Annual variations in indoor climate in the homes of elderly persons living in Dublin, Ireland and Tromso, Norway

Abstract

Seasonal variations in mortality occur throughout Europe as well as in other parts of the world, such as Japan, China and the southern hemisphere1–6 with a higher death rate in the winter (excess winter deaths). Mortality from cardiovascular disease (CVD) accounts for the majority of the excess winter deaths (up to 70% in some countries), while up to about half of the remaining may be accounted for by increases in respiratory disease.3,7 The majority of deaths from CVD occur in the elderly. For example, in Norway, CVD, including ischaemic heart disease and cerebrovascular disease, accounts for about 46% of all causes of death. About 90% of all CVD-related deaths occur in people who are ≥65 years. Cold exposure related to winter mortality from ischaemic heart disease, cerebrovascular disease, respiratory disease, and all causes in warm and cold regions of Europe have been previously investigated in a large European Economic Community supported study.7 The main findings of this study was that mortality increased to a greater extent with a given fall in temperature in regions with warm winters, in populations with cooler homes, and among people who wore fewer clothes and were less active outdoors. Similar findings regarding excess winter mortality were found in a comparative study between Norway and the Republic of Ireland, two countries that were not investigated in the Eurowinter study.6,8 A comparison of these two countries is of interest since they are demographically similar with respect to CVD mortality, but have different climates. In 1993, the population of Norway and the Republic of Ireland was 4 312 000 and 3 563 000, respectively and in both countries mortality due to CVD, accounted for approximately the same percent of deaths (1985–93: Norway 45% and Ireland 47%.6 Seasonal variation in …