Summary of findings 1. Summary of findings table ‐ Collaborative care compared to usual care for severe mental illness.

Collaborative care compared to usual care for severe mental illness
Patient or population: severe mental illness Setting: participants living in the community (including in independent living facilities or supported housing) Intervention: collaborative care Comparison: usual care
Outcomes	Anticipated absolute effects* (95% CI)		Relative effect (95% CI)	№ of participants (studies)	Certainty of the evidence (GRADE)	Comments
	Risk with usual care	Risk with collaborative care
Quality of life: average change in mental health component (proxy for binary quality of life) assessed with: SF‐12/WHOQOL‐BREF follow‐up: 12 months	‐	SMD 0.03 SD higher (0.26 lower to 0.32 higher)	‐	227 (3 RCTs)	⊕⊝⊝⊝ Very lowa,b,c	Very low‐certainty evidence did not show a difference between collaborative care and standard care in the mental health component of quality of life at 12 months.
Mental state: clinically important change (binary) assessed with: PANSS follow‐up: 12 months	512 per 1000	507 per 1000 (394 to 655)	RR 0.99 (0.77 to 1.28)	253 (1 RCT)	⊕⊕⊝⊝ Lowc,d	Low‐certainty evidence did not show a difference between collaborative care and standard care in mental state at 12 months.
Psychiatric hospital admissions assessed with: number of participants admitted to hospital follow‐up: 12 months	12 per 1000	60 per 1000 (8 to 460)	RR 5.15 (0.67 to 39.57)	253 (1 RCT)	⊕⊕⊝⊝ Lowc,d,e	Low‐certainty evidence did not show a difference between collaborative care and standard care in psychiatric hospital admissions at 12 months.
Quality of life: average change in physical health component (proxy for physical health) assessed with: SF‐12/WHOQOL‐BREF follow‐up: 12 months	‐	SMD 0.08 SD higher (0.18 lower to 0.33 higher)	‐	237 (3 RCTs)	⊕⊝⊝⊝ Very lowa,f	Very low‐certainty evidence did not show a difference between collaborative care and standard care in the physical health component of quality of life (proxy for physical health) at 12 months.
Disability (proxy for social functioning) assessed with: IDEAS follow‐up: 12 months	326 per 1000	449 per 1000 (316 to 635)	RR 1.38 (0.97 to 1.95)	253 (1 RCT)	⊕⊕⊝⊝ Lowd,g	Low‐certainty evidence showed some evidence of a difference between collaborative care and standard care in disability (proxy for improved social functioning) at 12 months; more participants receiving collaborative care improved.
Personal recovery ‐ not reported	‐	‐	‐	‐	‐	There is no evidence regarding the effect of collaborative care on personal recovery.
Experience of care/satisfaction ‐ not reported	‐	‐	‐	‐	‐	There is no evidence regarding the effect of collaborative care on satisfaction/personal experience of care.
*The risk in the intervention group (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; SMD: standardised mean difference
GRADE Working Group grades of evidence High 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.
See interactive version of this table: https://gdt.gradepro.org/presentations/#/isof/isof_question_revman_web_430621846341005525.

^a Downgraded two levels due to risk of bias: in two studies this outcome was rated as some concerns of risk of bias; in one study this outcome was rated as high risk of bias.
^b There is a heterogeneity of direction of effect across studies reporting this outcome. However, due to overlapping confidence intervals and low I2 we have not downgraded the certainty of evidence in relation to inconsistency.
^c Downgraded one level for indirectness. The interventions used in this study did not utilise Gunn's elements of collaborative care, although they were described by the study authors as collaborative care interventions. 
^d Downgraded one level for imprecision. This was based on considering a range of scenarios with varying control group rates and target relative risk reductions, the most extreme of which pertains to the assumption of a control group rate of 50% and a target relative risk reduction of 30%, which requires a total of 338 participants in order to achieve 80% power at the 5% significance level. The number of participants required for precision was not met in relation to this outcome.
^e GRADE Handbook guidance recommends upgrading the certainty of evidence where the risk ratio exceeds 5.0. However, we have chosen not to upgrade the certainty of evidence in relation to this outcome due to the small numbers of observed events (particularly in the control arm) and therefore the substantial uncertainty of the point estimate. 
^f Downgraded one level for indirectness. The intervention used in this study did not utilise Gunn's elements of collaborative care, although it was described by the study authors as a collaborative care intervention. Additionally we are utilising quality of life (physical health domain) as a proxy for physical health. 
^g Downgraded one level for indirectness. The intervention used in this study did not utilise Gunn's elements of collaborative care, although it was described by the study authors as a collaborative care intervention. Additionally we are utilising disability as a proxy for social functioning.