Journal of School of Public Health and

This cross- sectional study was done to assess the prevalence of chronic cough by age and date of birth (age-period-cohort analysis). Using data from two National Health Surveys in 1991 and 1999 (involving cross-sectional general population samples), we studied all cases of chronic cough recorded during the period of 1991 to 1999 in people aged 2 to 70 years. A birth cohort analysis was performed on the data. Comparison with earlier surveys showed that the prevalence of chronic cough had fallen from 4.5% to 1.8%. Age-period-cohort analyses of the age effect revealed that prevalence rate of chronic cough increased with age but in every age group it actually decreased after the 8-year period. The fact that different trends are observed in cross-sectional and cohort data points to a strong cohort effect. the prevalence of chronic cough is strongly determined by a person’s year of birth. Also for any given age group, prevalence rates were lower in younger compared to older cohorts.

Background and Aim: The present article attempts to define the current trend for age at first marriage, based on the nationwide Health Survey of 1999 and using the Brass model.

Material and Methods: The national Health survey was conducted in 1999 and involved 1/1000 of the total population, selected via cluster sampling (clusters of 8 households each).

The sample used for the present study consisted of 16000 women aged 15-49, including 3026 women in Tehran province. Variables used for analysis were current age, marital status, age at first marriage and residential area (urban/rural). The mean age at first marriage for married women was 17.8 years (sd=3.7) for the whole country, and 18.2 years (sd=3.7) for Tehran province.

Results: The Brass model fitted to the data revealed a significant decreasing trend for the proportion of married women in all age groups, especially in the 15-19 year-old category.

Conclusion: This obviously indicates an upward trend for age at first marriage.