Menarche age in Iran: A meta-analysis.
BACKGROUND
Research shows that the age at menarche, as an essential element in the reproductive health of women, had been decreasing in the 19(th) and 20(th) centuries, and shows a huge variation across different countries. There are numerous studies performed in Iran reporting a range of age at menarche. Thus, this meta-analysis aimed to determine the overall mean age at menarche of the girls in Iran.


METHODS
All relevant studies were reviewed using sensitive and standard keywords in the databases from 1950 to 2013. Two raters verified a total of 1088 articles based on the inclusion criteria of this study. Forty-seven studies were selected for this meta-analysis. Cochran test was used for samples' homogeneity (Tau-square). The mean age at menarche of the girls in Iran with 95% confidence interval (CI) from the random effects was reported.


RESULTS
The homogeneity assumption for the 47 reviewed studies was attained (Tau-square = 0.00). The mean (95% CI) menarche age of Iranian girls from the random effects was 12.81 (95% CI: 12.56-13.06) years.


CONCLUSIONS
The results of this study showed that mean age at menarche was less than that of some European developed countries such as Switzerland, Sweden, and Denmark, more than that reported in some countries such as Greece and Italy, and similar to the values obtained in the United States of America and Colombia. Lower age at menarche in Iran may be largely attributed to the changes in lifestyle and diet of the children.
Department of Midwifery, School of Nursing and Midwifery, Qazvin University of Medical Sciences, Qazvin, Iran.
Nasim
N
Bahrami
Department of Nursing, School of Nursing and Midwifery, Qazvin University of Medical Sciences, Qazvin, Iran.
Mohammad Ali
MA
Soleimani
Biostatistics Unit, Yong Loo Lin School of Medicine, National University Health System, Singapore.
Yiong Huak
YH
Chan
Liver and Gastrointestinal Disease Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
Morteza
M
Ghojazadeh
Department of Clinical Nutrition and Dietetics, Faculty of Nutrition Sciences and Food Technology, National Nutrition and food Technology Research Institute, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Parvin
P
Mirmiran
Iran; Menarche; meta-analysis