Table 2

Risk of bias for included studies

 Risk of bias itemsTotal score
AuthorStudy type123456789
ArmstrongRCT1011111017
BjersingRCT1011111107
BrandonRCT0111111118
BrosseauRCT1011011106
CoxRCT1111111119
DuncanRCT0111111107
FisherRCT1011011106
GusiRCT1011111118
HamdorfRCT1111011107
HinklemanRCT0111011106
IsaacsRCT1111111119
KamijoRCT0111111107
KayoRCT1011011117
LegrandRCT0011111106
MannerkorpiRCT1111011118
Moore-HarrisonRCT0011111106
MorrisonRCT0011111106
NegriRCT1011011106
PalmerRCT0111111006
ReuterRCT1111111119
RooksRCT1111111108
van UffelenRCT1011111107
CallahanPre–post0011111106
DallocchioPre–post0011111106
FantinPre–post0011111117
Figard-FabrePre–post0111111107
GelecekPre–post0111111006
HolmbergPre–post0011011105
MossPre–post0011111005
O'HalloranPre–post0011111005
O'HaraPre–post0010111004
CavanaughCT0111111107
FritzCT0010111105
ParkCT0111011106
RobertsCT0111111006
SilverthornCT0111111006
SongCT1011111118
TakahashiCT0101111106
ThomasCT0011101004
CyartoQuasi-experimental0111111107
McDevittQuasi-experimental0011111106
NgCohort study0010111004
  • (1) Randomisation, (2) exposure, (3) representativeness, (4) comparability, (5) attrition, (6) follow-up tools, (7) follow-up time scale, (8) precision of the results, (9) statistical power.

  • Grey scale indicates studies included in meta-analysis.

  • CT, controlled trial; RCT, randomised controlled trial.