Table 2 SIGN quality ratings of included studies

Arving et al., 2014 [32*] (RCT – Arving et al., 2007) [34]

Bennell et al., 2016 [35*]

Bogosian et al., 2015 [36*]

Small sample size of 40 may limit confidence.

Bonin et al., 2014 [37*] (RCT – Swift et al., 2012) [38]

Camacho et al., 2016 [39*] (RCT - Coventry et al., 2015 [40])

Chatterton et al., 2016 [41*] (RCT – Chambers et al., 2014) [42]

Comparison of 2 interventions, no control/ TAU

Chernyak et al., 2014 [43*] (RCT – Sattel et al., 2012) [44]

De Boer et al., 2014 [45*]

Small sample size with signficant drop out rates, therefore underpowered to detect no difference, which was the study’s hypothesis

Goossens et al., 2015 [46] (RCT – Leeuw et al., 2008) [47]

Small sample size and therefore likely underpowered to detect differences between two active treatments

Hedman-Lagerof et al., 2019 [17*] (RCT - Hedman-Lagerlof et al., 2018) [48]

Herman et al., 2017 [49] (RCT – Cherkin et al., 2016) [50]

Note that MBSR experimental group received an additional six hours of treatment (one day retreat) compared to the active control

Hersey et al., 2012 [51*]

Humphreys et al., 2013 [52*] (RCT - Lincoln et al., 2011) [53]

Humphreys et al., 2015 [54*] (RCT – Thomas et al., 2013 [55*, 56])

Ismail et al., 2018 [57*]

Training did not change nurses skills beyond the proficiency of those offering standard care on competency measures so limited differences between control and intervention.

Jansen et al., 2017 [58*] (RCT – Krebber et al., 2016) [59]

Johanssen et al., 2017 [60*] (RCT- Johanssen et al., 2016) [61]

Economic analysis based on assumption of 5-20 year survival after treatment

Kemani et al., 2015 [62*]

Small sample size may limit confidence

Ladapo et al., 2012 [63*] (RCT - Davidson et al., 2010 [64])

Larsen et al., 2016 [65*] (RCT – Larsen et al., 2014) [66]

Lengacher et al., 2015 [67*] (RCT – Lengacher et al., 2009) [68]

Luciano et al., 2013 [69*] (RCT – Luciano et al., 2011) [70]

Luciano et al., 2014 [71*]

Luciano et al., 2017 [72*]

Maes et al., 2014 [73*] (RCT – Cima et al., 2012) [74]

Mejia et al., 2014 [75*] (RCT - Cockayne et al., 2014) [76]

Mewes et al., 2015 [77*] (RCT – Duijts et al., 2012) [78]

Mosweu et al., 2017 [79*] (RCT - Moss-Morris et al., 2012) [80]

Small sample size may limit confidence.

Nobis et al., 2018 [81*] (RCT – Nobis et al., 2015) [82]

Norton et al., 2015 [83*] (RCT – Lamb et al., 2010 [84])

Parry et al., 2012 [85*]

Perri et al., 2014 [86*]

High quality study. Only rural population analysed.

Prioli et al., 2017 [87*] (RCT – Monti et al., 2013) [88]

Rolving et al., 2016 [89*] (RCT – Rolving et al., 2015) [90]

Schroder et al., 2017 [91*] (RCT - Schroder et al., 2012) [92]

Thiart et al., 2016 [93*]

Thomas et al., 2013 [55*, 56]

Tyrer et al., 2014 [94*]

Tyrer et al., 2017 [95*]

Small N of 34 in each arm. Type of training, supervision, and protocol adherence monitoring not outlined in the paper.

Van der Aa et al., 2017 [96*]

Van der Spek et al., 2018 [97*] (RCT - van der Spek et al., 2017) [98]

Van Eeden et al., 2015 [99*] (RCT protocol – Kootker et al., 2012) [100]

Van Ravesteijn et al., 2013a [101*] (RCT - Van Ravesteijn et al., 2013b) [102]

Visser et al., 2015 [103*] (RCT – Zonneveld et al., 2012) [104]

Watanabe et al., 2015 [15] (RCT – Watanabe et al., 2011) [105]

Zhang and Fu et al., 2016 [106*]

As well as 3 randomised groups, study included eligible patients declined intervention but agreed to give feedback