Importance of previous hospital stays on the risk of hospital re-admission in older adults: a real-life analysis of the PAERPA study population.

BACKGROUND: consideration of the first hospital re-admission only and failure to take account of previous hospital stays, which are the two significant limitations when studying risk factors for hospital re-admission. The objective of the study was to use appropriate statistical models to analyse the impact of previous hospital stays on the risk of hospital re-admission among older patients. METHODS: an exhaustive analysis of hospital discharge and health insurance data for a cohort of patients participating in the PAERPA ('Care Pathways for Elderly People at Risk of Loss of Personal Independence') project in the Hauts de France region of France. All patients aged 75 or over were included. All data on hospital re-admissions via the emergency department were extracted. The risk of unplanned hospital re-admission was estimated by applying a semiparametric frailty model, the risk of death by applying a time-dependent semiparametric Cox regression model. RESULTS: a total of 24,500 patients (median [interquartile range] age: 81 [77-85]) were included between 1 January 2015 and 31 December 2017. In a multivariate analysis, the relative risk (95% confidence interval [CI]) of hospital re-admission rose progressively from 1.8 (1.7-1.9) after one previous hospital stay to 3.0 (2.6-3.5) after five previous hospital stays. The relative risk [95%CI] of death rose slowly from 1.1 (1.07-1.11) after one previous hospital stay to 1.3 (1.1-1.5) after five previous hospital stays. CONCLUSION: analyses of the risk of hospital re-admission in older adults must take account of the number of previous hospital stays. The risk of death should also be analysed.

How to Compare the Length of Stay of Two Samples of Inpatients? A Simulation Study to Compare Type I and Type II Errors of 12 Statistical Tests.

BACKGROUND: Although many researchers in the field of health economics and quality of care compare the length of stay (LOS) in two inpatient samples, they often fail to check whether the sample meets the assumptions made by their chosen statistical test. In fact, LOS data show a highly right-skewed, discrete distribution in which most of the observations are tied; this violates the assumptions of most statistical tests. OBJECTIVES: To estimate the type I and type II errors associated with the application of 12 different statistical tests to a series of LOS samples. METHODS: The LOS distribution was extracted from an exhaustive French national database of inpatient stays. The type I error was estimated using 19 sample sizes and 1,000,000 simulations per sample. The type II error was estimated in three alternative scenarios. For each test, the type I and type II errors were plotted as a function of the sample size. RESULTS: Gamma regression with log link, the log rank test, median regression, Poisson regression, and Weibull survival analysis presented an unacceptably high type I error. In contrast, the Student standard t test, linear regression with log link, and the Cox models had an acceptable type I error but low power. CONCLUSIONS: When comparing the LOS for two balanced inpatient samples, the Student t test with logarithmic or rank transformation, the Wilcoxon test, and the Kruskal-Wallis test are the only methods with an acceptable type I error and high power.

Case-crossover study to examine the change in postpartum risk of pulmonary embolism over time.

BACKGROUND: Although the current guidelines recommend anticoagulation up until 6 weeks after delivery in women at high risk of venous thromboembolism (VTE), the risk of VTE may extend beyond 6 weeks. Our objective was to estimate the risk of a pulmonary embolism in successive 2-week intervals during the postpartum period. METHODS: In a population-based, case-crossover study, we analyzed the French national inpatient database from 2007 to 2013 (n = 5,517,680 singleton deliveries). Using ICD-10 codes, we identified women who were diagnosed with a postpartum pulmonary embolism between July 1st, 2008, and December 31st, 2013. Deliveries were identified during a case "period" immediately before the pulmonary embolism, and five different control periods one year before the pulmonary embolism. Using conditional logistic regression, Odds ratios (ORs) and 95% confidential intervals (CIs) were estimated for ten successive 2-week intervals that preceded the diagnosis of pulmonary embolism. RESULTS: We identified 167,103 cases with a pulmonary embolism during the inclusion period. After delivery, the risk of pulmonary embolism declined progressively over time, with an OR [95%CI] of 17.2 [14.0-21.3] in postpartum weeks 1 to 2 and 1.9 [1.4-2.7] in postpartum weeks 11 to 12. The OR [95%CI] in postpartum weeks 13 to 14 was 1.4 [0.9-2.0], and the OR did not fall significantly after postpartum week 14. CONCLUSIONS: Our findings indicate that women are at risk of a pulmonary embolism up to 12 weeks after delivery. The shape of the risk curve suggests that the risk decreases exponentially over time. Future research is needed to establish whether the duration of postpartum anticoagulation should be extended beyond 6 weeks.

Fetal Heart-Rate Variability: Validation of a New Continuous, Noninvasive Computerized Analysis.

OBJECTIVE: We developed a computerized heart-rate variability index related to the fetal parasympathetic activity: the Fetal Stress Index (FSI). The objective was to determine whether the FSI is related to the visual analysis of the fetal heart rate (FHR). METHODS: Thirty tracings recorded at a labor ward were classified according to the NICHD categories: (I) normal FHR tracing, (II) intermediate risk of acidosis, and (III) high risk. FSI was calculated as minimum, maximum, and mean, and was evaluated before the onset of the FHR pattern, during the 10 min following, and between 10 and 20 min after that. RESULTS: The FSI for categories II and III was similar to that of category I before the onset of the FHR pattern. FSI min was lower just after the onset of the abnormal FHR in category III, compared with that of category I (33 vs. 43, p < 0.001). Between 10 and 20 min after the onset of the abnormal FHR, we observed a significant reduction in FSI min in categories II and III (44 vs. 39 vs. 29.7, p < 0.0001). CONCLUSION: Although further studies are necessary for the sake of clinical validation, FSI could constitute an interesting method for the evaluation of fetal well-being.

The risks of pulmonary embolism and upper gastrointestinal bleeding beyond 35days after total hip replacement for coxarthrosis among middle-aged patients: A cross-over cohort.

Prophylactic anticoagulation is recommended up to 35days after total hip replacement (THR). Although several observational studies have assessed the incidence of thrombotic events or bleeding events after THR, the corresponding measures of association have never been studied concomitantly. Here, we evaluated the duration of the elevated risks (relative to the baseline risk) of both venous thromboembolic events and bleeding events after THR for coxarthrosis among middle-aged patients. This was a population-based, cross-over cohort study of data extracted from the French national inpatient database between 2007 and 2013. We included middle-aged patients (aged 45 to 69) having undergone THR for coxarthrosis. We compared the numbers of pulmonary embolisms (PEs) (respectively upper gastrointestinal bleedings (UGIBs)) following the THR with the numbers occurring during three unexposed periods one year later. This enabled us to estimate the odds ratio (OR) [95% confidence interval (CI)] for each of six successive 35-day intervals. The study included 108,099 patients. The ORs for PE were respectively 12.4 (95% CI, 8.6-17.8) (absolute risk difference rate per 100,000 (ARD/100,000)=130) and 5.0 (95% CI, 3.4-7.4) (ARD/100,000=52) for the first two 35-day intervals, and the risk was close to 1 thereafter. The risk of UGIB fell quickly, with an OR of 6.5 (95% CI, 4.6-9.1) (ARD/100,000=83) and 0.8 (95% CI, 0.4-1.6) for the first two 35-day intervals, respectively. The majority of UGIBs occurred during the inpatient stay for THR. Among middle-aged patients, the risk of a PE remains elevated beyond 35days after THR for coxarthrosis, whereas the risk of a UGIB remains elevated for the first 35days only.

Adverse drug events with hyperkalaemia during inpatient stays: evaluation of an automated method for retrospective detection in hospital databases.

BACKGROUND: Adverse drug reactions and adverse drug events (ADEs) are major public health issues. Many different prospective tools for the automated detection of ADEs in hospital databases have been developed and evaluated. The objective of the present study was to evaluate an automated method for the retrospective detection of ADEs with hyperkalaemia during inpatient stays. METHODS: We used a set of complex detection rules to take account of the patient's clinical and biological context and the chronological relationship between the causes and the expected outcome. The dataset consisted of 3,444 inpatient stays in a French general hospital. An automated review was performed for all data and the results were compared with those of an expert chart review. The complex detection rules' analytical quality was evaluated for ADEs. RESULTS: In terms of recall, 89.5% of ADEs with hyperkalaemia "with or without an abnormal symptom" were automatically identified (including all three serious ADEs). In terms of precision, 63.7% of the automatically identified ADEs with hyperkalaemia were true ADEs. CONCLUSIONS: The use of context-sensitive rules appears to improve the automated detection of ADEs with hyperkalaemia. This type of tool may have an important role in pharmacoepidemiology via the routine analysis of large inter-hospital databases.

A statistics-based approach of contextualization for adverse drug events detection and prevention.

Several papers propose to take contexts into account for adverse drug events (ADE) detection and prevention, notably to decrease over-alerting of clinical decision support systems (CDSS). However, no statistical argument has been published till now. This works demonstrates, based on statistical analysis, that contextualization is necessary for ADE detection and prevention by 3 steps. A database of 115,447 inpatients stays from 6 hospitals, and 236 ADE detection rules are used. Step 1: the patients differ significantly between and within hospitals, regarding their medical background, their medication and several outcomes. Step 2: The estimated ADE rates vary between and within hospitals. Step 3: even when comparable conditions are present, the probability of ADE occurrence may differ between and within hospitals. Those 3 steps demonstrate that contextualization is necessary, and pave the way for a statistics-based method to contextualize ADE prevention (CDSS) and ADE detection tools.

The ADE scorecards: a tool for adverse drug event detection in electronic health records.

Although several methods exist for Adverse Drug events (ADE) detection due to past hospitalizations, a tool that could display those ADEs to the physicians does not exist yet. This article presents the ADE Scorecards, a Web tool that enables to screen past hospitalizations extracted from Electronic Health Records (EHR), using a set of ADE detection rules, presently rules discovered by data mining. The tool enables the physicians to (1) get contextualized statistics about the ADEs that happen in their medical department, (2) see the rules that are useful in their department, i.e. the rules that could have enabled to prevent those ADEs and (3) review in detail the ADE cases, through a comprehensive interface displaying the diagnoses, procedures, lab results, administered drugs and anonymized records. The article shows a demonstration of the tool through a use case.

Clinical Decision Support Systems and Computerized Provider Order Entry: Contributions from 2020.

OBJECTIVES: To summarize research contributions published in 2020 in the field of clinical decision support systems (CDSS) and computerized provider order entry (CPOE), and select the best papers for the Decision Support section of the International Medical Informatics Association (IMIA) Yearbook 2021. METHODS: Two bibliographic databases were searched for papers referring to clinical decision support systems. From search results, section editors established a list of candidate best papers, which were then peer-reviewed by seven external reviewers. The IMIA Yearbook editorial committee finally selected the best papers on the basis of all reviews including the section editors' evaluation. RESULTS: A total of 1,919 articles were retrieved. 15 best paper candidates were selected, the reviews of which resulted in the selection of two best papers. One paper reports on the use of electronic health records to support a public health response to the COVID-19 pandemic in the United States. The second paper proposes a combination of CDSS and telemedicine as a technology-based intervention to improve the outcomes of depression as part of a cluster trial. CONCLUSIONS: As shown by the number and the variety of works related to clinical decision support, research in the field is very active. This year's selection highlighted the application of CDSS to fight COVID-19 and a combined technology-based strategy to improve the treatment of depression.

Distribution-Based Similarity Measures Applied to Laboratory Results Matching.

The use of international laboratory terminologies inside hospital information systems is required to conduct data reuse analyses through inter-hospital databases. While most terminology matching techniques performing semantic interoperability are language-based, another strategy is to use distribution matching that performs terms matching based on the statistical similarity. In this work, our objective is to design and assess a structured framework to perform distribution matching on concepts described by continuous variables. We propose a framework that combines distribution matching and machine learning techniques. Using a training sample consisting of correct and incorrect correspondences between different terminologies, a match probability score is built. For each term, best candidates are returned and sorted in decreasing order using the probability given by the model. Searching 101 terms from Lille University Hospital among the same list of concepts in MIMIC-III, the model returned the correct match in the top 5 candidates for 96 of them (95%). Using this open-source framework with a top-k suggestions system could make the expert validation of terminologies alignment easier.

Analysis of Hip Fractures in France During the First COVID-19 Lockdown in Spring 2020.

Importance: The COVID-19 pandemic has posed a number of unprecedented challenges to the health care system in France, where hip fractures in the elderly population are a major public health concern. Objective: To explore the association of the first nationwide COVID-19 lockdown in France with the absolute number of hip fractures among patients 50 years or older. Design, Setting, and Participants: This retrospective cohort study used data from the French national hospitals database to identify patients 50 years or older who were hospitalized for hip fracture in France from January to July 2019 and January to July 2020. Exposures: The first nationwide COVID-19 lockdown in France from March 16 to May 10, 2020. Main Outcomes and Measures: The main outcome was the number of hospitalizations for hip fracture from January to July 2020 (study period) compared with the number of hospitalizations for hip fracture during the same period in 2019 (control period). Hospitalization rate ratios (HRRs) comparing the study period with the control period were calculated for 3 intervals (before lockdown [January 1 to March 15], during lockdown [March 16 to May 10], and after lockdown [May 11 to July 31]) and were stratified by gender, age and hospital type. Results: The study included 46 393 patients hospitalized for hip fracture during January to July 2019 (34 589 [74.4%] women; mean [SD] age, 82.8 [10.5] years) and 44 767 patients hospitalized for hip fracture from January to July 2020 (33 160 [74.1%] women; mean [SD] age, 82.9 [10.5] years). During the lockdown in 2020, 10 429 patients (23.30%) were hospitalized for hip fracture compared with 11 782 patients (25.40%) during the same period in 2019 (HRR, 0.89; 95% CI, 0.86-0.91; P < .001). The lockdown period was associated with a decrease in the number of hip fractures of 11% among women (from 8756 in 2019 to 7788 in 2020) and 13% among men (from 3026 in 2019 to 2641 in 2020). When the absolute number of hip fractures was stratified by age group, the lockdown period was associated with a decrease in the number of hip fractures in all age groups except in patients older than 89 years (HRR, 0.97; 95% CI, 0.92-1.01; P = .17). In the group of patients aged 80 to 89 years, the number of hip fractures decreased from 4925 to 4370 (HRR, 0.89; 95% CI, 0.85-0.92; P < .001). During the lockdown, hospitalizations decreased by 33% (HRR, 0.67; 95% CI, 0.63-0.71; P < .001) in public university hospitals and by 24% (HRR, 0.76; 95% CI, 0.73-0.79; P < .001) in public general hospitals but increased by 46% (HRR, 1.46; 95% CI,1.38-1.54; P < .001) in private for-profit hospitals. Conclusions and Relevance: In this cohort study, hospitalizations for hip fractures in France decreased by 11% during the first nationwide COVID-19 lockdown. Further studies are needed to investigate the long-lasting consequences of the COVID-19 pandemic on the incidence of osteoporotic fractures.

Retrograde Extraperitoneal Laparoscopic Prostatectomy (RELP). A Prospective Study about 1,000 Consecutive Patients, with Oncological and Functional Results.

PURPOSE: Usual laparoscopic surgery of localized prostate cancer uses antegrade dissection. We describe and evaluate the original RELP (Retrograde Extraperitoneal Laparoscopic Prostatectomy). MATERIALS AND METHODS: A prospective cohort of 1005 patients with clinical localized cancer prostate were operated from December 1999 to September 2013, in Lyon (France), and followed up to 172 months (median: 60 months). Patients encountered a RELP procedure, a totally extra-peritoneal approach with a retrograde dissection from the apex to the bladder neck, and ascending dissection of the erectile neurovascular bundles, facilitated by the 30° optic telescope. Adjunctive treatments were: immediate radiotherapy (9.2%), salvage radiotherapy (13.4%), androgen deprivation therapy (10.8%), chemotherapy (1.4%), no treatment (75.8%). Results The mean age was 63.4, the Gleason score was 4+3 or worse in 24.9%, there were 2.3% unifocal tumors. The pathology stages were pT2A (8.71%), pT2B (2.80%), pT2C (69.0%), pT3A (13.1%), and pT3B (6.41%). There were 60.8% negative margins (R0) in total (90.1% for basal locations, and 75.8% for apical locations). The mean operating time was 115 minutes for the last 100 patients. The BPFSR (biological progression free survival rate, PSA≤0.10 ng/ml) was 71.9% at 5 years, and 61.4% at 10 years. The cancer specific survival rate was 99.4% at 5 years, and 98.3% at 10 years. After 12 months, 88.6% of patients did not require an incontinence pad, and 67.0% retained the pre-operative quality of their erection. CONCLUSION: RELP yields good oncologic results and quality of life, as good as robot-assisted surgery.

Institutionalization of older French adults with dementia: Role of the informal carer's degree of kinship.

BACKGROUND: The institutionalization of a patient with Alzheimer's disease or other dementia (ADOD) is the last resort for the latter's family and/or caregivers. We hypothesized that the degree of kinship between the patient and his/her caregiver would influence the likelihood of institutionalization. OBJECTIVE: To assess the association between institutionalization of patients with ADOD and the degree of kinship with the family caregiver. METHODS: A cross-sectional study of patients with ADOD aged 75 or over attending a memory center in France for the first time between 2011 and 2014, as recorded in the French National Alzheimer Database. Multivariable logistic regression was used to assess factors associated with institutionalization after adjustment for age, sex, the Mini-Mental State Examination score, educational level, and type of dementia. RESULTS: A total of 52,874 patients were included. The primary caregiver was most often a child (54.8%) or the spouse (36.7%). Compared with the "spouse" reference category, all the other caregiver categories were associated with a significantly greater likelihood of institutionalization; the odds ratio [95% confidence interval] was 4.68 [3.67-5.92] when the carer was a grandchild, 5.48 [4.93-6.09] for a child, 4.93 [4.11-5.91] for a daughter-/son-in-law, 8.76 [7.15-10.70] for a sibling, and 8.93 [7.48-10.65] for a niece/nephew. CONCLUSION: The likelihood of institutionalization of older patients with ADOD varied with the degree of kinship. Compared with the "spouse" reference category, the likelihood was higher for all other types of caregivers but was especially high when the caregiver was not a direct descendant of the patient.

A Decentralized Framework for Biostatistics and Privacy Concerns.

Biostatistics and machine learning have been the cornerstone of a variety of recent developments in medicine. In order to gather large enough datasets, it is often necessary to set up multi-centric studies; yet, centralization of measurements can be difficult, either for practical, legal or ethical reasons. As an alternative, federated learning enables leveraging multiple centers' data without actually collating them. While existing works generally require a center to act as a leader and coordinate computations, we propose a fully decentralized framework where each center plays the same role. In this paper, we apply this framework to logistic regression, including confidence intervals computation. We test our algorithm on two distinct clinical datasets split among different centers, and show that it matches results from the centralized framework. In addition, we discuss possible privacy leaks and potential protection mechanisms, paving the way towards further research.

Gastric Bypass But Not Sleeve Gastrectomy Increases Risk of Major Osteoporotic Fracture: French Population-Based Cohort Study.

The objective of this work was to investigate the risk of major osteoporotic fracture (MOF; hip, proximal humerus, wrist and distal forearm, and clinical spine) in bariatric surgery patients versus matched controls. Bariatric surgery is associated with an increase in fracture risk. However, it remains unclear whether the same degree of fracture risk is associated with sleeve gastrectomy, which has recently surpassed gastric bypass. Records from the French National Inpatient database were used from 2008 to 2018. Bariatric surgery patients, aged 40 to 65 years, with BMI ≥40 kg/m2 , hospitalized between January 1, 2010 and December 31, 2014, were matched to one control (1:1) by age, sex, Charlson comorbidity index, year of inclusion, and class of obesity (40 to 49.9 kg/m2 versus ≥50 kg/m2 ). We performed a Cox regression analysis to assess the association between the risk of any MOF and, respectively, (i) bariatric surgery (yes/no) and (ii) type of surgical procedure (gastric bypass, gastric banding, vertical banded gastroplasty, and sleeve gastrectomy) versus no surgery. A total of 81,984 patients were included in the study (40,992 in the bariatric surgery group, and 40,992 matched controls). There were 585 MOFs in the surgical group (2.30 cases per 1000 patient-year [PY]) and 416 MOFs in the matched controls (1.93 cases per 1000 PY). The risk of MOF was significantly higher in the surgical group (hazard ratio [HR] 1.22; 95% CI, 1.08-1.39). We observed an increase in risk of MOF for gastric bypass only (HR 1.70; 95% CI, 1.46-1.98) compared with the matched controls. In patients aged 40 to 65 years, gastric bypass but not sleeve gastrectomy or the other procedures increased risk of major osteoporotic fractures. © 2020 American Society for Bone and Mineral Research.

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.

Heimdall, a Computer Program for Electronic Health Records Data Visualization.

INTRODUCTION: Electronic health records (EHR) comprehend structured and unstructured data, that are usually time dependent, enabling the use of timelines. However, it is often difficult to display all data without inducing information overload. In both clinical usual care and medical research, users should be able to quickly find relevant information, with minimal cognitive overhead. Our goal was to devise simple visualization techniques for handling medical data in both contexts. METHODS: An abstraction layer for structured EHR data was devised after an informal literature review and discussions between authors. The "Heimdall" prototype was developed. Two experts evaluated the tool by answering 5 questions on 24 clinical cases. RESULTS: Temporal data was abstracted in three simple types: events, states and measures, with appropriate visual representations for each type. Heimdall can load and display complex heterogeneous structured temporal data in a straightforward way. The main view can display events, states and measures along a shared timeline. Users can summarize data using temporal, hierarchical compression and filters. Default and custom views can be used to work in problem- oriented ways. The evaluation found conclusive results. CONCLUSION: The "Heimdall" prototype provides a comprehensive and efficient graphical interface for EHR data visualization. It is open source, can be used with an R package, and is available at https://koromix.dev/files/R.

Statistically Prioritized and Contextualized Clinical Decision Support Systems, the Future of Adverse Drug Events Prevention?

Clinical decision support systems (CDSS) fail to prevent adverse drug events (ADE), notably due to over-alerting and alert-fatigue. Many methods have been proposed in the literature to reduce over-alerting of CDSS: enhancing post-alert medical management, taking into account user-related context, patient-related context and temporal aspects, improving medical relevance of alerts, filtering or tiering alerts on the basis of their strength of evidence, their severity, their override rate, or the probability of outcome. This paper analyzes the different options, and proposes the setup of SPC-CDSS (statistically prioritized and contextualized CDSS). The principle is that, when a SPC-CDSS is implemented in a medical unit, it first reuses actual clinical data, and searches for traceable outcomes. Then, for each rule trying to prevent this outcome, the SPC-CDSS automatically estimates the conditional probability of outcome knowing that the conditions of the rule are met, by retrospective secondary use of data. The alert can be turned off below a chosen probability threshold. This probability computation can be performed in each medical unit, in order to take into account its sensitivity to context.

Transforming French Electronic Health Records into the Observational Medical Outcome Partnership's Common Data Model: A Feasibility Study.

BACKGROUND: Common data models (CDMs) enable data to be standardized, and facilitate data exchange, sharing, and storage, particularly when the data have been collected via distinct, heterogeneous systems. Moreover, CDMs provide tools for data quality assessment, integration into models, visualization, and analysis. The observational medical outcome partnership (OMOP) provides a CDM for organizing and standardizing databases. Common data models not only facilitate data integration but also (and especially for the OMOP model) extends the range of available statistical analyses. OBJECTIVE: This study aimed to evaluate the feasibility of implementing French national electronic health records in the OMOP CDM. METHODS: The OMOP's specifications were used to audit the source data, specify the transformation into the OMOP CDM, implement an extract-transform-load process to feed data from the French health care system into the OMOP CDM, and evaluate the final database. RESULTS: Seventeen vocabularies corresponding to the French context were added to the OMOP CDM's concepts. Three French terminologies were automatically mapped to standardized vocabularies. We loaded nine tables from the OMOP CDM's "standardized clinical data" section, and three tables from the "standardized health system data" section. Outpatient and inpatient data from 38,730 individuals were integrated. The median (interquartile range) number of outpatient and inpatient stays per patient was 160 (19-364). CONCLUSION: Our results demonstrated that data from the French national health care system can be integrated into the OMOP CDM. One of the main challenges was the use of international OMOP concepts to annotate data recorded in a French context. The use of local terminologies was an obstacle to conceptual mapping; with the exception of an adaptation of the International Classification of Diseases 10th Revision, the French health care system does not use international terminologies. It would be interesting to extend our present findings to the 65 million people registered in the French health care system.

Fine-scale geographical distribution and ecological risk factors for Crohn's disease in France (2007-2014).

BACKGROUND: Geographical variations in Crohn's disease (CD) suggest that the environment has a role in the pathogenesis of this condition. AIMS: To describe the spatial distribution and the clustering of CD cases in France, and to assess the relationship between the prevalence of CD and environmental risk factors. METHODS: We identified all patients with CD included in the French hospital discharge database from 2007 to 2014. Age- and gender-smoothed standardised prevalence ratios over this period were computed for 5610 spatial units. An ecological regression analysis was used to assess the relationship between the risk of CD and ecological variables (health care, latitude, socio-economic deprivation, urbanisation, proportion of agricultural surfaces and density of industries). Local spatial clusters of high-CD prevalence were searched for using elliptic spatial scan statistics and characterised in a hierarchical ascendant classification based on the same ecological variables. RESULTS: About 129 089 patients with CD were identified, yielding a crude prevalence of 203 per 100 000 inhabitants. The overall spatial heterogeneity was statistically significant (P < .001). An elevated risk of CD was found to be significantly associated with high-social deprivation (relative risk [95% confidence interval] = 1.05 [1.02-1.08]) and high urbanisation (1.09 [1.04-1.14]). Sixteen significant spatial clusters of high-CD prevalence were identified; there were no common ecological variables. CONCLUSIONS: The geographical distribution of CD prevalence in France is not uniform, and is associated with high levels of social deprivation and urbanisation. Larger ecological databases integrating more detailed environmental and clinical information are needed.