Excess morbidity and mortality associated with influenza in England and Wales.

By means of a stepwise regression analysis, an estimate was made of the number of deaths and new sickness benefit claims associated with influenza in the winters of 1976--79. In the moderately widespread outbreak of 1976---76 there were 22250 estimated excess deaths, of which 19590 were in the age group 65 years and over. In the same winter there were 908000 estimated excess sickness benefit claims. The smaller outbreaks of the winters of 1976--79 were associated with between 4000 and 6000 excess deaths. An estimate of the effect of winter temperatures on mortality in the cold winter of 1978--79 gave a figure of 4500 deaths in excess of the number in the previous winter.