“…In total, 8 studies reported loneliness means (Ahrens et al, n.d.; Fanari and Segrin, 2021 ; Groarke et al, 2021 ; Lee et al, 2020 ; Rumas et al, 2021 ; Saidur et al, 2021 ; Stevenson and Wakefield, 2021 ; van Breen et al, 2021 ). One study of reported the mean of loneliness in 23 countries( van Breen et al, 2021 ). Five studies reported the means in two waves, one paper reported it in three waves, one study reported the means in 8 waves, and one paper reported it in four waves (the paper with a report in 23 countries; each country was included in the analysis, separately).…”