Table 1

Methodological quality of the included studies assessed using the modified Downs and Black checklist

ReportingExternal validityInternal validityPower
Performance biasReporting biasDetection biasSelection biasAttrition bias
123456789101112131415191617182021222324252627
Almonroeder and Benson25 +++++++++++
Almonroeder et al 26 ++++++++++++
Almonroeder et al 27 +++++++++++++
Atkins et al 28 ++++++++++++
Atkins et al 29 ++++++++++++
Bini and Hume30 +++++++++
Bini and Hume31 ++++++++++
Bini et al 32 +++++++++
Bini et al 33 ++++++++++++
Bonacci et al 34 +++++++++++
Bonacci et al 35 +++++++++++
Heino Brechter and Powers36 +++++++++++
Bressel37 ++++++++++++
Chen and Powers38 +++++++++++++
Chen et al 39 +++++++++++
Chinkulprasert et al 40 +++++++++++
Costigan et al 41 ++++++++
De Oliveira Silva et al 42 +++++++++++
Escamilla et al 43 ++++++++++
Escamilla et al 44 +++++++++++
Escamilla et al 45 ++++++++++
Escamilla et al 46 +++++++++++
Escamilla et al 47 +++++++++++
Fok et al 48 +++++++++++++
Han et al 49 ++++++++++
Herrington et al 50 ++++++++++++
Ho et al 51 ++++++++++++
Ho et al 52 +++++++++++
Hofmann et al 53 +++++++++++
Kernozek et al 54 +++++++++++++
Kernozek et al 55 ++++++++++++
Kujawa et al 56 +++++++++++
Kulmala et al 57 ++++++++++++
Lenhart et al 58 ++++++++++
Liao et al 59 ++++++++++++
Macdonald et al 60 +++++
Messier et al 61 +++++++++++
Mostamand et al 62 ++++++++++++
Peng et al 63 ++++++++++++
Powers et al 64 ++++++++++++
Powers et al 65 ++++++++++++
Richards et al 66 ++++++++++
Ristow et al 67 +++++++++++
Roos et al 68 +++++++
Sinclair69 +++++++++++
Sinclair and Bottoms70 +++++++++
Sinclair et al 71 +++++++++++
Sinclair et al 72 +++++++++++
Sinclair et al 73 +++++++++++
Sinclair et al 74 ++++++++++++
Sinclair et al 75 ++++++++++++++
Sinclair et al 76 +++++++++++
Sinclair et al 77 ++++++++++++
Sinclair et al 78 ++++++++++++++
Steinkamp et al 79 +++++++++++
Sussman et al 80 ++++++++++
Teng et al 81 +++++++++++++
Teng and Powers82 ++++++++++
Thoma et al 83 ++++++++++++
van Rossom et al 84 ++++++++++
Waiteman et al 85 ++++++++++++++
Wallace et al 86 ++++++++++
Wang et al 87 +++++++++++++++++
Ward and Powers88 +++++++++++
Whyte et al 89 ++++++++++++
Willson et al 90 +++++++++++++
Willson et al 91 ++++++++++++
Willy et al 92 +++++++++++++
Willy et al 93 ++++++++++++
Willy et al 94 +++++++++++++
Zavala et al 95 +++++++++++
  • Items scored as ‘+’ (yes) or ‘-’ (no or unable to determine). Item five scored as ‘++’ (clearly described), ‘+’ (partially described) or ‘-’ (no or unable to determine). In the modified version, item 27 is rated as ‘+’ (yes) or ‘-’ (no or unable to determine), instead of 0 to 5. Shaded cells indicate non-applicable items.