Pseudo-Outbreak ofLegionella pneumophilaSerogroup 8 Infection Associated With a Contaminated Ice Machine in a Bronchoscopy Suite

Objective.

To investigate the marked increase noted over an 8-month period in the number ofLegionella pneumophilaisolates recovered from bronchoalveolar lavage fluid specimens obtained during bronchoscopy in our healthcare system.

Setting.

Bronchoscopy suite that serves a 580-bed tertiary care center and a large, multisite, faculty practice plan with approximately 2 million outpatient visits per year.

Methods.

Cultures of environmental specimens from the bronchoscopy suite were performed, including samples from the air and water filters, bronchoscopes, and the ice machine, with the aim of identifyingLegionellaspecies. Specimens were filtered and acid-treated and then inoculated on buffered charcoal yeast extract agar. Serogrouping was performed on all isolates recovered from patient and environmental samples.

Results.

AUL. pneumophilaisolates recovered from patients were serogroup 8, a serogroup that is not usually recovered in our facility. An epidemiologic investigation of the bronchoscopy suite revealed the ice machine to be contaminated withL. pneumophilaserogroup 8. Patients were exposed to the organism as a result of a recently adopted practice in the bronchoscopy suite that involved directly immersing uncapped syringes of sterile saline in contaminated ice baths during the procedures. At least 1 patient was ill as a result of the pseudo-outbreak. Molecular typing of isolates recovered from patient and environmental samples revealed that the isolates were indistinguishable.

Conclusions.

Extensive cleaning of the ice machine and replacement of the machine's water filter ended the pseudo-outbreak. This episode emphasizes the importance of using aseptic technique when performing invasive procedures, such as bronchoscopies. It also demonstrates the importance of reviewing procedures in all patient areas to ensure compliance with facility policies for providing a safe patient environment.

Predictive distributions for between-study heterogeneity and simple methods for their application in Bayesian meta-analysis

Numerous meta-analyses in healthcare research combine results from only a small number of studies, for which the variance representing between-study heterogeneity is estimated imprecisely. A Bayesian approach to estimation allows external evidence on the expected magnitude of heterogeneity to be incorporated.

The aim of this paper is to provide tools that improve the accessibility of Bayesian meta-analysis. We present two methods for implementing Bayesian meta-analysis, using numerical integration and importance sampling techniques. Based on 14 886 binary outcome meta-analyses in the Cochrane Database of Systematic Reviews, we derive a novel set of predictive distributions for the degree of heterogeneity expected in 80 settings depending on the outcomes assessed and comparisons made. These can be used as prior distributions for heterogeneity in future meta-analyses.

The two methods are implemented in R, for which code is provided. Both methods produce equivalent results to standard but more complex Markov chain Monte Carlo approaches. The priors are derived as log-normal distributions for the between-study variance, applicable to meta-analyses of binary outcomes on the log odds-ratio scale. The methods are applied to two example meta-analyses, incorporating the relevant predictive distributions as prior distributions for between-study heterogeneity.

We have provided resources to facilitate Bayesian meta-analysis, in a form accessible to applied researchers, which allow relevant prior information on the degree of heterogeneity to be incorporated. © 2014 The Authors. Statistics in Medicine published by John Wiley & Sons Ltd.

A general method for handling missing binary outcome data in randomized controlled trials

AIMS

The analysis of randomized controlled trials with incomplete binary outcome data is challenging. We develop a general method for exploring the impact of missing data in such trials, with a focus on abstinence outcomes.

DESIGN

We propose a sensitivity analysis where standard analyses, which could include 'missing = smoking' and 'last observation carried forward', are embedded in a wider class of models.

SETTING

We apply our general method to data from two smoking cessation trials.

PARTICIPANTS

A total of 489 and 1758 participants from two smoking cessation trials.

MEASUREMENTS

The abstinence outcomes were obtained using telephone interviews.

FINDINGS

The estimated intervention effects from both trials depend on the sensitivity parameters used. The findings differ considerably in magnitude and statistical significance under quite extreme assumptions about the missing data, but are reasonably consistent under more moderate assumptions.

CONCLUSIONS

A new method for undertaking sensitivity analyses when handling missing data in trials with binary outcomes allows a wide range of assumptions about the missing data to be assessed. In two smoking cessation trials the results were insensitive to all but extreme assumptions.

Multivariate meta-analysis using individual participant data

When combining results across related studies, a multivariate meta-analysis allows the joint synthesis of correlated effect estimates from multiple outcomes. Joint synthesis can improve efficiency over separate univariate syntheses, may reduce selective outcome reporting biases, and enables joint inferences across the outcomes. A common issue is that within-study correlations needed to fit the multivariate model are unknown from published reports. However, provision of individual participant data (IPD) allows them to be calculated directly. Here, we illustrate how to use IPD to estimate within-study correlations, using a joint linear regression for multiple continuous outcomes and bootstrapping methods for binary, survival and mixed outcomes. In a meta-analysis of 10 hypertension trials, we then show how these methods enable multivariate meta-analysis to address novel clinical questions about continuous, survival and binary outcomes; treatment–covariate interactions; adjusted risk/prognostic factor effects; longitudinal data; prognostic and multiparameter models; and multiple treatment comparisons. Both frequentist and Bayesian approaches are applied, with example software code provided to derive within-study correlations and to fit the models.

Methods for calculating confidence and credible intervals for the residual between-study variance in random effects meta-regression models

BACKGROUND

Meta-regression is becoming increasingly used to model study level covariate effects. However this type of statistical analysis presents many difficulties and challenges. Here two methods for calculating confidence intervals for the magnitude of the residual between-study variance in random effects meta-regression models are developed. A further suggestion for calculating credible intervals using informative prior distributions for the residual between-study variance is presented.

METHODS

Two recently proposed and, under the assumptions of the random effects model, exact methods for constructing confidence intervals for the between-study variance in random effects meta-analyses are extended to the meta-regression setting. The use of Generalised Cochran heterogeneity statistics is extended to the meta-regression setting and a Newton-Raphson procedure is developed to implement the Q profile method for meta-analysis and meta-regression. WinBUGS is used to implement informative priors for the residual between-study variance in the context of Bayesian meta-regressions.

RESULTS

Results are obtained for two contrasting examples, where the first example involves a binary covariate and the second involves a continuous covariate. Intervals for the residual between-study variance are wide for both examples.

CONCLUSIONS

Statistical methods, and R computer software, are available to compute exact confidence intervals for the residual between-study variance under the random effects model for meta-regression. These frequentist methods are almost as easily implemented as their established counterparts for meta-analysis. Bayesian meta-regressions are also easily performed by analysts who are comfortable using WinBUGS. Estimates of the residual between-study variance in random effects meta-regressions should be routinely reported and accompanied by some measure of their uncertainty. Confidence and/or credible intervals are well-suited to this purpose.

Evertor muscle activity as a predictor of the mid-term outcome following treatment of the idiopathic and non-idiopathic clubfoot

Previous studies have identified clinical and demographic risk factors for recurrence in the treatment of idiopathic clubfoot (congenital talipes equinovarus). Evertor muscle activity is not usually considered amongst them. This study aimed to evaluate whether recurrence could be predicted by demographic, clinical and gait parameters. From a series of 103 children with clubfeet, 67 had completed a follow-up of two years: 41 male and 26 female, 38 with idiopathic and 29 with non-idiopathic deformities. The mean age was 3.2 years (2.1 to 6.3). Primary correction was obtained in all 38 children (100%) with an idiopathic deformity, and in 26 of 29 patients (90%) with a non-idiopathic deformity. Overall, 60 children (90%) complied with the abduction brace regime. At a mean follow-up of 31.4 months (24 to 62), recurrence was noted in six children (15.8%) in the idiopathic and 14 children (48.3%) in the non-idiopathic group. Significant correlation was found between poor evertor activity and recurrence in both groups. No statistically significant relationship was found between the rate of recurrence and the severity of the initial deformity, the age at the time of treatment, the number of casts required or the compliance with the brace.

After correction of idiopathic and non-idiopathic clubfoot using the Ponseti method, only poor evertor muscle activity was statistically associated with recurrence. The identification of risk factors for recurrent deformity allows clinicians to anticipate problems and advocate early additional treatment to improve muscle balance around the ankle.

Cite this article: Bone Joint J 2014;96-B:1264–8.

The effect of the environment on symptom dimensions in the first episode of psychosis: a multilevel study

BACKGROUND

The extent to which different symptom dimensions vary according to epidemiological factors associated with categorical definitions of first-episode psychosis (FEP) is unknown. We hypothesized that positive psychotic symptoms, including paranoid delusions and depressive symptoms, would be more prominent in more urban environments.

METHOD

We collected clinical and epidemiological data on 469 people with FEP (ICD-10 F10-F33) in two centres of the Aetiology and Ethnicity in Schizophrenia and Other Psychoses (AESOP) study: Southeast London and Nottinghamshire. We used multilevel regression models to examine neighbourhood-level and between-centre differences in five symptom dimensions (reality distortion, negative symptoms, manic symptoms, depressive symptoms and disorganization) underpinning Schedules for Clinical Assessment in Neuropsychiatry (SCAN) Item Group Checklist (IGC) symptoms. Delusions of persecution and reference, along with other individual IGC symptoms, were inspected for area-level variation.

RESULTS

Reality distortion [estimated effect size (EES) 0.15, 95% confidence interval (CI) 0.06-0.24] and depressive symptoms (EES 0.21, 95% CI 0.07-0.34) were elevated in people with FEP living in more urban Southeast London but disorganized symptomatology was lower (EES -0.06, 95% CI -0.10 to -0.02), after controlling for confounders. Delusions of persecution were not associated with increased neighbourhood population density [adjusted odds ratio (aOR) 1.01, 95% CI 0.83-1.23], although an effect was observed for delusions of reference (aOR 1.41, 95% CI 1.12-1.77). Hallucinatory symptoms showed consistent elevation in more densely populated neighbourhoods (aOR 1.32, 95% CI 1.09-1.61).

CONCLUSIONS

In people experiencing FEP, elevated levels of reality distortion and depressive symptoms were observed in more urban, densely populated neighbourhoods. No clear association was observed for paranoid delusions; hallucinations were consistently associated with increased population density. These results suggest that urban environments may affect the syndromal presentation of psychotic disorders.

Relaxing the independent censoring assumption in the Cox proportional hazards model using multiple imputation

The Cox proportional hazards model is frequently used in medical statistics. The standard methods for fitting this model rely on the assumption of independent censoring. Although this is sometimes plausible, we often wish to explore how robust our inferences are as this untestable assumption is relaxed. We describe how this can be carried out in a way that makes the assumptions accessible to all those involved in a research project. Estimation proceeds via multiple imputation, where censored failure times are imputed under user-specified departures from independent censoring. A novel aspect of our method is the use of bootstrapping to generate proper imputations from the Cox model. We illustrate our approach using data from an HIV-prevention trial and discuss how it can be readily adapted and applied in other settings. © 2014 The Authors. Statistics in Medicine published by John Wiley & Sons, Ltd.

Demonstrating compliance with protection objectives for non-human biota within post-closure safety cases for radioactive waste repositories

Over recent years, a number of approaches have been developed that enable the calculation of dose rates to animals and plants following the release of radioactivity to the environment. These approaches can be used to assess the potential impacts of activities that may release radioactivity to the environment, such as the operation of waste repositories. A number of national and international studies have identified screening criteria to indicate those assessment results below which further consideration is not generally required. However no internationally agreed criteria are currently available and consistency in criteria between countries has not been achieved. Furthermore, since screening criteria are not intended to be applied as limits, it is clear that they cannot always form a sufficient basis for assessing the adequacy of protection afforded. Typically, exceeding a screening value leads to a regulatory requirement to undertake a further, more detailed assessment. It does not, per se, imply that there is inadequate protection of the organism types at the specific site under assessment. Therefore, there is a need to develop a more structured approach to dealing with situations in which current screening criteria are exceeded. As a contribution to the developing international discussions, and as an interim measure for application where assessments are required currently, a two-tier, three zone framework is proposed here, relevant to the long term assessment of potential impacts from the deep disposal of radioactive wastes. The purpose of the proposed framework is to promote a proportionate and risk-based approach to the level of effort required in undertaking and interpreting an assessment.

Integration of tuberculosis and prevention of mother-to-child transmission of HIV programmes in South Africa

SETTING

One of the rural districts in KwaZulu-Natal Province, the epicentre of the human immunodeficiency virus (HIV) and tuberculosis (TB) epidemics in South Africa.

OBJECTIVES

To assess the integration of TB services into the prevention of mother-to-child transmission of HIV (PMTCT) programme and identify barriers to the integration of services.

DESIGN

Cross-sectional survey using exit interviews with pregnant women attending 10 antenatal care (ANC) clinics. Review of ANC PMTCT facility routine data. Qualitative interviews with 26 key informants on barriers to integration of TB-PMTCT services.

RESULTS

Of 150 women interviewed, 112 (75%) reported being educated on TB symptoms on the day of their visit; 56% were screened for TB symptoms and 27% were suspected to have TB; 26 (17%) women were HIV-positive and 2 (8%) were co-infected with TB. There was no record of provision of isoniazid prophylaxis for PMTCT clients with latent tuberculous infection. The predominant barriers to the integration of TB-PMTCT services included lack of skilled providers and their supervision, the physical layout of the TB-PMTCT services and the service delivery mechanisms.

CONCLUSION

The integration of TB prevention and care into the PMTCT programme was inadequate. Integration of TB services into the ANC PMTCT programme will require strong leadership to address barriers such as training gaps, lack of supervision and service delivery mechanisms.

A design-by-treatment interaction model for network meta-analysis with random inconsistency effects

Network meta-analysis is becoming more popular as a way to analyse multiple treatments simultaneously and, in the right circumstances, rank treatments. A difficulty in practice is the possibility of ‘inconsistency’ or ‘incoherence’, where direct evidence and indirect evidence are not in agreement. Here, we develop a random-effects implementation of the recently proposed design-by-treatment interaction model, using these random effects to model inconsistency and estimate the parameters of primary interest. Our proposal is a generalisation of the model proposed by Lumley and allows trials with three or more arms to be included in the analysis. Our methods also facilitate the ranking of treatments under inconsistency. We derive R and I² statistics to quantify the impact of the between-study heterogeneity and the inconsistency. We apply our model to two examples. © 2014 The Authors. Statistics in Medicine published by John Wiley & Sons, Ltd.

Community-based intervention to enhance provision of integrated TB-HIV and PMTCT services in South Africa

OBJECTIVE

To conduct an impact assessment of an intervention to enhance the provision of community-based integrated services for tuberculosis (TB), human immunodeficiency virus (HIV) and prevention of mother-to-child transmission (PMTCT).

METHODS

The intervention consisted of a combination of training of community care workers (CCWs), structural adjustments, harmonisation of scope of practice and stipend of CCWs and enhanced supervision of CCWs to provide comprehensive TB-HIV/PMTCT services in a rural South African district. A before and after study design was used with a household survey to assess the operational effectiveness of the intervention. Six clusters were randomised into intervention and control arms. Quantitative data were analysed using logistic regression, adjusting for cluster design.

RESULTS

Logistic regression analyses of the survey data show that CCWs from the intervention arm performed better in the provision of TB-HIV/PMTCT services, such as screening for TB and sexually transmitted infections, adherence to anti-tuberculosis treatment and antiretroviral therapy and counselling on infant feeding compared to the control CCWs (P < 0.05). However, intervention CCWs performed worse in the integrated management of childhood illnesses education and social welfare referrals (P < 0.05). The uptake of HIV testing increased significantly in the intervention arm, from 55% to 78% (P < 0.001).

CONCLUSION

The intervention was effective in enhancing the provision of community-based TB-HIV and PMTCT services. However, attention to other primary health care services is required to ensure that all key services are provided.

Retraining function in people with Parkinson's disease using the Microsoft kinect: game design and pilot testing

Background

Computer based gaming systems, such as the Microsoft Kinect (Kinect), can facilitate complex task practice, enhance sensory feedback and action observation in novel, relevant and motivating modes of exercise which can be difficult to achieve with standard physiotherapy for people with Parkinson’s disease (PD). However, there is a current need for safe, feasible and effective exercise games that are appropriate for PD rehabilitation. The aims of this study were to i) develop a computer game to rehabilitate dynamic postural control for people with PD using the Kinect; and ii) pilot test the game’s safety and feasibility in a group of people with PD.

Methods

A rehabilitation game aimed at training dynamic postural control was developed through an iterative process with input from a design workshop of people with PD. The game trains dynamic postural control through multi-directional reaching and stepping tasks, with increasing complexity across 12 levels of difficulty. Nine people with PD pilot tested the game for one session. Participant feedback to identify issues relating to safety and feasibility were collected using semi-structured interviews.

Results

Participants reported that they felt safe whilst playing the game. In addition, there were no adverse events whilst playing. In general, the participants stated that they enjoyed the game and seven of the nine participants said they could imagine themselves using the game at home, especially if they felt it would improve their balance. The Flow State Scale indicated participants were immersed in the gameplay and enjoyed the experience. However, some participants reported that they found it difficult to discriminate between different types and orientations of visual objects in the game and some also had difficulty with the stepping tasks, especially when performed at the same time as the reaching tasks.

Conclusion

Computer-based rehabilitation games using the Kinect are safe and feasible for people with PD although intervention trials are needed to test their safety, feasibility and efficacy in the home.

Should we reconsider lung transplantation through uncontrolled donation after circulatory death?

Lung transplantation through controlled donation after circulatory death (cDCD) has slowly gained universal acceptance with reports of equivalent outcomes to those through donation after brain death. In contrast, uncontrolled DCD (uDCD) lung use is controversial and requires ethical, legal and medical complexities to be addressed in a limited time. Consequently, uDCD lung use has not previously been reported in the United States. Despite these potential barriers, we present a case of a patient with multiple gunshot wounds to the head and the body who was unsuccessfully resuscitated and ultimately became an uDCD donor. A cytomegalovirus positive recipient who had previously consented for CDC high-risk, DCD and participation in the NOVEL trial was transplanted from this uDCD donor, following 3 h of ex vivo lung perfusion. The postoperative course was uneventful, and the recipient was discharged home on day 9. While this case represents a "best-case scenario," it illustrates a method for potential expansion of the lung allograft pool through uDCD after unsuccessful resuscitation in hospitalized patients.

Accuracy of the Microsoft Kinect sensor for measuring movement in people with Parkinson's disease

BACKGROUND

The Microsoft Kinect sensor (Kinect) is potentially a low-cost solution for clinical and home-based assessment of movement symptoms in people with Parkinson's disease (PD). The purpose of this study was to establish the accuracy of the Kinect in measuring clinically relevant movements in people with PD.

METHODS

Nine people with PD and 10 controls performed a series of movements which were measured concurrently with a Vicon three-dimensional motion analysis system (gold-standard) and the Kinect. The movements included quiet standing, multidirectional reaching and stepping and walking on the spot, and the following items from the Unified Parkinson's Disease Rating Scale: hand clasping, finger tapping, foot, leg agility, chair rising and hand pronation. Outcomes included mean timing and range of motion across movement repetitions.

RESULTS

The Kinect measured timing of movement repetitions very accurately (low bias, 95% limits of agreement <10% of the group mean, ICCs >0.9 and Pearson's r>0.9). However, the Kinect had varied success measuring spatial characteristics, ranging from excellent for gross movements such as sit-to-stand (ICC=.989) to very poor for fine movement such as hand clasping (ICC=.012). Despite this, results from the Kinect related strongly to those obtained with the Vicon system (Pearson's r>0.8) for most movements.

CONCLUSIONS

The Kinect can accurately measure timing and gross spatial characteristics of clinically relevant movements but not with the same spatial accuracy for smaller movements, such as hand clasping.

A multivariate model for the meta-analysis of study level survival data at multiple times

Motivated by our meta-analytic dataset involving survival rates after treatment for critical leg ischemia, we develop and apply a new multivariate model for the meta-analysis of study level survival data at multiple times. Our data set involves 50 studies that provide mortality rates at up to seven time points, which we model simultaneously, and we compare the results to those obtained from standard methodologies. Our method uses exact binomial within-study distributions and enforces the constraints that both the study specific and the overall mortality rates must not decrease over time. We directly model the probabilities of mortality at each time point, which are the quantities of primary clinical interest. We also present I² statistics that quantify the impact of the between-study heterogeneity, which is very considerable in our data set. © 2014 The Authors. Research Synthesis Methods published by John Wiley & Sons, Ltd.

Mini-probe ultrasonography for the staging of colon cancer: a systematic review and meta-analysis

AIM

With an increasing array of treatment modalities available for colon cancer, it is increasingly important to stage tumours accurately to allocate the appropriate management. This study evaluated the accuracy of mini-probe endoscopic ultrasound (EUS) in assigning clinical stage to colon cancer.

METHOD

An electronic search was performed in January 2013 using the Embase, MEDLINE and Cochrane databases. This was supplemented by a hand search of published abstracts from scientific meetings. Trials evaluating the accuracy of the mini-probe EUS compared with histopathological grade in determining the clinical stage of colon cancer were included in this pooled analysis. The main outcome measures included accuracy, sensitivity and specificity for T and N staging.

RESULTS

Ten studies were identified which compared the mini-probe EUS staging of 642 colon or rectal cancers with the histopathological specimen. The pooled sensitivity and specificity for staging were 0.91 and 0.98 for T1 tumours, 0.78 and 0.94 for T2 tumours, 0.97 and 0.90 for T3/T4 tumours and 0.63 and 0.82 for nodal staging. Eight per cent of T1/T2 tumours were upstaged to T3/T4 tumours and 5% of T3/T4 tumours were downstaged.

CONCLUSION

Mini-probe EUS is highly effective for assigning clinical stage in colon cancer and in identifying patients who may be suitable for nonsurgical treatment including neoadjuvant chemotherapy or endoscopic resection.

Indirect effects of a fungal entomopathogen, Lecanicillium lecanii (Hypocreales: Clavicipitaceae), on a coffee agroecosystem ant community

Fungal entomopathogens are widely distributed across natural and managed systems, with numerous host species and likely a wide range of community impacts. While the potential for fungal pathogens to provide biological control has been explored in some detail, less is known about their community interactions. Here we investigate the effects of fungal epizootics of the entomopathogen Lecanicillium lecanii (Zimmerman) on a keystone mutualism between Azteca instabilis (F. Smith), a dominant arboreal ant, and the green coffee scale (Coccus viridis Green), as well as broader impacts on a coffee agroecosystem ant community. We hypothesized that seasonal epizootics cause shifts in the foraging ranges of A. instabilis as the ants adapt to the loss of the resource. We further hypothesized that the magnitude of these shifts depends on the availability of alternate resources located in neighboring shade trees. To test these hypotheses, we induced an epizootic in experimental sites, which were compared with control sites. Surveys of ant activity were undertaken pre- and post-epizootic. We found a decrease in foraging activity of A. instabilis and increase in activity of other ant species in the experimental sites post-epizootic. The decrease in abundance of A. instabilis foragers was greater on plants in which an epizootic was induced than in other plants. This relationship was modified by shade tree density where higher shade tree density was associated with larger decreases in A. intabilis foraging activity in coffee plants. These results demonstrate the potential for fungal entomopathogens to influence the structure and diversity of ecological communities.