Biostatistics and Clinical Research

Paris, France

Biostatistics and Clinical Research

Paris, France
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Seror R.,Biostatistics and Clinical Research | Seror R.,French Institute of Health and Medical Research | Seror R.,University Paris Diderot | Seror R.,University Paris - Sud | And 14 more authors.
Annals of the Rheumatic Diseases | Year: 2010

Objective: To develop a disease activity index for patients with primary Sjögren's syndrome (SS): the European League Against Rheumatism (EULAR) Sjögren's syndrome disease activity index (ESSDAI). Methods: Thirty-nine SS experts participated in an international collaboration, promoted by EULAR, to develop the ESSDAI. Experts identified 12 organ-specific 'domains' contributing to disease activity. For each domain, features of disease activity were classified in three or four levels according to their severity. Data abstracted from 96 patients with systemic complications of primary SS were used to generate 702 realistic vignettes for which all possible systemic complications were represented. Using the 0-10 physician global assessment (PhGA) scale, each expert scored the disease activity of five patient profiles and 20 realistic vignettes. Multiple regression modelling, with PhGA used as the dependent variable, was used to estimate the weight of each domain. Results: All 12 domains were significantly associated with disease activity in the multivariate model, domain weights ranged from 1 to 6. The ESSDAI scores varied from 2 to 47 and were significantly correlated with PhGA for both real patient profiles and realistic vignettes (r=0.61 and r=0.58, respectively, p<0.001). Compared with 57 (59.4%) of the real patient profiles, 468 (66.7%) of the realistic vignettes were considered likely or very likely to be true. Conclusion: The ESSDAI is a clinical index designed to measure disease activity in patients with primary SS. Once validated, such a standardised evaluation of primary SS should facilitate clinical research and be helpful as an outcome measure in clinical trials.

Bourron O.,Pitie Salpetriere Hospital | Bourron O.,Ambroise Pare Hospital | Bourron O.,Institute of Cardiometabolism and Nutrition | Aubert C.E.,Pitie Salpetriere Hospital | And 19 more authors.
Journal of Clinical Endocrinology and Metabolism | Year: 2014

Objective: The aim of the study was to investigate whether there is a link between arterial calcification in type 2 diabetes and 1) conventional cardiovascular risk factors, 2) serum RANKL andOPG levels, and 3) neuropathy.Patients and Methods: We objectively scored, in a cross-sectional study, infrapopliteal vascular calcification using computed tomography scanning in 198 patients with type 2 diabetes, a high cardiovascular risk, and a glomerular filtration rate-30 mL/min. Color duplex ultrasonography was performed to assess peripheral arterial occlusive disease, and mediacalcosis. Peripheralneuropathywasdefinedby a neuropathy disability score-6. RANKL and OPG were measured in the serum by routine chemistry.Results: Below-knee arterial calcification was associated with arterial occlusive disease. In multivariate logistic regression analysis, the variables significantly and independently associated with the calcificationscorewereage(oddsratio[OR]=1.08; 95%confidenceinterval [CI] =1.04-1.13; P<.0001), male gender(OR=3.53; 95%CI=1.54-8.08; P=.003), previous cardiovascular disease(OR=2.78; 95%CI=1.39-5.59; P=.005), and neuropathy disability score (per 1 point, OR=1.21; 95% CI=1.05-1.38; P=.006). The association with ln OPG, significantly associated with calcification score in univariate analysis (OR=3.14; 95%CI=1.05-9.40; P=.045), wasnolonger significant in multivariate analysis. RANKLand OPG/RANKL were not significantly associated with the calcification score.Conclusions: Below-knee arterial calcification severity is clearly correlated with peripheral neuropathy severity and with several usual cardiovascular risk factors, but not with serum RANKL level.

Merad F.,Unit of General and Digestive Surgery | Baron G.,French Institute of Health and Medical Research | Baron G.,University of Paris Descartes | Pasquet B.,Biostatistics and Clinical Research | And 8 more authors.
World Journal of Surgery | Year: 2012

Background The P-POSSUM score, the most well known of predictive scores for postoperative mortality, requires validation for population and setting. Methods Validation methods included discrimination (C-index statistic), observed:expected (O:E) ratio, calibration with the Hosmer-Lemeshow test, and subgroup analysis (emergency surgery, cancer, age, organs). The study included 3,881 multisite patients undergoing major digestive surgery in France. Results Discrimination via the receiver operating characteristic curve was good (C-index = 0.87). The overall O:E ratio was 1 (95% confidence interval ([95 % CI]: 0.88-1.13), and therefore the quality of the surgical performance is within normal ranges. The O:E ratio, calculated by risk ranges, showed overestimation in the low risk range, especially in the 3 % to 6 % and 6 % to 10 % ranges. Calibration was poor (p<0.001). The model deviated from the normal pattern of calibration, with mortality lower than expected in the high-risk range. Subgroup analysis found reasonable to good discrimination of populations (C-index ranging from 0.78 to 0.93 except for liver surgery [0.67]) while calibration of individuals remained poor (p<0.001 to 0.02). Conclusions Good discrimination, as well as nonsignificant overall O:E values, makes P-POSSUM a valuable tool when it is used for surgical audit to compare mortality between populations for major digestive surgery. Conversely, poor calibration (goodness-of-fit), especially in subgroup analysis, and underestimation or overestimation of O:E ratios considerably limits the value of P-POSSUM for prediction of mortality in individuals. Therefore P-POSSUM should not be used to predict outcomes for one particular patient. © Société Internationale de Chirurgie 2012.

Legrain S.,Geriatric Unit | Legrain S.,University Paris Diderot | Tubach F.,University Paris Diderot | Tubach F.,Biostatistics and Clinical Research | And 16 more authors.
Journal of the American Geriatrics Society | Year: 2011

Objectives To determine whether a new multimodal comprehensive discharge-planning intervention would reduce emergency rehospitalizations or emergency department (ED) visits for very old inpatients. Design Six-month prospective, randomized (Zelen design), parallel-group, open-label trial. Setting Six acute geriatric units (AGUs) in Paris and its surroundings. Participants Six hundred sixty-five consecutive inpatients aged 70 and older (intervention group (IG) n = 317; control group (CG) n = 348). Intervention Intervention-dedicated geriatricians different from those in the study centers implemented the intervention, which targeted three risk factors for preventable readmissions and consisted of three components: comprehensive chronic medication review, education on self-management of disease, and detailed transition-of-care communication with outpatient health professionals. Measurements Emergency hospitalization or ED visit 3 and 6 months after discharge, as assessed by telephone calls to the participant, the caregiver, and the general practitioner and confirmed with the hospital administrative database. Results Twenty-three percent of IG participants were readmitted to hospital or had an ED visit 3 months after discharge, compared with 30.5% of CG participants (P =.03); at 6 months, the proportions were 35.3% and 40.8%, respectively (P =.15). Event-free survival was significantly higher in the IG at 3 months (hazard ratio (HR) = 0.72, 95% confidence interval (CI) = 0.53-0.97, P =.03) but not at 6 months (HR = 0.81, 95% CI = 0.64-1.04, P =.10). Conclusion This intervention was effective in reducing rehospitalizations and ED visits for very elderly participants 3 but not 6 months after their discharge from the AGU. Future research should investigate the effect of this intervention of transitional care in a larger population and in usual acute and subacute geriatric care. © 2011, The American Geriatrics Society.

PubMed | Biostatistics and Clinical Research, SEISIDA, Health Economics, IGM Institute of Management and 7 more.
Type: Journal Article | Journal: Journal of the International AIDS Society | Year: 2014

Patient preference to antiretroviral therapy (ART) characteristics should be a key consideration in treatment decisions. ART options exist for people living with HIV (PLWH), however concerns remain related to PLWH satisfaction with current ARTs. The current study examines patient preferences and the strength of preferences for treatment characteristics associated with ART.Patients preferences to ART were explored using a discrete choice experiment (DCE). Seven defined treatment characteristics (each with three categories) were identified from a literature review, input from experts, PLWH and physicians. A total of 1582 PLWH from France, Germany, Spain, Italy and the UK were recruited for the study. An adjusted odds ratio <1 signified lower odds of selecting a treatment with this characteristic category, compared to the reference category, independently of other characteristics.The patient preference analyses showed that participants preferred treatments with a rapid reduction in viral load (OR=0.78; 95% CI 0.74-0.81) and CD4 count (OR=0.86; 95% CI=0.82-0.89). Participants had a strong preference for avoiding diarrhoea (Odds ratio, OR=0.36 95% CI=0.33-0.38) and long term health problems (OR=0.30, 95% CI=0.28-0.32). Convenience related issues related to restrictions on taking drugs because of food or drug interactions were important to avoid (OR=0.80, 95% CI=0.76-0.83 and OR=0.72 95% CI=0.69-0.76 respectively). Participants also had a strong preference to avoid drugs which limited the effectiveness of future treatments (OR=0.70, 95% CI=0.67-0.73).Avoidance of diarrhoea and long-term complications were the most important drivers of patient choice. This study, from a large sample of European patients, demonstrates the importance to patients when different aspects of HIV treatment are considered simultaneously.

Ronot M.,University Paris Diderot | Ronot M.,Institute National Of La Santeet Of La Recherche Medicale | Asselah T.,University Paris Diderot | Paradis V.,University Paris Diderot | And 11 more authors.
Radiology | Year: 2010

Purpose: To prospectively assess the utility of perfusion computed tomography (CT) for differentiating minimal from intermediate fibrosis in treatment-naïve patients with chronic hepatitis C virus (HCV) infection. Materials and Methods: This study was approved by the Institutional Review Board, and informed consent was obtained. Fifty-two patients with treatment-naïve HCV infection underwent perfusion CT and percutaneous liver biopsy on the same day. Portal vein, arterial, and total liver perfusion;mean transit time; and distribution volumes for the right and left liver lobes were measured. Liver samples were scored for fibrosis, and fibrosis area was determined. Differences in quantitative perfusion parameters between patients with minimal fibrosis (score of F1) and those with intermediate fibrosis (score of F2 or F3) were tested. Results: In patients with intermediate fibrosis (F2 and F3) compared with those with minimal fibrosis (F1), the portal venous perfusion (87 mL · min-1 · 100 mL-1 ± 27 [standard deviation] vs 138 mL · min-1 · 100 mL-1 ± 112, P =.042) and total liver perfusion (107 mL · min-1 · 100 mL-1 ± 31 vs 169 mL · min-1 · 100 mL-1 ± 137, P = .02) were significantly decreased, and the mean transit time was significantly increased (16 seconds ± 4 vs 13 seconds ± 5, P = .025). At multivariate analysis, only the mean transit time was an independent factor(odds ratio, 1.18; 95% confidence interval: 1.02, 1.37; P = .030). Receiver operating characteristic curve analysis showed that a mean transit time threshold of 13.4 seconds allowed discrimination between minimal and intermediate fibrosis with a sensitivity of 71% and a specificity of 65%. Conclusion: The results of this study show that perfusion changes occur early during fibrosis in chronic HCV infection and can be detected with perfusion CT. Perfusion CT may help to discriminate minimal from intermediate fibrosis. Mean transit time appears to be the most promising perfusion parameter for differentiating between fibrosis stages, although the large amount of overlap in the measured parameters limits the clinical utility of this test at present. © RSNA, 2010.

Azria E.,Groupe Hospitalier Bichat Claude Bernard | Azria E.,University Paris Diderot | Guittet L.,Biostatistics and Clinical Research | Delahaye M.,Groupe Hospitalier Bichat Claude Bernard | And 6 more authors.
European Journal of Obstetrics Gynecology and Reproductive Biology | Year: 2011

Introduction: The North Paris community-based Perinatal Network was set up in 2003 to improve the quality of prenatal care in an area surrounding the Bichat Claude Bernard University Hospital characterized by high social deprivation. The aim of this study is to assess the impact of the network on early perinatal care. Materials and methods: A retrospective observational study on medical records was conducted over four periods: one year before the setting up of the network (2002), the year the network became operational (2003), and one year (2004) and five years (2008) after implementation. Endpoints were the proportion of women delivered in the institution who underwent first-trimester ultrasound screening and the proportion of nuchal translucency measurements deemed acceptable (image quality score from 4 to 9 according to the Herman scoring system). Results: Between 2002 and 2004, substantial improvements were noted in access to first-trimester ultrasound screening (55.8% in 2002, 65.9% in 2003, 71.9% in 2004, P < 0.05) and in the quality of nuchal translucency measurement (acceptable measurement over this period, 51.1%, 67.8% and 77.8%, respectively, P < 0.001). Five years after network set-up, indicators remained unchanged from those of 2004. The rate of first ultrasound screening performed was 72.1% and the rate of acceptable measurement 71.1%, both non-statistically different from 2004 rates. Conclusion: This perinatal network seems to be associated with an improvement in early prenatal care. However, the rate of first ultrasound performed remained unsatisfactory and to further improve these indicators, upstream social interventions are needed. Copyright © 2011 Published by Elsevier Ireland Ltd. All rights reserved.

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