Mortality rates and medical care expenditure Dutch seniors significantly higher in winter

The mortality rates of Dutch seniors differ significantly between the seasons, and are 21% higher in the winter compared to the summer. Medical care expenditure (MCE) rises with 13% from the summer to the winter. Herbert Rolden, researcher at Leyden Academy on Vitality and Ageing, concludes this based on research into seasonal variation in mortality, MCE and institutionalization in over 60,000 senior citizens in The Netherlands. The research was published in international peer-reviewed publication PLOS ONE.

The mortality rates of older people change with the seasons. However, it has not been properly investigated whether the seasons affect MCE and institutionalization. Seasonal variation in MCE is plausible, as health care costs rise exponentially before death. On the other hand, not all diseases are fatal. For instance, in cold months there are relatively more heart attacks and hip fractures, resulting in an increase in MCE and nursing home admissions.

In the study, Rolden and his fellow researchers found that the mortality risk and MCE of people over 65 years old in the working area of a regional Dutch health insurer are highest in the autumn and winter. If the search results are extrapolated to the entire population of senior citizens in Netherlands, this implies that there are annually about 7,000 more elderly deaths in autumn and winter, and that MCE in these seasons is more than 600 million euros higher than in spring and summer.

Possible causes

The seasonal variation in mortality, MCE and institutionalization in older people can have multiple causes. Most obvious are climate conditions such as temperature, humidity, air pressure and the presence or absence of sunlight. Rolden: "During extremely hot summer days, there is often a lot of media attention for the risks to elderly people. Our research suggests that the cold months are more dangerous. However, temperature cannot be the only reason for the discovered association. For instance, we see that the seasonal variation among residents of nursing homes, who stay inside most of the time, is similar to the elderly who live at home. " External factors can also play a role in the seasonal variation, such as air pollution or the flu virus, which is more common in winter: "Further research is needed on the precise impact that these factors have on mortality and disease among Dutch elderly."

The research ‘
Seasonal variation in mortality, medical care expenditure and institutionalization in older people: Evidence from a Dutch cohort of older health insurance clients‘ by Herbert J.A. Rolden, Jos H.T. Rohling, David van Bodegom and Rudi G.J. Westendorp has been published in international, peer-reviewed, open-access, online publication PLOS ONE on Monday 16 November 2015: