Influenza-attributable deaths, Canada 1990-1999.

The number of deaths attributable to influenza is believed to be considerably higher than the number certified by vital statistics registration as due to influenza. Weekly mortality data for Canada from the 1989/1990 to the 1998/1999 influenza seasons were analysed by cause of death, age group, and place of death to estimate the impact of influenza on mortality. A Poisson regression model was found to accurately predict all-cause, as well as cause-specific mortality, as a function of influenza-certified deaths, after controlling for seasonality, and trend. Influenza-attributable deaths were calculated as predicted less baseline-predicted deaths. In summary, throughout the 1990s there were on average just under 4000 deaths attributable to influenza annually (for an influenza-attributable mortality rate of 13/100,000 persons), varying from no detectable excess mortality for the 1990/1991 influenza season, to 6000-8000 influenza-attributable deaths for the more severe influenza seasons of 1997/1998 and 1998/1999. On average, 8% (95% CI 7-10) of influenza-attributable deaths were certified as influenza, although this percentage varied from 4% to 12% from year to year. Only 15% of the influenza-attributable deaths were certified as pneumonia, and for all respiratory causes, 40%. Deaths were distributed over most causes. The weekly pattern of influenza-certified deaths was a good predictor of excess all-cause mortality.

A modification of the Guiot-Gillingham stereotaxic frame to allow of angular insertion.

A method of modification of the Guior-Gillingham Stereotaxic frame is described, which will allow of angular insertion of a leucotome or electrode. In our experience, this has prevented the complication of radiation damage and hemianopia and it also permits greater flexibility in the operative approach to structures at or near the midline.

Electrophysiologic assessment of the lower portion of the auditory pathway in the human subject. A preliminary report on auditory evoked eighth nerve and brain stem potentials including their relation to the electrocochleogram.

The electrophysiologic approaches to the assessment of electrical activity of the various portions of the human auditory pathway are reviewed. A method of detection of click evoked eighth nerve and brain stem responses with the use of surface electrodes is described. Preliminary observations in the normal subject with different stimulus parameters and in patients with unilateral deafness are presented. Simultaneous recordings of the eighth nerve and brain stem responses with the cortical evoked response and with the extratympanic electrocochleogram are described. The technique of click evoked eighth nerve and brain stem potentials offers us an additional method of objective assessment of auditory function in a human subject.