Using Multivariate Capture-Recapture Techniques and Statewide Hospital Discharge Data to Assess the Validity of a Cancer Registry for Epidemiologic Use

Estimation of Completeness of Cancer Registration for Patients Referred to Shiraz Selected Centers through a Two Source Capture Re-capture Method, 2009 Data

BACKGROUND

Cancer has important social consequences with cancer registration as the basis of moving towards prevention. The present study aimed to estimate the completeness of registration of the ten most common cancers in patients referred to selected hospitals in Shiraz, Iran by using capture-recapture method.

MATERIALS AND METHODS

This cross-sectional analytical study was performed in 2014 based on the data of 2009, on a total of 4,388 registered cancer patients. After cleaning data from two sources, using capture-recapture common findings were identified. Then, the percentage of the completeness of cancer registration was estimated using Chapman and Chao methods. Finally, the effects of demographic and treatment variables on the completeness of cancer registration were investigated.

RESULTS

The results showed that the percentages of completeness of cancer registration in the selected hospitals of Shiraz were 58.6% and 58.4%, and influenced by different variables. The age group between 40-49 years old was the highest represented and for the age group under 20 years old was the lowest for cancer registration. Breast cancer had the highest registration level and after that, thyroid and lung cancers, while colorectal cancer had the lowest registration level.

CONCLUSIONS

According to the results, the number of cancers registered was very few and it seems that factors like inadequate knowledge of some doctors, imprecise diagnosis about the types of cancer, incorrectly filled out medical documents, and lack of sufficient accuracy in recording data on the computer cause errors and defects in cancer registration. This suggests a necessity to educate and teach doctors and other medical workers about the methods of documenting information related to cancer and also conduct additional measures to improve the cancer registration system.

Estimation of the gastric cancer incidence in Tehran by two- source capture-recapture

INTRODUCTION

Capture-recapture methods have been suggested for reducing costs of disease registration as well as reducing bias in incidence estimations. This study aimed to estimate the gastric cancer incidence in theTehran metropolis population during 2002-2006.

MATERIALS AND METHODS

We investigated new cases of gastric cancer reported by three sources; death certificates, pathology reports, and medical records to Tehran population-based cancer registry during 2002-2006. G2 statistics and the two-source capture-recapture method were used to select the best-fitted log-linear model and to estimate incidence, respectively. EXCEL software version 2007 and SPSS software version 16 were used for this research.

RESULTS

The number of reported cases was 4,463, with an average age of 68.5 (±12.9) years. We found the model that combined two sources of data including pathology reports and medical records and furthermore complemented by death certificates as the best model. The reported and the estimated incidences were 11.0 and 27.1 per 100,000 respectively.

CONCLUSIONS

The incidence estimated by two- source capture-recapture method is about three times higher than the incidence reported by the sources under investigation. It is recommended to move towards the implementation of population-based cancer registration using various sources of data collection to achieve more accurate data.

Estimation of esophageal cancer incidence in Tehran by log- linear method using population-based cancer registry data

BACKGROUND

Having knowledge or estimation of cancer incidence is necessary for planning and implementation of any cancer prevention and control programs. Population-based registries provide valuable information to achieve these objectives but require extra techniques to estimate the incidence rate. The present study aimed to estimate the esophageal cancer incidence using a log-linear method based on Tehran population-based cancer registry data.

MATERIALS AND METHODS

New cases of esophageal cancer reported by three sources of pathology reports, medical records, and death certificates to Tehran Metropolitan Area Cancer Registry Center during 2002-2006 were entered into the study and the incidence rate was estimated based on log-linear models. We used Akaike statistics to select the best-fit model.

RESULTS

During 2002-2006, 1,458 new cases of esophageal cancer were reported by the mentioned sources to the population-based cancer registry. Based on the reported cases, cancer incidence was 4.5 per 100,000 population and this was estimated to be 10.5 per 100,000 by the log-linear method.

CONCLUSIONS

Based on the obtained results, it can be concluded that an estimated incidence for 2004 of 8.3 per 100,000 population could be a good benchmark for the incidence of esophageal cancer in the population of Tehran metropolis.