63 for the KIDSCREEN children self-report and r = 0.22-0.40 for the KIDSCREEN parent proxy report. Known group differences in HRQoL between physically/mentally healthy and ill children were observed in the KIDSCREEN-10 self and proxy scores. Associations with self-reported psychosomatic complaints were r = -0.52 (-0.36) for the KIDSCREEN-10 self-report (proxy-report). Statistically significant differences in KIDSCREEN-10 self and proxy scores were found by socioeconomic status, age, and gender. CONCLUSIONS: Our results indicate that the KIDSCREEN-10 provides a valid measure of a general HRQoL factor in children and adolescents, but the instrument does not represent well most of the single dimensions of the original KIDSCREEN-52. Test-retest reliability was slightly below a priori defined thresholds.

The KIDSCREEN-52 quality of life measure for children and adolescents: psychometric results from a cross-cultural survey in 13 European countries.

OBJECTIVE: This study assesses the reliability and validity of the European KIDSCREEN-52 generic health-related quality of life (HRQoL) questionnaire for children and adolescents. RESEARCH DESIGN: The KIDSCREEN-52, which measures HRQoL in 10 dimensions, was administered to a representative sample of 22,827 children and adolescents (8 to 18 years) in 13 European countries. Psychometric properties were assessed using the Classical Test Theory approach, Rasch analysis, and structural equation modeling (SEM). A priori expected associations between KIDSCREEN scales and sociodemographic and health-related factors were examined. Test-retest reliability was assessed in 10 countries. RESULTS: For the overall sample, Cronbach's alpha values ranged from 0.77 to 0.89. Scaling success (Multitrait Analysis Program) was >97.8% for all dimensions and Rasch analysis item fit (INFITmsq) ranged from 0.80 to 1.27. The intraclass correlation coefficients ranged from 0.56 to 0.77. No sizeable differential item functioning (DIF) was found by age, sex or health status. Four items showed DIF across countries. The specified SEM fitted the data well (root mean square error of approximation: 0.06, comparative fit index: 0.98). Correlation coefficients between Pediatric Quality of Life Inventory, Child Health and Illness Profile-Adolescent Edition, and Youth Quality of Life Instrument scales and KIDSCREEN dimensions assessing similar constructs were moderate for those (r = 0.44 to 0.61). Statistically significant differences between children with and without physical and mental health problems (Children with Special Health Care Needs screener: d = 0.17 to 0.42, Strengths and Difficulties Questionnaire: d = 0.32 to 0.72) were found in all dimensions. All dimensions showed a gradient according to socioeconomic status. CONCLUSIONS: The KIDSCREEN-52 questionnaire has acceptable levels of reliability and validity. Further work is needed to assess longitudinal validity and sensitivity to change.

Methods and representativeness of a European survey in children and adolescents: the KIDSCREEN study.

BACKGROUND: The objective of the present study was to compare three different sampling and questionnaire administration methods used in the international KIDSCREEN study in terms of participation, response rates, and external validity. METHODS: Children and adolescents aged 8-18 years were surveyed in 13 European countries using either telephone sampling and mail administration, random sampling of school listings followed by classroom or mail administration, or multistage random sampling of communities and households with self-administration of the survey materials at home. Cooperation, completion, and response rates were compared across countries and survey methods. Data on non-respondents was collected in 8 countries. The population fraction (PF, respondents in each sex-age, or educational level category, divided by the population in the same category from Eurostat census data) and population fraction ratio (PFR, ratio of PF) and their corresponding 95% confidence intervals were used to analyze differences by country between the KIDSCREEN samples and a reference Eurostat population. RESULTS: Response rates by country ranged from 18.9% to 91.2%. Response rates were highest in the school-based surveys (69.0%-91.2%). Sample proportions by age and gender were similar to the reference Eurostat population in most countries, although boys and adolescents were slightly underrepresented (PFR <1). Parents in lower educational categories were less likely to participate (PFR <1 in 5 countries). Parents in higher educational categories were overrepresented when the school and household sampling strategies were used (PFR = 1.78-2.97). CONCLUSION: School-based sampling achieved the highest overall response rates but also produced slightly more biased samples than the other methods. The results suggest that the samples were sufficiently representative to provide reference population values for the KIDSCREEN instrument.

Does the school performance variable used in the International Health Behavior in School-Aged Children (HBSC) Study reflect students' school grades?

BACKGROUND: Given the pressure that educators and policy makers are under to achieve academic standards for students, understanding the relationship of academic success to various aspects of health is important. The international Health Behavior in School-Aged Children (HBSC) questionnaire, being used in 41 countries with different school and grading systems, has contained an item assessing perceived school performance (PSP) since 1986. Whereas the test-retest reliability of this item has been reported previously, we determined its convergent and discriminant validity. METHODS: This cross-sectional study used anonymous self-report data from Austrian (N = 266), Norwegian (N = 240), and Canadian (N = 9,717) samples. Students were between 10 and 17 years old. PSP responses were compared to the self-reported average school grades in 6 subjects (Austria) or 8 subjects (Norway), respectively, or to a general, 5-category-based appraisal of most recent school grades (Canada). RESULTS: Correlations between PSP and self-reported average school grade scores were between 0.51 and 0.65, representing large effect sizes. Differences between the median school grades in the 4 categories of the PSP item were statistically significant in all 3 samples. The PSP item showed predominantly small associations with some randomly selected HBSC items or scales designed to measure different concepts. CONCLUSIONS: The PSP item seems to be a valid and useful question that can distinguish groups of respondents that get good grades at school from those that do not. The meaning of PSP may be context-specific and may have different connotations across student populations from different countries with different school systems.

Testing the structural and cross-cultural validity of the KIDSCREEN-27 quality of life questionnaire.

OBJECTIVES: The aim of this study is to assess the structural and cross-cultural validity of the KIDSCREEN-27 questionnaire. METHODS: The 27-item version of the KIDSCREEN instrument was derived from a longer 52-item version and was administered to young people aged 8-18 years in 13 European countries in a cross-sectional survey. Structural and cross-cultural validity were tested using multitrait multi-item analysis, exploratory and confirmatory factor analysis, and Rasch analyses. Zumbo's logistic regression method was applied to assess differential item functioning (DIF) across countries. Reliability was assessed using Cronbach's alpha. RESULTS: Responses were obtained from n = 22,827 respondents (response rate 68.9%). For the combined sample from all countries, exploratory factor analysis with procrustean rotations revealed a five-factor structure which explained 56.9% of the variance. Confirmatory factor analysis indicated an acceptable model fit (RMSEA = 0.068, CFI = 0.960). The unidimensionality of all dimensions was confirmed (INFIT: 0.81-1.15). Differential item functioning (DIF) results across the 13 countries showed that 5 items presented uniform DIF whereas 10 displayed non-uniform DIF. Reliability was acceptable (Cronbach's alpha = 0.78-0.84 for individual dimensions). CONCLUSIONS: There was substantial evidence for the cross-cultural equivalence of the KIDSCREEN-27 across the countries studied and the factor structure was highly replicable in individual countries. Further research is needed to correct scores based on DIF results. The KIDSCREEN-27 is a new short and promising tool for use in clinical and epidemiological studies.

The KIDSCREEN-27 quality of life measure for children and adolescents: psychometric results from a cross-cultural survey in 13 European countries.

OBJECTIVE: To assess the construct and criterion validity of the KIDSCREEN-27 health-related quality of life (HRQoL) questionnaire, a shorter version of the KIDSCREEN-52. METHODS: The five-dimensional KIDSCREEN-27 was tested in a sample of 22,827. For criterion validity the correlation with and the percentage explained variance of the scores of the KIDSCREEN-52 instrument were examined. Construct validity was assessed by testing a priori expected associations with other generic HRQoL measures (YQOL-S, PedsQL, CHIP), indicators of physical and mental health, and socioeconomic status. Age and gender differences were investigated. RESULTS: Correlation with corresponding scales of the KIDSCREEN-52 ranged from r = 0.63 to r = 0.96, and r2 ranged from 0.39 to 0.92. Correlations between other HRQoL questionnaires and KIDSCREEN-27 dimensions were moderate to high for those assessing similar constructs (r = 0.36 to 0.63). Statistically significant and sizeable differences between physically and mentally healthy and ill children were found in all KIDSCREEN-27 dimensions together with strong associations with psychosomatic complaints (r = -0.52). Most of the KIDSCREEN-27 dimensions showed a gradient according to socio-economic status, age and gender. CONCLUSIONS: The KIDSCREEN-27 seems to be a valid measure of HRQoL in children and adolescents. Further research is needed to assess longitudinal validity and sensitivity to change.

KIDSCREEN-52 quality-of-life measure for children and adolescents.

This study describes the development and reports the first psychometric results of the European KIDSCREEN-52 generic health-related quality-of-life questionnaire for children and adolescents. The KIDSCREEN-52, including ten dimensions, was applied in a European survey involving 12 countries (i.e., Austria, Switzerland, Czech Republic, Germany, Greece, Spain, France, Hungary, The Netherlands, Poland, Sweden and the UK) and 22,110 children and adolescents aged between 8 and 18 years of age. Questionnaire development included a literature search, expert consultation, and focus group discussions with children and adolescents. After definition of dimensions and collection of items, a translation process following international translation guidelines, cognitive interviews and a pilot test were performed. Analysis regarding psychometric properties showed Cronbach-alpha ranged from 0.77 to 0.89. Correlation coefficients between KINDL(R) and KIDSCREEN-52 dimensions were high for those assessing similar constructs (r = 0.51-0.68). All KIDSCREEN-52 dimensions showed a gradient according to socioeconomic status and most dimensions showed a gradient according to psychosomatic health complaints. The first results demonstrate that the KIDSCREEN-52 questionnaire is a promising cross-cultural measure of health-related quality-of-life assessment for children and adolescents in Europe.