ObjectivesWe examine the mortality of men and women within the first year after all-cause and cause-specific hospital admission to investigate whether the sex differences in mortality after hospitalisation are higher than in the corresponding general and non-hospitalised population.DesignThis is a population-based, longitudinal study with nationwide coverage. The study population was identified by linking the National Patient Register with the Central Population Register using a 5% random sample of the Danish population.SettingThe population born between 1898 and 1961, who was alive and residing in Denmark after 1977, was followed up between 1977 and 2011 with respect to hospital admissions and mortality while aged 50–79.Primary outcome measuresThe absolute sex differences in the 1-year risk of dying after all-cause and cause-specific hospital admission. The hospitalised population sex differentials were then compared with the sex differences in a general and a non-hospitalised population, randomly matched by age, sex and hospitalisation status.ResultsThe risk of dying was consistently higher for hospitalised men and women. At all ages, the absolute sex differences in mortality were largest in the hospitalised population, were smaller in the general population and were smallest in the non-hospitalised population. This pattern was consistent across all-cause admissions, and with respect to admissions for neoplasms, circulatory diseases and respiratory diseases. For all-cause hospital admissions, absolute sex differences in the 1-year risk of dying resulted in 43.8 excess male deaths per 1,000 individuals within the age range 50–79, while the levels were lower in the general and the non-hospitalised population, at levels of 13.5 and 6.6, respectively.ConclusionsThis study indicates a larger male disadvantage in mortality following hospitalisation, pointing towards an association between the health status of a population and the magnitude of the female advantage in mortality.