Table 3

Characteristics of included studies

Author(s) (year)	Purpose of study	Country	Methods	Quality score (%)	Setting	Participants	Sample size				Results or outcomes
Author(s) (year)	Purpose of study	Country	Methods	Quality score (%)	Setting	Participants	PLWCI	CP	CW	Total	Results or outcomes
Clarke (2004)40	To influence SDM	Australia 3	Qualitative interviews and observations	75	Extended care	PLWD and CW	13		13	26	Four positive and five negative carer characteristics were identified that impacted on decision-making.
Fetherstonhaugh et al (2013)43	To understand SDM		Qualitative interviews	80	Home	PLWD		6		6	Three pairs of conflicting attributes identified: (1) subtle support versus taking over; (2) hanging on versus letting go; and (3) being central versus being excluded
Milte et al (2015)49	To understand SDM		Quantitative observed family meetings	83	Intermediate care	Older people, CPs and HCPs	51	51	2	104	Geriatricians’ performance in SDM was mixed; above baseline skill level in some areas and below in others. Longer meetings=better SDM by clinicians.
Tyrrell et al (2006)12	To measure SDM	France 1	Qualitative interviews	83	Home	PLWD and care partner	21	21		42	PLWD did not feel listened to and had limited freedom to participate in decision-making. Carers were more satisfied than PLWD.
Span (2016)52	To facilitate SDM	Holland 1	Qualitative interviews, focus groups, specialist consultation and workshops	75	Home	PLWD, CPs and HCPs				84	18 topics of problems and eight topics addressing decision-making emerged. Only eight topics were identified by both PLWD and care partners.
Smebye et al (2012)11	To understand SDM	Norway 1	Mixed methods interviews and observations	95	Home and extended care	PLWD, CPs and HCPs	10	10	10	30	Care staff do not base mental competence on standardised tests; values and relationships as important as logic. New decision-making categories emerged. Autonomous decision-making occurred but SDM was most typical.
Ferm et al (2010)42	To facilitate SDM	Sweden 2	Mixed methods interviews	95	Home	PLWD HD	5			5	Talking Mats increased communication but effectiveness depended on conversation topic.
Kjellberg (2002)47	To understand SDM	Sweden 2	Qualitative interviews	70	Home, extended and day care	People living with LD	23			23	Of the nine theoretical combinations of levels of decision-making identified, only five emerged.
Bailey et al (2011)38	To measure SDM	UK 5	Quantitative electronic decision-making tasks and questionnaire	79	Day services	People living with LD	24			24	Decision-making task performances improved when using the visual aid designed. Although not sustained without the visual aid the improvement was regained when the aid was reintroduced.
Boyle (2014)39	To measure SDM		Qualitative creative interaction, observation and interviews	85	Home	PLWD and CPs	5	5		10	Identified that agency related to SDM is demonstrated within six relevant themes.
Godwin (2014)44	To facilitate SDM		Mixed methods consultation	90	Extended care	PLWD	34		42	76	Residents were able to demonstrate preferences relating to their environment and enjoyed the consultation process.
Murphy and Oliver (2013)50	To facilitate SDM		Mixed methods researcher-facilitated discussion	65	Home	PLWD and CPs	18	18		18	Participants felt more involved in discussions when using Talking Mats although feeling of involvement was significantly higher for carers than for PLWD.
Samsi and Manthorpe (2013)51	To understand SDM		Qualitative interviews	90	Home	PLWD and CPs	15	15		30	Three underlying principles identified if decision-making is negotiated and how dynamics changed: importance of autonomy, decision-specific approach and made on someone’s behalf described as ‘best interest'.
Feinberg and Whitlatch (2002)41	To measure SDM	USA 6	Quantitative interviews	80	Home	PLWD and CPs	51	51		102	Lower income and carer financial strain correlated with how well the PLWD felt their carer knew their care wishes (more financial strain=less understanding)
Hirschman et al (2005)45	To understand SDM		Interviews	70	Home and extended care	PLWD and CPs	48	48		96	Spousal carer— wife (90%) versus husband (21%). Half care partners of PLWD formally ‘lacking capacity’ still involved them in decision-making.
Horton-Deutsch et al (2007)46	To understand SDM		Mixed methods interviews	85	Home	PLWD and CPs	20	20		40	75% PLWD had always involved HCP and/or spouse in decisions. 50% PLWD decisions changed 80% in line with CP wishes. Only 55% of dyads congruent throughout. 20% PLWD maintained choice.
Menne et al (2008)48	To measure SDM		Quantitative interviews Demographic information including MMSE scores Capacity evaluation	100	Home	PLWD and CPs	217	217		434	PLWD consistently considered themselves to have more involvement in decision-making than their care partners perceived them to be.
Menne and Whitlatch (2007)23	To measure SDM		Quantitative secondary data analysis	86	Home	PLWD and CPs	215	215		430	Greater decision-making involvement associated with younger, female, educated, non-spousal CP, fewer months since diagnosis, fewer problems with ADLs, fewer depressive symptoms, and place more importance on autonomy/self-identity.
Whitlatch et al (2005)53	To measure SDM		Mixed methods interviews	100	Home	PLWD and CPs	111	111		222	Values and preferences correlated with CP perceptions of PLWD quality of life and involvement in decision-making and with PLWD perception of own quality of life and involvement in decision-making.

ADL, activities of daily living; CP, care partner; CW, care worker; HCP, healthcare professional; HD, Huntington’s disease; LD, learning disability; MMSE, Mini-Mental State Examination; PLWCI, person living with cognitive impairment; PLWD, person living with dementia; SDM, shared decision-making.