Robust Inference for Univariate Proportional Hazards Frailty Regression Models

We consider a class of semiparametric regression models which are one-parameter extensions of the Cox [J. Roy. Statist. Soc. Ser. B 34 (1972) 187-220] model for right-censored univariate failure times. These models assume that the hazard given the covariates and a random frailty unique to each individual has the proportional hazards form multiplied by the frailty. The frailty is assumed to have mean 1 within a known one-parameter family of distributions. Inference is based on a nonparametric likelihood. The behavior of the likelihood maximizer is studied under general conditions where the fitted model may be misspecified. The joint estimator of the regression and frailty parameters as well as the baseline hazard is shown to be uniformly consistent for the pseudo-value maximizing the asymptotic limit of the likelihood. Appropriately standardized, the estimator converges weakly to a Gaussian process. When the model is correctly specified, the procedure is semiparametric efficient, achieving the semiparametric information bound for all parameter components. It is also proved that the bootstrap gives valid inferences for all parameters, even under misspecification. We demonstrate analytically the importance of the robust inference in several examples. In a randomized clinical trial, a valid test of the treatment effect is possible when other prognostic factors and the frailty distribution are both misspecified. Under certain conditions on the covariates, the ratios of the regression parameters are still identifiable. The practical utility of the procedure is illustrated on a non-Hodgkin's lymphoma dataset.Comment: Published by the Institute of Mathematical Statistics (http://www.imstat.org) in the Annals of Statistics (http://www.imstat.org/aos/) at http://dx.doi.org/10.1214/00905360400000053

Individual patient data meta-analysis of randomized controlled trials of community occupational therapy for stroke patients

<p><b>Background and Purpose:</b> Trials of occupational therapy for stroke patients living in the community have varied in their findings. It is unclear why these discrepancies have occurred.</p> <p><b>Methods:</b> Trials were identified from searches of the Cochrane Library and other sources. The primary outcome measure was the Nottingham Extended Activities of Daily Living (NEADL) score at the end of intervention. Secondary outcome measures included the Barthel Index or the Rivermead ADL (Personal ADL), General Health Questionnaire (GHQ), Nottingham Leisure Questionnaire (NLQ), and death. Data were analyzed using linear or logistic regression with a random effect for trial and adjustment for age, gender, baseline dependency, and method of follow-up. Subgroup analyses compared any occupational therapy intervention with control.</p> <p><b>Results:</b> We included 8 single-blind randomized controlled trials incorporating 1143 patients. Occupational therapy was associated with higher NEADL scores at the end of intervention (weighted mean difference [WMD], 1.30 points, 95% confidence intervals [CI], 0.47 to 2.13) and higher leisure scores at the end of intervention (WMD, 1.51 points; 95% CI, 0.24 to 2.79). Occupational therapy emphasizing activities of daily living (ADL) was associated with improved end of intervention NEADL (WMD, 1.61 points; 95% CI, 0.72 to 2.49) and personal activities of daily living (odds ratio [OR], 0.65; 95% CI, 0.46 to 0.91), but not NLQ. Leisure-based occupational therapy improved end of intervention NLQ (WMD, 1.96 points; 95% CI, 0.27 to 3.66) but not NEADL or PADL.</p> <p><b>Conclusions:</b> Community occupational therapy significantly improved personal and extended activities of daily living and leisure activity in patients with stroke. Better outcomes were found with targeted interventions.</p&gt

Decreasing the level of hemicelluloses in sow’s lactation diet affects the milk composition and post-weaning performance of low birthweight piglets

Hemicelluloses (HC) are polysaccharides constituents of the cell walls of plants. They are fermented in the gut to produce volatile fatty acids (VFA). The present study investigated the effects of decreasing HC level in a sow’s lactation diet on sow performances, offspring development and milk composition. From 110 days (d) of gestation until weaning (26 ± 0.4 d post-farrowing), 40 Swiss Large White sows were assigned to one of the four dietary treatments: (1) T13 (HC: 127 g/kg), (2) T11 (HC: 114 g/kg), (3) T9 (HC: 94 g/kg) and (4) T8 (HC: 80 g/kg). Milk was collected at 3 and 17d of lactation. At birth, piglets were divided into two groups according to their birthweight (BtW): normal (N-BtW; BtW >1.20 kg) or low (L-BtW; BtW ≤1.20 kg). Decreased HC levels in the maternal diet linearly increased (p ≤.05) the body weight of L-BtW piglets at two weeks post-weaning and linearly decreased (p ≤.05) diarrhoea incidence and duration in this category. The concentrations of copper, threonine and VFA, as well as the proportion of butyrate, in milk linearly increased (p ≤.05), whereas lactose content linearly decreased (p ≤.05) with decreased HC in the maternal diet. The present study provides evidence that decreasing HC level in a sow’s lactation diet can positively affect the composition and VFA profile of milk and ultimately favour the growth and health of L-BtW piglets.Highlights The results of this study showed that decreasing the level of hemicelluloses in a sow’s lactation diet modified milk composition and had positive effects on the post-weaning performance of low birthweight piglets. This study highlighted the role of dietary fibres in the maternal diet to alleviate body weight variations at two weeks post-weaning. Nevertheless, before advising pig producers, further research should elucidate the optimal level of hemicelluloses for lactating sows

Bath Chairs, Bureaux and Birds

The project selected was an investigation into office fu rniture from an industrial producer/consumer angle.The first stage took the form of an investigation into the needs of an office system in a modern office situation involving interviews with office users, the reading of research articles on ergonomics and office needs and then correlating these with knowledge of production and distribution pro· cesses in order to reach a solution acceptable to all concerned

Monitoring and Management of Childhood Asthma in Asian Countries

BACKGROUND: A recent study by the International Study of Asthma and Allergies in Childhood has shown that asthma symptom prevalence is still increasing in parts of Asia. As such, it is important to know how well asthma is being managed. Practices of physicians in India, China, Sri Lanka, Australia, Singapore, Indonesia, Philippines, and Taiwan in monitoring and treating childhood asthma were examined. METHODS: A 6-page standardized questionnaire was sent to physicians via post. The questionnaire is made up of 3 parts, including (1) methods of monitoring of childhood asthma, (2) practices in managing acute asthma exacerbations, and (3) choice of therapy in maintenance treatment. RESULTS: Our study reflects mostly the practices of physicians who practice in urban regions. Of respondents, 41.4% were general pediatricians, whereas 26.3% were general practitioners. A small fraction of physicians used score cards or diaries to monitor asthma, ranging from 0% (Philippines and Australia) to 15.9% (India). Only 8.1% (Sri Lanka) to 52.0% (Australia) use either a peak flow meter and/or spirometry to monitor asthma. However, for frequency of use, 35% (China) to 94% (Indonesia) never or seldom make use of a peak flow meter, and 33% (China) to 97.6% (Indonesia) never or seldom use spirometry for monitoring. Most physicians treat acute asthma appropriately with short-acting bronchodilators. For maintenance treatment, an inhaled corticosteroid was the most frequently chosen first-choice therapy. However, a significant fraction of physicians chose a long-acting β-agonist monotherapy as a first-choice treatment for asthma maintenance. For infants, the percentage ranged from 1.4% (Australia) to 76.3% (Indonesia); in preschoolers, 1.8% (Australia) to 43.3% (Indonesia); and in older children, 0% (Philippines) to 28.8% (Indonesia). These results may be related to the overall affluence of each nation. CONCLUSIONS: There is much room for improvement in increasing physicians' awareness to guidelines for more effective management of pediatric asthma in Southeast Asia, especially regarding the high use of long-acting β-agonist monotherapy, even in young children

Performances, meat quality and boar taint of castrates and entire male pigs fed a standard and a raw potato starch-enriched diet

In Europe there is increasing concern about the common practice of surgical castration of piglets without anaesthesia. One possible alternative to completely avoid castration is entire male pig production. Thus, the objective of the study was to compare the growth performance, carcass characteristics, organ weights, meat quality traits, fat score and boar taint compounds in the adipose tissue of group-penned entire male pigs and castrates. Furthermore, the effect of raw potato starch (RPS) fed for 7 days prior to slaughter was determined. Pigs (n = 36) were blocked by BW into 12 blocks (3 littermates/block) and assigned to three experimental groups: surgical castrates (C); entire males (EM); and entire males offered RPS (30 g RPS/100 g diet) for 7 days prior to slaughter (EM+). Pigs had ad libitum access to the feed from 22 to 107 kg, individual feed intake was recorded daily and BW once a week. Entire males grew slower (EM: 771, EM+: 776 v. C: 830 g/day; P 0.05) differ among experimental groups but the adipose tissue was more unsaturated in entire males than in C as indicated by the higher fat scores (EM: 69.1, EM+: 67.2 v. C: 63.6; P < 0.01). Feeding RPS reduced (P = 0.04) the skatole tissue concentrations (expressed in μg/g lipid) in EM+ (0.22) compared to EM (0.85), whereas androstenone and indole levels were not (P 0.60) affected (EM: 1.7 and 0.10, EM+: 2.0 and 0.09, respectively). Although the current results confirmed the high efficiency of entire males compared to castrates, the observed high androstenone levels represent a major challenge to implement entire males productio

Growth performance, carcass characteristics and meat quality of group-penned surgically castrated, immunocastrated (Improvac®) and entire male pigs and individually penned entire male pigs

The objective of the study was to compare growth performance, carcass characteristics, meat quality and fatty acid composition of the adipose tissue of group-penned barrows, immunocastrated boars and entire males. Furthermore, the effect of housing of entire males on the aforementioned parameters was evaluated. At 55.2 days of age, 52 Swiss Large White pigs were blocked by litter and assigned by BW to four experimental groups: barrows (C), immunocastrated boars (IC), entire males (EMG) reared in group pens and entire males (EMP) reared in individual pens. In experiment 1, the effects of the method of castration were investigated (experimental groups C, IC and EMG). In experiment 2, the effects of housing on entire male pigs were evaluated (experimental groups EMG and EMP). All pigs had ad libitum access to standard diets from weaning to 107 kg BW. The two vaccinations (Improvac®) were applied to the IC pigs at an average BW of 22.6 and 73.0 kg. In experiment 1, average daily gain (ADG) did not (P > 0.05) differ among the experimental groups. However, EMG consumed less feed and had a better feed-conversion ratio than C (P 0.05) differ between EMP and EMG. However, EMP pigs consumed more feed than EMG pigs and had a poorer feed efficiency (P < 0.01 for each). In conclusion, EMG pigs had a better feed efficiency than IC pigs and their carcasses were leaner, but the risk of boar tainted pork was elevated. Group-housing negatively affected average daily feed intake but not ADG of entire males. At the moment, immunocastration offers a good approach to avoid castration and minimize the risk of boar tain

A Lightweight Data Preprocessing Strategy with Fast Contradiction Analysis for Incremental Classifier Learning

A prime objective in constructing data streaming mining models is to achieve good accuracy, fast learning, and robustness to noise. Although many techniques have been proposed in the past, efforts to improve the accuracy of classification models have been somewhat disparate. These techniques include, but are not limited to, feature selection, dimensionality reduction, and the removal of noise from training data. One limitation common to all of these techniques is the assumption that the full training dataset must be applied. Although this has been effective for traditional batch training, it may not be practical for incremental classifier learning, also known as data stream mining, where only a single pass of the data stream is seen at a time. Because data streams can amount to infinity and the so-called big data phenomenon, the data preprocessing time must be kept to a minimum. This paper introduces a new data preprocessing strategy suitable for the progressive purging of noisy data from the training dataset without the need to process the whole dataset at one time. This strategy is shown via a computer simulation to provide the significant benefit of allowing for the dynamic removal of bad records from the incremental classifier learning process

Pre‐emptive and preventive opioids for postoperative pain in adults undergoing all types of surgery

Background: Postoperative pain is a common consequence of surgery and can have deleterious effects. It has been suggested that the administration of opioid analgesia before a painful stimulus may improve pain control. This can be done in two ways. We defined 'preventive opioids' as opioids administered before incision and continued postoperatively, and 'pre‐emptive opioids' as opioids given before incision but not continued postoperatively. Both pre‐emptive and preventive analgesia involve the initiation of an analgesic agent prior to surgical incision with the aim of reducing intraoperative nociception and therefore postoperative pain.Objectives: To assess the efficacy of preventive and pre‐emptive opioids for reducing postoperative pain in adults undergoing all types of surgery.Search methods: We searched the following electronic databases: CENTRAL, MEDLINE, Embase, AMED, and CINAHL (up to 18 March 2018). In addition, we searched for unpublished studies in three clinical trial databases, conference proceedings, grey literature databases, and reference lists of retrieved articles. We did not apply any restrictions on language or date of publication.Selection criteria: We included parallel‐group randomized controlled trials (RCTs) only. We included participants aged over 15 years old undergoing any type of surgery. We defined postincision opioids as the same intervention administered after incision whether single dose (as comparator with pre‐emptive analgesia) or continued postoperatively (as comparator with preventive analgesia) (control group). We considered studies that did and did not use a double‐dummy placebo (e.g. intervention group received active drug before incision and placebo after incision; control group received placebo before incision and active drug after incision).Data collection and analysis: We used the standard methodological procedures expected by Cochrane. Our primary outcomes were: early acute postoperative pain (measured within six hours and reported on a 0‐to‐10 scale) and respiratory depression. Our secondary outcomes included: late acute postoperative pain (24 to 48 hours and reported on a 0‐to‐10 scale), 24‐hour morphine consumption, and adverse events (intraoperative bradycardia and hypotension). We used GRADE to assess the quality of the evidence for each outcome.Main results: We included 20 RCTs, including one unpublished study with 1343 participants. Two studies were awaiting classification as the full text for these studies was not available. One study evaluated pre‐emptive opioids, and 19 studies evaluated preventive opioids. We considered only one study to be at low risk of bias for most domains. The surgeries and opioids used varied, although roughly half of the included studies were conducted in abdominal hysterectomy, and around a quarter used morphine as the intervention. All studies were conducted in secondary care.Pre‐emptive opioids compared to postincision opioidsFor pre‐emptive opioids in dental surgery, there may be a reduction in early acute postoperative pain (mean difference (MD) ‐1.20, 95% confidence interval (CI) ‐1.75 to ‐0.65; 40 participants; 1 study; low‐quality evidence). This study did not report on adverse events (respiratory depression, bradycardia, or hypotension). There may be a reduction in late acute postoperative pain (MD ‐2.10, 95% CI ‐2.57 to ‐1.63; 40 participants; 1 study; low‐quality evidence). This study did not report 24‐hour morphine consumption.Preventive opioids compared to postincision opioidsFor preventive opioids, there was probably no reduction in early acute postoperative pain (MD 0.11, 95% CI ‐0.32 to 0.53; 706 participants; 10 studies; I2 = 61%; moderate‐quality evidence). There were no events of respiratory depression in four studies (433 participants). There was no important reduction in late acute postoperative pain (MD ‐0.06, 95% CI ‐0.13 to 0.01; 668 participants; 9 studies; I2 = 0%; moderate‐quality evidence). There may be a small reduction in 24‐hour morphine consumption (MD ‐4.91 mg, 95% CI ‐9.39 mg to ‐0.44 mg; 526 participants; 11 studies; I2 = 82%; very low‐quality evidence). There may be similar rates of bradycardia (risk ratio (RR) 0.33, 95% CI 0.01 to 7.88; 112 participants; 2 studies; I2 = 0%; low‐quality evidence) and hypotension (RR 1.08, 95% CI 0.25 to 4.73; 88 participants; 2 studies; I2 = 0%; low‐quality evidence).Authors' conclusions: Due to the low quality of the evidence, we are uncertain whether pre‐emptive opioids reduce postoperative pain. Based on the trials conducted thus far, there was no clear evidence that preventive opioids result in reductions in pain scores. It was unclear if there was a reduction in morphine consumption due to very low‐quality of evidence. Too few studies reported adverse events to be able to draw any definitive conclusions. Once assessed, the two studies awaiting classification may alter the conclusions of the review