Iranian Journal of

Recently, capture-recapture studies have been used and researchers tend to use these studies in the health field. Therefore, we discussed the basic concepts of these studies. First, we described capture-recapture studies. Then, the important assumptions and calculations were presented according to the close population assumption. Statistical formulas were presented for two-capture methods and dependency between the two lists was discussed. Then, we addressed more than two capture methods.

  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.

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.