Background: The oldest old (aged over 90 years) are the fastest growing section of the UK population. Limited data exist regarding the effect of age, location, co-morbidity and physical performance status on outcome of acute illness in this age group.
Methods: We performed a prospective study in people aged ≥ 90 years using hospital audit data in three hospitals in England and Scotland. We examined the characteristics of those admitted over three consecutive calendar months and calculated risk ratios of death and prolonged length of acute hospital stay (>7 days).
Results: A total of 419 patients were included in this study (68% female, median age 93 years). There were similarities in presentation and diagnoses, but patients in Scotland (n = 164) were more likely to be admitted from sheltered housing or nursing homes than those in England (n = 255). Patients in England were significantly less likely to be able to mobilize < 10 m (41 vs. 34%, P < 0.001) but had lower prevalence of hypertension (40 vs. 55%, P = 0.02), ischaemic heart disease (30% vs. 45%, P = 0.02) and fewer prescribed medications (median 2 vs. 3, P < 0.001). Mortality was similar for the England and Scotland centres (P = 0.98). Previously recognized risk factors for death following hospital admission and length of stay e.g. older age, higher number of co-morbidities and poor mobility were not predictive in this study.
Conclusion: The 'oldest old' should not be considered as a homogenous group and findings from single-centre studies involving this age group may not be generalizable. We found no conclusive evidence that patient-related factors predict outcome in this age group in acute medical admission settings.