Table 1.
Incidence of Delirium and Its Outcomes*
| Population | Prevalence (range) †, Incidence (range) | Outcomes (Adjusted Relative Risks‡, RR) |
|---|---|---|
| Surgical | ||
| Cardiac | - - - 11%-46% |
Cognitive Dysfunction (RR=1.7) Functional Decline (RR = 1.9) |
| Non-Cardiac | - - - 13% - 50% |
Functional Decline (RR = 2.1) Cognitive Dysfunction (RR = 1.6) |
| Orthopedic | 17% 12% – 51% |
Dementia/ Cognitive Dysfunction (RR = 6.4 – 41.2) Institutionalization (RR = 5.6) |
| Medical | ||
| General Medical | 18% – 35% 11% – 14% |
Mortality (RR= 1.5 –1.6) Functional decline (RR = 1.5) |
| Geriatric Units | 25% 20% – 29% |
Falls (RR = 1.3) Mortality (RR = 1.9) Institutionalization (RR = 2.5) |
| Intensive Care | 7%–50% 19% – 82% |
Mortality (RR = 1.4 – 13.0) Longer LOS (RR = 1.4 – 2.1) Extended Mechanical Ventilation (RR = 8.6) |
| Stroke | - - - 10% - 27% |
Mortality (RR = 2.0) Any of 3 outcomes: increased LOS, functional impairment, or death (RR= 2.1) |
| Dementia | 18% 56% |
Cognitive Decline (RR = 1.6–3.1) Institutionalization (RR = 9.3) Mortality (RR = 5.4) |
| Palliative Care/Cancer | - - - 47% |
- - - |
| Nursing Home/Postacute Care | 14% 20% - 22% |
Mortality (RR = 4.9) |
| Emergency Department | 8% - 17% - - - |
Mortality (RR = 1.7) |
LOS=length of stay; RR=relative risk. See Appendix Tables 4–5 for complete list of references and further details on all articles. All values in this table were derived from selected articles meeting the following criteria: sample size of ≥100 or more; satisfaction of STROBE criteria for setting, participants, measurement and statistical methods; and using a validated delirium instrument. An additional inclusion criterion for incidence studies was serial delirium assessments at no more than 3 day intervals by trained research staff or clinicians.
The sum of both prevalence and incidence yields the overall occurrence rates of delirium in each setting.
Adjusted relative risks were derived from studies that provided adjustment for at least one covariable.