Table 1. Details of included studies.

Authors	Year	Country	Participants					QA
			Who	N	Age (mean)	MM	Recruited from
Tran, Barnes et al.[24]	2015	34 diffe-rent	Adult participants with at least one chronic condition	1053	35–57 (47)	63%	34 different mainly Western countries through the internet	27
Sav et al.[25]	2013	Australia	People with chronic conditions and their unpaid carers	85	16–83 (57)	88%	Four culturally and geographically diverse districts	28
Noël et al.[26]	2004	US	Patients having two or more chronic illnesses	60	30–89	100%	Eight primary care clinics within the Veterans Health Administration—Four in large urban metropolitan settings, four in rural communities	24,5
Eton et al.[27]	2015	US	1st round: Patients with one or more chronic condition and complex self-care 2nd round: Diabetic, heart failure and kidney failure patients	50	25–85 (56)	98%	Mayo Clinic Rochester (specialized treatment) and Hennepin County Medical Center Minneapolis (large safety-net hospital)	28,5
Ridgeway et al. [28]								28,5
Gallacher et al.[29]	2011	UK	Patients with chronic heart failure and comorbidities	47	45–88 (73)	100%	Primary care	25
Kahn et al.[30]	2014	US	Low income US primary care patients with chronic kidney disease	34	(62)	>94%	Two primary care (safety net) practices in Buffalo, a low-income African-American area which constitutes a”Health Professional Shortage Area”	26,5
Tran, Montory et al.[31]	2012	France	Patients with at least one chronic condition	22	53–76 (70)	NA	Department of internal medicine of a French hospital and a general practitioner clinic in Paris	27,5
Bayliss et al.[32]	2003	US	Adults with two or more self-reported conditions	16	31–70+ (61)	100%	Urban family practices in the Carenet network (serving disadvantaged populations) in Denver, Colorado	26

MM = Proportion of participants with multimorbidity in %. QA = Quality assessment score. Maximum score 29 [23].