This study primarily designed to estimate life expectancies at birth for Iranian rural population, also to assess the application of Vital Horoscope system as a source of mortality information. It was for the first time that data from VH system were corrected due to underreport to estimate life expectancy at birth and the other mortality indices in Iran. The results showed that, life expectancy at birth for males was 71.5 years and for females was 74.4 years. Adjusted child (under 5) mortality rate by sex for males and females was 25.9 and 23.8 per 1000 live births respectively. Adult mortality for males was 167.2 and 98.3 for females per 1000. Besides completeness of the death reporting was 88% for males and 79% for females.
Study by Malekafzali in 1997 showed identical results (70.7 for males and 73.4 for males). This is in spite of the health progress during this time period (19
). It might be because of unadjustment and didn’t consider correction procedure of the rates. A study on estimation of life expectancy for Kohgiloye & Boyer Ahmad Province in 2003 shows same results (70.8 for males and 73.8 for females) (18
). VH data has been used as a source to calculate the health indices including mortality indices but there were no adjustment for death underreporting this may result in over estimation of the life expectancy in the previous studies.
A study based on data from national death registration program in 2003 estimated life expectancy at birth for males and females 70.09 and 73.17 years, respectively. In this study, data on mortality were available only for 23 out o 30 provinces of Iran (20
). Khosravi also estimated life expectancy at birth for 68.7 for males and 71.2 for females. Results of these two national studies are lower than results presented here. These two separate studies had corrected data on death by Growth Balance Method as we did but reported lower Life expectancy than the presented study. Which may indicate the better quality of the data from VH that results in the smaller correction factor was lower in this study compare to mentioned studies (2
According to a report by WHO the life expectancy for the Iranian people in 2008 was 70 years for males and 75 for females taking the consideration it is estimated based on the model and by indirect methods, our results are concordant to them. Also the life expectancy is higher for females, similar to these study findings. Adult mortality rates, estimated by WHO, were 0.153 for males and 0.124 for females, respectively. Compare to the present study the adult mortality rate for males, is higher and it is lower for females. This may be due to the method of the estimation and also the rates projected by WHO are for entire population of Iran but we present the results for rural population only (24
Adjusted adult mortality rate for males was higher than females and was 167.2 and 98.3, respectively. This is concordant to other studies as Khosravi et al. showed higher adult mortality rate for males than females (0.124 for females and 0.175 for males)(2
). Furthermore, national burden of disease study showed the YLL rate (years of potential life lost) was 100.4 year per 1,000 males in comparison with 65.3 years per 1,000 people for females Corrected child (under5) mortality was 29.34 for males and 21.08 for females (25
). Adult mortality rate for male is estimated 0.152 for males and 0.124 for females based on statistical models by WHO (24
), again it is higher for males.
Child mortality rate as the fourth Goal of Millennium Development Goals (MDGs) is an important indicator which reflect the living environmental and economic setting (23
). Moreover, this indicator can reflect both infant mortality rate and child (1–4 year) (27
). In present study, we attempted to estimate it after adjustment for underreport. It was 25.9 and 23.8 per 1000 live births for males and females respectively. These results are consistent to other sources as estimated rates by WHO were 37 per 1000 for males and 28 for females. Although WHO estimates are for the whole population of Iran (24
In order to adjust death rates to construct the life table and estimate life expectancy at birth we assess the Vital Horoscope system to evaluate the completeness of death registration. Results showed this system has an acceptable completeness that it was higher for males than females (88% for males and 79% for females) which is consistent with the study by Pourmalek (90% for males and 79% for females) (20
). This shows that Vital Horoscope system can act as good as a national mortality data source and is a strength point for health information system in Iran.
Stability of the population is one of the assumptions of the Brass Growth Balance method (9
). It is ideal to use data of two censuses which is done by a 10 years interval. In this case it is necessary to have data on mortality between two censuses which were not available now (9
). To under 5 adjustment we used results of Demographic and Health Survey 2000 (DHS) (22
). Due to the fact that there was no new estimation for child mortality rate in rural population based on new survey, we used rates projected based on the results of this study.
This study was carried out to estimate life expectancies at birth for rural population of Iran. Obviously, levels of mortality are different between the provinces. It is suggested to study on inequality in health indicators such as life expectancy at the provincial level of Iran. Although data on VH system are used for estimate various health indicators, it is strongly recommended to investigate the accuracy of data from this system.