New threats from an old enemy. A physician update on pneumococcus

Pneumonia and influenza together are the sixth-leading cause of death in this country. Physicians have the tools and influence to prevent many of these deaths and significantly improve their patients' health and quality of life. There is no reason for these tools to be underused.     

Methods old and new for analyzing occupational cohort data

The person-years approach to analyzing mortality data from occupational cohorts was introduced in the midtwentieth century. It cross-classifies all observed deaths and observation times into cells, computes the number of expected deaths for each cell based on referenced mortality rates, and then examines the ratio of total number of observed deaths to total number of expected deaths (the standardized mortality ratio). The maximum likelihood method of statistical inference was developed in the early twentieth century. However, only recently has it been applied to the analysis of occupational cohort data. When so applied, it provides estimates of measures of association between exposures and disease by maximizing the probability of the observed data. This paper shows how recent developments in the use of this tool justify and extend the person-years approach. In particular, problems with the standardized mortality ratio cited in the literature are shown to result from reliance on assumptions that are inappropriate for the data at hand. Methods for testing these assumptions are described. The discussion is illustrated with examples from occupational cohort studies of lung cancer.     

Pruritus: a new look at an old problem

Pruritus, a frequent complaint heard by family physicians, is a complex physiological phenomenon mediated by histamine and other peptides. It is associated with a number of common dermatologic diseases but has significant psychological factors as well. In some patients pruritus may be an important marker of systemic disease. Diagnostic approach includes a careful physical examination of primary skin lesions and goal-directed laboratory tests. Careful skin care and oral antihistamines are basic measures to alleviate pruritus.     

Nanotechnology and the occupational physician

Nanoparticles differ from the same material at larger scale in chemical and physical properties. Evidence from studies of fibres leads to the conclusion that inhalation of nanotubes could be dangerous and should be regulated. Air pollution research has suggested that particles may be more toxic to cells at the nanoscale. At present the marketing of nanoparticles is advancing more rapidly than research into their safety and toxicology, and one serious inhalation episode has been reported in Germany from apparent use of a nanoproduct. This rapidly developing industry will make an impact on the work of occupational physicians, first in universities and small concerns but later more widely. The future safety of workers and consumers is dependent on research into hazard and risk, an area in which the UK and most other countries are dragging their feet. However, a resource, the Safety of Nanomaterials Interdisciplinary Research Consortium, has been established in the UK to assist those active in this field.