“…As shown in table 1, approximately 10 (43.48%) studies had no comparison groups (Bughi et al, 2009;Hassed et al, 2008;Hassed et al, 2009;Lee & Graham, 2001;Klamen, 1997;Redwood & Polak, 2007;Simard & Henry, 2009;;Soskis, 1978;Zeitlin et al, 2000;) and 13 (56.52%) studies had comparison groups (Finkelstein et al, 2007;Holtzworth-Munroe et al, 1985;Jain et al, 2007;Kelly et al, 1982;Kiecolt-Glaser et al, 1986;MacLaughin et al, 2010;Michie & Sandhu, 1994;Mitchell et al, 1983;Nathan et al, 1987;Rosenzweig et al, 2003;Shapiro et al, 1998;Whitehouse et al, 1996;Yusoff, 2011). Out of 13, about seven studies randomly assigned participants to control and intervention groups (Holtzworth-Munroe et al, 1985;Jain et al, 2007;Kiecolt-Glaser et al, 1986;Mitchell et al, 1983;Nathan et al, 1987;Shapiro et al, 1998;Whitehouse et al, 1996).…”