An application of the two-source capture-recapture method to estimate the completeness of the Tuscany Cancer Registry, Italy

Five-year lung cancer mortality risk analysis and topography in Xuan Wei: a spatiotemporal correlation analysis

Background

In Xuan Wei, China, the lung cancer mortality rate is rising significantly more than that of the nation overall. However, it remains unclear 1) if improved diagnosis can just partially explain this observation and how other local risk factors may be correlated with the lung cancer mortality rate and 2) how the lung cancer mortality rates differ within Xuan Wei and how these spatiotemporal patterns are linked with local risk factors. To increase etiological knowledge, this study evaluated the spatial and temporal distributions of the health effects (the lung cancer mortality rates) from 2011 to 2015.

Methods

Four steps of spatial analysis were applied, as follows: 1) hotspot analysis to determine the geographical patterns of lung cancer mortality, 2) spatially-weighted sum to identify areas with higher health risks, 3) bivariate statistical analysis to assess the overall correlation between coal mines and lung cancer mortality, and 4) geographically-weighted regression to test for correlations among different towns within Xuan Wei.

Results

Women had higher lung cancer mortality rates than those in men, with an increasing trend in both sexes over time. The incidence rates in Laibin Town were the highest in Xuan Wei every year. Over the 5-year study period, the lung cancer mortality was increasingly concentrated in Laibin, Shuanglong, and Longchang, where the smoky coal mines are most concentrated. The population-level health risks from the coal mine in Xuan Wei were mapped and divided into five types of risk areas (Type I – Type IV). Correlation analysis revealed that there was no significant correlation between lung cancer mortality as a whole and coal mine distribution during the 5-year study period. However, the geographically-weighted regression revealed a stronger correlation in medium (Type III) and second-lowest (Type IV) health risks.

Conclusions

Xuan Wei lung cancer mortality has increased continuously since the third national retrospective surveys on the causes of death by the Ministry of Health of the People’s Republic of China (2004–2005), especially for local women and residents over 35 years of age. Geographically, lung cancer in Xuan Wei showed unique spatiotemporal clustering. The local lung cancer mortality was significantly correlated with the smoky coal mine geographically. Some specific towns (Laibin, Shuanglong, and Longchang) within Xuan Wei manifested high correlations between lung cancer mortality and coal mines. The effects of coal mines on lung cancer mortality rates also spread geographically outward from these areas. Public health concern regarding lung cancer in Xuan Wei should prioritize higher-risk towns surrounded by smoking coal mines. Intervention strategies for particular toxic coal types require further studies on their chemical characteristics and mechanisms of carcinogenesis. Additional studies are also warranted to systematically examine the local environmental health risks related to coal industries and combustion air pollution and eventually to conduct early screening of lung cancer for local people who are more exposed to smoky coal in high-risk areas.

Estimating the Esophagus Cancer Incidence Rate in Ardabil, Iran: A Capture-Recapture Method

Background:

Accurate cancer registry and awareness of cancer incidence rate is essential in order to define strategies for cancer prevention and control programs. Capture-recapture methods have been recommended for reducing bias and increase the accuracy of cancer incidence estimation.

Objectives:

This study aimed to estimate the esophagus cancer incidence by capture-recapture method based on Ardabil population-based cancer registry data.

Patients and Methods:

Total 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. All duplicated cases between three sources were identified and removed using Excel software. Some characteristics such as name, surname, father’s name, date of birth and ICD codes related to their cancer type were used for data linkage and finding the common cases among three sources. The incidence rate per 100,000 was estimated based on capture-recapture method using the log-linear models. We used BIC, G² and AIC statistics to select the best-fit model.

Results:

After removing duplicates, total 471 new cases of esophagus cancer were reported from three sources. The model with linkage between pathology reports, medical record sources and independence with the death certificates source was the best fitted model. The reported incidence rate for the years 2006 and 2008 was 18.77 and 18.51 per 100,000, respectively. In log-linear analysis, the estimated incidence rate for the years 2006 and 2008 was 49.71 and 53.87 per 100,000 populations, respectively.

Conclusions:

Based on the obtained results, it can be concluded that none of the sources of pathology reports, death certificates and medical records individually or collectively were fully covered the incidence cases of esophagus cancer and need to apply some changes in data abstracting and case finding.

Data quality at the Singapore Cancer Registry: An overview of comparability, completeness, validity and timeliness

AIM

To provide a comprehensive evaluation of the quality of the data at the Singapore Cancer Registry (SCR).

METHODS

Quantitative and semi-quantitative methods were used to assess the comparability, completeness, accuracy and timeliness of data for the period of 1968-2013, with focus on the period 2008-2012.

RESULTS

The SCR coding and classification systems follow international standards. The overall completeness was estimated at 98.1% using the flow method and 97.5% using the capture-recapture method, for the period of 2008-2012. For the same period, 91.9% of the cases were morphologically verified (site-specific range: 40.4-100%) with 1.1% DCO cases. The under-reporting in 2011 and 2012 due to timely publication was estimated at 0.03% and 0.51% respectively.

CONCLUSION

This review shows that the processes in place at the SCR yields data which are internationally comparable, relatively complete, valid, and timely, allowing for greater confidence in the use of quality data in the areas of cancer prevention, treatment and control.

Estimating the completeness of gastric cancer registration in Ardabil/Iran by a capture-recapture method using population-based cancer registry data

BACKGROUND

Knowledge of cancer incidences is essential for cancer prevention and control programs. Capture-recapture methods have been recommended for reducing bias and increasing the accuracy of cancer incidence estimations. This study aimed to estimate the completeness of gastric cancer registration by the capture-recapture method based on Ardabil population-based cancer registry data.

MATERIALS AND METHODS

All new cases of gastric cancer reported by three sources, pathology reports, death certificates and medical records that reported to Ardabil population-based cancer registry in 2006 and 2008 were enrolled in the study. The duplicate cases based on the similarity of first name, surname and fathers names were identified between sources. The estimated number of gastric cancers was calculated by the log-linear method using Stata 12 software.

RESULTS

A total of 857 new cases of gastric cancer were reported from three sources. After removing duplicates, the reported incidence rates for the years 2006 and 2008 were 35.3 and 32.5 per 100,000 population, respectively. The estimated completeness calculated by log-linear method for these years was 36.7 and 36.0, respectively.

CONCLUSIONS

These results indicate that none of the sources of pathology reports, death certificates and medical records individually or collectively fully cover the incident cases of gastric cancer. We can obtain more accurate estimates of incidence rates using the capture-recapture method.

A prediction model to estimate completeness of electronic physician claims databases

OBJECTIVES

Electronic physician claims databases are widely used for chronic disease research and surveillance, but quality of the data may vary with a number of physician characteristics, including payment method. The objectives were to develop a prediction model for the number of prevalent diabetes cases in fee-for-service (FFS) electronic physician claims databases and apply it to estimate cases among non-FFS (NFFS) physicians, for whom claims data are often incomplete.

DESIGN

A retrospective observational cohort design was adopted.

SETTING

Data from the Canadian province of Newfoundland and Labrador were used to construct the prediction model and data from the province of Manitoba were used to externally validate the model.

PARTICIPANTS

A cohort of diagnosed diabetes cases was ascertained from physician claims, insured resident registry and hospitalisation records. A cohort of FFS physicians who were responsible for the diagnosis was ascertained from physician claims and registry data.

PRIMARY AND SECONDARY OUTCOME MEASURES

A generalised linear model with a γ distribution was used to model the number of diabetes cases per FFS physician as a function of physician characteristics. The expected number of diabetes cases per NFFS physician was estimated.

RESULTS

The diabetes case cohort consisted of 31,714 individuals; the mean cases per FFS physician was 75.5 (median = 49.0). Sex and years since specialty licensure were significantly associated (p < 0.05) with the number of cases per physician. Applying the prediction model to NFFS physician registry data resulted in an estimate of 18,546 cases; only 411 were observed in claims data. The model demonstrated face validity in an independent data set.

CONCLUSIONS

Comparing observed and predicted disease cases is a useful and generalisable approach to assess the quality of electronic databases for population-based research and surveillance.

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.

Bayesian estimation of a cancer population by capture-recapture with individual capture heterogeneity and small sample

BACKGROUND

Cancer incidence and prevalence estimates are necessary to inform health policy, to predict public health impact and to identify etiological factors. Registers have been used to estimate the number of cancer cases. To be reliable and useful, cancer registry data should be complete. Capture-recapture is a method for estimating the number of cases missed, originally developed in ecology to estimate the size of animal populations. Capture recapture methods in cancer epidemiology involve modelling the overlap between lists of individuals using log-linear models. These models rely on assumption of independence of sources and equal catchability between individuals, unlikely to be satisfied in cancer population as severe cases are more likely to be captured than simple cases.

METHODS

To estimate cancer population and completeness of cancer registry, we applied M(th) models that rely on parameters that influence capture as time of capture (t) and individual heterogeneity (h) and compared results to the ones obtained with classical log-linear models and sample coverage approach. For three sources collecting breast and colorectal cancer cases (Histopathological cancer registry, hospital Multidisciplinary Team Meetings, and cancer screening programmes), individual heterogeneity is suspected in cancer population due to age, gender, screening history or presence of metastases. Individual heterogeneity is hardly analysed as classical log-linear models usually pool it with between-"list" dependence. We applied Bayesian Model Averaging which can be applied with small sample without asymptotic assumption, contrary to the maximum likelihood estimate procedure.

RESULTS

Cancer population estimates were based on the results of the M(h) model, with an averaged estimate of 803 cases of breast cancer and 521 cases of colorectal cancer. In the log-linear model, estimates were of 791 cases of breast cancer and 527 cases of colorectal cancer according to the retained models (729 and 481 histological cases, respectively).

CONCLUSIONS

We applied M(th) models and Bayesian population estimation to small sample of a cancer population. Advantage of M(th) models applied to cancer datasets, is the ability to explore individual factors associated with capture heterogeneity, as equal capture probability assumption is unlikely. M(th) models and Bayesian population estimation are well-suited for capture-recapture in a heterogeneous cancer population.

Estimation of cancer cases using capture-recapture method in Northwest Iran

BACKGROUND

Under-ascertainment and over-ascertainment are common phenomena in surveillance and registry systems of health-related events. Capture-recapture is one of the methods which is applied to determine the sensitivity of surveillance or registry systems to recognize cancer cases. This study aimed to estimate the number of cancers using data available both in the Cancer Registry Center of Northwestern Iran and in the Population-based Cancer Registry Center of Iran.

MATERIAL AND METHODS

The studied population consisted of all cancerous cases in the northwest of Iran from 2008 to 2010. All data were extracted from two resources and entered into Microsoft Excel software. After removing common and repeat cases the data were statistically analyzed using a capture-recapture studies' specific software "CARE 1.4". Estimations were calculated by Chapman and Petersen methods with the approximate confidence interval of 95%.

RESULTS

From 2008 to 2010, the number of all cancer cases was estimated to be 21,652 (CI 95%: 19,863-22,101). Sensitivity rate of all cancer cases was 83.9% and that of Population-based Cancer Registry Center of Iran was 52%. It was 93.1% considering both resources.

CONCLUSION

Using two resources and the capture-recapture method rather than a single resource may be a more reliable method to estimate the number of cancer cases.

A practical framework for data management processes and their evaluation in population-based medical registries

INTRODUCTION

We present a framework for data management processes in population-based medical registries. Existing guidelines lack the concreteness we deem necessary for them to be of practical use, especially concerning the establishment of new registries. Therefore, we propose adjustments and concretisations with regard to data quality, data privacy, data security and registry purposes.

MATERIALS AND METHODS

First, we separately elaborate on the issues to be included into the framework and present proposals for their improvements. Thereafter, we provide a framework for medical registries based on quasi-standard-operation procedures.

RESULTS

The main result is a concise and scientifically based framework that tries to be both broad and concrete. Within that framework, we distinguish between data acquisition, data storage and data presentation as sub-headings. We use the framework to categorise and evaluate the data management processes of a German cancer registry.

DISCUSSION

The standardisation of data management processes in medical registries is important to guarantee high quality of the registered data, to enhance the realisation of purposes, to increase efficiency and to enable comparisons between registries. Our framework is destined to show how one central impediment for such standardisations - lack of practicality - can be addressed on scientific grounds.

Inpatient electronic prescribing data can be used to identify 'lost' discharge codes for diabetes

AIM

Accurate assessment of missed discharge codes for diabetes is critical for effective planning of hospital diabetes services. We wished to estimate the frequency of missed discharge diagnostic codes for diabetes and the impact missed codes would have on diabetes-related payments to the hospital.

METHODS

We linked Patient Administration System data to the Prescribing Information and Communication System. We defined diabetes as those having a discharge code for diabetes in the Patient Administration System and those on anti-diabetic medication in the Prescribing Information and Communication System. Based on the two sources, we calculated the estimated missed discharge codes for diabetes using the capture-recapture technique. We generated the Healthcare Resource Group for a given admission before and after correction for the missed code to estimate the impact that correction would make on payments to the hospital.

RESULTS

Among the 171 067 admissions linked, 22 412 (13.1%) had a code for diabetes at discharge. An additional 2706 admissions were classified as having diabetes based on prescription data. The capture-recapture technique estimated there were 4588 (2.7% of all admissions) admissions with diabetes missed by current coding, of which 2706 (60%) would be obtained from prescription data. After adding a diabetes diagnostic code, 12.8% of the missed admissions with diabetes resulted in a change to the Healthcare Resource Group tariff code and payment.

CONCLUSION

The use of electronic prescription data is a simple solution to correct for missed discharge diagnostic codes.

A comparison of two surveillance strategies for selected birth defects in Florida

OBJECTIVE

We linked data from two independent birth defects surveillance systems with different case-finding methods in an overlapping geographic area to assess Florida's suveillance of birth defects (e.g., neural tube defects, orofacial clefts, gastroschisis/omphalocele, and chromosomal defects), focusing on sensitivity and completeness of ascertainment measures.

METHODS

Live-born infants identified from each system born during 2003-2006 in a nine-county catchment area with specific birth defects were linked to birth certificates. Using the enhanced surveillance system as a gold standard, we calculated the sensitivity of the Florida Birth Defects Registry (FBDR) for identifying infants. Next, we used capture-recapture models to estimate the completeness of case ascertainment and the prevalence of each birth defect in the catchment area. We used multivariable logistic regression models with backward elimination to estimate adjusted odds ratios and 95% confidence intervals for factors significantly associated with the FBDR's failure to capture infants ultimately identified by enhanced surveillance.

RESULTS

The FBDR's sensitivity was 89.3%, and the overall completeness of ascertainment was estimated as 86.6%. Defect-specific sensitivity and completeness of ascertainment varied significantly by defect. The combined defect-specific sensitivity for all malformations under study was 86.6%; completeness of ascertainment ranged from 45.6% for anencephaly to 88.6% for Down syndrome, 87.9% for spina bifida without anencephaly, and 87.0% for orofacial clefts.

CONCLUSIONS

For the defects under study, the FBDR captured nearly nine of every 10 infants born with selected birth defects. However, the FBDR's ability to identify specific defects was both more limited and defect dependent with widely varying defect-specific sensitivities.

Evaluation of data quality at the Gambia national cancer registry

The Gambia National Cancer Registry (GNCR) is one of the few nationwide population-based cancer registries in sub-Saharan Africa. Most registries in sub-Saharan Africa are limited to cities; therefore, the GNCR is important in providing estimates of cancer incidence in rural Africa. Our study assesses the quality of its data. The methods proposed by Bray and Parkin, and Parkin and Bray (Eur J Cancer 2009;45:747-64) were applied to the registry data from 1990 to 2009 to assess comparability, validity and completeness. The system used for classification and coding of neoplasms followed international standards. The percentage of cases morphologically verified was 18.1% for men and 33.1% for women, and that of death certificate only cases was 6.6 and 3.6%, respectively. Incidence rates in rural regions were lower than in the urban part of the country, except amongst young male adults. Comparison with other West African registries showed that the incidences of liver and uterine cervical cancer were comparable, but those of prostate and breast in The Gambia were relatively low. The overall completeness was estimated at 50.3% using the capture-recapture method. The GNCR applies international standard practices to data collection and handling, providing valuable data on cancer incidence in sub-Saharan Africa. However, the data are incomplete in the rural and elderly populations probably because of health care access and use.

Investigating the completeness of a histopathological cancer registry: estimation by capture-recapture analysis in a French geographical unit Alpes-Maritimes, 2008

INTRODUCTION

Cancer population studies require reliable and complete baseline data, which should theoretically be available by collecting histopathology records. The completeness of such a collection was evaluated using capture-recapture analysis based on three data sources concerning breast and colorectal cancers over an identical period and within the same geographical area.

METHOD

The total number of breast and colon cancer cases was estimated using capture-recapture analysis based on the number of cases which were common or not between sources recording screened, diagnosed and treated cancers in the French Alpes Maritimes district.

RESULT

The estimated total number of new cases of breast cancer diagnosed among Alpes Maritimes residents women aged 50-75 was 791 (95% CI: 784-797) in 2008. Of these 791 cases, 729 were identified through histopathology records, thus amounting to 92.2% completeness (95% CI: 91.5-93.0%). The total estimated number of new cases of colorectal cancer diagnosed among Alpes Maritimes residents aged 50-75 was 527 (95% CI: 517-536). Of these 527 cases, 481 were identified through histopathology records, thus amounting to 91.3% completeness (95% CI: 89.7-93.0%).

CONCLUSION

The estimated completeness of cancer records collected from histopathology laboratories was higher than 90% for new cases of breast and colorectal cancer within the age range concerned by the screening programme. A verified and validated histopathology data collection may be useful for cancer population studies.

Completeness of hepatitis, brucellosis, syphilis, measles and HIV/AIDS surveillance in Izmir, Turkey

Background

According to the surveillance system in Turkey, most diseases are notified only by clinicians, without involving laboratory notification. It is assumed that a considerable inadequacy in notifications exists; however, this has not been quantified by any researcher. Our aim was to evaluate the completeness of communicable disease surveillance in the province of Izmir, Turkey for the year of 2003 by means of estimating the incidences of diseases.

Methods

Data on positive laboratory results for the notifiable and serologically detectable diseases hepatitis A, B, C, brucellosis, syphilis, measles and HIV detected in 2003 in Izmir (population 3.5 million) were collected from serology laboratories according to WHO surveillance standards and compared to the notifications received by the Provincial Health Directorate. Data were checked for duplicates and matched. Incidences were estimated with the capture-recapture method. Sensitivities of both notifications and laboratory data were calculated according to these estimates.

Results

Among laboratories performing serologic tests (n = 158) in Izmir, 84.2% accepted to participate, from which 23,515 positive results were collected. Following the elimination of duplicate results as well as of cases residing outside of Izmir, the total number was 11,402. The total number of notifications was 1802. Notification rates of cases found in laboratories were 31.6% for hepatitis A, 12.1% for acute hepatitis B, 31.8% for brucellosis, 25.9% for syphilis and 100% for HIV confirmation.

Conclusions

It was discovered that for hepatitis A, B, C, brucellosis and syphilis, there is a considerable under-notification by clinicians and that laboratory data has the potential of contributing greatly to their surveillance. The inclusion of laboratories in the surveillance system of these diseases could help to achieve completeness of reporting.

Evaluation of data quality in the cancer registry: principles and methods Part II. Completeness

The completeness of cancer registry data -- the extent to which all of the incident cancers occurring in the population are included in the registry database -- is an extremely important attribute of a cancer registry. Only a high degree of completeness in case-finding procedures will ensure cancer incidence rates and survival proportions are close to their true value. This second instalment of a two-part review of data quality methods at the cancer registry, focuses on the principles and techniques available for estimating completeness, separating methods into those that are semi-quantitative -- in that they give an indication of the degree of completeness relative to other registries or over time, and more quantitative techniques -- those that provide a numerical evaluation of the extent to which all eligible cases have been registered.

Comparison with manual registration reveals satisfactory completeness and efficiency of a computerized cancer registration system

Automated software for cancer registration, called Open Registry and developed by ourselves was adopted by the Varese (population-based) Cancer Registry starting from 1997. Since the use of automated cancer registration is increasing, it is important to assess the quality and completeness of the automated data being produced. In this study, we assessed the completeness of the automatically generated data by comparison with a gold standard of all cases identified by manual and automatic systems for the year 1997 when the automated system was introduced, and the manual system was still in operation. We also evaluated the efficiency of the automated system. 5027 cases were generated automatically; 2959 (59%) were accepted automatically and 2068 (41%) were flagged for manual checking. Sixty-nine cases (1.3%) were not recorded automatically, the most common reason (0.8%) being that the incidence record was dated 1998, even though the case was incident in 1997. A total of 98.7% of all cases found were picked up by the automated system. A completeness figure of 98.7% indicates that the automatic procedure is a valid alternative to manual methods for routine case generation. The fact that 59% of cases were registered automatically indicates that the system can speed up data production and enhance registry efficiency.

Problems in using birth certificate files in the capture-recapture model to estimate the completeness of case ascertainment in a population-based birth defects registry in New York State

BACKGROUND

The limitations and underlying assumptions of the capture-recapture methods have hindered their application in epidemiological settings, especially in evaluating the completeness of birth defects registries. This study explored the possibility of using birth certificates as the secondary data source in a simple two-source capture-recapture model to estimate the completeness of case ascertainment of the Congenital Malformations Registry (CMR) for selected major birth defects.

METHODS

The CMR and the birth certificates were used as the primary and secondary sources, respectively. Children who were born in 1996-2001 and had selected major birth defects were identified from the two sources. The accuracy of the diagnoses was examined by comparing the individual birth defect categories of the children from the two sources.

RESULTS

Discrepancies in birth defect categories in the two data sources and false positives in the birth certificates were the major problems encountered in estimating the completeness of the CMR using the simple two-source capture-recapture method. The estimated completeness for selected major birth defects was only about 71%. Stratified analyses resulted in relatively high estimated completeness for oral clefts (90%) and Down syndrome (88%). CONCLUSIONS Although the birth certificate data was not a good source for estimating the completeness of case ascertainment of the CMR using capture-recapture methods, the analyses provided reasonable estimates for some conditions that were relatively easy to identify and diagnose at birth, such as oral clefts and Down syndrome.

Using Medicare Data to Estimate the Number of Cases Missed by a Cancer Registry

BACKGROUND

Cancer surveillance is essential for assessing patterns of cancer occurrence. State cancer registries do not capture all available cases potentially biasing results. Secondary data may be useful in identifying new cases and estimating the number of cases missed.

OBJECTIVE

We sought to create 2 distinct data sources from Medicare claims to use in combination with registry data as 3 sources for a capture-recapture analysis to estimate the capture rate and bias in capture of a statewide cancer registry.

METHODS

Data from the Virginia cancer registry (Registry) were merged with Medicare inpatient (Part A) as well as Medicare outpatient and physician claims (Part B) to provide 3 sources to estimate missing cases. A 3-source loglinear model was used to estimate the number of missing cancer cases for breast, lung, colorectal, and prostate cancer. Models included main effects and interactions. Additional analysis looked at the effect of demographic and comorbidity variables.

RESULTS

Loglinear models demonstrated mostly positive dependence between the 3 sources, implying that 2-source models would underestimate missing cases and overestimate capture rates. Using capture-recapture estimates of total number of cancer cases as the denominator, capture rates for Registry ranged from 59% (colorectal) to 74% (lung). When the aggregate of cases found by either Medicare or Registry were used the capture rates ranged from 74% (prostate) to 89% (breast). Further analysis indicated that capture rates differed by demographic characteristics.

CONCLUSION

We conclude that Medicare claims are useful to supplement a Registry, estimate the number of missing cases, and assess bias in capture.

Increasing trends of cervical adenocarcinoma incidence in Central Italy despite Extensive Screening Programme, 1985–2000

Incidence rates of adenocarcinoma of the uterine cervix have been reported to be increasing in several countries, but not in Italy. The aim of the present study was to analyse trends in cervical cancer incidence by histological type in two districts of Central Italy (Florence and Prato), covered by the Tuscany Cancer Registry (RTT), where cytological screening had been available since the 1970s. Incident cervical cancers during 1985-2000 were 1012. Estimated Annual Percent Change (EAPC) by age-groups and histological type were computed. Incidence increased for adenocarcinoma (EAPC = +5.7%; 95% confidence interval (CI)+2.8; +8.6); whereas, it decreased for squamous cancer (EAPC = -1.9%; 95% CI-3.8; 0) and for other or not specified types (EAPC = -4.4%; 95% CI-10.0; +1.5). Adenocarcinoma increased significantly among younger women (<55 years) but not among older ones, whereas squamous cell cancer decreased among older women only. The burden of cervical cancers might increase in the future if no specific preventive strategies for adenocarcinoma are implemented.

Unexpected reduction of mortality rates from melanoma in males living in central Italy

A registry-based study has been carried out in central Italy to investigate cutaneous melanoma incidence and mortality trends. The incidence of invasive (1492 cases analysed) and in situ (224 cases) cutaneous melanomas increased significantly from 1985 to 1997, in both genders. The increase of invasive tumours was mainly due to 'thin' (<or=1.00 mm) lesions, while thick ones showed stable rates. From 1985 to 1999, we evidenced a statistically significant decrease in mortality among males, the estimated annual percent change (EAPC) was -3.3%/year (P<=0.012), but this was not observed among females (EAPC=0.2, P=0.896). The stage at diagnosis was worse for males than females at the beginning of the analysed period, therefore the former had more possibilities for improvement than females. This may partially explain this finding since mortality rates among females were also quite low during the late 1980s. However, the stable incidence rates of the thick forms of melanoma make this finding largely unexpected, and difficult to understand assuming that in the last decade no 'clear-cut' improvements in survival have been documented as a result of new treatments in advanced melanomas.