BackgroundThe aim of this study was to measure health related quality of life (HRQOL) in Iranian children with type 1 diabetes and to test the psychometric properties of the Persian version of the PedsQL™ 4.0 Generic Core Scales and the PedsQL™ 3.0 Diabetes Module.MethodsParticipants were 94 children and adolescents diagnosed with type 1 diabetes for at least 3 months in Shiraz, southern Iran. Convergent, discriminant, and construct validity of the PedsQL™ 4.0 Generic Core Scales and the PedsQL™ 3.0 Diabetes Module were assessed. Moreover, internal consistency was checked by Cronbach's alpha coefficient.ResultsCronbach's α for the PedsQL™ 4.0 Generic Core Scales and the PedsQL™ 3.0 Diabetes Module was greater than 0.80 both in the child self-report and parent proxy-report. Both generic and disease-specific versions of the PedsQL showed excellent convergent and acceptable discriminant validity except for 'diabetes symptoms' subscale in the child self-report of the disease-specific module. Moreover, Iranian children with diabetes, as compared with other countries, had lower HRQOL scores.ConclusionsWhile this study showed that the Persian version of the PedsQL™ 4.0 Generic Core Scales has good psychometric properties in children with type 1 diabetes, the PedsQL™ 3.0 Diabetes Module needs some modifications to be used as a disease-specific quality of life (QOL) measure. Also, more support should be provided for the care of Iranian children with diabetes.

ObjectivesThis study aimed to assess whether male and female Iranian medical students perceived the meaning of the items in the Depression Anxiety Stress Scales-21 consistently. MethodsA convenience sample of 783 preclinical medical students from the first to sixth semester was invited to this cross-sectional study. Of the 477 respondents, 238 were male and 239 were female. All participants completed the Persian version of the Depression Anxiety Stress Scales-21. The graded response model was used to assess measurement invariance of the instrument across the gender groups. Categorical confirmatory factor analysis was used to evaluate the construct validity of the measure. Moreover, internal consistency was assessed via Cronbach's Alpha. ResultsStatistically significant differential item functioning was flagged for just item 6 in the depression subscales (c2=6.5, df=1, p=0.011). However, removing or retaining the item 6 in the stress subscale did not change our findings significantly, when we compared stress scores across two genders. The results of categorical confirmatory factor analysis supported the fit of the three-factor model of Depression Anxiety Stress Scales-21. Moreover, Cronbach’s alpha was greater than 0.7 in depression, anxiety and stress subscales. ConclusionsThis study revealed that Depression Anxiety Stress Scales-21 is an invariant measure across male and female medical students. Hence, this reliable and valid instrument can be used for meaningful comparison of distress scores between medical student genders. Gender comparisons of medical students’ psychological profiles provide a better insight into gender influences on the outcome of medical education and medical practice.

In this systematic review, we assessed available evidence for cross-cultural measurement invariance of assessment scales for child and adolescent psychopathology as an indicator of cross-cultural validity. A literature search was conducted using the Medline, PsychInfo, Scopus, Web of Science, and Google Scholar databases. Cross-cultural measurement invariance data was available for 26 scales. Based on the aggregation of the evidence from the studies under review, none of the evaluated scales have strong evidence for cross-cultural validity and suitability for cross-cultural comparison. A few of the studies showed a moderate level of measurement invariance for some scales (such as the Fear Survey Schedule for Children-Revised, Multidimensional Anxiety Scale for Children, Revised Child Anxiety and Depression Scale, Revised Children's Manifest Anxiety Scale, Mood and Feelings Questionnaire, and Disruptive Behavior Rating Scale), which may make them suitable in cross-cultural comparative studies. The remainder of the scales either showed weak or outright lack of measurement invariance. This review showed only limited testing for measurement invariance across cultural groups of scales for pediatric psychopathology, with evidence of cross-cultural validity for only a few scales. This study also revealed a need to improve practices of statistical analysis reporting in testing measurement invariance. Implications for future research are discussed.

BackgroundItem response theory (IRT) is extensively used to develop adaptive instruments of health-related quality of life (HRQoL). However, each IRT model has its own function to estimate item and category parameters, and hence different results may be found using the same response categories with different IRT models. The present study used the Rasch rating scale model (RSM) to examine and reassess the psychometric properties of the Persian version of the PedsQLTM 4.0 Generic Core Scales.MethodsThe PedsQLTM 4.0 Generic Core Scales was completed by 938 Iranian school children and their parents. Convergent, discriminant and construct validity of the instrument were assessed by classical test theory (CTT). The RSM was applied to investigate person and item reliability, item statistics and ordering of response categories.ResultsThe CTT method showed that the scaling success rate for convergent and discriminant validity were 100% in all domains with the exception of physical health in the child self-report. Moreover, confirmatory factor analysis supported a four-factor model similar to its original version. The RSM showed that 22 out of 23 items had acceptable infit and outfit statistics (<1.4, >0.6), person reliabilities were low, item reliabilities were high, and item difficulty ranged from -1.01 to 0.71 and -0.68 to 0.43 for child self-report and parent proxy-report, respectively. Also the RSM showed that successive response categories for all items were not located in the expected order.ConclusionsThis study revealed that, in all domains, the five response categories did not perform adequately. It is not known whether this problem is a function of the meaning of the response choices in the Persian language or an artifact of a mostly healthy population that did not use the full range of the response categories. The response categories should be evaluated in further validation studies, especially in large samples of chronically ill patients.

Background:Body weight is made up of lean and fat mass and both are involved in growth and development. Impression of these two components in bone density accrual has been controversial.Objectives:The aim of this study was to evaluate the relationship between fat and lean mass and bone density in Iranian children and adolescents.Patients and Methods:A cross-sectional study was performed on 472 subjects (235 girls, 237 boys) aged 9-18 years old in Fars Province. The participants' weight, height, waist circumference, stage of puberty, and level of physical activity were recorded. Bone Mineral Content (BMC), Bone Mineral Density (BMD), total body fat and lean mass were measured using dual-energy X-ray absorptiometry.Results:Results showed that 12.2% of boys and 12.3% of girls were overweight and 5.5% of boys and 4.7% of girls were obese. Obese individuals had greater total body BMD (0.96 ± 0.11) than normal-weight ones (0.86 ± 0.11) (P < 0.001). We found the greatest correlation between total body BMD and total body lean mass (R = 0.78. P < 0.001) and the least correlation with total body fat percentage (R = 0.03, P = 0.44). Total lean mass in more active boys was 38.1 ± 10.9 and in less active boys was 32.3 ± 11.0 (P < 0.001). The results of multiple regression analysis showed that age and total body lean mass were independent factors of BMD in growing children and adolescents.Conclusions:These findings suggest that lean mass was the most important predictor of BMD in both genders. Physical activity appears to positively impact on lean mass and needs to be considered in physical education and health-enhancing programs in Iranian school children.