Study (timing of outcome measurement post baseline measurement)

WHOQoL

CANSAS

EQ-5D

UCLA 3-item Loneliness Scale

K10

HADS

WEMWBS

SWEMWBS

PAM

RCFS

MWM-OA

ULS-8

Campaign to End Loneliness Measurement Tool

Aggar 2019 [20] (6 months)

Significant improvement in overall health satisfaction, physical and psychological QoL

Slight increases but no significant changes in met and unmet health and welfare needs

Significant improvement in self-reported health status

Slight declines but no significant changes in self-rated loneliness

No significant changes in distress

Carnes 2017 [21] (8 months)

No significant changes in depression or anxiety

Elston 2019 [22] (3 months)

Significant improvement in well-being

Significant improvement in patient activation

Significant improvement in frailty

Giebel 2021 [23] (3 and 6 months)

Significant improvement in well-being

Pescheny 2019 [24] (not stated)

Thomson 2017 [25] (mid and post intervention: 5 and 10 weeks)

Significant improvement in self-rated emotions

Wakefield 2020 [26] (4 and 6 - 9 months)

Significant increase in self-reported QoL. Number of group memberships (1-item from Hayward et al., 2014) had non-significant, positive effect onQoL

Social support (4-item scale from Haslam et al., 2005) was a negative, non-significant predictor of loneliness

Woodall 2018 (not stated) [27]

Significant decrease in anxiety and depression

Significant improvement in well-being

Significant improvement in relationships and social networks