Comparison 1. Interventions for involving patients in decision‐making about their health care vs usual care for older patients with multi‐morbidity.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Health status: high self‐rated health (CDC 'Healthy Days Measure') at 6 months	1	41	Risk Ratio (M‐H, Random, 95% CI)	1.4 [0.36, 5.49]
2 Health status: health‐related quality of life (EQ‐5D‐5L measure) at 15 months	1	1546	Mean Difference (Random, 95% CI)	0.0 [‐0.02, 0.02]
3 Treatment burden (Multi‐morbidity Treatment Burden Questionnaire) at 15 months	1	1251	Mean Difference (Random, 95% CI)	‐0.46 [‐1.78, 0.86]
4 Patient enablement and engagement: patient activation (Patient Activation Measure) at 6 months	1	41	Mean Difference (IV, Random, 95% CI)	0.60 [‐9.23, 10.43]
5 Patient enablement and engagement: medication adherence (Morisky Medication Adherence Scale) at 6 months	1	1546	Mean Difference (Fixed, 95% CI)	0.06 [‐0.05, 0.17]
6 Patient evaluation of care/the intervention: care related to priorities (adapted question from General Practice Patient Survey) at 15 months	1	1211	Odds Ratio (Random, 95% CI)	1.85 [1.44, 2.38]
7 Carer evaluation of care: carer experience (Carer Experience Questionnaire) at 15 months	1	94	Mean Difference (Random, 95% CI)	6.51 [0.25, 12.77]
8 Resource use and cost: number of nurse consultations (review of medical records) at 15 months	1	1517	Rate Ratio (Random, 95% CI)	1.37 [1.17, 1.61]
9 Quality of care: number of indicators of high‐risk prescribing (review of medical records) at 15 months	1	1521	Rate Ratio (Random, 95% CI)	1.04 [0.87, 1.25]