Identifying Newborns with Hypoxic-Ischemic Encephalopathy in Hospital Discharge Data: A Validation Study.

Hospital discharge databases (HDDs) are increasingly used for research on health of newborns. Linkage between a French population-based cohort of newborns with hypoxic-ischemic encephalopathy (HIE) and national HDD showed that the HIE ICD-10 code was not accurately reported. Our results suggest that HDD should not be used for research on neonatal HIE without prior validation of HIE ICD-10 codes.

National cancer incidence is estimated using the incidence/mortality ratio in countries with local incidence data: is this estimation correct?

BACKGROUND: In countries with local cancer registration, the national cancer incidence is usually estimated by multiplying the national mortality by the incidence/mortality (I/M) ratio from pooled registries. This study aims at validating this I/M estimation in France, by a comparison with estimation obtained using the ratio of incidence over hospital discharge (I/HD) or the ratio of incidence over health insurance data (long-duration diseases, I/LDD). METHODS: This comparison was performed for 22 cancer sites over the period 2004-2006. In France, a longitudinal I/M approach was developed relying on incidence and mortality trend analyses; here, the corresponding estimations of national incidence were extracted for 2004-2006. The I/HD and I/LDD estimations were performed using a common cross-sectional methodology. RESULTS: The three estimations were found similar for most cancers. The relative differences in incidence rates (vs. I/M) were below 5% for numerous cancers and below 10% for all cancers but three. The highest differences were observed for thyroid cancer (up to +21% in women and +8% in men), skin melanoma (up to +13% in women and +8% in men), and Hodgkin disease in men (up to +15%). Differences were also observed in women aged over 60 for cervical cancer. Except for thyroid cancer, differences were mainly due to the smoothing performed in the I/M approach. CONCLUSION: Our results support the validity of I/M approaches for national estimations, except for thyroid cancer. The longitudinal version of this approach has, furthermore, the advantage of providing smoothed estimations and trend analyses, including useful birth-cohort indicators, and should thus be preferred.

[Critical analysis of French DRG based information system (PMSI) databases for the epidemiology of cancer: a longitudinal approach becomes possible]. / Analyse critique des données du PMSI pour l'épidémiologie des cancers : une approche longitudinale devient possible.

BACKGROUND: Use of French Diagnosis Related Groups (DRGs) program databases, apart from financial purposes, has recently been improved since a unique anonymous patient identification number has been created for each inpatient in administrative case mix database. Based on the work of the group for cancer epidemiological observation in the Rhône-Alpes area, (ONC-EPI group), we review the remaining difficulties in the use of DRG data for epidemiological purposes and we consider a longitudinal approach based on analysis of database over several years. We also discuss limitations of this approach. DIFFICULTIES: The main problems are related to a lack of quality of administrative data, especially coding of diagnoses. These errors come from missing or inappropriate codes, or not being in accordance with prioritization rules (causing an over- or under-reporting or inconsistencies in coding over time). One difficulty, partly due to the hierarchy of coding and the type of cancer, is the choice of an extraction algorithm. In two studies designed to estimate the incidence of cancer cared in hospitals (breast, colon-rectum, kidney, ovaries), a first algorithm, including a code of cancer as principal diagnosis with a selection of surgical procedures less performed than the second one including a code of cancer as principal diagnosis only, for which the number of hospitalizations per patient ratio was stable across time and space. The chaining over several years allows, by tracing the trajectory of the patient, to detect and correct inaccuracies, errors and missing values, and for incidence studies, to correct incident cases by removing prevalent cases. DISCUSSION: However, linkage, complete only since 2007, does not correct data in all cases. Ways of future improvement certainly pass through improved algorithms for case identification and especially by linking DRG data with other databases.

Identifying prevalent cases of breast cancer in the French case-mix databases.

OBJECTIVES: Little is known about cancer prevalence due to a lack of systematic recording of cancer patient follow-up data. To estimate the annual hospital prevalence of breast cancer in the general population of the Isère department (1.1 million inhabitants) in the Rhône-Alpes region, the second largest region in France (6 million inhabitants), we used the inpatient case-mix data, available in most European countries, to develop a method of cancer case identification. METHODS: A selection process was applied to the acute care hospital datasets among women aged 18 years or older, living in the Isère department and treated for breast cancer between 2004 and 2007. The first step in case selection was based on the national anonymous unique patient identifier. The second step consisted of retrieving all hospital stays for each case. The third step was designed to detect inconsistencies in the coding of the primary localization. An algorithm based on ICD-10 code for the hospital admission diagnosis was used to rule out hospitalizations unrelated to breast cancer. Five possible models for estimating prevalence were created combining selection steps with the admission diagnosis algorithm. RESULTS: Hospital prevalence over the four-year period varied from 6073 breast cancer cases for the simplest model (first selection step without the admission diagnosis algorithm) to 4951 when the first selection step was associated with the breast cancer code as admission diagnosis. The model combining the third selection step with a breast cancer-specific admission reason provided 5275 prevalent cases. CONCLUSION: The last model seems more appropriate for case-mix-data coding. Selecting admission diagnosis improved specificity. Combining all hospital stays for each patient has improved diagnostic sensitivity.

[Some interpretation of regional estimates of the incidence of cancer in France over the period 1980--2005]. / Eléments d'interprétation des estimations régionales de l'incidence du cancer en France sur la période 1980--2005.

Francim Network has already provided French national estimations of cancer incidence then regional estimations for Metropolitan France. The present technical note summarizes the underlying hypotheses and the limits of the method and suggests some aspects of interpretation of those regional results in terms of absolute numbers and of standardized rates. Results on "all cancers" illustrate those comments.

Is it possible to estimate the incidence of breast cancer from medico-administrative databases?

One approach to estimate cancer incidence in the French Départements is to quantify the relationship between data in cancer registries and data obtained from the PMSI (Programme de Médicalisation des Systèmes d'Information Médicale). This relationship may then be used in Départements without registries to infer the incidence from local PMSI data. We present here some methodological solutions to apply this approach. Data on invasive breast cancer for 2002 were obtained from 12 Départemental registries. The number of hospital stays was obtained from the National PMSI using two different algorithms based on the main diagnosis only (Algorithm 1) or on that diagnosis associated to a mention of "resection" (Algorithm 2). Considering registry data as gold standard, a calibration approach was used to model the ratio of the number of hospital stays to the number of incident cases. In Départements with registries, validation of the predictions was done through cross-validation. In Départements without registries, validation was done through a study of homogeneity of the mean number of hospital stays per patient. Cross-validation showed that the estimates predicted by the model were true with data extracted by Algorithm 1 but not by Algorithm 2. However, with Algorithm 1, there was an important heterogeneity between French Départements as to the mean number of hospital stays per patient, which had an important impact on the estimations. In the near future, the method will allow using medico-administrative data (after calibration with registry data) to estimate Départemental incidence of selected cancers.

Sarcomas and malignant phyllodes tumours of the breast--a retrospective study.

BACKGROUND: Although most breast cancers are adenocarcinomas of the mammary gland, primary breast sarcomas may also arise from mammary gland mesenchymal tissue. The annual incidence of primary breast sarcoma is low and has been estimated at 45 new cases per 10 million women. These tumours are at high risk of recurrence and are known to have poor prognosis. Phyllodes tumours represent a specific subset of these breast soft tissue tumours. They are composed of a connective tissue stroma and epithelial elements. Pathological presentation ranges from grade I to malignant phyllodes tumours (grade III) where the stromal component clearly exhibits a sarcoma pattern. MATERIALS AND METHODS: SAPHYR (SArcoma and PHYllode Retrospective) is a retrospective study of the experience of Leon Bérard Cancer Centre (Lyon, France) from 1966 to August 2004. SAPHYR aims to describe the characteristics of primary breast sarcomas and to define potential survival factors to be evaluated in future prospective studies. RESULTS: We included 70 patients. Half of them presented at least one recurrence (35/70). Median disease-free-survival (DFS) was 1.15 years. At 3 years, median overall survival had not been reached and more than 61% of the patients were alive. Quality of surgical resection was significantly (p=0.036) different whether patients were in the R0 group (72%) or not (38%). No survival difference was found between malignant phyllodes (grade III) and other primary breast sarcomas (angiosarcomas excluded). Histology revealed three significantly (p=0.0003) different prognostic groups: phyllodes grade I and II (DFS=57%), angiosarcomas (DFS=7%) and phyllodes grade III and other primary breast sarcomas (DFS=45%). DISCUSSION: Phyllodes tumours and primary breast sarcomas are totally different from epithelial breast cancers and should be considered as a distinct group of rare tumours. The first goal of treatment is to achieve negative margins (R0). We propose to treat the patients according to the clinical practice guidelines in use for soft tissue sarcomas and address them to a reference centre for sarcoma. Treating rare tumours in the same place should permit us to standardise pathological data and to include patients into multicentric radiotherapy or chemotherapy protocols to improve overall survival. As further prospective studies are needed, European oncology groups must join their forces to create a prospective Rare Cancer Network.

[Childhood cancer incidence and survival rates in the Rhône-Alpes regional paediatric registry 1987-1999]. / Les cancers de l'enfant de la région Rhône-Alpes: incidence et survie 1987-1999.

UNLABELLED: Cancer is rare in children, and pediatric malignancies represent only 1% of all cancers. OBJECTIVES: The cure rate is high and increasing, and ongoing data collection is therefore warranted. MATERIALS AND METHODS: Here we report the incidence and survival rates of childhood cancers between 1987 and 1999 in the Rhône-Alpes region of France. RESULTS: A total of 1945 cases were recorded during the study period, with an average of 149.6 new cases per year. The approximate incidence rate was 134.1/10(6) per year and the age-standardized incidence rate was 139.2/10(6) per year. The histological distribution and 5-year survival rates were respectively 30.2 and 73% for leukemia, 12.3 and 91.6% for lymphoma, 24.7 and 60.1% for CNS tumors, 9.1 and 71.1% for neuroblastoma, 2.5 and 94.1% for retinoblastoma, 5.8% and 89.9% for renal tumors, 1 and 75% for liver tumors, 6.1 and 60.9% for bone tumors, 4.1 and 58.6% for soft-tissue tumors, 1.1 and 71% for germ cell tumors, and 2.4 and 85.1% for carcinomas. CONCLUSION: The overall survival rate was 75%. Long-term treatment complications warrant further studies of children who survive into adulthood.

[Causes of death of COGEMA active workers, 1980-1995]. / Causes de décès des travailleurs actifs de la COGEMA, 1980-1995.

BACKGROUND: Populations exposed to risks at work show a deficit in deaths in comparison with the national population, the "healthy worker effect". This effect has been observed among former nuclear workers. The aim of our cross-sectional study was to evaluate the mortality in a metallurgy worker population, and to study the impact of the choice of the reference population on the estimation of the Standardized Mortality Ratio (SMR). METHODS: The studied population was the COGEMA Metallurgy Department workers, aged 25 years to 64, during the period 1980-1995 in two regions of France (North--La Hague; South--Cadarache, Marcoule, Miramas and Pierrelatte). In order to account for geographical variability and the difference in mortality between the working population and the non-working population, we used several reference populations: national population, regional population, "working" national population (farmers not present in COGEMA and non-workers excluded), and "working" regional population. RESULTS: All SMRs were increased when we used a "working" regional reference compared with the national reference population. Among men, eight pathologies presented a significant deficit with a national reference, whereas only two pathologies showed a deficit with the "working" regional reference. CONCLUSION: The use of a reference population close to the study population enabled us to reduce the Healthy Worker Effect among metallurgy workers at COGEMA plants.