Sequential trials in the context of competing risks: Concepts and case study, with R and SAS code.

Sequential designs and competing risks methodology are both well established. Their combined use has recently received some attention from a theoretical perspective, but their joint application in practice has been discussed less. The aim of this paper is to provide the applied statistician with a basic understanding of both sequential design theory and competing risks methodology and how to combine them in practice. Relevant references to more detailed theoretical discussions are provided, and all discussions are illustrated using a real case study. Extensive R and SAS code is provided in the online Supplementary Material.

Switching from abacavir/lamivudine plus nevirapine to abacavir/lamivudine/dolutegravir in virologically controlled HIV-infected adults (SWAD study).

INTRODUCTION: The metabolic pathways of dolutegravir suggest a potential predator effect of nevirapine on dolutegravir pharmacokinetics and switching from a nevirapine- to a dolutegravir-containing regimen could lead to a lower and suboptimal exposure to dolutegravir several weeks after the switch in case of persistent inducer effect. PATIENTS AND METHOD: Prospective, pilot, single-arm, open-label, non-comparative, bicentric study to evaluate the pharmacokinetics, virologic outcomes, safety, and patient satisfaction of switching from abacavir/lamivudine and nevirapine to a single tablet of abacavir/lamivudine/dolutegravir. The primary endpoint was the maintenance of virologic suppression (HIV-1 RNA<50 copies/mL) at week 12. Secondary endpoints were virologic suppression at week 48, safety and tolerability, patient satisfaction, and pharmacokinetic interaction between nevirapine and dolutegravir. Fifty-three adults on stable abacavir/lamivudine and nevirapine regimen for a median duration of 6years and virologically suppressed for 9.6years were included. RESULTS: Dolutegravir reached steady state by week 4/week 12 when expected by day 5/day 10. All subjects maintained plasma HIV-RNA˂50 copies/mL at week 12 and week 48. Abacavir/lamivudine/dolutegravir was well-tolerated, with two cases of serious adverse events deemed unrelated to study drugs (coronary syndrome in both cases), and one discontinuation for renal impairment at week 24 with a slight improvement after dolutegravir discontinuation. Level of treatment satisfaction remained high after the switch. CONCLUSION: The transient predator effect of nevirapine on dolutegravir had no clinical consequences after switching from nevirapine to dolutegravir, neither on safety nor maintenance of virologic suppression. It also had no consequences on patient satisfaction.

Adding corticosteroids to the pudendal nerve block for pudendal neuralgia: a randomised, double-blind, controlled trial.

OBJECTIVE: To compare the effect of corticosteroids combined with local anaesthetic versus local anaesthetic alone during infiltrations of the pudendal nerve for pudendal nerve entrapment. DESIGN: Randomised, double-blind, controlled trial. SETTING: Multicentre study. POPULATION: 201 patients were included in the study, with a subgroup of 122 women. METHODS: CT-guided pudendal nerve infiltrations were performed in the sacrospinous ligament and Alcock's canal. There were three study arms: patients in Arm A (n = 68) had local anaesthetic alone, those in Arm B (n = 66) had local anaesthetic plus corticosteroid and those in Arm C (n = 67) local anaesthetic plus corticosteroid with a large volume of normal saline. MAIN OUTCOME MEASURES: The primary end-point was the pain intensity score at 3 months. Patients were regarded as responders (at least a 30-point improvement on a 100-point visual analogue scale of mean maximum pain over a 2-week period) or nonresponders. RESULTS: Three months' postinfiltration, 11.8% of patients in the local anaesthetic only arm (Arm A) were responders versus 14.3% in the local anaesthetic plus corticosteroid arms (Arms B and C). This difference was not statistically significant (P = 0.62). No statistically significant difference was observed in the female subgroup between Arm A and Arms B and C (P = 0.09). No significant difference was detected for the various pain assessment procedures, functional criteria or quality-of-life criteria. CONCLUSIONS: Corticosteroids provide no additional therapeutic benefits compared with local anaesthetic and should therefore no longer be used. TWEETABLE ABSTRACT: Steroid infiltrations do not improve the results of local anaesthetic infiltrations in pudendal neuralgia.

Randomized clinical trial of ultrasonic scissors versus conventional haemostasis to compare complications and economics after total thyroidectomy (FOThyr).

BACKGROUND: The benefits of single-use ultrasonic scissors in thyroid surgery are still debated. Although this device has been shown to reduce operating time compared with conventional haemostasis, its cost-effectiveness has never been demonstrated. The aim of this study was to evaluate the efficacy, cost-effectiveness and safety of ultrasonic scissors for total thyroidectomy. METHODS: This was a prospective, randomized, multicentre trial conducted at 13 hospital sites. The primary endpoint was the percentage of patients with hypocalcaemia (serum calcium level below 2 mmol/l) on day 2. Secondary endpoints included postoperative complications and costs, with calculation of incremental cost differences and cost-effectiveness ratios. RESULTS: In total, 1329 patients who underwent total thyroidectomy were included in the analysis: 670 were randomized to treatment with ultrasonic scissors and 659 to conventional haemostasis. There was no difference between groups in the rate of complications, including hypocalcaemia on day 2 (19.7 per cent in ultrasonic scissors group versus 20.3 per cent in conventional haemostasis group; P = 0·743). Median operating times were significantly shorter with ultrasonic scissors (90 versus 100 min with conventional haemostasis; P < 0·001). Total mean(s.d.) direct costs at 6 months were €4311(1547) and €4011(1596) respectively (P < 0·001). CONCLUSION: Ultrasonic scissors were no more clinically effective than conventional haemostasis, but use of these devices was more costly. Registration number: NCT01551914 (http://www.clinicaltrials.gov).

Antireflux versus conventional self-expanding metallic Stents (SEMS) for distal esophageal cancer: results of a multicenter randomized trial.

INTRODUCTION: Self-expanding metal stents (SEMS) are commonly used in the palliation of dysphagia in patients with inoperable esophageal carcinoma. However, they predispose to gastroesophageal reflux when deployed across the gastroesophageal junction. The aims of this study were to: 1) assess the influence of the antireflux valve on trans-prosthetic reflux (primary outcome); and 2) compare the results of SEMS with and without antireflux valve in terms of reflux symptoms, quality of life (QOL), improvement of dysphagia and adverse events (secondary outcomes). PATIENTS AND METHODS: Thirty-eight patients were enrolled in nine centers. Carcinomas were locally advanced (47 %) or metastatic. After randomization, patients received either a covered SEMS with antireflux valve (n = 20) or a similar type of SEMS with no antireflux device but assigned to standard proton pump inhibitor therapy and postural advice (n = 18). Trans-prosthetic reflux was assessed at day 2 using a radiological score based on barium esophagography performed after Trendelenburg maneuver and graded from 0 (no reflux) to 12 (maximum). Monthly telephone interviews were conducted for Organisation Mondiale de la Santé (OMS) scoring from 0 (excellent) to 5 (poor), QOL assessment (based on the Reflux-Qual Simplifié scoring system) from 0 (poor) to 100 (excellent), dysphagia scoring from 0 (no dysphagia) to 5 (complete dysphagia) and regurgitation scoring from 0 (no regurgitation) to 16 (maximum). RESULTS: No difference was noted in terms of age, sex, size of lesion, prosthesis length or need for dilation prior to SEMS placement. No difficulty in placing SEMS nor complications were noted. Radiological scores of reflux were found to be significantly lower in patients with an antireflux stent compared to the conventional stent and associated measures. The regurgitation scores were significantly decreased in patients with antireflux stents during the first 2 months after stent placement and thereafter, they were similar in the two groups. QOL and dysphagia were improved in both groups. Survival rates were comparable in the two groups. CONCLUSIONS: No difference was observed between the two types of SEMS regarding the palliation of dysphagia and improvement of QOL. However, SEMS with an antireflux valve were more effective in preventing trans-prosthetic gastroesophageal reflux but at the cost of an increased likehood of minor adverse events (migrations and/or obstruction of the SEMS).

[Predictors of success of external cephalic version: Bi-center study]. / Facteurs prédictifs de réussite d'une version par manœuvre externe : étude bicentrique.

OBJECTIVES: In the literature, success rate of external cephalic version (ECV) is 39 to 65%. This study aims to identify potential predictors of a successful ECV. MATERIALS AND METHODS: Retrospective bi-center study performed from January 2011 through December 2012 at Angers University Hospital and Nantes University Hospital from January 2011 through December 2011. Were identified the demographic and ultrasonography characteristics of patients and the data of the process. RESULTS: One hundred and seventy-eight patients were included, 88 in Angers and 90 in Nantes; 16.3% of ECV were successful. Multiparity (OR 28.45; P<0.01) and transverse position (OR 0.63; P<0.01) are the two significant predictors. There is no significant difference found for center, operator, position of the placenta, amniotic fluid or presence of a uterine scar. CONCLUSION: The success rate in our two French university centers is much lower than that reported in the literature. Parity and transverse position are the only 2 significant predictors of ECV success.

Determinants in treatment decision-making in older patients with symptomatic severe aortic stenosis.

BACKGROUND: Three treatment options are available for patients with aortic stenosis: surgical aortic valve replacement (SAVR), transcatheter aortic valve implantation (TAVI) and medical treatment (MT). However, little is known about how Heart Team treatment decisions are made under routine conditions. The aim of this study was to identify the cardiac and geriatric components associated with treatment decision-making in older patients with symptomatic severe aortic stenosis. METHODS: Between 2011 and 2013, 337 consecutive patients ≥75 years old referred for pre-operative evaluation in Nantes University Hospital had a comprehensive cardiac and geriatric assessment. In this observational retrospective study, relationships between treatment decision-making and cardiac or geriatric components were evaluated through multivariable models. RESULTS: Surgical aortic valve replacement was proposed to 108 patients, TAVI to 131 and medical treatment to 98 patients. Mean age was 83±4 years and 51% were women. Geriatric components associated with treatment decision-making between SAVR vs. TAVI were age (p<0.001, OR=0.790), comorbidity score (p=0.027, OR=0.86), functional status (p<0.001, OR=1.46), and gait speed (p<0.001, OR=0.23). Cardiac components associated with decision-making between SAVR vs. TAVI were history of previous cardiac surgery (p<0.001, OR=0.09), left ventricular ejection fraction <50% (p<0.001, OR=0.14), coronary artery disease requiring revascularization (p=0.019, OR=0.4). Between TAVI vs. medical treatment, only history of previous cardiac surgery and presence of another severe valve disease were significant. CONCLUSION: Comorbidities, functional status and physical performance, were significantly associated with the consensual treatment decision-making, independently of cardiac components in older patients with symptomatic severe aortic stenosis.

Factors predictive of lymph node metastasis in the follicular variant of papillary thyroid carcinoma.

BACKGROUND: The treatment of papillary thyroid carcinomas larger than 1 cm usually consists of total thyroidectomy and central lymph node dissection (LND). In patients with the follicular variant of papillary thyroid carcinoma (FVPTC), preoperative cytology and intraoperative frozen-section analysis cannot always establish the diagnosis. The aim of this study was to evaluate predictive factors for lymph node metastasis in patients with FVPTC and to identify patients who might benefit from LND. METHODS: The study included patients with FVPTC treated by total thyroidectomy and LND between 2000 and 2010 in four departments. When fewer than six non-involved lymph nodes were removed, the patient was excluded from the analysis. RESULTS: Some 199 patients were included. The median tumour size was 17 (range 1-85) mm, and tumours were classified as T1a in 28 patients, T1b in 40, T2 in 53, and T3 in 78. Eighty-one patients (40·7 per cent) had lymph node metastasis (51 classified as N1a and 30 as N1b). Four risk factors were predictive of lymph node metastasis in the multivariable analysis: multifocality (odds ratio (OR) 2·36, 95 per cent confidence interval 1·15 to 4·86), angiolymphatic invasion (OR 3·67, 1·01 to 13·36), absence of tumour capsule (OR 3·00, 1·47 to 6·14) and tumour involvement of perithyroid tissue (OR 3·89, 1·85 to 8·18). The rate of lymph node metastasis varied between 14 and 94 per cent depending on the presence of risk factors. CONCLUSION: The rate of lymph node metastasis in patients with FVPTC varies widely according to the presence or absence of predictive risk factors.

Ammonia plasma concentration and prolonged infusion of remifentanil in patients with acute kidney injury.

BACKGROUND: Glycine is an excipient of remifentanil and may induce side effects. To investigate glycine and ammonia concentration with the use of remifentanil in Intensive Care Unit patients with acute kidney injury (AKI) defined by a decrease in creatinine clearance above 50%. METHODS: Prospective open-label cohort study in three surgical Intensive Care Units. Thirty-three patients with AKI and requiring sedation for at least 72 hours. Sedation with remifentanil and midazolam or propofol was adapted every six hours according to ATICE. Glycine and ammonia plasma concentrations were measured at H0 (start of infusion) and every 12 hours during a continuous intravenous 72 hours remifentanil infusion, and 24 hours after the end of the infusion. Clinical and biological glycine or ammonia toxicity were evaluated. RESULTS: Fifteen patients required continuous veno-venous hemodiafiltration (CVVHDF). Glycine and ammonia plasma concentrations exceeded the normal value respectively for 11 (33%) and 15 (45%) patients before remifentanil infusion (H0). Accumulation of glycine or ammonia was observed neither for patients with or without CVVHDF. For patients without CVVHDF, the plasma ammonia concentration at the end of remifentanil infusion was significantly correlated with the creatinine clearance at H72 (P=0.03) and with the mean rate of remifentanil infusion (P=0.002). No side effect was reported. CONCLUSION: Remifentanil was not associated with an accumulation of glycine or ammonia in patients with AKI. Plasma ammonia concentration was correlated with the mean rate of remifentanil and creatinine clearance. A 72-hours remifentanil infusion appeared safe for sedation of patients with AKI.

[Withholding or withdrawing of life sustaining therapies in emergency context. Perception by anaesthesiologists]. / Limitation ou arrêt de thérapeutiques actives en situations d'urgence. Le point de vue des anesthésistes réanimateurs.

OBJECTIVES: One objective is to state more accurately the difficulties met by the anaesthesiologists in an emergency context in case of withholding or withdrawing life sustaining therapies. STUDY DESIGN AND PARTICIPANTS: A questionnaire addressed to anaesthesiologists of nine hospitals in the extreme West part of France. MATERIALS AND METHODS: The questionnaires were sent and returned by mail in order to guarantee confidentiality. RESULTS: The participation rate was 40% with 172 questionnaires analysed. Ninety-eight per cent of the anaesthesiologists have already participated in a withholding or withdrawing life sustaining treatments, and in an emergency context in 92% of the cases. In that last case, criteria related to the severity of the clinic presentation and to the short-term death probability influence the decision made to interrupt life-sustaining therapies. For 93% of anaesthesiologists, the decision should be collegial, but 50% of them had already made such a decision alone. The withdrawal of ventilatory support was the most difficult decision to make. Withdrawing mechanical ventilation or extubating appeared impossible for 23.4 and 50% of the anaesthesiologists respectively. Providing comfort care to the patients with end of life decision was essential for 100% of the anaesthesiologists, but 11% of them used and considered analgesic and sedation after withholding or withdrawing life sustaining treatments as euthanasia. The complaint possibility worried 57% of the anaesthesiologists and influenced the writing of the process or giving information to the families respectively for 65 and 75%. The righting of the medical files could be improved for 92% of the anaesthesiologists. CONCLUSION: The decision of withholding and withdrawing life sustaining treatments in an emergency context is based on the conviction of short-term death probability. Withholding and withdrawing life sustaining treatments is a decision made according to the principles of collegiality and necessary comfort cares, but the procedure can still be improved, especially in the redaction of the medical file and the ethical and juridical control of these extreme situations.

Melanoma gene expression and clinical course.

Evidence for the in vitro lymphocyte response against autologous melanoma has been accumulating over the past 10 years, leading to the identification of numerous melanoma-associated antigens recognised by T cells. These antigens are targets for specific immunotherapy protocols. However, their expression is heterogeneous during tumour progression and may contribute to therapeutic escape mechanisms and disease progression. This study was designed to chart the importance of these escape mechanisms, and to assess the relationship between gene expression and the clinical profile (especially survival data) of patients with melanoma. We studied the expression of certain melanoma genes in tissue biopsies from 202 patients using reverse transcriptase-polymerase chain reaction (RT-PCR). The evaluated genes were Melan-A, tyrosinase, Na-17A, MAGE-1, MAGE-3 and Ny-ESO-1. We then correlated the results to the patients' survival data. 202 samples (cutaneous, nodal and visceral biopsies) were analysed by RT-PCR. No relationship was found between clinical data and gene expression. No relationship was found between survival data and gene expression, when samples of all stages were combined in the analysis. However, interactions between gene expression and disease stage were significant. When stage III samples alone were considered, MAGE-3 expression alone or in association with the expression of the other tumour-specific genes was found to be significantly associated with a higher disease-free survival (respectively, P = 0.0349; 0.007). Our results provided no evidence for a relationship between gene expression and clinical data, or between gene expression and survival data. However, with regard to certain sub-groups, such as stage III samples, tumour gene expression was significantly associated with survival.

Cytomegalovirus: its potential role in the development of cutaneous T-cell lymphoma.

To investigate the potential role of CMV in cutaneous T-cell lymphoma (CTCL), we studied cytomegalovirus (CMV) seroprevalence in parapsoriasis (PP), mycosis fungoides (MF) and Sézary syndrome (SS) compared with healthy control patients. In cases where CMV seropositivity was observed, CMV PCR analyses were performed on skin biopsies. CMV seroprevalence was 37.1% in the control group, 50.68% in the PP + MF + SS group (P = 0.08), 56.2% in the MF + SS group (P = 0.07), 40% in the PP group (P = 0.9), 66.67% in the MF group (P = 0.009), 42.86% in the SS group (P = 0.9). CMV PCR in initial skin biopsies were all negative. However, PCR CMV was positive in two SS skin biopsies realized at an advanced stage. Our results show that latent CMV infection may play a role in the susceptibility of MF in predisposed subjects by inducing T-cell proliferation and resistance to apoptosis. Concerning SS, an immunosuppressive state may be responsible for CMV reactivation that in turn may interfere with evolution of the disease.

Anti-inflammatory effects of lithium gluconate on keratinocytes: a possible explanation for efficiency in seborrhoeic dermatitis.

Topical lithium (Li) gluconate has a beneficial effect on seborrhoeic dermatitis (SD), unlike oral lithium (Li) used in psychiatry. SD is an inflammatory dermatitis associated, in most of cases, with colonization by lipophilic yeasts of the genus Malassezia. However, the exact mechanism of action of Li gluconate in SD still remains unknown. The aim of our study was to investigate the effect of topical Li on cytokine secretion and innate immunity. For this purpose, we investigated first the modulatory effect of Li on two pro-inflammatory and two anti-inflammatory cytokine secretion and second, the modulatory effect of Li on Toll-like receptor (TLR) 2 and 4 expression by unstimulated and stimulated keratinocytes. Two different skin models were used: keratinocytes in monolayer and skin explants. In some of them, inflammation was induced with LPS (1 mug/ml) or zymosan (2 mg/ml). Then the skin models were incubated with Li gluconate (Labcatal*, Montrouge, France) at three different concentrations (1.6, 3, 5 mM) determined according to viability MTT test. Expression of TNFalpha, IL6, IL10, TGFbeta1, TLR2 and TLR4 was detected by immunohistochemistry (IHC). Cytokines were quantified by ELISA methods. Our results showed that the effect of Li on keratinocytes is dose-dependent. At low concentration (1.6 mM), Li enhanced TNFalpha secretion, whereas, at higher concentration (5 mM), Li significantly enhanced IL10 expression and secretion. However, there was no significant modulation of Li on IL6 and TGFbeta1 secretion. Moreover, Li at 5 mM significantly decreased TLR2 and TLR4 expressions by differentiated keratinocytes. As Li concentration during topical treatment is probably closer to 5 mM than to 1 mM, the therapeutic effect of Li gluconate in DS may be explained by two anti-inflammatory actions: an increased expression and secretion of IL10 and a decreased expression of TLR2 and TLR4 by keratinocytes. The diminution of TLR2 expression by Li may not allow MF to trigger inflammation response in lesional skin.

Prospective study of risk factors of relapse after treatment of acne with oral isotretinoin.

BACKGROUND: The effectiveness of oral isotretinoin against acne is undeniable. However, few data on the maintenance of effect after treatment termination have been published. OBJECTIVE: The purpose of the study was to identify the risk factors of relapse after stopping isotretinoin. METHOD: This prospective open study examined 52 patients with moderate to severe acne at the Dermatological Clinic of the Nantes University Hospital (France). Variables likely to influence relapse were studied using the Cox model. RESULTS: 27 patients (52%) relapsed after stopping treatment. In multivariate analysis, severe seborrhoea and a high score of inflammatory lesions at the end of the treatment, an early age, a family history of acne, prepubertal acne and acne extended to the trunk were the factors increasing significantly the risk of relapse. CONCLUSION: Our data allow to define more precisely the profile of acne patients for whom the risk of relapse is highest and who should therefore be followed up quite regularly after treatment termination.