Publication bias in pharmacogenetics of adverse reaction to antiseizure drugs: An umbrella review and a meta-epidemiological study.

Publication bias may lead to a misestimation in the association between pharmacogenetic biomarkers (PGx) and antiseizure drug's adverse effects (AEs). We aimed to assess its prevalence in this field. We searched for systematic reviews assessing PGx of antiseizure drug's AEs. For each unique association between a PGx, a drug and its AE, we used the available odds ratio (ORs) to generate corresponding funnel plots. We estimated the prevalence of publication bias using visual inspections and asymmetry tests. We explored the impact of publication bias using ORs adjusted for potential publication bias. Twenty-two associations were available. Our visual analysis suggested a publication bias in five out twenty-two funnel plots (23% [95%CI: 8; 45]). The Egger's test showed a significant publication bias in one (HLA-B*15:02 and phenytoin-induced Stevens-Johnson syndrome or toxic epidermal necrolysis, p = 0.03) out of nine (11% [95%CI: 0; 48]) and the Begg's test in one (HLA-B*15:02 and carbamazepine-induced serious cutaneous reactions, p = 0.02) out of ten (10% [95%CI: 0; 45]) assessable funnel plots. Adjusting for publication bias may reduce by half the ORs of the pharmacogenetics associations. Publication bias in the pharmacogenetic of antiseizure drug's AEs is not uncommon and may affect the estimation of the effect of such biomarkers. When conducting pharmacogenetic studies, it is critical to publish also the negative one.

Murine typhus complicated by sHLH mimicking adult-onset Still's disease.

INTRODUCTION: Adult-onset Still's disease (AOSD) is a rare multisystemic disorder and a diagnostic challenge for physicians because of the wide range of differential diagnoses. Common features of AOSD and secondary hemophagocytic lymphohistiocytosis (sHLH) could favour diagnostic uncertainty, in particular in case of infection-related sHLH. OBSERVATION: A 61-year-old man was admitted to our internal medicine department for suspected AOSD. He reported a 2-week history of sudden onset fever, headaches, myalgia, sore throat, diarrhoea, and an erythematous macular rash of the trunk as well as petechial purpuric lesions on both legs on return from Reunion Island. Laboratory tests found cytopenia, hepatic cytolysis, hypertriglyceridaemia, and hyperferritinaemia. Hemophagocytosis was diagnosed on bone marrow aspiration in favour of the diagnosis of secondary hemophagocytic lymphohistiocytosis (sHLH). Subcutaneous anakinra (100mg) was initiated to treat sHLH with favourable course. Oral doxycycline was added 3days later because of atypical features for AOSD diagnosis such as diarrhoea, hypergammaglobulinaemia, and doubtful serologies for Rickettsia and Coxiella. Three weeks later, Rickettsia typhi serology was checked again and revealed an increase in IgG titer>4 times that confirmed the diagnosis of murine typhus. A diagnosis of murine typhus complicated by sHLH was retained, successfully treated by anakinra and doxycycline. CONCLUSION: Our observation shows that AOSD diagnosis has to be stringent due to the many differential diagnoses, particularly infection complicated by sHLH, which may be rare. It is important to consider murine typhus in patients returning from endemic areas, such as La Reunion or other tropical areas, when they present fever of unknown origin with non-specific clinical features. Moreover, this case illustrates the effectiveness of IL-1 blockers as a treatment for symptomatic sHLH without severity criteria, regardless of the aetiology.

Off-label use of biologics for the treatment of refractory and/or relapsing granulomatosis with polyangiitis.

OBJECTIVE: To describe the efficacy and safety of off-label use of biologics for refractory and/or relapsing granulomatosis with polyangiitis (GPA). METHODS: We conducted a French retrospective study including GPA patients who received off-label biologics for refractory and/or relapsing disease after failure of conventional immunosuppressive regimens. RESULTS: Among 26 patients included, 18 received infliximab (IFX), 2 adalimumab (ADA) and 6 abatacept (ABA). Biologics were initiated in median as 4th-line therapy (IQR 3-6) for relapsing and/or refractory disease in 23 (88%) and/or significant glucocorticoid-dependency in 8 cases (31%). At biologics initiation, median (IQR) BVAS and prednisone dose in anti- TNF-α and ABA recipients were 7 (3-8) and 2 (1-6), and 20 (13-30) mg/day and 20 (15-25) mg/day, respectively. Clinical manifestations requiring biologics were mainly pulmonary and ENT manifestations in 58% each. Anti-TNF-α and ABA were continued for a median duration of 8 months (IQR 6-13) and 11 months (IQR 6-18) respectively. Anti-TNF-α recipients showed remission, partial response and treatment failure in 10%, 30% and 60% at 6 months, and 25%, 20% and 55% at 12 months, respectively. ABA recipients showed remission, partial response and treatment failure in 17%, 33% and 50% at 6 months and 17%, 33% and 50% at 12 months. One patient treated with IFX experienced life-threatening reaction while one patient treated with ABA experienced a severe infection. CONCLUSION: This real-life study suggests that off-label use of anti-TNF-α and abatacept shows efficacy in less than 50% of refractory and/or relapsing GPA.

Issues and limitations of available biomarkers for fluoropyrimidine-based chemotherapy toxicity, a narrative review of the literature.

Fluoropyrimidine-based chemotherapies are widely used to treat gastrointestinal tract, head and neck, and breast carcinomas. Severe toxicities mostly impact rapidly dividing cell lines and can occur due to the partial or complete deficiency in dihydropyrimidine dehydrogenase (DPD) catabolism. Since April 2020, the European Medicines Agency (EMA) recommends DPD testing before any fluoropyrimidine-based treatment. Currently, different assays are used to predict DPD deficiency; the two main approaches consist of either phenotyping the enzyme activity (directly or indirectly) or genotyping the four main deficiency-related polymorphisms associated with 5-fluorouracil (5-FU) toxicity. In this review, we focused on the advantages and limitations of these diagnostic methods: direct phenotyping by evaluation of peripheral mononuclear cell DPD activity (PBMC-DPD activity), indirect phenotyping assessed by uracil levels or UH2/U ratio, and genotyping DPD of four variants directly associated with 5-FU toxicity. The risk of 5-FU toxicity increases with uracil concentration. Having a pyrimidine-related structure, 5-FU is catabolised by the same physiological pathway. By assessing uracil concentration in plasma, indirect phenotyping of DPD is then measured. With this approach, in France, a decreased 5-FU dose is systematically recommended at a uracil concentration of 16 ng/ml, which may lead to chemotherapy under-exposure as uracil concentration is a continuous variable and the association between uracil levels and DPD activity is not clear. We aim herein to describe the different available strategies developed to improve fluoropyrimidine-based chemotherapy safety, how they are implemented in routine clinical practice, and the possible relationship with inefficacy mechanisms.

[Human papillomavirus and systemic lupus erythematosus]. / Papillomavirus humain et lupus érythémateux systémique.

Infection with human papillomavirus (HPV) is one of the most widespread sexually transmitted diseases and the main risk factor for cervical cancer. Underlying conditions, like immunosuppression, favour the persistence and the progression of cervical lesions to an aggressive form. Patients with autoimmune diseases, and particularly systemic lupus erythematosus (SLE), may be prone to HPV infection and cervical dysplasia. However, the risk factors for developing persistent HPV-related infection, dysplasia and cancer are not identified for patients with SLE. The existence of an increased risk of cervical cancer compared to the general population remains debated. Thus, HPV vaccine is recommended for SLE patients as well as for the general population. Vaccine coverage of SLE patients is not known in France. Adolescents with chronic health condition seem to be insufficiently vaccinated regarding their vulnerability to infectious diseases. Strategies are required to decrease HPV vaccination barriers.

Direct oral anticoagulants in the treatment of acute venous thromboembolism in patients with obesity: A systematic review with meta-analysis.

BACKGROUND: Direct oral anticoagulants' (DOAC) pharmacokinetics are affected by obesity. Their efficacy and safety in obesity (BMI≥30 kg/m2) and morbid obesity (BMI≥40 kg/m2) are still unclear in the treatment of venous thromboembolism (VTE). OBJECTIVES: To compare the efficacy/safety of DOAC versus vitamin K antagonist (VKA)/low molecular weight heparin (LMWH) for the treatment of VTE in patients with obesity and morbid obesity. The primary efficacy/safety outcomes were VTE recurrence and major bleeding (MB). Clinically relevant non-MB and mortality were also evaluated. METHODS: A systematic literature search (MEDLINE, EMBASE, CENTRAL, Web of Science) identified studies evaluating DOAC in the treatment of VTE in patients with obesity and reporting one of the outcomes. Relative risks (RR) and 95 % confidence intervals (CI) were estimated using the Mantel-Haenszel method. RESULTS: We included 21 studies (50,360pts) of which 16,150 patients had a BMI≥30 kg/m2 and 6443 patients had a BMI≥40 kg/m2. VTE recurrence was similar with DOAC compared to VKA/LMWH in patients with obesity (RR 1.03;95 %CI 0.93-1.15;p = 0.55) and morbid obesity (RR 1.06;95 %CI 0.94-1.19;p = 0.35). DOAC were also associated with a reduction in MB (RR 0.57;95 %CI 0.34-0.94;p = 0.03 and RR 0.71;95 %CI 0.50-1.00;p = 0.05 in patients with obesity and morbid obesity, respectively). Subgroup analyses comparing randomized controlled trials to observational studies showed consistent results. No difference was observed in regards of clinically relevant non-MB and mortality. CONCLUSION: There is no signal for differences in VTE recurrence in patients with obesity and morbid obesity treated with DOAC compared to VKA/LMWH, while DOAC likely reduce the risk of MB compared to VKA/LMWH.

[Secondary ITP in adults]. / Les purpuras thrombopéniques immunologiques secondaires de l'adulte.

Secondary forms of immune thrombocytopenia (ITP) represent approximately 20% of all ITP cases in adulthood and this rate increases with age. Since some causes may influence both the prognosis and outcome but also the management of ITP, a minimal workup must be performed at ITP diagnosis to look for an associated or underlying cause. Among adults, B-cell lymphomas and mainly chronic lymphocytic leukemia, systemic auto-immune diseases such as systemic lupus or primary immunodeficiencies mainly represented by common variable immunodeficiency are the most frequent causes of secondary ITP. Whereas first-line therapy used for secondary ITP is usually similar to the one commonly used in primary ITP and relies mostly on corticosteroids±intravenous immunoglobulin according to the severity of bleeding, second and third-line treatments must take into account the type and degree of activity of the underlying disease.

Twice- or Once-Daily Dosing of Direct Oral Anticoagulants, a systematic review and meta-analysis.

AIM: The direct oral anticoagulants (DOAC) have similar half-lives, but the dosing regimen varies between once daily (QD) or twice daily (BID). For some prescribers, the QD regimen improves compliance. Others prefer BID regimens to promote better stability of plasma concentrations, particularly in the event of missed doses. Limited level of evidence provides guidance about the best treatment strategy. The purpose of this study was to compare the treatment effect of QD vs. BID administration of DOACs in major orthopedic surgery (MOS), non-valvular atrial fibrillation (NVAF), venous thromboembolism (VTE), and acute coronary syndrome (ACS). METHODS: We conducted a systematic review up to April 2020. We included phase II clinical trials comparing DOAC QD vs BID with same daily dose. We extracted data for the occurrence of major thrombosis (proximal deep vein thrombosis, pulmonary embolism, myocardial infarction, ischemic stroke) and major hemorrhage (ISTH criteria and recommendations of the European Medicines Agency for surgical patients). Relative risks (RR) were combined using a fixed and random effects weighted meta-analysis. RESULTS: Twelve randomized, controlled, phase II trials were included (10,716 patients), representing 24 dosing regimen comparisons of apixaban, darexaban, edoxaban, rivaroxaban, letaxaban, and dabigatran. There was no difference for major thrombotic event (RRBID/QD = 1.06, 95%IC 0.86-1.30) nor for major bleeding (RRBID/QD = 1.02, 95%IC 0.84-1.23) between the BID vs QD regimens, without heterogeneity (I2 = 0%). CONCLUSION: Our study does not support a global difference in term of efficacy and safety of the BID and QD regimens of DOAC in MOS, NVAF, VTE and ACS.

[Tryptase: A practical guide for the physician]. / Dosage de la tryptase : un guide d'utilisation pour le clinicien.

Tryptase is the most abundant endopeptidase released by mast cells degranulation, involved in many pro and anti-inflammatory processes. Normal serum tryptase range is 0-11.4 µg/L. Tryptase is a useful diagnostic tool for anaphylaxis, systemic mastocytosis (SM) and mast cell activation syndrome (MCAS), where specific threshold values must be used. SM diagnosis criteria include evidence of dense mast cell infiltrate either in the bone marrow or the affected organ (such as skin), presence of KIT D816V mutation and elevated serum tryptase level (>20 µg/L). In SM, tryptase level is correlated with the burden of mast cells in bone marrow. MCAS should be considered in case of severe and recurrent typical clinical signs of systemic mast cell activation involving at least two organs, associated with an increase in serum tryptase level of 20% + 2 µg/L from the individual's baseline. Anaphylaxis is the most severe among hypersensitivity reactions. A clonal mast cell disorder is a central question in anaphylaxis and appropriate explorations should be conducted in these patients. Triggers for anaphylactic reactions vary significantly in the general population and in patients with MS or MCAS. Finally, physicians must be aware of the many pathological and physiological situations that affect tryptase levels.

[Aceruloplasminemia, a rare condition not to be overlooked]. / L'acéruléoplasminémie héréditaire, une pathologie à ne pas méconnaître.

Aceruloplasminemia is a rare iron-overload disease that should be better known by physicians. It is an autosomal recessive disorder due to mutations in ceruloplasmin gene causing systemic iron overload, including cerebral and liver parenchyma. The impairment of ferroxidase ceruloplasmin activity leads to intracellular iron retention leading aceruloplasminemia symptoms. Neurologic manifestations include cognitive impairment, ataxia, extrapyramidal syndrome, abnormal movements, and psychiatric-like syndromes. Physicians should search for aceruloplasminemia in several situations with high ferritin levels: microcytic anaemia, diabetes mellitus, neurological and psychiatric disorders. Diagnosis approach is based on the study of transferrin saturation and hepatic iron content evaluated by magnetic resonance imaging of the liver. Ceruloplasmin dosage is required in case of low transferrin saturation and high hepatic iron content and genetic testing is mandatory in case of serum ceruloplasmin defect. Neurological manifestations occur in the sixties decade and leads to disability. Iron chelators are widely used. Despite their efficacy on systemic and cerebral iron overload, iron chelators tolerance is poor. Early initiation of iron chelation therapy might prevent or slowdown neurodegeneration, highlighting the need for an early diagnosis but their clinical efficacy remains uncertain.

DOAC compared to LMWH in the treatment of cancer related-venous thromboembolism: a systematic review and meta-analysis.

Low molecular weight heparins (LMWH) are the standard of care for the treatment of cancer-associated venous thromboembolism (CA-VTE). We performed a systematic review and meta-analysis to compare the effects of direct oral anticoagulants (DOAC) versus LMWH for the treatment of CA-VTE. The primary efficacy and safety outcomes were VTE recurrence and major bleeding (MB). The secondary outcomes were clinically relevant non-MB (CRNMB), all-cause mortality and the net clinical benefit. We searched MEDLINE, EMBASE, CENTRAL and Web of Science (inception-December 2019) and abstracts of relevant conferences (2000-2019) to identify randomized controlled trials comparing DOAC and LMWH for the treatment of CA-VTE. Relative risks (RR) and 95% confidence intervals were estimated (Mantel-Haenszel method, random-effects models). A non-inferiority analysis with a margin of 1.3 for the upper boundary of the RR was conducted for the primary outcomes. From 637 references, we included four publications which encompass three trials (1756 patients). Compared to LMWH, DOAC were associated with a trend for decreased VTE recurrence (RR 0.51; 95%CI 0.25-1.03; p = 0.06; I2 = 51%), whereas MB (RR 1.64; 95%CI 1.00-2.69; p = 0.05; I2 = 0%) and CRNMB (RR 1.83; 95%CI 1.04-3.20; p = 0.03; I2 = 50%) were significantly more frequent with DOAC. Conversely, all-cause mortality (RR 1.06; 95%CI 0.83-1.35; p = 0.64; I2 = 36%) and net clinical benefit (RR 0.74; 95%CI 0.38-1.42; p = 0.36; I2 = 65%) were comparable. DOAC were non-inferior to LMWH in preventing CA-VTE recurrence, but were associated with an increased risk of MB and CRNMB. Further studies are required to confirm these results and inform on the risk/benefit ratio for specific populations.

Acute renal and splenic infarctions: a review.

BACKGROUND: Renal and splenic infarctions are close entities, with few data concerning their clinical, biological and radiological features. AIM: The aim of this study was to compare the clinical presentations, etiologies and outcomes of acute renal infarctions (RI) and splenic infarctions (SI). DESIGN: A retrospective multicentric cohort study included patients of the 6 university hospitals in Lyon with RI, SI, or associated RI-SI infarctions was conducted. METHODS: All consecutive cases diagnosed by CT imaging, between January 2013 and October 2016, were included. The exclusion criteria were causes of infarction that did not require additional investigations. RESULTS: A total of 161 patients were selected for analysis: 34 patients with RI, 104 patients with SI and 23 patients with both RI-SI. Mean ± SD age of patients was 63.2 ± 16.6 years; 59.6% were male. Only 5/161 (3.1%) were healthy prior to the event. The main symptoms were diffuse abdominal pain (26.4%), followed by nausea/vomiting (18.3%) and fever (16.4%).The causes of RI or SI varied significantly within the three groups. Hypercoagulable state was associated with SI, and embolic disease and arterial injury were associated with RI. Extensive (i.e.>2/3 of organ volume) (OR 6.22, 95%CI 2.0119.22) and bilateral infarctions (OR 15.05, 95%CI 1.79-126.78) were significantly associated with hemodynamic shocks. The survival at 1 month follow-up did not significantly differ between the three groups. CONCLUSION: Acute RI and SI are heterogenous entities in regards to their clinical presentation, etiology, associated venous or arterial thrombosis, but prognoses were not different at short term follow-up.

Survival and prognosis factors in systemic sclerosis: data of a French multicenter cohort, systematic review, and meta-analysis of the literature.

BACKGROUND: Data on survival and prognosis factors in incident cohorts are scarce in systemic sclerosis (SStc). To describe survival, standardized mortality ratio (SMR), and prognosis factors in systemic sclerosis (SSc), we analyzed a multicenter French cohort of incident patients and performed a systematic review of the literature and meta-analysis. METHODS: A multicenter, French cohort study was conducted between January 1, 2000, and December 31, 2013. Patients were followed-up until July 1, 2016. A systematic review of the literature was carried out in MEDLINE and EMBASE up to July 2017. Meta-analysis was performed using all available data on SMR and hazard ratios of prognosis factors. RESULTS: A total of 625 patients (493 females, 446 lcSSc) were included. During the study period, 104 deaths (16.6%) were recorded and 133 patients were lost to follow-up. Overall survival rates at 1, 3, 5, and 10 years from diagnosis were 98.0%, 92.5%, 85.9%, and 71.7% respectively in the French cohort. Overall SMR was 5.73 (95% CI 4.68-6.94). Age at diagnosis > 60 years, diffuse cutaneous SSc, scleroderma renal crisis, dyspnea, 6-min walking distance (6MWD), forced vital capacity < 70%, diffusing capacity of the lungs for carbon monoxide < 70%, pulmonary hypertension (PH), telangiectasia, valvular disease, malignancy, anemia, and CRP > 8 mg/l were associated with a poorer survival after adjustment. Eighteen studies (11,719 patients) were included in the SMR meta-analysis and 36 studies (26,187 patients) in the prognosis factor analysis. Pooled SMR was 3.45 (95%CI 3.03-3.94). Age at disease onset, male sex, African origin, diffuse cutaneous SSc, anti-Scl70 antibodies, cardiac and renal involvement, interstitial lung disease, PH, and malignancy were significantly associated with a worse prognosis. Anti-centromere antibodies were associated with a better survival. CONCLUSIONS: Overall, our study highlights a high mortality rate in SSc patients and confirms previously described prognosis factors related to skin extension and organ involvement while identifying additional prognosis factors such as autoantibody status, telangiectasia, 6MWD, and valvular disease.

Outcomes following a negative computed tomography pulmonary angiography according to pulmonary embolism prevalence: a meta-analysis of the management outcome studies.

Essentials Computed tomographic pulmonary angiography (CTPA) is used to exclude pulmonary embolism. This meta-analysis explores the occurrence of venous thromboembolic events (VTE) after a CTPA. Occurrence of VTE after a negative CTPA is ˜8% in study subgroups with a prevalence of PE ≥ 40%. CTPA may be insufficient to safely rule out VTE as a stand-alone diagnostic test for this subgroup. SUMMARY: Background Outcome studies have reported the safety of computed tomographic pulmonary angiography (CTPA) as a stand-alone imaging technique to rule out pulmonary embolism (PE). Whether this can be applied to all clinical probabilities remains controversial. Objectives We performed a meta-analysis to determine the proportion of patients with venous thromboembolic events (VTE) despite a negative CTPA according to pretest PE prevalence. Methods We searched MEDLINE, EMBASE and the Cochrane Library (January 1990 to May 2017) for outcome studies recruiting patients with suspected PE using CTPA as a diagnostic strategy. The primary outcome was the cumulative occurrence of VTE at 3 months following a negative CTPA. Results Twenty-two different studies were identified. VTE was confirmed in 2.4% of patients (95% CI, 1.3-3.8%) either at the time of the index event or in the 3 months follow-up. Subgroup analyses suggested that the cumulative occurrence of VTE was related to pretest prevalence of PE, as VTE occurred in 1.8% (95% CI, 0.5-3.7%), 1.4% (95% CI, 0.7-2.3%), 1.0% (95% CI, 0.5-1.8%) and 8.1% (95% CI, 3.5-14.5%) of subgroups of patients with a PE prevalence < 20%, 20-29%, 30-39% and ≥ 40%, respectively. This was further confirmed using meta-regression analysis. Conclusions The negative predictive value of CTPA for VTE varies according to pretest prevalence of PE, and is likely to be insufficient to safely rule out VTE as a stand-alone diagnostic test amongst patients at the highest pretest probability of VTE. Prospective studies are required to validate the appropriate diagnostic algorithm for this subgroup of patients.

[Impact of the 2009 Afssaps guidelines on the management of venous thromboembolic disease in emergency department: Before/after study]. / Impact des recommandations Afssaps 2009 sur la prise en charge de la maladie thromboembolique veineuse aux urgences : étude avant/après.

INTRODUCTION: The French Agency for Health Safety of Products published recommendations of good practices (RGP) for the treatment of venous thromboembolic disease in 2009. Four of these recommendations apply to the initial management of the disease, with the objective of this study is to determine whether the development and diffusion of the four RGP has had an impact on the practice. METHODS: A retrospective before/after study comparing 132 patients treated in emergency department of the Civil Hospices of Lyon for pulmonary embolism (PE) and/or deep venous thrombosis (DVT) in 2008-2009 ("before") and 153 patients in 2010-2011 ("after"). RESULTS: In the "before" period, 70 patients were treated for DVT and 62 patients for PE. In the "after" period, 50 patients were treated for DVT and 103 patients for PE. The compliance rate was not significantly different for the two periods for each RGP except for the indication of low molecular weight Heparin (LMWH) or fondaparinux in the absence of severe renal failure (21% "before" vs. 45% "after"; P=0.02) for patients with PE. Management for the four recommendations was conform for 5.6% of eligible patients in the "before" period and for 3.7% for the "after" period. CONCLUSION: Our study shows that globally there is no impact of RGP. The reasons appear multiple with first, the mere dissemination and the absence of implementation of these guidelines.

Coxiella burnetii infection (Q fever) mimicking systemic lupus erythematosus: two cases.

Q fever has extremely polymorphic features, and has been reported to be associated with positivity of several autoimmune antibodies. We report two cases of atypical Q fever with a clinical presentation highly suggestive of an inflammatory systemic disease with positivity of autoimmune antibodies, mimicking systemic lupus erythematosus.

Assessment of clinically relevant bleeding as a surrogate outcome for major bleeding: validation by meta-analysis of randomized controlled trials.

Essentials Surrogacy of clinically relevant bleeding (CRB) for major bleeding has never been validated. Our meta-analysis evaluated CRB surrogacy in trials of new versus traditional anticoagulants. Surrogacy was not validated in orthopedic surgery, venous thromboembolism or atrial fibrillation The difficulty in demonstrating the surrogacy may reflect a lack of homogeneity in its definition SUMMARY: Background Clinically relevant bleeding (CRB), comprising major bleeding and clinically relevant non-major bleeding, has been used as a surrogate for major bleeding in most anticoagulant trials. The validity of this surrogate to estimate trade-off between thrombotic and bleeding events in clinical trials was never assessed. Methods We systematically reviewed randomized phase III trials comparing new anticoagulants with the standard of care for venous thromboembolism prevention following major orthopedic surgery, venous thromboembolism (VTE) treatment, or stroke and systemic embolism prevention in atrial fibrillation (AF), and reporting both major bleeding and CRB rates. The validity of CRB as a surrogate for major bleeding was assessed according to the strength of the association between the relative risks of major bleeding and CRB, measured by the use of R2trial and its 95% confidence interval (CI). Results In the postoperative prophylactic setting (13 studies), major bleeding and CRB rates were 1.12% and 3.56%, respectively, and R2trial was 0.69 (95% CI 0.34-0.93). For acute VTE studies (n = 12), major bleeding and CRB rates were 1.87% and 9.07%; the corresponding R2trial values were 0.28 (95% CI 0.01-0.80) and 0.68 (95% CI 0.09-1.00) when only double-blind studies were considered (n = 7). For AF studies (n = 7; 22 strata), major bleeding and CRB rates were 4.82% and 15.3%, and R2trial was 0.59 (95% CI 0.15-0.82). Conclusion Despite an apparent correlation between CRB and major bleeding in major orthopedic surgery, AF, and double-blind acute VTE studies, the wide CIs suggest that CRB might not be an acceptable surrogate outcome in any of these settings.