A multilevel analysis of condom use among adolescents in the European Union.

OBJECTIVES: This study examined which individual and national factors affect condom use among adolescents. STUDY DESIGN: Multilevel analysis. METHODS: This study reviewed the data on bullying, alcohol use and condom use provided by 18 European countries and subnational entities in the Health Behaviour in School-Aged Children survey. Another eight contextual variables were also analysed. Three multilevel logistic regression models were applied consecutively (analysing for crude geographical and school variance in condom use, adjusting for gender and adjusting all variables for one another). RESULTS: Among the 15-year-olds studied, 7.0% of the total variance in condom use was explained by school-related factors (intraschool-level correlation) and 5.8% by national/subnational factors. In the empty model, condom use was significantly associated with gender, alcohol consumption, predominant national religion and national prevalence of human immunodeficiency virus (HIV). In the full model, there was also a significant association with the Human Development Index ranking, gross domestic product, Gini coefficient and the Gender-related Development Index. CONCLUSIONS: This study suggests that while alcohol, gender, human development level, income, religion and HIV prevalence affect condom use in young Europeans, these factors do not explain all or even most of the variation. Nonetheless, since some of these factors are not traditionally associated with young people's sexual and reproductive health, these findings should enable more nuanced health policy programming.

Vertebral morphometry reference data by X-ray absorptiometry (MXA) in Iranian women.

The anterior, medial, and posterior heights and the A/P and M/P ratios of the spine (T5-L4) in 41 normal premenopausal Iranian women were determined using an imaging densitometer (Expert XL) and dual energy X-ray absorptiometry (DXA) method. All the women were healthy (age 20-39 years, and height 149-171 cm), without any signs of vertebral fractures, and with normal bone mineral density (BMD) of the spine and femoral neck (T-score>-1.5). The vertebral heights were normalized using the Expert XL software, and the average vertebral height for the L2-L4 vertebrae was taken to minimize the effect of variation of body size among the subjects. The Z-score for all vertebral heights (T5-L4) averaged -0.68, with the A/P and M/P ratios coming to +0.34 and +0.49, respectively. It showed the normalization procedure not to correct the differences of vertebral heights in Iranian women. The average of the three heights (H (avg)) correlated fairly well with the stature of the subject (r=0.47, p<0.05), but no correlation was found between H (avg) and subject age (p>0.05). The lower vertebral heights in older women in comparison with the younger women (0.4 mm) obtained in our study can be attributed to the relatively shorter stature of older women (mean 154 vs 159 cm for younger women, p<0.05). It was concluded that the normalization procedure used in the software does not equally apply to Iranian women due to their having different heights than those of American and northern European women, from whom the reference data for the Expert XL software have been gathered. The reference values thus obtained are therefore not accurate for our population group and a separate study with a bigger and more varied sample group is needed for obtaining more definitive results.

Social capital and leisure time physical activity: a population based multilevel analysis in Malmö, Sweden.

OBJECTIVE: To investigate the influence of social capital and individual factors on the level of leisure time physical inactivity in the neighbourhoods. METHODS: The public health survey in Malmö 1994 is a cross sectional study. A total of 5600 people aged 20-80 years were invited to answer a postal questionnaire. The participation rate was 71%. A multilevel logistic regression model, with individuals at the first level and neighbourhoods at the second, was performed. The effect (intra-area correlation, cross level modification, and odds ratios) was analysed of individual and neighbourhood (the 1993 migration out of an area as a proxy for social capital) factors on leisure time physical inactivity after adjustment for individual factors. RESULTS: Neighbourhood factors accounted for 5.0% of the crude total variance in physical inactivity. This effect was significantly reduced when the individual factors, especially country of origin, education, and social participation, were included in the model. In contrast, it was not reduced by the introduction of the contextual social capital variable. CONCLUSION: This study suggests that in the neighbourhoods of Malmö leisure time physical inactivity is mainly affected by individual factors.