We observed greater heterogeneity in some risk factors; old age, illness severity (APACHE II), length of hospitalisation, low albumin, visual impairment and urinary catheterisation and less heterogeneity for male sex, dementia and polypharmacy (for forest plots, seesupplementary data in Age and Ageing online, Appendix 2, Figure 1–9). Here, ALB is linked to dementia.