Anne-Sophie Jannot

Citation bias favoring statistically significant studies was present in medical research

OBJECTIVE Statistically significant studies may be cited more than negative studies on the same topic. We aimed to assess here whether such citation bias is present across the medical literature. STUDY DESIGN AND SETTING We conducted a cohort study of the association between statistical significance and citations. We selected all therapeutic intervention studies included in meta-analyses published between January and March 2010 in the Cochrane database, and retrieved citation counts of all individual studies using ISI Web of Knowledge. The association between the statistical significance of each study and the number of citations it received between 2008 and 2010 was assessed in mixed Poisson models. RESULTS We identified 89 research questions addressed in 458 eligible articles. Significant studies were cited twice as often as nonsignificant studies (multiplicative effect of significance: 2.14, 95% confidence interval: 1.38-3.33). This association was partly because of the higher impact factor of journals where significant studies are published (adjusted multiplicative effect of significance: 1.14, 95% confidence interval: 0.87-1.51). CONCLUSION A citation bias favoring significant results occurs in medical research. As a consequence, treatments may seem more effective to the readers of medical literature than they really are.

Assessment of recurrence and complications following uncomplicated diverticulitis

The natural history of sigmoid diverticulitis has been inferred from population‐based or retrospective studies. This study assessed the risk of a recurrent attack following the first episode of uncomplicated diverticulitis.

New combined serum creatinine and cystatin C quadratic formula for GFR assessment in children.

BACKGROUND AND OBJECTIVES The estimated GFR (eGFR) is important in clinical practice. To find the best formula for eGFR, this study assessed the best model of correlation between sinistrin clearance (iGFR) and the solely or combined cystatin C (CysC)- and serum creatinine (SCreat)-derived models. It also evaluated the accuracy of the combined Schwartz formula across all GFR levels. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS Two hundred thirty-eight iGFRs performed between January 2012 and April 2013 for 238 children were analyzed. Regression techniques were used to fit the different equations used for eGFR (i.e., logarithmic, inverse, linear, and quadratic). The performance of each model was evaluated using the Cohen κ correlation coefficient and the percentage reaching 30% accuracy was calculated. RESULTS The best model of correlation between iGFRs and CysC is linear; however, it presents a low κ coefficient (0.24) and is far below the Kidney Disease Outcomes Quality Initiative targets to be validated, with only 84% of eGFRs reaching accuracy of 30%. SCreat and iGFRs showed the best correlation in a fitted quadratic model with a κ coefficient of 0.53 and 93% accuracy. Adding CysC significantly (P<0.001) increased the κ coefficient to 0.56 and the quadratic model accuracy to 97%. Therefore, a combined SCreat and CysC quadratic formula was derived and internally validated using the cross-validation technique. This quadratic formula significantly outperformed the combined Schwartz formula, which was biased for an iGFR≥91 ml/min per 1.73 m(2). CONCLUSIONS This study allowed deriving a new combined SCreat and CysC quadratic formula that could replace the combined Schwartz formula, which is accurate only for children with moderate chronic kidney disease.

Impact of recipient body mass index on short-term and long-term survival of pancreatic grafts.

Background The impact of recipient body mass index on graft and patient survival after pancreas transplantation is not well known. Methods We have analyzed data from all pancreas transplant recipients reported in the Scientific Registry of Transplant Recipients between 1987 and 2011. Recipients were categorized into BMI classes, as defined by the World Health Organization. Short-term (90 days) and long-term (90 days to 5 years) patient and graft survivals were analyzed according to recipient BMI class using Kaplan-Meier estimates. Hazard ratios were estimated using Cox proportional hazard models. Results A total of 21,075 adult recipients were included in the analysis. Mean follow-up was 5±1.1 years. Subjects were overweight or obese in 39%. Increasing recipient BMI was an independent predictor of pancreatic graft loss and patient death in the short term (P<0.001), especially for obese class II patient survival (hazard ratio, 2.07; P=0.009). In the long term, obesity, but not overweight, was associated with higher risk of graft failure (P=0.01). Underweight was associated with a higher risk of long-term death (P<0.001). Conclusion These results question the safety of pancreas transplantation in obese patients and suggest that they may be directed to alternate therapies, such as behavioral modifications or bariatric surgery, before pancreas transplantation is considered.

Risk factors for early and late biliary complications in pediatric liver transplantation

BC are a common source of morbidity after pediatric LT. Knowledge about risk factors may help to reduce their incidence. Retrospective analysis of BC in 116 pediatric patients (123 LT) (single institution, 05/1990–12/2011, medium follow‐up 7.9 yr). One‐, five‐, and 10‐yr survival was 91.1%, no patient died of BC. Prevalence and risk factors for anastomotic and intrahepatic BC were examined. There were 29 BC in 123 LT (23.6%), with three main categories: 10 (8.1%) primary anastomotic strictures, eight (6.5%) anastomotic leaks, and three (2.4%) intrahepatic strictures. Significant risk factors for anastomotic leaks were total operation time (increase 1.26‐fold) and early HAT (<30 days post‐LT; increase 5.87‐fold). Risk factor for primary anastomotic stricture was duct‐to‐duct choledochal anastomosis (increase 5.96‐fold when compared to biliary‐enteric anastomosis). Risk factors for intrahepatic strictures were donor age >48 yr (increase 1.09‐fold) and MELD score >30 (increase 1.2‐fold). To avoid morbidity from anastomotic BC in pediatric LT, the preferred biliary anastomosis appears to be biliary‐enteric. Operation time should be kept to a minimum, and HAT must by all means be prevented. Children with a high MELD score or receiving livers from older donors are at increased risk for intrahepatic strictures.

The Diagnosis-Wide Landscape of Hospital-Acquired AKI

BACKGROUND AND OBJECTIVES The exploration of electronic hospital records offers a unique opportunity to describe in-depth the prevalence of conditions associated with diagnoses at an unprecedented level of comprehensiveness. We used a diagnosis-wide approach, adapted from phenome-wide association studies (PheWAS), to perform an exhaustive analysis of all diagnoses associated with hospital-acquired AKI (HA-AKI) in a French urban tertiary academic hospital over a period of 10 years. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS We retrospectively extracted all diagnoses from an i2b2 (Informatics for Integrating Biology and the Bedside) clinical data warehouse for patients who stayed in this hospital between 2006 and 2015 and had at least two plasma creatinine measurements performed during the first week of their stay. We then analyzed the association between HA-AKI and each International Classification of Diseases (ICD)-10 diagnostic category to draw a comprehensive picture of diagnoses associated with AKI. Hospital stays for 126,736 unique individuals were extracted. RESULTS Hemodynamic impairment and surgical procedures are the main factors associated with HA-AKI and five clusters of diagnoses were identified: sepsis, heart diseases, polytrauma, liver disease, and cardiovascular surgery. The ICD-10 code corresponding to AKI (N17) was recorded in 30% of the cases with HA-AKI identified, and in this situation, 20% of the diagnoses associated with HA-AKI corresponded to kidney diseases such as tubulointerstitial nephritis, necrotizing vasculitis, or myeloma cast nephropathy. Codes associated with HA-AKI that demonstrated the greatest increase in prevalence with time were related to influenza, polytrauma, and surgery of neoplasms of the genitourinary system. CONCLUSIONS Our approach, derived from PheWAS, is a valuable way to comprehensively identify and classify all of the diagnoses and clusters of diagnoses associated with HA-AKI. Our analysis delivers insights into how diagnoses associated with HA-AKI evolved over time. On the basis of ICD-10 codes, HA-AKI appears largely underestimated in this academic hospital.

[OP.2B.08] ETIOLOGY OF RENAL INFARCTIONS: A RETROSPECTIVE ANALYSIS OF 229 CONSECUTIVE CASES ADMITTED TO A SINGLE TERTIARY CENTER OVER 15 YEARS

Objective: Renal infarction (RI) is a rare disease (0.004% of patients admitted to emergency units), due to a disruption of renal blood flow of the main ipsilateral renal artery (RA) or of one of its segmental branches due to either a local in-situ or a general mechanism. The local mechanism includes RA occlusion, dissection, aneurysm or stenosis which 1) may lead to in-situ RA thrombosis or renal emboli and 2) can be due to various etiologies including atherosclerosis disease (ASD), fibromuscular dysplasia (FMD), dissecting hematoma (DH), extension of an aortic dissection (AoD) to the RA, miscellaneous arterial disease (AD), iatrogenic post-RA catheterization/surgery complication (IC) or post-renal trauma complication (T). The general mechanism includes thromboembolic disease (TED) due to arrhythmia, aortic thromboembolism, or a hypercoagulable state. The aim of this study is to analyze the various RI causes. Design and method: Patients with RI admitted consecutively to our tertiary hospital center between 07/2000 and 06/2015 were retrospectively identified from the weekly reports of our multidisciplinary rounds. Main clinical and biological characteristics of the patients were extracted from our clinical data warehouse. All identified patients had renal CT-angiogram (CTA) which was reviewed by two readers blind to the first radiological report to confirm RI diagnosis and assess its underlying mechanism/etiology. In case of discrepancy between the independent CTA reading and the initial CTA or multidisciplinary meeting report (n = 41), the final diagnosis was made by a vascular radiologist on a third independent reading. Results: We identified a total of 278 patients of whom 49 were excluded and the 229 remaining had confirmed RI. The 2 most frequent mechanisms of RI were RA occlusions (48%) and dissections (36%) (table). RA occlusions were mainly due to ASD. RA dissections mainly related to DH (43%) and FMD (20%). 19% of RI were due to a complication of an endovascular or surgical procedure. Figure. No caption available. Conclusions: In this large case series, RI was predominantly due to in-situ mechanisms mainly related to RA occlusion or dissection. RA occlusions were more frequently associated with ASD whereas RA dissections were mainly related to DH and FMD.

[OP.2A.07] TRENDS IN PATIENTS ATTENDING A TERTIARY HYPERTENSION UNIT: PATIENTS’ CHARACTERISTICS AND TREATMENT STRATEGIES STRONGLY EVOLVED OVER THE LAST 15 YEARS

Objective: Patients attending for the first time to a tertiary hypertension unit represent a sample of the general population of hypertensive patients from a region. Even though it is a biased sample, the longitudinal analysis with time of the data of these patients represents in part real life data and may show trends in adherence to guidelines by their primary care physicians and by patients themselves. Our tertiary hypertension unit has a computerized medical record with more than hundred structured items recorded at each visit. We analyzed changes in patients and treatment characteristics referred to our center over 15 years. Figure. No caption available. Design and method: We extracted the data of the first visit of all patients attending for the first time our unit between 07/2000 and 06/2015 from our Clinical DataWarehouse. We analyzed patients’ characteristics and treatment evolution between three periods of 5 years. We then analyzed treatment determinants among periods using multivariate analyses, taking into account all patients characteristics. Results: A total of 17856 patients were included in the study. The prevalence of comorbidities (diabetes, dyslipidemia, renal and heart failure, coronary artery disease, obesity) declared by patients increased with time whereas age remained stable over the three periods. The prevalence of smokers (current or past) decreased with time. Patients declared more frequently regular physical activity with time. Familial history of cardiovascular events strongly decreased. The number of patients treated with at least one antihypertensive treatment strongly increased as well as the number of antihypertensive classes per patient. The prescription rate of angiotensin receptor blockers and calcium-channel blockers increased whereas that of loop diuretics and beta blockers decreased with time. In a multivariate analysis, each anti-hypertensive class was associated with almost all recorded patients’ characteristics. Conclusions: Patients’ characteristics and treatment strategies strongly evolved over the last 15 years in Paris area. We showed that treatment strategy in real life was based on many patients’ characteristics. Therefore, clinicians personalized their treatment decision by taking into account all patients’ characteristics. This study offers the opportunity to provide real life algorithms for personalized treatment strategy.