Temporal trends in pregnancy weight gain and birth weight in Bavaria 2000-2007: slightly decreasing birth weight with increasing weight gain in pregnancy

Aims: To assess temporal trends in birth weight and pregnancy weight gain in Bavaria from 2000 to 2007. Methods: Data on 695,707 mother and infant pairs (singleton term births) were available from a compulsory reporting system for quality assurance, including information on birth weight, maternal weight at delivery and at booking, maternal smoking, age, and further anthropometric and lifestyle factors. Pregnancy weight gain was defined as: weight prior to delivery minus weight at first booking minus weight of the newborn. Results: Although mean weight gain during pregnancy increased considerably from 10.10 to 10.73 kg in seven years, the mean birth weight in mature singletons decreased slightly from 3433 to 3414 g. These trends could not be explained by concurrent changes in the rates of primiparity, smoking and gestational diabetes. Conclusions: These German data confirm an increased weight gain during pregnancy with adjustment for potential confounders

Statistical process monitoring to improve quality assurance of inpatient care

BACKGROUND Statistical Process Monitoring (SPM) is not typically used in traditional quality assurance of inpatient care. While SPM allows a rapid detection of performance deficits, SPM results strongly depend on characteristics of the evaluated process. When using SPM to monitor inpatient care, in particular the hospital risk profile, hospital volume and properties of each monitored performance indicator (e.g. baseline failure probability) influence the results and must be taken into account to ensure a fair process evaluation. Here we study the use of CUSUM charts constructed for a predefined false alarm probability within a single process, i.e. a given hospital and performance indicator. We furthermore assess different monitoring schemes based on the resulting CUSUM chart and their dependence on the process characteristics. METHODS We conduct simulation studies in order to investigate alarm characteristics of the Bernoulli log-likelihood CUSUM chart for crude and risk-adjusted performance indicators, and illustrate CUSUM charts on performance data from the external quality assurance of hospitals in Bavaria, Germany. RESULTS Simulating CUSUM control limits for a false alarm probability allows to control the number of false alarms across different conditions and monitoring schemes. We gained better understanding of the effect of different factors on the alarm rates of CUSUM charts. We propose using simulations to assess the performance of implemented CUSUM charts. CONCLUSIONS The presented results and example demonstrate the application of CUSUM charts for fair performance evaluation of inpatient care. We propose the simulation of CUSUM control limits while taking into account hospital and process characteristics

The selection of optimal discriminant procedures for discrete data.

The statistical literature contains a wide variety of reports on procedures for discriminant analysis. They range from the classical linear discriminant and logistic model at one end of the spectrum through to the recent recursive partitioning and neural network based procedures in the field of pattern recognition at the other extreme. By contrast the literature offers little advice concerning choice of procedure especially for discrete data. This thesis therefore addresses the problem of selection of optimal discriminant procedures for discrete data.The problem is approached by identifying key determinants of procedure choice such as prior information about the data, sample size and the performance expected of the procedure. Two new ways of assessing performance of a discriminant are suggested for the discrete data situation. The first of these, the n- criterion, is a weighted sum of posteriors for correctly allocated and misallocated objects. The second consists of analysing performance in relation to the distribution of relative differences between the two largest posteriors. A selection tree is constructed on the basis of these two approaches.The results indicate that the n-criterion exhibits low variance as well as low bias but also has the ability to differentiate better than the customary error rate. The use of classification thresholds proves particularly useful in the detection of optimal procedures for discrete data. A structured approach using a selection tree is demonstrated and evaluated.Integration of the developed techniques into statistical software packages is recommended

Perinatal health monitoring in Europe: results from the EURO-PERISTAT project

Data about deliveries, births, mothers and newborn babies are collected extensively to monitor the health and care of mothers and babies during pregnancy, delivery and the post-partum period, but there is no common approach in Europe. We analysed the problems related to using the European data for international comparisons of perinatal health. We made an inventory of relevant data sources in 25 European Union (EU) member states and Norway, and collected perinatal data using a previously defined indicator list. The main sources were civil registration based on birth and death certificates, medical birth registers, hospital discharge systems, congenital anomaly registers, confidential enquiries and audits. A few countries provided data from routine perinatal surveys or from aggregated data collection systems. The main methodological problems were related to differences in registration criteria and definitions, coverage of data collection, problems in combining information from different sources, missing data and random variation for rare events. Collection of European perinatal health information is feasible, but the national health information systems need improvements to fill gaps. To improve international comparisons, stillbirth definitions should be standardised and a short list of causes of fetal and infant deaths should be developed

Primary care management of chronic insomnia: a qualitative analysis of the attitudes and experiences of Australian general practitioners

BACKGROUND: Chronic insomnia is a highly prevalent disorder, with ten to thirty percent of Australian adults reporting chronic difficulties falling asleep and/or staying asleep such that it causes significant daytime impairment. Current Australian general practice guidelines recommend cognitive behavioural therapy for insomnia (CBTi) as first line treatment for insomnia, however research suggests that most general practice consultations for insomnia result in a prescription for hypnotic or sedative medicines. Although the first point of contact for patients experiencing symptoms of insomnia is often general practice, little is known about the current role, experiences and capacity of Australian general practitioners to manage insomnia. This study aimed to address that gap by exploring the attitudes and opinions of general practitioners regarding insomnia management, to inform the development and implementation of new models of best practice insomnia care within general practice. METHODS: A descriptive, pragmatic qualitative study. Purposive sampling was used to recruit practising Australian general practitioners, varying in age, years of experience and geographic location. Semi-structured interviews were conducted, and data analysed using thematic analysis.  RESULTS: Twenty-eight general practitioners participated in the study. Three major themes were identified: 1) Responsibility for insomnia care; 2) Complexities in managing insomnia; and 3) Navigating treatment pathways. Whilst general practitioners readily accepted responsibility for the management of insomnia, provision of care was often demanding and difficult within the funding and time constraints of general practice. Patients presenting with comorbid mental health conditions and insomnia, and decision-making regarding long-term use of benzodiazepines presented challenges for general practitioners. Whilst general practitioners confidently provided sleep hygiene education to patients, their knowledge and experience of CBTi, and access and understanding of specialised referral pathways for insomnia was limited.  CONCLUSIONS: General practitioners report that whilst assessing and managing insomnia can be demanding, it is an integral part of general practice. Insomnia presents complexities for general practitioners. Greater clarity about funding options, targeted education about effective insomnia treatments, and referral pathways to specialist services, such as benzodiazepine withdrawal support and psychologists, would benefit insomnia management within general practice

Interinstitutional variations in mode of birth after a previous caesarean section : a cross-sectional study in six German hospitals

Aims: Regional and interinstitutional variations have been recognized in the increasing incidence of caesarean section. Modes of birth after previous caesarean section vary widely, ranging from elective repeat caesarean section (ERCS) and unplanned repeat caesarean section (URCS) after trial of labour to vaginal birth after caesarean section (VBAC). This study describes interinstitutional variations in mode of birth after previous caesarean section in relation to regional indicators in Germany. Material and methods: A cross-sectional study using the birth registers of six maternity units (n=12,060) in five different German states (n=370,209). Indicators were tested by χ2 and relative deviations from regional values were expressed as relative risks and 95% confidence intervals. Results: The percentages of women in the six units with previous caesarean section ranged from 11.9% to 15.9% (P=0.002). VBAC was planned for 36.0% to 49.8% (P=0.003) of these women, but actually completed in only 26.2% to 32.8% (P=0.66). Depending on the indicator, the units studied deviated from the regional data by up to 32% [relative risk 0.68 (0.47–0.97)] in respect of completed VBAC among all initiated VBAC. Conclusions: There is substantial interinstitutional variation in mode of birth following previous caesarean section. This variation is in addition to regional patterns

Interrupted time series study found mixed effects of the impact of the Bavarian smoke-free legislation on pregnancy outcomes

In 2007 the German government passed smoke-free legislation, leaving the details of implementation to the individual federal states. In January 2008 Bavaria implemented one of the strictest laws in Germany. We investigated its impact on pregnancy outcomes and applied an interrupted time series (ITS) study design to assess any changes in preterm birth, small for gestational age (primary outcomes), and low birth weight, stillbirth and very preterm birth. We included 1,236,992 singleton births, comprising 83,691 preterm births and 112,143 small for gestational age newborns. For most outcomes we observed unclear effects. For very preterm births, we found an immediate drop of 10.4% (95%CI − 15.8, − 4.6%; p = 0.0006) and a gradual decrease of 0.5% (95%CI − 0.7, − 0.2%, p = 0.0010) after implementation of the legislation. The majority of subgroup and sensitivity analyses confirm these results. Although we found no statistically significant effect of the Bavarian smoke-free legislation on most pregnancy outcomes, a substantial decrease in very preterm births was observed. We cannot rule out that despite our rigorous methods and robustness checks, design-inherent limitations of the ITS study as well as country-specific factors, such as the ambivalent German policy context have influenced our estimation of the effects of the legislation

Perinatal health monitoring through a European lens: eight lessons from the Euro-Peristat report on 2015 births

International audienceNo abstract availabl

B Cell Antigen Presentation Promotes Th2 Responses and Immunopathology during Chronic Allergic Lung Disease

Background: The role of B cells in allergic asthma remains undefined. One mechanism by which B cells clearly contribute to allergic disease is via the production of specific immunoglobulin, and especially IgE. Cognate interactions with specific T cells result in T cell help for B cells, resulting in differentiation and immunoglobulin secretion. Proximal to (and required for) T cell-dependent immunoglobulin production, however, is antigen presentation by B cells. While interaction with T cells clearly has implications for B cell function and differentiation, this study investigated the role that B cells have in shaping the T cell response during chronic allergic lung disease. Methodology/Principal Findings: In these studies, we used a clinically relevant mouse model of chronic allergic lung disease to study the role of B cells and B cell antigen presentation in this disease. In these studies we present several novel findings: 1) Lung B cells from chronically allergen challenged mice up-regulated MHC II and costimulatory molecules CD40, CD80 and CD86. 2) Using in vitro studies, B cells from the lungs of allergen challenged mice could present antigen to T cells, as assessed by T cell proliferation and the preferential production of Th2 cytokines. 3) Following chronic allergen challenge, the levels of Th2 cytokines IL-4 and IL-5 in the lungs and airways were significantly attenuated in B cell 2/2 mice, relative to controls. 4) B cell driven Th2 responses and mucus hyper secretion in the lungs were dependent upon MHC II expression by B cells. Conclusions/Significance: Collectively, these results provide evidence for antigen presentation as a novel mechanism b

Aerosol optical properties in the southeastern United States in summer – Part 2: Sensitivity of aerosol optical depth to relative humidity and aerosol parameters

Aircraft observations of meteorological, trace gas, and aerosol properties were made between May and September 2013 in the southeastern United States (US). Regionally representative aggregate vertical profiles of median and interdecile ranges of the measured parameters were constructed from 37 individual aircraft profiles made in the afternoon when a well-mixed boundary layer with typical fair-weather cumulus was present (Wagner et al., 2015). We use these 0–4 km aggregate profiles and a simple model to calculate the sensitivity of aerosol optical depth (AOD) to changes in dry aerosol mass, relative humidity, mixed-layer height, the central diameter and width of the particle size distribution, hygroscopicity, and dry and wet refractive index, while holding the other parameters constant. The calculated sensitivity is a result of both the intrinsic sensitivity and the observed range of variation in these parameters. These observationally based sensitivity studies indicate that the relationship between AOD and dry aerosol mass in these conditions in the southeastern US can be highly variable and is especially sensitive to relative humidity (RH). For example, calculated AOD ranged from 0.137 to 0.305 as the RH was varied between the 10th and 90th percentile profiles with dry aerosol mass held constant. Calculated AOD was somewhat less sensitive to aerosol hygroscopicity, mean size, and geometric standard deviation, σg. However, some chemistry–climate models prescribe values of σg substantially larger than we or others observe, leading to potential high biases in model-calculated AOD of  ∼  25 %. Finally, AOD was least sensitive to observed variations in dry and wet aerosol refractive index and to changes in the height of the well-mixed surface layer. We expect these findings to be applicable to other moderately polluted and background continental air masses in which an accumulation mode between 0.1–0.5 µm diameter dominates aerosol extinction