Iranian Journal of

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  Background and Objectives : Awareness of the cancer incidence is essential for cancer prevention and control programs. Capture-recapture methods have been recommended for reducing bias and increasing the accuracy of cancer incidence estimation. This study aimed to estimate the incidence of gastric cancer by the capture-recapture method based on Ardabil population-based cancer registry data.

 Methods: All new cases of gastric cancer reported by three sources, i.e. pathology reports, death certificates, and medical records, reported to Ardabil population-based cancer registry between 2006 and 2008 were enrolled in the study. The duplicate cases based on the similarity of the first name, surname, and father's name were identified among sources. The estimated incidence was calculated by the log-linear method using the Stata 12 software.

  Results : A total 857 new cases of gastric cancer were reported from three sources. After removing duplicates, the reported incidence rate was 35.3 and 32.5 per 100,000 population for the years 2006 and 2008, respectively. The estimated incidence rate calculated by the log-linear method for these years was 96.2 and 90.4 per 100,000 population, respectively.

  Conclusion: The results showed that none of the sources of pathology reports, death certificates, and medical records, individually or collectively, fully covered the incidence of gastric cancer. We can obtain more accurate estimates of the incidence rate using the capture-recapture method.

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Background and Objectives: completeness of registration is used as one of the measures of the quality of a cancer registry, which is the degree to which reportable incident cases of cancer in the population of interest is actually recorded in the registry.

Methods: After removing the duplicates, a total of 471 new cases of esophagus cancer reported by three sources of pathology reports, medical records, and death certificates to Ardabil Province Cancer Registry Center in 2006 and 2008 were enrolled in the study. The incidence rate was estimated based on the capture-recapture method and the use of the log-linear models. BIC, G2 and Akaike statistics were used to select the best-fit model.

Results: In this study, a model with linkage between pathology reports and medical records and a model with death certificates alone, independent of the previous two sources, was the best fitted model. The estimated total completeness of esophagus cancer in 2006 and 2008 was 36% .The source that had the most completeness for esophagus cancers was pathology reports with 21.17%. The estimated incidence rate calculated by the log-linear method for the years 2006 and 2008 was 49.71 and 53.87 per 100,000 population, respectively.

Conclusion: Based on the obtained results, it can be concluded that the low degree of completeness in Ardabil Province requires some changes in data abstracting and case finding such as the use of personal national code and electronic health records to create a more accurate cancer registry.

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Background and Objectives: The Covid-19 epidemic began in Wuhan, China in the late 2019 and became a global epidemic in March 2020. In this regard, one of the most important indicators of the healthcare systems is the in-hospital mortality rate, which occurs with a time lag of one to two weeks after hospitalization. The aim of this study was to investigate the relative risk of Covid-19 mortality considering this time lag according to the number of daily hospitalizations.
 
Methods: The data included the number of daily hospitalizations and deaths from Covid-19 from 15 May 2020 to 10 February 2021 in Iran, which was obtained from the Github database. A log-linear distributed lag model was used to evaluate the relationship and lag effect between daily hospitalization and relative risk of death.
 
Results: The mean number of daily hospitalizations and deaths were 1342.2 ± 7 731.5 and 190.6 11±118.6 in the study period, respectively. It was found that an increase in the number of daily hospitalizations had a significant relationship with an increase in the relative risk of death on the same day and in the following days. As the number of hospitalizations exceeded 2000 patients per day, the cumulative relative risk of death increased to more than one.
 
Conclusion: The results showed that the number of hospitalizations exceeding 2000 people per day was an alert for the country's healthcare system. Overall, prevention and observance of health protocols in the first level followed by early diagnosis of the disease, improving the hospitals facilities and preparedness of healthcare staff can reduce the relative risk of death in the possible future peaks.