Summary of findings 1. Non‐pharmacological multicomponent interventions for preventing delirium in hospitalised non‐ICU patients.

Multicomponent delirium prevention intervention compared with usual care for hospitalised adults
Patients: adults (aged 18 years and over) in hospital for any reason Settings: receiving care in general hospital settings (excluding those in intensive care or high dependency units; also known as level 3 and level 2 critical care settings) Intervention: multicomponent interventions designed to prevent delirium Comparison: usual hospital care
Outcomes No of participants (studies)	Illustrative comparative risks* (95% CI)		Relative effect  (95% CI)	Certainty of the evidence  (GRADE)	Comments
	Assumed risk Risk with usual care	Corresponding risk Risk with multicomponent intervention
Incidence of delirium during hospital admission validated diagnostic instruments1 3693 participants (14 studies)	184 per 10002	105 per 1000  (85 to 216)	RR 0.57 (0.46 to 0.71)	⨁⨁⨁◯ MODERATE3
Inpatient mortality 2640 participants (10 studies)	45 per 10002	52 per 1000 (37 to 73)	RR 1.17 (0.79 to 1.74)	⊕⊕◯◯ LOW4
New diagnosis of dementia (at any time point after randomisation) Not measured	No relevant studies	No relevant studies	No relevant studies	No relevant studies
Duration of delirium (days) (any time during hospital admission) 351 participants (6 studies)	The mean duration of delirium in the control groups ranged from 2.1 to 10.2 days	The mean duration of delirium in the intervention groups was 0.93 days shorter (2.01 days shorter to 0.14 days longer)		⊕⊕◯◯ LOW5
Delirium severity (any time during hospital admission) validated diagnostic instruments6 147 participants (5 studies)		The standardised mean severity of delirium in the intervention groups was 0.49 standard deviations lower (1.13 lower to 0.14 higher)10		⊕◯◯◯ VERY LOW7	A standardised mean severity of 0.49 standard deviations represents a moderate effect. The 95% confidence interval encompasses a very large effect and little or no effect, indicating serious imprecision.
Length of hospital admission (days) 3351 participants (10 studies)	The mean length of hospital admission in the control groups ranged from 5 to 38 days	The mean length of admission in the intervention groups was 1.30 days shorter (2.56 days shorter to 0.04 days shorter)		⨁⨁◯◯ LOW8
Discharge from hospital to new long‐term care placement 536 participants (1 study)	247 per 10002	190 per 1000 (136 to 264)	RR 0.77  (0.55 to 1.07)	⊕⊕◯◯ LOW9

* The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95%CI).
CI: Confidence interval; RR: Risk ratio;

GRADE Working Group grades of evidence
HHigh certainty: we are very confident that the true effect lies close to that of the estimate of the effect.
Moderate certainty: we are moderately confident in the effect estimate; the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different.
Low certainty: our confidence in the effect estimate is limited; the true effect may be substantially different from the estimate of the effect.
Very low certainty: we have very little confidence in the effect estimate; the true effect is likely to be substantially different from the estimate of effect.

1. Delirium was diagnosed using the CAM, DRS‐R‐98, DSM‐IV, DSM‐V criteria
2. The assumed risk is the risk in the control group
3. Downgraded one level for study limitations (high risk of performance bias due to the lack of blinding of participants and personnel in all studies (due to the nature of the intervention) and outcome assessors unblinded in 6 studies)
4. Downgraded one level for inconsistency and one level for imprecision (pooled estimate includes both no effect, appreciable benefit and appreciable harm)
5. Downgraded one level for study limitations (high risk of performance bias due to lack of blinding of participants and personnel) and one level for imprecision (Minimal important difference (MID) of 1 day assumed. 95% confidence limits around the pooled estimate of mean difference includes both ’no difference’, and the MID)
6. Delirium severity was assessed using CAM, CAM‐S, DRS‐R‐98
7. Downgraded one level for study limitations (high risk of performance bias due to lack of blinding of participants and personnel and outcome assessors unblinded in 3 studies) and two levels for serious imprecision (based on small, pooled sample size of 147 participants)
8. Downgraded one level for study limitations (high risk of performance bias due to lack of blinding of participants and personnel; outcome assessors unblinded in 4 studies) and one level for inconsistency (significant statistical heterogeneity, with I² = 91%)
9. Downgraded one level for study limitations (high risk of performance bias due to lack of blinding of participants, personnel and outcome assessors) and one level for imprecision (based on results from a single study)