Bayesian estimation of a random effects heteroscedastic probit model

Summary Bayesian analysis is given of a random effects binary probit model that allows for heteroscedasticity. Real and simulated examples illustrate the approach and show that ignoring heteroscedasticity when it exists may lead to biased estimates and poor prediction. The computation is carried out by an efficient Markov chain Monte Carlo sampling scheme that generates the parameters in blocks. We use the Bayes factor, cross‐validation of the predictive density, the deviance information criterion and Receiver Operating Characteristic (ROC) curves for model comparison.     

To what extent does IQ 'explain' socio-economic variations in function?

Background  

The aims of this study were to examine the extent to which higher intellectual abilities protect higher socio-economic groups from functional decline and to examine whether the contribution of intellectual abilities is independent of childhood deprivation and low birth weight and other socio-economic and developmental factors in early life.     

Discordant repeat size and phenotype in Kennedy syndrome

Previous reports in the literature have described correlation of increasing repeat length with severity of the phenotype, in Kennedy syndrome. We describe male siblings with different repeat lengths, with lack of expression of the phenotype in the sibling with the longer repeat length. The phenotype was identical to motor neurone disease. There is variability of expression in Kennedy syndrome and repeat length even in siblings cannot be taken as a conclusive indicator of severity. CAG repeat length cannot be used to predict the natural history of Kennedy disease. The diagnosis of Kennedy syndrome should be considered in male patients presenting with atypical motor neurone disease.     

Symptoms of irritable bowel syndrome in a British urban community: consulters and nonconsulters.

Because the prevalence of the irritable bowel syndrome (IBS) in the general population is unknown, a questionnaire of intestinal symptoms was administered to a stratified random sample of 1058 women and 838 men. Subjects were asked if they had consulted a physician about such symptoms. One or more symptoms occurred frequently in 47% of women and 27% of men. Diagnosable IBS, defined as three or more symptoms, was present in 13% of women and 5% of men. Abdominal pain was the most common symptom, and recurrent intestinal pain was reported by 20% of women and 10% of men. All symptoms were more common in women except runny or watery stools. Most symptoms including pain were unrelated to age. Only half the people with diagnosable IBS had consulted a physician about it. The likelihood of consulting a physician was directly proportional to the number of symptoms and was similar in men and women after controlling for the number of symptoms. Of individual symptoms, the one most strongly associated with consulting was abdominal pain, especially in men. It is concluded that IBS is prevalent at all ages, especially in women, that it is nearly always painful, and that people with multiple symptoms are more likely to consult a physician.     

INTERFERONS IN ONCOLOGY

SUMMARY The interferons are natural glycoproteins secreted in response to various stimuli, including viral infection. They have antiviral, antiproliferative and immunomodulatory effects on different target cell populations. Since recombinant human interferons have become available, they have been tested in a wide range of malignancies. They are well established in the treatment of hairy cell leukaemia, chronic myelogenous leukaemia and multiple myeloma. Although they have documented activity against lymphoma, melanoma, renal cell cancer and carcinoid tumours, their role in the treatment of these tumours is less clear. In the common solid tumours, such as lung cancer and colorectal cancer, the use of interferons remains experimental. Here we will summarise their practice applications in oncology, using randomised studies where available to establish their place in multi-modality treatment. We will not discuss their use as antiviral or immunomodulating agents in viral and autoimmune diseases, multiple sclerosis or after organ transplantation.