Abstract
Background. Under count is a common phenomenon in health systems. One of the methods used for sensitivity identification of care system or identification of cases in registry is capture recapture method. Using two resources, this study aimed to estimate the actual mortality rates of under five-year-old children.
Methods. This study was conducted by capture-recapture method (two resources), using the recorded data in death cause systems of the Iranian Ministry of Health and Medical Education (MOHME) and Treatment and Registry Office. The population included all children aged five years in Tabriz, Iran. We also considered all the death cases in the target population from 2020.03.20 to 2021.03.20. The death cases were extracted from two resources and entered into the Microsoft Excel software. After removing duplicate cases with a special formula, we obtained the actual mortality rates using capture-recapture method with 95% confidence interval (CI) and estimated the actual mortality rates and death cases.
Results. In 2020, the death rate of under five-year-old children was calculated to be 344 cases (338 to 350 with 95% CI). The sensitivity rate of causal registry system for all death cases in the target population was 43.17%. Also, the mortality rate of under one-year-old children was calculated as 275 cases (271 to 280 with 95% CI). While the sensitivity rate of causal death for the mortality of under one-year-old children was 92.72%, it was 82.28% for the Registry Office.
Conclusion. A combination of different software for death information registry and the registration of information in the occurrence location could be efficient techniques to reduce under count registrations. It is believed that better and more reliable information could be obtained on death case numbers through using two lists and capture-recapture method compared to using one of the two resources.
Extended Abstract
Background
The mortality rate of children in Iran is not accurate due to different reasons, including no hospital reports or reports of stillbirths instead of death of newborns, inaccuracy of physicians issuing death certificates regardless of death reports in rural areas, not reporting death cases lacking a birth certificate, etc. In addition, generally, the registration of mortality cases is low in the country. In some cases, the mortality rates of provinces do not necessarily match those of the country, being below the country rates, which suggests the possibility of under-count. Capture-recapture method is used to identify the care system sensitivity or record the cases. Using two resources, this research aimed to identify the actual mortality rates of under five-year-old children in Tabriz, Iran.
Methods
Capture-recapture method was used for the first time by Peterson in 1896 for the estimation of fish population in one area. The first idea of these studies is very simple. At first, a random sampling is done in a population (society), and the marked samples are returned to the society. It is assumed that these marked samples are distributed freely between other sampling units. After that, using another sampling and rates of marked numbers in the second sample, the total number of the society is estimated. This study was conducted by capture-recapture method (two resources), using the recorded data in death cause systems of the Iranian Ministry of Health and Medical Education (MOHME) and Treatment and Registry Office. The studied population included all children aged under five years old in Tabriz and the deaths occurred in 2020. The death cases were extracted from two resources and entered into the Microsoft Excel software; the typographical mistakes in the common information were studied and corrected. In the next step, the information was arranged by name, last name, father's name, mother's name, and age. After finding and removing duplicates using Chapman's special formula, Poisson distribution, and 95% confidence interval (CI), the number of deaths was obtained and the mortality rate was calculated.
Results
According to registration organization reports, a total of 21,850 alive birth cases were reported in Tabriz in 2020. Using the recorded data in death cause systems of the MOHME and Treatment and Registry Office, there were 631 death cases related to under five-year-old children in Tabriz; 353 cases were registered in the causal death records and 278 cases were registered in the civil registration organization. These rates for under one-year-old children were 523, 279, and 244 cases, respectively. At the city level, the obtained mortality rates were lower than those of the province and country. The accurate estimation of children's mortality was achieved by 95% accuracy, using the obtained capture-recapture method. The average estimates of under five-year-old children's death were calculated as 344 cases, and the actual mortality rate of five-year-old children was calculated to be 15.75 in one thousand alive births. This rate had been reported about 14.69 in one thousand in causal death programs (4.27 discrepancy), and about 11.48 in one thousand (1.06 discrepancy and in registration organization). In the case of under one-year-old children's death, the average mortality was found 275 cases and the actual rate was calculated 12.51 cases. This rate was reported 11.67 in one thousand in causal death program (with 0.84 discrepancy) and 10.34 in one thousand (with 2.17 discrepancy) in civil registration organization. According to the obtained results, there were undercounts in the two resources; in this year, the sensitivity of causal death program for all under five-year-old children's death was 93.58%, while it was 73.17% for the civil registration organization. Regarding under one-year-old children’s death, this rate was 92.72% for causal death program and 82.28% for civil registration organization.
Conclusion
It seems necessary to complete the software data and prevent undercount registration or delay in registration through recording information in the death place. To improve this information, it is necessary to provide adequate training for the personnel directly responsible for issuing the death certificates. It is suggested that by using two sources and the catch-and-catch method, a better estimate of the number of deaths can be obtained compared to using each of the sources alone.