Understanding NHS hospital admissions in England: linkage of Hospital Episode Statistics to the Hertfordshire Cohort Study

Background: concern over the sustainability of the National Health Service (NHS) is often focussed on rising numbers of hospital admissions, particularly among older people. Hospital admissions are enumerated routinely by the Hospital Episode Statistics (HES) Service, but published data do not allow individual-level service use to be explored. This study linked information on Hertfordshire Cohort Study (HCS) participants with HES inpatient data, with the objective of describing patterns and predictors of admissions among individuals. Methods: 2,997 community-dwelling men and women aged 59-73 years completed a baseline HCS assessment between 1998 and 2004; HES and mortality data to 31 March 2010 were linked with the HCS database. This paper describes patterns of hospital use among the cohort at both the admission and individual person level. Results: the cohort experienced 8,741 admissions; rates were 391 per 1,000 person-years among men (95% CI: 380, 402) and 327 among women (95% CI: 316, 338), P < 0.0001 for gender difference. A total of 1,187 men (75%) and 981 women (69%) were admitted to hospital at least once; among these, median numbers of admissions were 3 in men (inter-quartile range, (IQR): 1, 6) and 2 in women (IQR: 1, 5). Forty-eight percent of those ever admitted had experienced an emergency admission and 70% had been admitted overnight. Discussion: It is possible to link routinely collected HES data with detailed information from a cohort study. Hospital admission is common among community-dwelling 'young-old' men and women. These linked datasets will facilitate research into lifecourse determinants of hospital admission and inform strategies to manage demand on the NHS.