A comparison of 7 random-effects models for meta-analyses that estimate the summary odds ratio

Comparative trials that report binary outcome data are commonly pooled in systematic reviews and meta-analyses. This type of data can be presented as a series of 2-by-2 tables. The pooled odds ratio is often presented as the outcome of primary interest in the resulting meta-analysis. We examine the use of 7 models for random-effects meta-analyses that have been proposed for this purpose. The first of these models is the conventional one that uses normal within-study approximations and a 2-stage approach. The other models are generalised linear mixed models that perform the analysis in 1 stage and have the potential to provide more accurate inference. We explore the implications of using these 7 models in the context of a Cochrane Review, and we also perform a simulation study. We conclude that generalised linear mixed models can result in better statistical inference than the conventional 2-stage approach but also that this type of model presents issues and difficulties. These challenges include more demanding numerical methods and determining the best way to model study specific baseline risks. One possible approach for analysts is to specify a primary model prior to performing the systematic review but also to present the results using other models in a sensitivity analysis. Only one of the models that we investigate is found to perform poorly so that any of the other models could be considered for either the primary or the sensitivity analysis

Hypertension is frequently present in patients with reflux esophagitis or Barrett's esophagus but not in those with non-ulcer dyspepsia

Background: Elevated mortality due to cardiovascular disease has been reported for patients with Barrett's esophagus (BE). We compared the prevalence of risk factors for cardiovascular disease in patients with BE, reflux esophagitis (RE), and non-ulcer dyspepsia (NUD) with that of the general population. Methods: Patients with upper gastrointestinal complaints and BE, RE, or NUD were compared with a matched cohort from the general population using a questionnaire and blood pressure and cholesterol measurements. Results: Hypertension occurred more frequently in patients with BE (odds ratio 5.1, P<0.0001) and RE (odds ratio 3.8, P<0.001), but not in those with NUD. Serum total cholesterol was higher in BE (P=0.02) and borderline in RE (P=0.06) but not in NUD. Mean HDL cholesterol levels, body mass index, and smoking did not differ. Conclusions: This study suggests that BE and RE found at diagnostic endoscopy are associated with an increased prevalence of hypertension and a higher total cholesterol level than in the general population. If so, this would explain the increased mortality during the follow-up of BE patients, and it should be taken into account when designing or evaluating follow-up studies of BE

Diermeel in diervoeders? : een methodische discussie met stakeholders

In dit rapport wordt verslag gedaan van een workshop die ten doel had een beter inzicht te krijgen in de belangen van de Nederlandse samenleving met betrekking tot de vraag of het beleid ten aanzien van dierlijke eiwitten in diervoeders versoepeld kan worden. Daarbij is gebruik maakt van een nieuwe, brede afwegingsmethodiek (TRAK) waarmee het mogelijk is verschillende beleidsscenario's' aan de hand van verschillende waarden te beoordelen en te scoren

Does experience influence the forces exerted on maxillary incisors during laryngoscopy? A manikin study using the Macintosh laryngoscope

The influence of the level of experience of the laryngoscopist on the duration of laryngoscopy, the forces exerted on the tongue and on the maxillary incisors during laryngoscopy, were investigated. Five groups (anaesthetists, residents in anaesthesia, nurse anaesthetists, surgeons and medical students), each consisting of 15 individuals, participated in the study. An intubation manikin was used with a laryngoscope modified so that the forces applied during laryngoscopy could be measured. The mean duration of laryngoscopy in these groups was 23.4 sec, 17.6 sec, 27.1 sec, 26.8 sec and 42.7 sec, respectively. The maximally applied forces on the tongue were 71.7 N, 60.5 N, 65.9 N, 74.2 N and 69.7 N, respectively. The maximally applied forces on the maxillary incisors were 49.9 N, 36.3 N, 41.1 N, 58.3 N and 53.9 N, respectively. These results indicate the level of experience has a significant influence on the duration of laryngoscopy but seems to have little influence on the forces applied to the tongue and the maxillary incisors

Naar 20% reductie van voedselverspilling in 2015 : een verkenning van behoeften en kansen

In dit rapport wordt aangegeven wat de belangrijke aanknopingspunten vormen voor vermindering van voedselverspilling, welke aandachtspunten prioriteit hebben voor de korte en lange termijn, en met welke partijen samengewerkt kan worden om de reductiedoelstelling te behalen

Eten van waarde : voedselkwaliteit in Nederland

Het rapport geeft weer wat consumenten vinden van de maatschappelijke aspecten van voedselproductie en -consumptie en consumenten deze mening vertalen in hun aankopen en consumptie. Centraal in deze studie staat dus de mening en opvatting van Nederlandse consumenten alsook zijn gedrag inzake vijf (van de negen) voedselwaarden, die het ministerie van LNV van belang acht: gezondheid, milieu, dierenwelzijn, rechtvaardigheid en ambachtelijkhei

Increased incidence of cytogenetic abnormalities in chorionic villus samples from pregnancies established by in vitro fertilization and embryo transfer (IVF-ET)

We studied 201 pregnancies that were established by in vitro fertilization and embryo transfer (IVF–ET) and compared the frequency of cytogenetic abnormalities with that found in a large control population matched for indication group (advanced maternal age) and time of sampling. A total of 252 IVF–ET fetuses were cytogenetically analysed by either chorionic villus sampling (CVS; n = 80) or amniocentesis (n = 172). Eleven chromosome abnormalities were found in the CVS group (13·8 per cent); among them, a 45, X/46, X, dic(q11)/46, X, del(Y)(q11) mosaic that was found in an IVF pregnancy established by intracytoplasmic sperm injection (ICSI), four cases of trisomy 21, and three cases of trisomy 7 confined to the placenta. The results indicate a statistically significant three‐to five‐fold increase in both confined placental abnormalities (P<0·008) and true fetal chromosome anomalies (P<0·04). In the amniocentesis group, identical rates (1·7 per cent) of chromosome abnormalities were found in the IVF–ET and control groups. It is concluded that late first trimester, but not early second trimester, IVF–ET pregnancie

Patients with Cluster A Personality Disorders in Psychotherapy: An Effectiveness Study

Abstract BACKGROUND: While psychopharmacological studies are common in patients with cluster A personality disorders, the effects of psychotherapy have received little attention. The aim of this study is to explore whether psychotherapeutic treatment yields health gains for these patients. METHODS: The study was conducted between March 2003 and June 2008 in 6 mental health care centres in the Netherlands, with a sample of 57 patients with a DSM-IV-TR axis II cluster A diagnosis. Patients were assigned to 3 settings of psychotherapeutic treatment (outpatient, day hospital, inpatient), and effectiveness was assessed at 18 months after baseline. An intention-to-treat analysis was conducted for psychiatric symptoms (Brief Symptom Inventory), psychosocial functioning (Outcome Questionnaire-45) and quality of life (EQ-5D), using multilevel statistical modelling. As the study was non-randomised, the propensity score method was used to control for initial differences. RESULTS: Patients in the day hospital and inpatient group improved substantially in terms of psychiatric symptoms, social and interpersonal functioning, and quality of life. Patients in the outpatient group showed less improvement. Direct comparison of the improvement of psychiatric symptoms showed significant results in favour of day hospital (p = 0.046) and inpatient (p = 0.01) treatment, as compared to outpatient treatment. However, due to substantial baseline differences, this direct comparison should be judged carefully. CONCLUSIONS: Cluster A psychopathology is not a contraindication to benefit from psychotherapy. This is especially true for more intensive forms like inpatient and day hospital treatment. Future research should focus more on psychotherapeutic treatment to gain further insight into effective treatment options for this patient grou

European regulatory agenices should employ full time statisticians

No abstract available