[Role of French hospital claims databases from care units in epidemiological studies: the example of the "Cohorte Enfant Scanner" study]

Childhood cancer risks estimates following CT scans: an update of the French CT cohort study

OBJECTIVES

Increased risks of central nervous system (CNS) tumors and leukemia associated with computed tomography (CT) exposure during childhood have been reported in recent epidemiological studies. However, no evidence of increased risks was suggested in a previous analysis of the French CT cohort. This study benefits from an updated cohort with a longer follow-up and a larger sample size of patients.

METHODS

The patients were followed from the date of their first CT (between 2000 and 2011) until their date of cohort exit defined as the earliest among the following: 31 December 2016, date of death, date of first cancer diagnosis or date of their 18^th birthday. Cancer incidence, vital status, cancer predisposing factors (PFs), and additional CT scans were collected via external national databases. Hazard ratios (HRs) associated to cumulative organ doses and sex were estimated from Cox models.

RESULTS

At the end of follow-up, mean cumulative doses were 27.7 and 10.3 mGy for the brain and the red bone marrow (RBM), respectively. In patients without PFs, an HR per 10 mGy of 1.05 (95% CI: 1.01-1.09) for CNS tumors, 1.17 (95% CI: 1.09-1.26) for leukemia, and 0.96 (95% CI: 0.63-1.45) for lymphoma was estimated. These estimates were not modified by the inclusion of CT scans performed outside the participating hospitals or after the inclusion period.

CONCLUSIONS

This study shows statistically significant dose-response relationships for CNS tumors and leukemia for patients without PFs.

KEY POINTS

• Computed tomography is the most important contributor to the collective dose for diagnostic imaging to the French population. • Concerns have been raised about possible cancer risks, particularly after exposure to CT in childhood, due to the greater radiation sensitivity of children and to their longer life expectancy. • Analysis of the updated French CT cohort shows statistically significant dose-response relationships for CNS tumors and leukemia.

Exposure to low-dose ionising radiation from cardiac catheterisation and risk of cancer: the COCCINELLE study cohort profile

PURPOSE

The COCCINELLE study is a nationwide retrospective French cohort set up to evaluate the risk of cancer in patients who undergone cardiac catheterisation (CC) procedures for diagnosis or treatment of congenital heart disease during childhood.

PARTICIPANTS

Children who undergone CC procedures from 1 January 2000 to 31 December 2013, before the age of 16 in one of the 15 paediatric cardiology departments which perform paediatric CC in mainland France were included. The follow-up started at the date of the first recorded CC procedure until the exit date, that is, the date of death, the date of first cancer diagnosis, the date of the 18th birthday or the 31 December 2015, whichever occurred first. The cohort was linked to the National Childhood Cancer Registry to identify patients diagnosed with cancer and with the French National Directory for the Identification of Natural Persons to retrieve the patients' vital status.

FINDINGS TO DATE

A total of 17 104 children were included in the cohort and followed for 110 335 person-years, with 22 227 CC procedures collected. Among the patients, 81.6% received only one procedure. Fifty-nine cancer cases were observed in the cohort. Standardised incidence ratios (SIRs) were increased for all-cancer (SIR=3.8, 95% CI: 2.9 to 4.9), leukaemia (SIR=3.3, 95% CI: 2.0 to 5.4), lymphoma (SIR=14.9, 95% CI: 9.9 to 22.5) and solid cancers excluding central nervous system (CNS) tumours (SIR=3.3, 95% CI: 2.0 to 5.5) compared with the general population.

FUTURE PLANS

Dose reconstruction is currently underway to estimate individual cumulative doses absorbed to relevant organs, including red bone marrow and brain for respectively haematologic disorders and CNS tumours risk estimation. A dose-response analysis will be conducted with consideration to confounding factors such as age at exposure, gender, predisposing factors to cancer and other sources of medical diagnostic low-dose ionising radiation.

Psychiatric Adverse Events Associated With Infliximab: A Cohort Study From the French Nationwide Discharge Abstract Database

Introduction

Infliximab (IFX) was the first anti-tumor necrosis factor (TNFα) antibody to be used in the treatment of severe chronic inflammatory diseases, such as Crohn’s disease and rheumatoid arthritis. A number of serious adverse drug reactions are known to be associated with IFX use; they include infections, malignancies, and injection site reactions. Although a few case reports have described potential psychiatric adverse events (including suicide attempts and manic episodes), the latter are barely mentioned in IFX’s summary of product characteristics. The objective of the present retrospective study was to detect potential psychiatric adverse events associated with IFX treatment by analyzing a national discharge abstract database.

Materials and Methods

We performed an historical cohort study by analyzing data from the French national hospital discharge abstract database (PMSI) between 2008 and 2014. All patients admitted with one of the five diseases treated with IFX were included.

Results

Of the 325,319 patients included in the study, 7,600 had been treated with IFX. The proportion of hospital admissions for one or more psychiatric events was higher among IFX-exposed patients (750 out of 7,600; 9.87%) than among non-exposed patients (17,456 out of 317,719; 5.49%). After taking account of potential confounders in the cohort as a whole, a semi-parametric Cox regression analysis gave an overall hazard ratio (HR) [95% confidence interval] (CI) of 4.5 [3.95; 5.13] for a hospital admission with a psychiatric adverse event during treatment with IFX. The HR (95%CI) for a depressive disorder was 4.97 (7.35; 6.68). Even higher risks were observed for certain pairs of adverse events and underlying pathologies: psychotic disorders in patients treated for ulcerative colitis (HR = 5.43 [2.01; 14.6]), manic episodes in patients treated for severe psoriasis (HR = 12.6 [4.65; 34.2]), and suicide attempts in patients treated for rheumatoid arthritis (HR = 4.45 [1.11; 17.9]).

Discussion

The present retrospective, observational study confirmed that IFX treatment is associated with an elevated risk of psychiatric adverse events. Depending on the disease treated, physicians should be aware of these potential adverse events.

Burden of Clostridium difficile Infections in French Hospitals in 2014 From the National Health Insurance Perspective

OBJECTIVE

To describe the hospital stays of patients with Clostridium difficile infection (CDI) and to measure the hospitalization costs of CDI (as primary and secondary diagnoses) from the French national health insurance perspective

DESIGN

Burden of illness study

SETTING

All acute-care hospitals in France

METHODS

Data were extracted from the French national hospitalization database (PMSI) for patients covered by the national health insurance scheme in 2014. Hospitalizations were selected using the International Classification of Diseases, 10threvision (ICD-10) code for CDI. Hospital stays with CDI as the primary diagnosis or the secondary diagnosis (comorbidity) were studied for the following parameters: patient sociodemographic characteristics, mortality, length of stay (LOS), and related costs. A retrospective case-control analysis was performed on stays with CDI as the secondary diagnosis to assess the impact of CDI on the LOS and costs.

RESULTS

Overall, 5,834 hospital stays with CDI as the primary diagnosis were included in this study. The total national insurance costs were €30.7 million (US $33,677,439), and the mean cost per hospital stay was €5,267±€3,645 (US $5,777±$3,998). In total, 10,265 stays were reported with CDI as the secondary diagnosis. The total national insurance additional costs attributable to CDI were estimated to be €85 million (US $93,243,725), and the mean additional cost attributable to CDI per hospital stay was €8,295±€17,163, median, €4,797 (US $9,099±$8,827; median, $5,262).

CONCLUSION

CDI has a high clinical and economic burden in the hospital, and it represents a major cost for national health insurance. When detected as a comorbidity, CDI was significantly associated with increased LOS and economic burden. Preventive approaches should be implemented to avoid CDIs.

Infect Control Hosp Epidemiol 2017;38:906–911

Assessment of the French National Health Insurance Information System as a tool for epidemiological surveillance of malaria

OBJECTIVE

Epidemiological surveillance of malaria in France is based on a hospital laboratory sentinel surveillance network. There is no comprehensive population surveillance. The objective of this study was to assess the ability of the French National Health Insurance Information System to support nationwide malaria surveillance in continental France.

MATERIALS AND METHODS

A case identification algorithm was built in a 2-step process. First, inclusion rules giving priority to sensitivity were defined. Then, based on data description, exclusion rules to increase specificity were applied. To validate our results, we compared them to data from the French National Reference Center for Malaria on case counts, distribution within subgroups, and disease onset date trends.

RESULTS

We built a reusable automatized tool. From July 1, 2013, to June 30, 2014, we identified 4077 incident malaria cases that occurred in continental France. Our algorithm provided data for hospitalized patients, patients treated by private physicians, and outpatients for the entire population. Our results were similar to those of the National Reference Center for Malaria for each of the outcome criteria.

DISCUSSION

We provided a reliable algorithm for implementing epidemiological surveillance of malaria based on the French National Health Insurance Information System. Our method allowed us to work on the entire population living in continental France, including subpopulations poorly covered by existing surveillance methods.

CONCLUSION

Traditional epidemiological surveillance and the approach presented in this paper are complementary, but a formal validation framework for case identification algorithms is necessary.

Prognosis of patients with chronic hepatitis B in France (2008-2013): A nationwide, observational and hospital-based study

BACKGROUND & AIMS

How risk factors associated with chronic hepatitis B (CHB) modify liver disease progression and mortality has been scarcely reported outside of Asia. We aimed to evaluate these risk factors in a French population between 2008 and 2013.

METHODS

All individuals discharged with CHB from acute and post-acute care hospitals in Metropolitan France between January 2008 and December 2013 were selected. Associations between liver- and non-liver-related risk factors and both liver disease progression (end-stage liver disease or hepatocellular carcinoma) and mortality were assessed by multivariate Cox proportional hazard models.

RESULTS

Overall, liver disease progression, liver transplantation and death were recorded in 7479 (15.5%), 433 (8.2%) and 5299 (11.0%) patients, respectively. An additional liver-related risk factor was recorded in 5426 (72.6%) patients with liver disease progression and 2699 (75.5%) patients with liver transplantation or liver death. Adjusted hazard ratios (95% confidence interval) for liver disease progression of hepatitis D virus co-infection, hepatitis C virus co-infection, alcohol use disorders, diabetes mellitus, and other rare causes of chronic liver disease were 1.44 (1.35-1.53), 1.77 (1.68-1.87), 3.37 (3.20-3.55), 1.40 (1.32-1.48), and 2.19 (1.98-2.42), respectively. All liver-related risk factors increased the risk of all-cause mortality, especially after liver disease progression. Adjusted hazard ratios for liver disease progression and in-hospital mortality of HIV co-infection without acquired immune deficiency syndrome (AIDS) were 0.60 (0.52-0.70) and 0.63 (0.51-0.78), respectively.

CONCLUSIONS

In France, 2008-2013, liver disease progression among patients with CHB was closely related to other risk factors. HIV co-infected patients without AIDS had better outcomes, suggesting better care in this group of patients.

LAY SUMMARY

In France, 2008-2013, about three-quarters of patients with chronic hepatitis B who progressed to a liver-related complication, including liver transplantation and liver-related death, had an additional liver-related risk factor. Despite a higher prevalence of liver-related risk factors, HIV co-infected patients without AIDS had better outcomes. Prognosis of patients with chronic hepatitis B is closely related to other risk factors. Treatment of patients with chronic hepatitis B, including control of chronic hepatitis B-associated risk factors, is more efficient in HIV co-infected patients.

EPI-CT: design, challenges and epidemiological methods of an international study on cancer risk after paediatric and young adult CT

Computed tomography (CT) has great clinical utility and its usage has increased dramatically over the years. Concerns have been raised, however, about health impacts of ionising radiation exposure from CTs, particularly in children, who have a higher risk for some radiation induced diseases. Direct estimation of the health impact of these exposures is needed, but the conduct of epidemiological studies of paediatric CT populations poses a number of challenges which, if not addressed, could invalidate the results. The aim of the present paper is to review the main challenges of a study on the health impact of paediatric CTs and how the protocol of the European collaborative study EPI-CT, coordinated by the International Agency for Research on Cancer (IARC), is designed to address them. The study, based on a common protocol, is being conducted in Belgium, Denmark, France, Germany, the Netherlands, Norway, Spain, Sweden and the United Kingdom and it has recruited over one million patients suitable for long-term prospective follow-up. Cohort accrual relies on records of participating hospital radiology departments. Basic demographic information and technical data on the CT procedure needed to estimate organ doses are being abstracted and passive follow-up is being conducted by linkage to population-based cancer and mortality registries. The main issues which may affect the validity of study results include missing doses from other radiological procedures, missing CTs, confounding by CT indication and socioeconomic status and dose reconstruction. Sub-studies are underway to evaluate their potential impact. By focusing on the issues which challenge the validity of risk estimates from CT exposures, EPI-CT will be able to address limitations of previous CT studies, thus providing reliable estimates of risk of solid tumours and leukaemia from paediatric CT exposures and scientific bases for the optimisation of paediatric CT protocols and patient protection.

Burden of herpes zoster: the direct and comorbidity costs of herpes zoster events in hospitalized patients over 50 years in France

Background

The objectives of this study were to describe hospital stays related to HZ and to evaluate the direct and indirect cost of hospitalizations due to HZ among patients aged over 50 years.

Methods

The hospitalizations of people aged over 50 years were selected from the French national hospital 2011 database (PMSI) using ICD-10 diagnosis codes for HZ.

Firstly, stays with HZ as principal or related diagnostic were described through the patient characteristics, type of hospitalization and the related costs. Secondly, a retrospective case–control analysis was performed on stays with HZ as comorbidity in 5 main hospitalizations causes (circulatory, respiratory, osteo-articular, digestive systems and diabetes) to assess the impact of HZ as co-morbidity on the length of stay, mortality rate and costs.

Results

In the first analysis, 2,571 hospital stays were collected (60 % of women, mean age: 76.3 years and mean LOS: 9.5 days). The total health assurance costs were 10,8 M€. Mean cost per hospital stay was 4,206€. In the second analysis, a significant difference in LOS and costs was shown when HZ was associated as comorbidity in other hospitalization’s causes.

Conclusions

HZ directly impacts on the hospital cost. When present as comorbidity for other medical reasons, HZ significantly increases the length of hospital stay with subsequent economic burden for the French Health System.

[Evaluation of the metrological quality of the medico-administrative data for perinatal indicators: A pilot study in 3 university hospitals]

BACKGROUND

In order to assess public health policies for the perinatal period, routinely produced indicators are needed for the whole population. In France, these indicators are used to compare the national public health policy with those of other European countries. French administrative and medical data (PMSI) are straightforward and reliable and may be a valuable source of information for research. This study aimed to measure the quality of PMSI data from three university health centers for core indicators in perinatal health.

METHOD

PMSI data were compared with medical files in 2012 from 300 live births after 22 weeks of amenorrhea, drawn at random from University Hospitals in Dijon, Paris and Nancy. The variables were chosen based on the Europeristat Project's core and recommended indicators, as well as those of the French National Perinatal survey conducted in 2010. The information gathered blindly from the medical files was compared with the PMSI data positive predictive value (PPV) and the sensitivity was used to assess data quality.

RESULTS

Data on maternal age, parity and mode of delivery as well as the rates of premature births were superimposable for the two sources. The PPV for epidural injection was 96.2% and 94.3% for perineal tears. Overall, maternal morbidity was underdocumented in the PMSI, so the PPV was 100.0% for pre-existing diabetes, 88.9% for gestational diabetes and 100.0% for high blood pressure with a rate of 9.0% in PMSI and 6.3% in the medical files. The PPV for bleeding during labor was 89.5%.

CONCLUSION

To conclude, PMSI data are apparently becoming more and more reliable for two reasons: on one hand, the importance of these data for budgetary promotion in hospitals; on the other, the increasing use of this information for statistical and epidemiological purposes.

[Completeness assessment of the Breton registry of congenital abnormalities: A checking tool based on hospital discharge data]

BACKGROUND

Exhaustiveness is required for registries. In the Breton registry of congenital abnormalities, cases are recorded at the source. We use hospital discharge data in order to verify the completeness of the registry. In this paper, we present a computerized tool for completeness assessment applied to the Breton registry.

METHODS

All the medical information departments were solicited once a year, asking for infant medical stays for newborns alive at one year old and for mother's stays if not. Files were transmitted by secure messaging and data were processed on a secure server. An identity-matching algorithm was applied and a similarity score calculated. When the record was not linked automatically or manually, the medical record had to be consulted. The exhaustiveness rate was assessed using the capture recapture method and the proportion of cases matched manually was used to assess the identity matching algorithm.

RESULTS

The computerized tool bas been used in common practice since June 2012 by the registry investigators. The results presented concerned the years 2011 and 2012. There were 470 potential cases identified from the hospital discharge data in 2011 and 538 in 2012, 35 new cases were detected in 2011 (32 children born alive and 3 stillborn), and 33 in 2012 (children born alive). There were respectively 85 and 137 false-positive cases. The theorical exhaustiveness rate reached 91% for both years. The rate of exact matching amounted to 68%; 6% of the potential cases were linked manually.

CONCLUSION

Hospital discharge databases contribute to the quality of the registry even though reports are made at the source. The implemented tool facilitates the investigator's work. In the future, use of the national identifying number, when allowed, should facilitate linkage between registry data and hospital discharge data.

Are the studies on cancer risk from CT scans biased by indication? Elements of answer from a large-scale cohort study in France

BACKGROUND

Recent epidemiological results suggested an increase of cancer risk after receiving computed tomography (CT) scans in childhood or adolescence. Their interpretation is questioned due to the lack of information about the reasons for examination. Our objective was to estimate the cancer risk related to childhood CT scans, and examine how cancer-predisposing factors (PFs) affect assessment of the radiation-related risk.

METHODS

The cohort included 67,274 children who had a first scan before the age of 10 years from 2000 to 2010 in 23 French departments. Cumulative X-rays doses were estimated from radiology protocols. Cancer incidence was retrieved through the national registry of childhood cancers; PF from discharge diagnoses.

RESULTS

During a mean follow-up of 4 years, 27 cases of tumours of the central nervous system, 25 of leukaemia and 21 of lymphoma were diagnosed; 32% of them among children with PF. Specific patterns of CT exposures were observed according to PFs. Adjustment for PF reduced the excess risk estimates related to cumulative doses from CT scans. No significant excess risk was observed in relation to CT exposures.

CONCLUSIONS

This study suggests that the indication for examinations, whether suspected cancer or PF management, should be considered to avoid overestimation of the cancer risks associated with CT scans.

Predicted cancer risks induced by computed tomography examinations during childhood, by a quantitative risk assessment approach

The potential adverse effects associated with exposure to ionizing radiation from computed tomography (CT) in pediatrics must be characterized in relation to their expected clinical benefits. Additional epidemiological data are, however, still awaited for providing a lifelong overview of potential cancer risks. This paper gives predictions of potential lifetime risks of cancer incidence that would be induced by CT examinations during childhood in French routine practices in pediatrics. Organ doses were estimated from standard radiological protocols in 15 hospitals. Excess risks of leukemia, brain/central nervous system, breast and thyroid cancers were predicted from dose-response models estimated in the Japanese atomic bomb survivors' dataset and studies of medical exposures. Uncertainty in predictions was quantified using Monte Carlo simulations. This approach predicts that 100,000 skull/brain scans in 5-year-old children would result in eight (90 % uncertainty interval (UI) 1-55) brain/CNS cancers and four (90 % UI 1-14) cases of leukemia and that 100,000 chest scans would lead to 31 (90 % UI 9-101) thyroid cancers, 55 (90 % UI 20-158) breast cancers, and one (90 % UI <0.1-4) leukemia case (all in excess of risks without exposure). Compared to background risks, radiation-induced risks would be low for individuals throughout life, but relative risks would be highest in the first decades of life. Heterogeneity in the radiological protocols across the hospitals implies that 5-10 % of CT examinations would be related to risks 1.4-3.6 times higher than those for the median doses. Overall excess relative risks in exposed populations would be 1-10 % depending on the site of cancer and the duration of follow-up. The results emphasize the potential risks of cancer specifically from standard CT examinations in pediatrics and underline the necessity of optimization of radiological protocols.

Risk of cancer associated with cardiac catheterization procedures during childhood: a cohort study in France

BACKGROUND

Radiation can be used effectively for diagnosis and medical treatment, but it can also cause cancers later on. Children with congenital heart disease frequently undergo cardiac catheterization procedures for diagnostic or treatment purposes. Despite the clear clinical benefit to the patient, the complexity of these procedures may result in high cumulative radiation exposure. Given children's greater sensitivity to radiation and the longer life span during which radiation health effects can develop, an epidemiological cohort study is being launched in France to evaluate the risks of leukaemia and solid cancers in this specific population.

METHODS/DESIGN

The study population will include all children who have undergone at least one cardiac catheterization procedure since 2000 and were under 10 years old and permanent residents of France at the time of the procedure. Electronically stored patient records from the departments of paediatric cardiology of the French national network for complex congenital heart diseases (M3C) are being searched to identify the children to be included. The minimum dataset will comprise: identification of the subject (file number in the centre or department, full name, sex, date and place of birth), and characteristics of the intervention (date, underlying disease, type of procedure, technical details, such as fluoroscopy time and dose area product, (DAP), which are needed to reconstruct the doses received by each child). The cohort will be followed up through linkage with the two French paediatric cancer registries, which have recorded all cases of childhood leukaemia and solid cancers in France since 1990 and 2000, respectively. Radiation exposure will be estimated retrospectively for each child. 4500 children with catherizations between 2000 and 2011 have been already included in the cohort, and recruitment is ongoing at the national level. The study is expected to finally include a total of 8000 children.

DISCUSSION

This French cohort study is specifically designed to provide further knowledge about the potential cancer risks associated with paediatric cardiac catheterization procedures. It will also provide new information on typical dose levels associated with these procedures in France. Finally, it should help improve awareness of the importance of radiation protection in these procedures.