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

The National Cancer Database Conforms to the Standardized Framework for Registry and Data Quality

BACKGROUND

Standardization of procedures for data abstraction by cancer registries is fundamental for cancer surveillance, clinical and policy decision-making, hospital benchmarking, and research efforts. The objective of the current study was to evaluate adherence to the four components (completeness, comparability, timeliness, and validity) defined by Bray and Parkin that determine registries' ability to carry out these activities to the hospital-based National Cancer Database (NCDB).

METHODS

Tbis study used data from U.S. Cancer Statistics, the official federal cancer statistics and joint effort between the Centers for Disease Control and Prevention (CDC) and the National Cancer Institute (NCI), which includes data from National Program of Cancer Registries (NPCR) and Surveillance, Epidemiology, and End Results (SEER) to evaluate NCDB completeness between 2016 and 2020. The study evaluated comparability of case identification and coding procedures. It used Commission on Cancer (CoC) standards from 2022 to assess timeliness and validity.

RESULTS

Completeness was demonstrated with a total of 6,828,507 cases identified within the NCDB, representing 73.7% of all cancer cases nationwide. Comparability was followed using standardized and international guidelines on coding and classification procedures. For timeliness, hospital compliance with timely data submission was 92.7%. Validity criteria for re-abstracting, recording, and reliability procedures across hospitals demonstrated 94.2% compliance. Additionally, data validity was shown by a 99.1% compliance with histologic verification standards, a 93.6% assessment of pathologic synoptic reporting, and a 99.1% internal consistency of staff credentials.

CONCLUSION

The NCDB is characterized by a high level of case completeness and comparability with uniform standards for data collection, and by hospitals with high compliance, timely data submission, and high rates of compliance with validity standards for registry and data quality evaluation.

Development and quality appraisal of a new English breast screening linked data set as part of the age, test threshold, and frequency of mammography screening (ATHENA-M) study

OBJECTIVES

To build a data set capturing the whole breast cancer screening journey from individual breast cancer screening records to outcomes and assess data quality.

METHODS

Routine screening records (invitation, attendance, test results) from all 79 English NHS breast screening centres between January 1, 1988 and March 31, 2018 were linked to cancer registry (cancer characteristics and treatment) and national mortality data. Data quality was assessed using comparability, validity, timeliness, and completeness.

RESULTS

Screening records were extracted from 76/79 English breast screening centres, 3/79 were not possible due to software issues. Data linkage was successful from 1997 after introduction of a universal identifier for women (NHS number). Prior to 1997 outcome data are incomplete due to linkage issues, reducing validity. Between January 1, 1997 and March 31, 2018, a total of 11 262 730 women were offered screening of whom 9 371 973 attended at least one appointment, with 139 million person-years of follow-up (a median of 12.4 person years for each woman included) with 73 810 breast cancer deaths and 1 111 139 any-cause deaths. Comparability to reference data sets and internal validity were demonstrated. Data completeness was high for core screening variables (>99%) and main cancer outcomes (>95%).

CONCLUSIONS

The ATHENA-M project has created a large high-quality and representative data set of individual women's screening trajectories and outcomes in England from 1997 to 2018, data before 1997 are lower quality.

ADVANCES IN KNOWLEDGE

This is the most complete data set of English breast screening records and outcomes constructed to date, which can be used to evaluate and optimize screening.

Completeness of regional cancer registry data in Northwest Russia 2008-2017

BACKGROUND

A national framework for population-based cancer registration was established in Russia in the late 1990s. Data comparability and validity analyses found substantial differences across ten population-based cancer registries (PBCRs)in Northwest Russia, and only four out of ten met international standards. This study aimed to assess the completeness of the PBCR data of those registries.

METHODS

Qualitative and quantitative methods recommended for completeness and timeliness assessment were applied to the data from ten Russian regional PBCRs in Northwest Russia, covering a population of 13 million. We used historic data methods (using several European PBCRs reference rates), mortality-to-incidence ratios (M:I) comparison, and death certificate methods to calculate the proportion of unregistered cases (Lincoln-Petersen estimator and Ajiki formula).

RESULTS

Incidence rate trends of different cancer types were stable over time (except one region - Leningrad oblast). A slight drop in incidence rates in older age groups for several sites in the Northwestern regions was observed compared to the reference from European countries. Comparing M:I ratios against five-year survival revealed systematic differences in Leningrad oblast and Vologda oblast. Assessment of completeness revealed low or unrealistic estimates in Leningrad oblast and completeness below 90% in St. Petersburg. In other regions, the completeness was above 90%. The national annual report between 2008-2017 did not include about 10% of the cases collected later in the registry database of St. Petersburg. This difference was below 3% for Arkhangelsk oblast, Murmansk oblast, Novgorod oblast, Vologda oblast and the Republic of Karelia.

CONCLUSIONS

Eight out of ten regional PBCRs in Northwest Russia collected data with an acceptable degree of completeness. Mostly populated St. Petersburg and Leningrad oblast did not reach such completeness. PBCR data from several regions in Northwest Russia are suitable for epidemiological research and monitoring cancer control activities.

Quality indicators: completeness, validity and timeliness of cancer registry data contributing to the European Cancer Information System

Population-based Cancer Registries (PBCRs) are tasked with collecting high-quality data, important for monitoring cancer burden and its trends, planning and evaluating cancer control activities, clinical and epidemiological research and development of health policies. The main indicators to measure data quality are validity, completeness, comparability and timeliness. The aim of this article is to evaluate the quality of PBCRs data collected in the first ENCR-JRC data call, dated 2015.

Methods

All malignant tumours, except skin non-melanoma, and in situ and uncertain behaviour of bladder were obtained from 130 European general PBCRs for patients older than 19 years. Proportion of cases with death certificate only (DCO%), proportion of cases with unknown primary site (PSU%), proportion of microscopically verified cases (MV%), mortality to incidence (M:I) ratio, proportion of cases with unspecified morphology (UM%) and the median of the difference between the registration date and the incidence date were computed by sex, age group, cancer site, period and PBCR.

Results

A total of 28,776,562 cases from 130 PBCRs, operating in 30 European countries were included in the analysis. The quality of incidence data reported by PBCRs has been improving across the study period. Data quality is worse for the oldest age groups and for cancer sites with poor survival. No differences were found between males and females. High variability in data quality was detected across European PBCRs.

Conclusion

the results reported in this paper are to be interpreted as the baseline for monitoring PBCRs data quality indicators in Europe along time.

Cancer survival: left truncation and comparison of results from hospital-based cancer registry and population-based cancer registry

Background

Cancer survival is an important indicator for evaluating cancer prognosis and cancer care outcomes. The incidence dates used in calculating survival differ between population-based registries and hospital-based registries. Studies examining the effects of the left truncation of incidence dates and delayed reporting on survival estimates are scarce in real-world applications.

Methods

Cancer cases hospitalized at Nantong Tumor Hospital during the years 2002-2017 were traced with their records registered in the Qidong Cancer Registry. Survival was calculated using the life table method for cancer patients with the first visit dates recorded in the hospital-based cancer registry (HBR) as the diagnosis date (OSH), those with the registered dates of population-based cancer (PBR) registered as the incidence date (OSP), and those with corrected dates when the delayed report dates were calibrated (OSC).

Results

Among 2,636 cases, 1,307 had incidence dates registered in PBR prior to the diagnosis dates of the first hospitalization registered in HBR, while 667 cases with incidence dates registered in PBR were later than the diagnosis dates registered in HBR. The 5-year OSH, OSP, and OSC were 36.1%, 37.4%, and 39.0%, respectively. The "lost" proportion of 5-year survival due to the left truncation for HBR data was estimated to be between 3.5% and 7.4%, and the "delayed-report" proportion of 5-year survival for PBR data was found to be 4.1%.

Conclusion

Left truncation of survival in HBR cases was demonstrated. The pseudo-left truncation in PBR should be reduced by controlling delayed reporting and maximizing completeness. Our study provides practical references and suggestions for evaluating the survival of cancer patients with HBR and PBR.

Evaluation of data quality at the Hungarian National Cancer Registry, 2000-2019

BACKGROUND

The Hungarian National Cancer Registry (HNCR) was legally established as a population-based cancer registry in 1999, and its operation started in 2000 supporting the planning and development of the Hungarian oncology network as well as informing national cancer control policies. Ensuring comparable, accurate, and complete data on malignant and in situ neoplasms is critical in determining the applicability of the database. The aim of this study was to perform a comprehensive evaluation of the data quality at the HNCR.

METHODS

Based on qualitative and semiquantitative methods from current international guidelines, we assess the comparability, completeness, validity, and timeliness of the collected data over the diagnostic period 2000-2019, with a focus on the year 2018.

RESULTS

Coding practices and the classification system used at the HNCR are based on the International Classification of Diseases (ICD-10), which differs from the internationally recommended ICD-O. The annual trends in incidence did not indicate major fluctuations, that may have resulted from data collection discrepancies, while comparisons of the mortality-to-incidence ratio (M:I) compared with 1 minus 5-year observed survival indicated some systematic differences requiring further exploration. The age-standardized (European standard) incidence rate per 100 000 measured by the HNCR in 2018 was very high: 647.9 for men and 501.6 for women, 11.6% and 14.6% higher than the International Agency for Research on Cancer (IARC) estimates respectively. Behind the overall differences between the two data sources, we identified that the vast majority were due to ill-defined ICD codes: malignant neoplasm of other and ill-defined sites (C76), and malignant neoplasm without specification of site (C80). Otherwise, there were no major discrepancies by localization. The proportion of morphologically verified cancer cases was 57.8% overall, that of death certificates was 2.3%, and that of unknown primary tumors was 1.4%.

CONCLUSION

Further implementations and interventions are required to ensure that the operations, coding practices, and the classification system used at the national registry are in accordance with international standards, and to increase the completeness and validity of the collected cancer data. In particular, the low morphologically verified proportion questions the overall accuracy of the stated diagnoses within the database. Nevertheless, our examination implies that the data of the HNCR are reasonably comparable, and without doubt fulfill the requirements to support national oncology services and cancer planning. However, most importantly, a review of registry personnel and resource requirements to run the national population-based cancer registry should be an essential part of Hungary's national cancer strategy.

Comparability and validity of cancer registry data in the northwest of Russia

BACKGROUND

Despite the elaborate history of statistical reporting in the USSR, Russia established modern population-based cancer registries (PBCR) only in the 1990s. The quality of PBCRs data has not been thoroughly analyzed. This study aims at assessing the comparability and validity of cancer statistics in regions of the Northwestern Federal District (NWFD) of Russia.

MATERIAL AND METHODS

Data from ten Russian regional PBCRs covering ∼13 million (∼5 million in St. Petersburg) were processed in line with IARC/IACR and ENCR recommendations. We extracted and analyzed all registered cases but focused on cases diagnosed between 2008 and 2017. For comparability and validity assessment, we applied established qualitative and quantitative methods.

RESULTS

Data collection in NWFD is in line with international standards. Distributions of diagnosis dates revealed higher variation in several regions, but overall, distributions are relatively uniform. The proportion of multiple primaries between 2008 and 2017 ranged from 6.7% in Vologda Oblast to 12.4% in Saint-Petersburg. We observed substantial regional heterogeneity for most indicators of validity. In 2013-2017, proportions of morphologically verified cases ranged between 61.7 and 89%. Death certificates only (DCO) cases proportion was in the range of 1-14% for all regions, except for Saint-Petersburg (up to 23%). The proportion of cases with a primary site unknown was between 1 and 3%. Certain cancer types (e.g., pancreas, liver, hematological malignancies, and CNS tumors) and cancers in older age groups showed lower validity.

CONCLUSION

While the overall level of comparability and validity of PBCRs data of four out of ten regions of NWFD of Russia meets the international standards, differences between the regions are substantial. The local instructions for cancer registration need to be updated and implemented. The data validity assessment also reflects pitfalls in the quality of diagnosis of certain cancer types and patient groups.

Incidence of Non-melanoma Eyelid Malignancies in Bulgaria (2000-2015)

PURPOSE

Malignant eyelid tumours are the most common malignancies in ophthalmic practice. We report here the incidence of non-melanoma eyelid malignancies in Bulgaria, for the period 2000-2015.

METHODS

All cases coded with the International Classification of Diseases (ICD) code C 44.1, received from the Bulgarian National Cancer Registry, were used for estimating crude incidence rates by age and sex. In addition, directly age standardized incidence rates for non-melanoma eyelid malignancies are presented based on the European Standard population (year 2013) for Bulgaria and the region of Varna.

RESULTS

Over the 16-year period there were 3,046 cases in total, of which 1,457 (47.8%) were among men. The age standardized rate (ASR) of non-melanoma eyelid malignancies in men was 2.9 per 100,000 (95% CI 2.79-3.11), in women it was 2.4 per 100,000 (95% CI 2.30-2.54), and the mean ASR was 2.6 per 100,000 (95% CI 2.53-2.73) for both sexes during the period. The ASR increased for women and for both sexes combined.The risk of eyelid malignancies was higher for men than for women with RR of 1.21 (95% CI 1.08-1.41) during the whole period. The risk was higher in women up to the age of 55 and over 55 years it was higher in men.

CONCLUSION

We report results for the incidence of eyelid non-melanoma malignancies in a south-eastern European country, Bulgaria. They are comparable with earlier reports from other European countries.

Ascertainment of cancer in longitudinal research: The concordance between the Rotterdam Study and the Netherlands Cancer Registry

Complete and accurate registration of cancer is needed to provide reliable data on cancer incidence and to investigate aetiology. Such data can be derived from national cancer registries, but also from large population‐based cohort studies. Yet, the concordance and discordance between these two data sources remain unknown. We evaluated completeness and accuracy of cancer registration by studying the concordance between the population‐based Rotterdam Study (RS) and the Netherlands Cancer Registry (NCR) between 1989 and 2012 using the independent case ascertainment method. We compared all incident cancers in participants of the RS (aged ≥45 years) to registered cancers in the NCR in the same persons based on the date of diagnosis and the International Classification of Diseases (ICD) code. In total, 2,977 unique incident cancers among 2,685 persons were registered. Two hundred eighty‐eight cancers (9.7%) were coded by the RS that were not present in the NCR. These were mostly nonpathology‐confirmed lung and haematological cancers. Furthermore, 116 cancers were coded by the NCR, but not by the RS (3.9%), of which 20.7% were breast cancers. Regarding pathology‐confirmed cancer diagnoses, completeness was >95% in both registries. Eighty per cent of the cancers registered in both registries were coded with the same date of diagnosis and ICD code. Of the remaining cancers, 344 (14.5%) were misclassified with regard to date of diagnosis and 72 (3.0%) with regard to ICD code. Our findings indicate that multiple sources on cancer are complementary and should be combined to ensure reliable data on cancer incidence.

What's new?

While national cancer registries and population‐based cohort studies are the primary sources of data on cancer risk and incidence, the degree to which these data sets are concordant remains unknown. In this investigation, the authors evaluated concordance between the population‐based Rotterdam Study and the Netherlands Cancer Registry. The two data sets were highly concordant for pathology‐confirmed cancers and cancer site. Non‐pathology‐confirmed cancers, however, were under‐registered in the Netherlands Cancer Registry, potentially resulting in underestimation of cancer incidence. The findings highlight the important role that different sources of cancer diagnosis registration serve in providing reliable estimates of cancer incidence.

Completeness of a newly implemented general cancer registry in northern France: Application of a three-source capture-recapture method

BACKGROUND

Completeness, timeliness and accuracy are important qualities for registries. The objective was to estimate the completeness of the first two years of full registration (2008/2009) of a new population-based general cancer registry, at the time of national data centralisation.

METHODS

Records followed international standards. Numbers of cases missed were estimated from a three-source (pathology labs, healthcare centres, health insurance services) capture-recapture method, using log-linear models for each gender. Age and place of residence were considered as potential variables of heterogeneous catchability.

RESULTS

When data were centralized (2011/2012), 4446 cases in men and 3642 in women were recorded for 2008/2009 in the Registry. Overall completeness was estimated at 95.7% (95% CI: 94.3-97.2) for cases in men and 94.8% (95% CI: 92.6-97.0) in women. Completeness appeared higher for younger than for older subjects, with a significant difference of 4.1% (95% CI: 1.4-6.7) for men younger than 65 compared with their older counterparts. Estimates were collated with the number of cases registered in 2014 for the years 2008/2009 (4566 cases for men/3755 for women), when additional structures had notified cases retrospectively to the Registry. These numbers were consistent with the stratified capture-recapture estimates.

CONCLUSION

This method appeared useful to estimate the completeness quantitatively. Despite a rather good completeness for the new Registry, the search for cases among older subjects must be improved.

Validation of data quality in the Swedish National Register for Breast Cancer

Background

The National Breast Cancer Register (NBCR) of Sweden was launched in 2008 and is used for quality assurance, benchmarking, and research. Its three reporting forms encompass Notification, Adjuvant therapy and Follow-up. Target levels are set by national and international guidelines. This national validation assessed data quality of the register.

Methods

Data recorded through the Notification form were evaluated for completeness, timeliness, comparability and validity. Completeness was assessed by cross-linkage to the Swedish Cancer Register (SCR). Comparability was analyzed by comparing registration routines in NBCR with national and international guidelines. Timeliness was defined as the difference between the earliest date of diagnosis and the reporting date to NBCR. Validity was assessed by re-abstraction of medical chart data for 800 randomly selected patients diagnosed in 2013.

Results

The completeness of the NBCR was high with a coverage across regions and years (2010–2014) of 99.9%. Of all incident cases reported to the NBCR in 2013 (N = 8654), 98.5% were included within 12 months and differences between health regions were essentially negligible. Coding procedures followed guidelines and were uniformly adhered to. The proportion of missing values was < 5% for most variables and reported information generally had high exact agreement (> 90%).

Conclusions

Completeness of data, comparability and agreement in the NBCR was high. For clinical quality purposes and benchmarking, improved timeliness is warranted. Assessment of validity has resulted in a thorough review of all variables included in the Notification form with clarifications and revision of selected variables.

Indicators of Data Quality at the Cancer Registry Zurich and Zug in Switzerland

Data quality is an important issue in cancer registration. This paper provides a comprehensive overview of the four main data quality indicators (comparability, validity, timeliness, and completeness) for the Cancer Registry Zurich and Zug (Switzerland). We extracted all malignant cancer cases (excluding non-melanoma skin cancer) diagnosed between 1980 and 2014 in the canton of Zurich. Methods included the proportion of morphologically verified cases (MV%), the proportion of DCN and DCO cases (2009-2014), cases with primary site uncertain (PSU%), the stability of incidence rates over time, age-specific incidence rates for childhood cancer, and mortality:incidence (MI) ratios. The DCO rate decreased from 6.4% in 1997 to 0.8% in 2014 and was <5% since 2000. MV% was 95.5% in 2014. PSU% was <3% over the whole period. The incidence rate of all tumours increased over time with site-specific fluctuations. The overall M:I ratio decreased from 0.58 in 1980 to 0.37 in 2014. Overall, data quality of the Cancer Registry Zurich and Zug was acceptable according to the methods presented in this review. Most indicators improved over time with low DCO rates, high MV%, low PSU%, relatively low M:I ratios and age-specific incidence of childhood cancer within reference ranges.

Evaluation of data quality at the National Cancer Registry of Ukraine

BACKGROUND

Cancer notification has been mandatory in Ukraine since 1953, with the National Cancer Registry of Ukraine (NCRU) established in 1996. The aim of this study was to provide a comprehensive evaluation of the data quality at the NCRU.

METHODS

Qualitative and semi-quantitative methods were used to assess the comparability, completeness, validity and timeliness of cancer incidence data from the NCRU for the period 2002-2012.

RESULTS

Cancer registration procedures at the NCRU are in accordance with international standards and recommendations. Semi-quantitative methods suggested the NCRU's data was reasonably complete, although decreases in age-specific incidence and mortality rates in the elderly indicated some missing cases at older ages. The proportion of microscopically-verified cases increased from 73.6% in 2002 to 82.3% in 2012, with death-certificate-only (DCO) proportions stable at around 0.1% and unknown stage recorded in 9.6% of male and 7.5% of female solid tumours. Timeliness was considered acceptable, with reporting >99% complete within a turn-around time of 15 months.

CONCLUSION

While timely reporting of national data reflects the advantages of a mandatory data collection system, a low DCO% and observed age-specific declines suggest possible underreporting of incidence and mortality data, particularly at older ages. Overall, the evaluation indicates that the data are reasonably comparable and thus may be used to describe the magnitude of the cancer burden in Ukraine. Given its central role in monitoring and evaluation of cancer control activities, ensuring the sustainability of NCRU operations throughout the process of healthcare system reform is of utmost importance.

Cross-sectional study evaluating data quality of the National Cancer Registration and Analysis Service (NCRAS) prostate cancer registry data using the Cluster randomised trial of PSA testing for Prostate cancer (CAP)

OBJECTIVES

To compare the completeness and agreement of prostate cancer data recorded by the National Cancer Registration and Analysis Service (NCRAS) with research-level data specifically abstracted from medical records from the Cluster randomised triAl of prostate specific antigen (PSA) testing for Prostate cancer (CAP) trial.

DESIGN

Cross-sectional comparison study.

PARTICIPANTS

We included 1356 men from the CAP trial cohort who were linked to the NCRAS registry.

PRIMARY AND SECONDARY OUTCOME MEASURES

Completeness of prostate cancer data in NCRAS and CAP and agreement for tumour, node, metastases (TNM) stage (T1/T2; T3; T4/N1/M1) and Gleason grade (4-6; 7; 8-10), measured by differences in proportions and Cohen's kappa statistic. Data were also stratified by year and pre-2010 versus post-2010, when NCRAS reporting standards changed.

RESULTS

Compared with CAP, completeness was lower in NCRAS for Gleason grade (41.2% vs 76.7%, difference 35.5, 95% CI 32.1 to 39.0) and TNM stage (29.9% vs 67.6%, difference 37.6, 95% CI 34.1 to 41.1). NCRAS completeness for Gleason grade (pre-2010 vs post-2010 31.69% vs 64%; difference 32.31, 95% CI 26.76 to 37.87) and TNM stage (19.31% vs 55.50%; difference 36.19, 95% CI 30.72 to 41.67) improved over time. Agreement for Gleason grade was high (Cohen's kappa, κ=0.90, 95% CI 0.88 to 0.93), but lower for TNM stage (κ=0.41, 95% CI 0.37 to 0.51) overall. There was a trend towards improved agreement on Gleason grade, but not TNM stage, when comparing pre-2010 and post-2010 data.

CONCLUSION

NCRAS case identification was very high; however, data on prostate cancer grade was less complete than CAP, and agreement for TNM stage was modest. Although the completeness of NCRAS data has improved since 2010, the higher completeness rate in CAP demonstrates that gains could potentially be achieved in routine registry data. This study's findings highlight a need for improved recording of stage and grade data in the source medical records.

Evolution of Cancer Registration Combining Online Reporting with Follow-up in the Community: Practices in Guangzhou, China

Background:

An efficient registration system with accurate and timely information on cancer incidence and mortality is key to development of policies to prevent and control cancer. A traditional registration system usually needs 3-4 years to collect data and publish a cancer report. However, researchers, policymakers and healthcare professionals need to know the latest cancer registration data quickly.

Methods:

A computer system has been operating with cases reported online by hospitals and followed up in communities at the Cancer Registry of Guangzhou (CRG) since 2008. The comparability, completeness, accuracy and timeliness of collected data were here evaluated.

Results:

From 2010 to 2014, 181,194 cancer cases from 1,916,253 medical records of cancer were reported to the CRG online. 53,473 cases were deleted as duplicates (47,906), wrong diagnoses (410) or residents of other places (5,157) during the follow up. Successful final follow-up rates were over 90% for both newly and previously diagnosed cases by general practitioners in community clinics. The CRG coding and classification system follows international standards. The annual trends for all sites by sex were stable from 2010 to 2014. All age-specific incidence rates for childhood cancers were within the limits of the respective international references. The overall M: I ratio for all sites but C44 was 56.7%., ratios for most sites in Guangzhou being between Hong Kong and Shanghai. A total of 75.7% of the cancer cases reported in 2010–2012 were morphologically verified. Ninety five percent of new cases completed registration within 29.0 months in 2010, reducing to 8.0 months in 2014.

Conclusion:

The online report system with community follow up at the CRG yields reasonably accurate and close-to-complete data. It takes less time to confirm diagnosis and other information so that reporting annual incidence one year after the close of registration becomes possible.

Histologic subtypes of ovarian carcinoma: selected diagnostic and classification problems in Bulgaria: is low hospital volume an issue?

PURPOSE

To provide an overview of the morphologic subtypes of ovarian carcinomas in Bulgaria in relation to current healthcare organization using Bulgarian National Cancer Registry data. Further, we investigated hospital volume as a factor influencing the quality of care for patients with ovarian cancer.

METHODS

Bulgarian National Cancer Registry ovarian carcinoma data were retrieved (2009-2011) and distribution of histologic types was analyzed. Cases were divided and compared with respect to main treatment: no surgery, surgery at hospitals dealing with ≥30 ovarian cancer patients/year (high volume), and surgery at hospitals dealing with <30 ovarian cancer patients/year (low volume). We then estimated the odds of being diagnosed with adenocarcinoma and carcinoma not otherwise specified (NOS) vs specified morphologies (serous, endometrioid, clear cell, and mucinous), including age, grade, stage, and hospital volume, in a logistic regression model.

RESULTS

A total of 2,041 ovarian carcinomas were distributed as follows: serous 47.7%, mucinous 11.9%, endometrioid 5.8%, clear cell 1.8%, and adenocarcinoma and carcinoma NOS 32.5%. More than half of cancer patients (n = 1,100, 53.9%) were surgically treated in low-volume hospitals and they had a larger proportion of cases with adenocarcinoma and carcinoma NOS: 33.3%, in comparison with 24.0% in high-volume hospitals (p<0.0001). The odds of being diagnosed with unspecified morphology, assumed as a proxy of suboptimal quality of care, are higher for patients surgically treated in low-volume hospitals (odds ratio 1.50 [95% confidence interval 1.21-1.87]) compared with high-volume hospitals after adjustment for age, stage, and grade.

CONCLUSIONS

The results of our study may serve policymakers and healthcare professionals when optimizing diagnosis and treatment of ovarian cancer in Bulgaria.

Temporal changes in the cervical cancer burden in Bulgaria: Implications for eastern european countries going through transition

INTRODUCTION

In most developed countries, incidence of cervical cancer declined likely due to well-established cervical cancer screening programs. However, such decline has not been identified in Eastern Europe, where such programs are not well established.

METHODS

This study utilized data of the Bulgarian Cancer Registry for the period 1993-2013. Age-standardized incidence and mortality trends were analyzed using Joinpoint regression. Maps were created to illustrate spatial distributions of rates.

RESULTS

The northern region of Bulgaria showed a larger cervical cancer burden than the southern region and rural women tended to be diagnosed at older ages (p<0.0001) and later stages (p<0.0001) than urban women. The distribution of disease stages changed over the 21 years, with most common stages of diagnosis being stage II in 1993 (39.2%) to stage I in 2013 (44.7%; p<0.0001). While age-standardized mortality slightly increased over the 21 years (from 4.8 to 5.2 per 100,000; p=0.009), age-standardized incidence increased from 14.0 to 21.4 per 100,000 up until 2006 (p<0.001), after which it plateaued.

CONCLUSIONS

The lack of a similar plateau in mortality may be because the second most prevalent stage of diagnosis in recent years was stage III, indicating diagnosis at advanced symptomatic stages. Cervical cancer incidence is expected to continue to decrease if screening programs are strengthened and human papillomavirus vaccines are widely utilized. As Bulgaria has shared cervical cancer trends with other Eastern European countries in the past, it may be beneficial to develop future prevention interventions based on a regional, rather than a country-specific level.

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.

Effectiveness of Implementation of Electronic Malaria Information System as the National Malaria Surveillance System in Thailand

Background

In moving toward malaria elimination, one strategy is to implement an active surveillance system for effective case management. Thailand has developed and implemented the electronic Malaria Information System (eMIS) capturing individualized electronic records of suspected or confirmed malaria cases.

Objective

The main purpose of this study was to determine how well the eMIS improves the quality of Thailand’s malaria surveillance system. In particular, the focus of the study was to evaluate the effectiveness of the eMIS in terms of the system users’ perception and the system outcomes (ie, quality of data) regarding the management of malaria patients.

Methods

A mixed-methods technique was used with the framework based on system effectiveness attributes: data quality, timeliness, simplicity, acceptability, flexibility, stability, and usefulness. Three methods were utilized: data records review, survey of system users, and in-depth interviews with key stakeholders. From the two highest endemic provinces, paper forms matching electronic records of 4455 noninfected and 784 malaria-infected cases were reviewed. Web-based anonymous questionnaires were distributed to all 129 eMIS data entry staff throughout Thailand, and semistructured interviews were conducted with 12 management-level officers.

Results

The eMIS is well accepted by system users at both management and operational levels. The data quality has enabled malaria personnel to perform more effective prevention and control activities. There is evidence of practices resulting in inconsistencies and logical errors in data reporting. Critical data elements were mostly completed, except for a few related to certain dates and area classifications. Timeliness in reporting a case to the system was acceptable with a delay of 3-4 days. The evaluation of quantitative and qualitative data confirmed that the eMIS has high levels of simplicity, acceptability, stability, and flexibility.

Conclusions

Overall, the system implemented has achieved its objective. The results of the study suggested that the eMIS helps improve the quality of Thailand’s malaria surveillance system. As the national malaria surveillance system, the eMIS’s functionalities have provided the malaria staff working at the point of care with close-to-real-time case management data quality, covering case detection, case investigation, drug compliance, and follow-up visits. Such features has led to an improvement in the quality of the malaria control program; the government officials now have quicker access to both individual and aggregated data to promptly react to possible outbreak. The eMIS thus plays one of the key roles in moving toward the national goal of malaria elimination by the next decade.

Childhood central nervous system tumour mortality and survival in Southern and Eastern Europe (1983-2014): Gaps persist across 14 cancer registries

AIM

Childhood central nervous system (CNS) tumour registration and control programs in Southern and Eastern Europe remain thin, despite the lethal nature of the disease. Mortality/survival data were assembled to estimate the burden of malignant CNS tumours, as well as the potential role of sociodemographic survival determinants across 14 cancer registries of this region.

METHODS

Average age-adjusted mortality rates were calculated, whereas time trends were quantified through Poisson and Joinpoint regressions. Kaplan-Meier curves were derived for the maximum and the more recent (10 and 5 year) registration periods. Multivariate Cox regression models were used to assess demographic and disease-related determinants.

RESULTS

Variations in mortality (8-16 per million) and survival (5-year: 35-69%) were substantial among the participating registries; in most registries mortality trend was stable, whereas Bulgaria, having the highest starting rate, experienced decreasing annual mortality (-2.4%, p=0.001). A steep decrease in survival rates was evident before the second year of follow-up. After controlling for diagnostic subgroup, age, gender and diagnostic year, Greece seemed to present higher survival compared with the other contributing registries, although the follow-up period was short. Irrespective of country, however, rural residence was found to impose substantial adverse repercussions on survival (hazard ratio (HR): 1.2, 95% confidence interval (CI): 1.1-1.4).

CONCLUSION

Cross-country mortality and survival variations possibly reflect suboptimal levels of health care delivery and cancer control in some regions of Southern and Eastern Europe, notwithstanding questionable death certification patterns or follow-up procedures. Continuous childhood cancer registration and linkage with clinical data are prerequisite for the reduction of survival inequalities across Europe.