Completion and Publication Rates of Randomized Controlled Trials in Surgery: An Empirical Study.

OBJECTIVE: To investigate the prevalence of discontinuation and nonpublication of surgical versus medical randomized controlled trials (RCTs) and to explore risk factors for discontinuation and nonpublication of surgical RCTs. BACKGROUND: Trial discontinuation has significant scientific, ethical, and economic implications. To date, the prevalence of discontinuation of surgical RCTs is unknown. METHODS: All RCT protocols approved between 2000 and 2003 by 6 ethics committees in Canada, Germany, and Switzerland were screened. Baseline characteristics were collected and, if published, full reports retrieved. Risk factors for early discontinuation for slow recruitment and nonpublication were explored using multivariable logistic regression analyses. RESULTS: In total, 863 RCT protocols involving adult patients were identified, 127 in surgery (15%) and 736 in medicine (85%). Surgical trials were discontinued for any reason more often than medical trials [43% vs 27%, risk difference 16% (95% confidence interval [CI]: 5%-26%); P = 0.001] and more often discontinued for slow recruitment [18% vs 11%, risk difference 8% (95% CI: 0.1%-16%); P = 0.020]. The percentage of trials not published as full journal article was similar in surgical and medical trials (44% vs 40%, risk difference 4% (95% CI: -5% to 14%); P = 0.373). Discontinuation of surgical trials was a strong risk factor for nonpublication (odds ratio = 4.18, 95% CI: 1.45-12.06; P = 0.008). CONCLUSIONS: Discontinuation and nonpublication rates were substantial in surgical RCTs and trial discontinuation was strongly associated with nonpublication. These findings need to be taken into account when interpreting surgical literature. Surgical trialists should consider feasibility studies before embarking on full-scale trials.

Disparities in treatment rates of paediatric end-stage renal disease across Europe: insights from the ESPN/ERA-EDTA registry.

BACKGROUND Considerable disparities exist in the provision of paediatric renal replacement therapy (RRT) across Europe. This study aims to determine whether these disparities arise from geographical differences in the occurrence of renal disease, or whether country-level access-to-care factors may be responsible. METHODS Incidence was defined as the number of new patients aged 0-14 years starting RRT per year, between 2007 and 2011, per million children (pmc), and was extracted from the ESPN/ERA-EDTA registry database for 35 European countries. Country-level indicators on macroeconomics, perinatal care and physical access to treatment were collected through an online survey and from the World Bank database. The estimated effect is presented per 1SD increase for each indicator. RESULTS The incidence of paediatric RRT in Europe was 5.4 cases pmc. Incidence decreased from Western to Eastern Europe (-1.91 pmc/1321 km, P < 0.0001), and increased from Southern to Northern Europe (0.93 pmc/838 km, P = 0.002). Regional differences in the occurrence of specific renal diseases were marginal. Higher RRT treatment rates were found in wealthier countries (2.47 pmc/€10 378 GDP per capita, P < 0.0001), among those that tend to spend more on healthcare (1.45 pmc/1.7% public health expenditure, P < 0.0001), and among countries where patients pay less out-of-pocket for healthcare (-1.29 pmc/11.7% out-of-pocket health expenditure, P < 0.0001). Country neonatal mortality was inversely related with incidence in the youngest patients (ages 0-4, -1.1 pmc/2.1 deaths per 1000 births, P = 0.10). Countries with a higher incidence had a lower average age at RRT start, which was fully explained by country GDP per capita. CONCLUSIONS Inequalities exist in the provision of paediatric RRT throughout Europe, most of which are explained by differences in country macroeconomics, which limit the provision of treatment particularly in the youngest patients. This poses a challenge for healthcare policy makers in their aim to ensure universal and equal access to high-quality healthcare services across Europe.

Process and pattern in cichlid radiations - inferences for understanding unusually high rates of evolutionary diversification

The cichlid fish radiations in the African Great Lakes differ from all other known cases of rapid speciation in vertebrates by their spectacular trophic diversity and richness of sympatric species, comparable to the most rapid angiosperm radiations. I review factors that may have facilitated these radiations and compare these with insights from recent work on plant radiations. Work to date suggests that it was a coincidence of ecological opportunity, intrinsic ecological versatility and genomic flexibility, rapidly evolving behavioral mate choice and large amounts of standing genetic variation that permitted these spectacular fish radiations. I propose that spatially orthogonal gradients in the fit of phenotypes to the environment facilitate speciation because they allow colonization of alternative fitness peaks during clinal speciation despite local disruptive selection. Such gradients are manifold in lakes because of the interaction of water depth as an omnipresent third spatial dimension with other fitness-relevant variables. I introduce a conceptual model of adaptive radiation that integrates these elements and discuss its applicability to, and predictions for, plant radiations.

Quaternary uplift rates of the Central Anatolian Plateau, Turkey: insights from cosmogenic isochron-burial nuclide dating of the Kızılırmak River terraces

The Central Anatolian Plateau (CAP) in Turkey is a relatively small plateau (300 × 400 km) with moderate average elevations of ∼1 km situated between the Pontide and Tauride orogenic mountain belts. Kızılırmak, which is the longest river (1355 km) within the borders of Turkey, flows within the CAP and slowly incises into lacustrine and volcaniclastic units before finally reaching the Black Sea. We dated the Cappadocia section of the Kızılırmak terraces in the CAP by using cosmogenic burial and isochron-burial dating methods with 10Be and 26Al as their absolute dating can provide insight into long-term incision rates, uplift and climatic changes. Terraces at 13, 20, 75 and 100 m above the current river indicate an average incision rate of 0.051 ± 0.01 mm/yr (51 ± 1 m/Ma) since ∼1.9 Ma. Using the base of a basalt fill above the modern course of the Kızılırmak, we also calculated 0.05–0.06 mm/yr mean incision and hence rock uplift rate for the last 2 Ma. Although this rate might be underestimated due to normal faulting along the valley sides, it perfectly matches our results obtained from the Kızılırmak terraces. Although up to 5–10 times slower, the Quaternary uplift of the CAP is closely related to the uplift of the northern and southern plateau margins respectively.

Collagen application reduces complication rates of mid-substance ACL tears treated with dynamic intraligamentary stabilization.

PURPOSE Dynamic intraligamentary stabilization was recently proposed as an option for the treatment of acute ACL ruptures. The aim of this study was to investigate the feasibility of the procedure in mid-substance ACL ruptures and examine whether the additional application of a bilayer collagen I/III membrane would provide for a superior outcome. METHODS The study group consisted of patients presenting with a mid-substance ACL rupture undergoing dynamic intraligamentary stabilization using the Ligamys™ device along with application of a collagen I/III membrane to the surface of the ACL (group A, n = 23). The control group comprised a matched series of patients presenting with a mid-substance ACL rupture also treated by dynamic intraligamentary stabilization Ligamys™ repair, however, without additional collagen application (group B, n = 33). Patients were evaluated preoperatively and at 24-month follow-up for stability as well as Tegner and Lysholm scores. Knee laxity was measured as a difference in anterior translation (ΔAP) and pivot shift. Any events occurring during the follow-up period of 24 months were documented. Logistic regression of complications was performed, and adjustment undertaken where necessary. RESULTS A high total complication rate of 78.8 % was noted in group B, compared to group A (8.7 %) (p = 0.002). The addition of a collagen membrane was the only independent prognostic factor associated with reduced complications (OR 8.0, CI 2.0-32.2, p = 0.003, for collagen-free treatment). In group B, 6 patients suffered a re-rupture with subsequent instability requiring secondary hamstring reconstruction surgery, and 11 developed extension loss requiring arthroscopic debridement, whilst in group A, 2 patients required arthroscopic debridement for loss of exension, with no further encountered complication. Median Lysholm score was significantly higher in group A compared to group B (median 100 range 93-100 vs median 95 range 60-100, p = 0.03) at final follow-up. CONCLUSIONS A high complication rate following ACL Ligamys™ repair of mid-substance ruptures was noted. Application of a collagen membrane to the surface of the ACL resulted in a reduced incidence of extension deficit and re-ruptures. The results indicate that solitary ACL Ligamys™ repair does not present an appropriate treatment modality for mid-substance ACL ruptures. Collage application proved to provide healing benefits with superior clinical outcome after ACL repair. LEVEL OF EVIDENCE Case control study, Level III.

Intersystem crossing rates of S1 state keto-amino cytosine at low excess energy

The amino-keto tautomer of supersonic jet-cooled cytosine undergoes intersystem crossing (ISC) from the v = 0 and low-lying vibronic levels of its S1(¹ππ*) state. We investigate these ISC rates experimentally and theoretically as a function of S1 state vibrational excess energy Eexc. The S1 vibronic levels are pumped with a ~5 ns UV laser, the S1 and triplet state ion signals are separated by prompt or delayed ionization with a second UV laser pulse. After correcting the raw ISC yields for the relative S1 and T1ionization cross sections, we obtain energy dependent ISC quantum yields Q corr ISC =1% –5%. These are combined with previously measured vibronic state-specific decay rates, giving ISC rates kISC = 0.4–1.5 ⋅ 10⁹ s⁻¹, the corresponding S1⇝S0internal conversion (IC) rates are 30–100 times larger. Theoretical ISC rates are computed using SCS-CC2 methods, which predict rapid ISC from the S1; v = 0 state with kISC = 3 ⋅ 10⁹ s⁻¹ to the T1(³ππ*) triplet state. The surprisingly high rate of this El Sayed-forbidden transition is caused by a substantial admixture of ¹nOπ* character into the S1(¹ππ*) wave function at its non-planar minimum geometry. The combination of experiment and theory implies that (1) below Eexc = 550 cm⁻¹ in the S1 state, S1⇝S0internal conversion dominates the nonradiative decay with kIC ≥ 2 ⋅ 10¹⁰ s⁻¹, (2) the calculated S1⇝T1 (¹ππ*⇝³ππ*) ISC rate is in good agreement with experiment, (3) being El-Sayed forbidden, the S1⇝T1 ISC is moderately fast (kISC = 3 ⋅ 10⁹ s⁻¹), and not ultrafast, as claimed by other calculations, and (4) at Eexc ~ 550 cm⁻¹ the IC rate increases by ~50 times, probably by accessing the lowest conical intersection (the C5-twist CI) and thereby effectively switching off the ISC decay channels.

High Rates of Smoking Especially in Female Crohn's Disease Patients and Low Use of Supportive Measures to Achieve Smoking Cessation--Data from the Swiss IBD Cohort Study

BACKGROUND AND AIMS Smoking is a crucial environmental factor in inflammatory bowel disease [IBD]. However, knowledge on patient characteristics associated with smoking, time trends of smoking rates, gender differences and supportive measures to cease smoking provided by physicians is scarce. We aimed to address these questions in Swiss IBD patients. METHODS Prospectively obtained data from patients participating in the Swiss IBD Cohort Study was analysed and compared with the general Swiss population [GSP] matched by age, sex and year. RESULTS Among a total of 1770 IBD patients analysed [49.1% male], 29% are current smokers. More than twice as many patients with Crohn's disease [CD] are active smokers compared with ulcerative colitis [UC] [UC, 39.6% vs CD 15.3%, p < 0.001]. In striking contrast to the GSP, significantly more women than men with CD smoke [42.8% vs 35.8%, p = 0.025], with also an overall significantly increased smoking rate compared with the GSP in women but not men. The vast majority of smoking IBD patients [90.5%] claim to never have received any support to achieve smoking cessation, significantly more in UC compared with CD. We identify a significantly negative association of smoking and primary sclerosing cholangitis, indicative of a protective effect. Psychological distress in CD is significantly higher in smokers compared with non-smokers, but does not differ in UC. CONCLUSIONS Despite well-established detrimental effects, smoking rates in CD are alarmingly high with persistent and stagnating elevations compared with the GSP, especially in female patients. Importantly, there appears to be an unacceptable underuse of supportive measures to achieve smoking cessation.

Endoscopic Biopsy for Intra- and Paraventricular Tumors: Rates of Complications, Mortality, and Tumor Cell Dissemination

Background and Study Aim Intra- and paraventricular tumors are frequently associated with cerebrospinal fluid (CSF) pathway obstruction. Thus the aim of an endoscopic approach is to restore patency of the CSF pathways and to obtain a tumor biopsy. Because endoscopic tumor biopsy may increase tumor cell dissemination, this study sought to evaluate this risk. Patients, Materials, and Methods Forty-four patients who underwent endoscopic biopsies for ventricular or paraventricular tumors between 1993 and 2011 were included in the study. Charts and images were reviewed retrospectively to evaluate rates of adverse events, mortality, and tumor cell dissemination. Adverse events, mortality, and tumor cell dissemination were evaluated. Results Postoperative clinical condition improved in 63.0% of patients, remained stable in 30.4%, and worsened in 6.6%. One patient (2.2%) had a postoperative thalamic stroke leading to hemiparesis and hemineglect. No procedure-related deaths occurred. Postoperative tumor cell dissemination was observed in 14.3% of patients available for follow-up. Conclusions For patients presenting with occlusive hydrocephalus due to tumors in or adjacent to the ventricular system, endoscopic CSF diversion is the procedure of first choice. Tumor biopsy in the current study did not affect safety or efficacy.