Latent class analysis identification of syndromes in Alzheimer's disease: A Bayesian approach

Latent variable models have been used extensively in the social sciences. In this work a latent class analysis is used to identify syndromes within Alzheimer's disease. The fitting of the model is done in a Bayesian framework, and this is examined in detail here. In particular, the label switching problem is identified, and solutions presented. Graphical summaries of the posterior distribution are included

Trust the patient not the doctor: the determinants of quality of life in cervical dystonia

Background: Mood disorder is common in cervical dystonia and can impact on quality of life. It often precedes the onset of cervical dystonia and does not improve with botulinum toxin therapy. Objective: To assess health-related quality of life in relation to mood disorder and measures of severity, disability and pain, in cervical dystonia patients receiving botulinum toxin therapy. Methods: In a single-center, University Hospital movement disorders clinic, we conducted a comprehensive, cross-sectional study of disease severity, non-motor symptoms, mood and health-related quality of life in patients with cervical dystonia receiving botulinum toxin therapy using TWSTRS-2 for pain, severity and disability; Beck Anxiety Inventory and Beck Depression Inventory. We assessed all variables in relation to health-related quality of life assessed by Cervical Dystonia Impact Profile-58 and the Euro-QoL Utility Index. Results: In 201 patients (136 women), mean age 61.5 years, significant determinants of impaired health related quality of life were: being a woman, reporting a history of anxiety or depression, prevalent pain, disability, anxiety and/or depression but not physician-assessed disease severity. Conclusion: Patient-reported measures of pain, disability and, most markedly, mood disorder, are significant factors affecting quality of life; these were totally unrelated to the neurologist-rated measure of disease severity. Mood disorders, the predominant predictor of quality of life, were not addressed in the botulinum toxin clinic

The use of continuous data versus binary data in MTC models: a case study in rheumatoid arthritis.

Estimates of relative efficacy between alternative treatments are crucial for decision making in health care. When sufficient head to head evidence is not available Bayesian mixed treatment comparison models provide a powerful methodology to obtain such estimates. While models can be fit to a broad range of efficacy measures, this paper illustrates the advantages of using continuous outcome measures compared to binary outcome measures

Equine rhinitis a virus infection in thoroughbred racehorses—A putative role in poor performance?

The aim of this study was to identify respiratory viruses circulating amongst elite racehorses in a training yard by serological testing of serial samples and to determine their impact on health status and ability to race. A six-month longitudinal study was conducted in 30 Thoroughbred racehorses (21 two-year-olds, five three-year-olds and four four-year-olds) during the Flat racing season. Sera were tested for the presence of antibodies against equine herpesvirus 1 and 4 (EHV-1 and EHV-4) and equine rhinitis viruses A and B (ERAV and ERBV) by complement fixation (CF) and equine arteritis virus (EAV) by ELISA. Antibodies against equine influenza (EI) were measured by haemagglutination inhibition (HI). Only ERAV was circulating in the yard throughout the six-month study period. Seroconversion to ERAV frequently correlated with clinical respiratory disease and was significantly associated with subsequent failure to race (p = 0.0009). Over 55% of the two-year-olds in the study seroconverted to ERAV in May and June. In contrast, only one seroconversion to ERAV was observed in the older horses. They remained free of any signs of respiratory disease and raced successfully throughout the study period. The importance of ERAV as a contributory factor in the interruption of training programmes for young horses may be underestimated

Sleep apnoea and its relationship with cardiovascular, pulmonary, metabolic and other morbidities.

Sleep apnoea (OSAS) is a multisystem disorder. There is a high prevalence of cardiovascular and metabolic morbidities in patients investigated for sleep apnoea. We aim to evaluate any association between cardiovascular, metabolic and pulmonary co morbidities in patients investigated for OSAS and whether clinical findings based on Epworth sleep score (ESS) and snoring helps in diagnosing sleep apnoea. 258 consecutive patients who were electively admitted for sleep assessment in Peamount Hospital, Dublin from Sept 2009 to Aug 2011 were retrospectively reviewed. 139/258 were diagnosed as OSAS. Cardiovascular, metabolic and pulmonary co morbidities were 46.12%, 37.2% and 29% respectively. There is no correlation found between ESS, Snoring with Apnoea Hypopnoea Index in OSAS group. Screening for OSAS should be considered in patients with certain cardiovascular and metabolic disorders. PSG is so far considered the gold standard investigation to diagnose OSAS and better clinical evaluating tools need to be formulated

Percutaneous vascular interventions for acute ischaemic stroke.

Most disabling strokes are due to blockage of a large artery in the brain by a blood clot. Prompt removal of the clot with intra-arterial thrombolytic drugs or mechanical devices, or both, can restore blood flow before major brain damage has occurred, leading to improved recovery. However, these so-called percutaneous vascular interventions can cause bleeding in the brain

Mood disorder affects age at onset of adult-onset cervical dystonia

Mood disorder is common in cervical dystonia, affects quality of life and may precede the onset of the dystonia. There is controversy as to whether mood disorder is part of the primary process or secondary to the disability. We assessed the characteristics of cervical dystonia patients in relation to a past history of mood disorder. Methods: At a University Hospital clinic, in all consenting patients with cervical dystonia, we uniformly collected demographic data, medical history, and prospectively, measures of prevalent mood disorder. Results: In 193 patients (128 women and 65 men) mean age at onset was 43.9 years and mean duration of cervical dystonia was 17.5 years. Men had earlier age at onset of cervical dystonia than women (p=0.0037). A history of a mood disorder was reported in 53/128 (41%) women with a significantly earlier median age at onset of cervical dystonia (42 years) than 75/128 (59%) women with no history of mood disorder (48 years) (p = 0.005); 33 (26%) women with mood disorder prior to dystonia also had an earlier age at onset of dystonia than the 75 without such a history (p = 0.0154). A history of mood disorder was more common in women (41%) than men (31%); 54/128 (42%) women and 21/65 (32%) men had current mood disorder symptoms. Conclusions: In our cervical dystonia clinic population significant differences in the age at onset in women with, and without, a history of mood disorder strongly indicates that anxiety and depression are primary non-motor (and premotor) symptoms of cervical dystonia

What information is used in treatment decision aids? A systematic review of the types of evidence populating health decision aids

Background: Patient decision aids (DAs) are support tools designed to provide patients with relevant information to help them make informed decisions about their healthcare.  While DAs can be effective in improving patient knowledge and decision quality, it is unknown what types of information and evidence are used to populate such decision tools. Methods: Systematic methods were used to identify and appraise the relevant literature and patient DAs published between 2006-2015. Six databases (Academic Search Complete, AMED, CINAHL, Biomedical Reference Collection, General Sciences and MEDLINE) and reference list searching were used. Articles evaluating the effectiveness of the DAs were appraised using the Cochrane Risk of Bias tool. The content, quality and sources of evidence in the decision aids were evaluated using the IPDASi-SF and a novel classification system. Findings were synthesised and a narrative analysis was performed on the results. Results: Thirteen studies representing ten DAs met the inclusion criteria. The IPDASI-SF score ranged from 9 to 16 indicating many of the studies met the majority of quality criteria. Sources of evidence were described but reports were sometimes generic or missing important information. The majority of DAs incorporated high quality research evidence including systematic reviews and meta-analyses. Patient and practice evidence was less commonly employed, with only a third of included DAs using these to populate decision aid content. The quality of practice and patient evidence ranged from high to low. Contextual factors were addressed across all DAs to varying degrees and covered a range of factors. Conclusions: This is an initial study examining the information and evidence used to populate DAs. While research evidence and contextual factors are well represented in included DAs, consideration should be given to incorporating high quality information representing all four pillars of evidence based practice when developing DAs. Further, patient and expert practice evidence should be acquired rigorously, DAs should report the means by which such evidence is obtained with citations clearly provided

A frailty instrument for primary care: findings from the Survey of Health, Ageing and Retirement in Europe (SHARE).

Background: A frailty paradigm would be useful in primary care to identify older people at risk, but appropriate metrics at that level are lacking. We created and validated a simple instrument for frailty screening in Europeans aged ≥50. Our study is based on the first wave of the Survey of Health, Ageing and Retirement in Europe (SHARE, http://www.share-project.org), a large population-based survey conducted in 2004-2005 in twelve Europea

Survival of patients discharged to long term care

Data on the life expectancy of elderly people in long term care facilities will be important for effective service planning and monitoring quality of care. To date there are no such data from an Irish perspective. A random sample of patients discharged to long term care between Jan 1st 1997 and December 31st 2003 from a single Dublin hospital was studied. Death by January 1st 2005 was ascertained through the register of births deaths and marriage. Median survival was calculated and factors associated with mortality were determined in a logistic regression. Mean (sd) age was 82 (11) years and 61 (29%) were female. Median survival was 30.3 (95%CI 22.4-45.0) months (mean Irish life expectancy at this age is about 78 months). Three factors were independently associated with death by 2 years: age (Odds ratio 1.11 [95%CI 1.05-1.17, F ratio 15.1, p=0.0001] per year), male gender (Odds ratio 1.52 [95%CI 1.05-3.68, F ratio 5.2, p=0.024]) and discharge to continuing care (Odds ratio 1.96 [1.05-3.68, F ratio 4.4, p=0.037]). These results (which are the first such Irish data) show that patients discharged to long term care are a frail group with a reduced life expectancy. Encouragingly survival for this cohort (25% at 1 year) was similar to that seen in other countries. Data on nursing home survival will allow more accurate planning of long term residential services and help monitor quality of care