Table 2

Meta-analysis of outcomes and level of evidence

VariableOverall effectStudies (N)Sample size (N)Level of evidence
MD95% CIP valuesI2 P valuesStatistical method
Cupping versus waitlist (sole)
 Pain (VAS)−2.42−3.98 to –0.860.00293<0.00001Random inverse variance5241Very low
 Pain (VAS) omitting one study−1.48−1.86 to –1.10<0.0000100.57Random inverse variance4181
 Disability (NDI)−4.34−6.77 to –1.910.000560.35Random inverse variance3141Low
 QoL
 (physical component of SF-36)
2.46−0.36 to 5.290.09240.27Random inverse variance3141Low
 QoL
 (mental component of SF-36)
5.320.83 to 9.800.02320.23Random inverse variance3141Low
Cupping versus active control (sole)
 Pain (VAS)−0.89−1.42 to –0.370.000988<0.00001Random inverse variance9870Low
 Pain (VAS) of dry cupping−1.48−1.86 to –1.10<0.0000100.57Random inverse variance3149
 Pain (VAS) of wet cupping−0.70−1.32 to –0.070.0392<0.00001Random inverse variance6721
 Pain (VAS) of wet cupping omitting one study−0.49−0.78 to –0.200.0008350.19Random inverse variance5521
 Disability (NDI)−4.36−8.67 to –0.040.05620.05Random inverse variance4213Very low
 QoL (SF-36)
 (physical component of SF-36)
5.442.09 to 8.780.00170.30Random inverse variance2109Low
 QoL (SF-36)
 (mental component of SF-36)
0.44−4.05 to 4.930.8500.59Random inverse variance2109Low
Cupping with active control versus control (add-on)
 Pain (VAS)−0.87−1.14 to –0.61<0.00001190.29Random inverse variance5534Low
 Disability (NDI)3.61−3.93 to 11.150.35Random inverse variance156Low
  • MD, mean difference; NDI, Neck Disability Index; QoL, quality of life; SF-36, 36-Item Short Form Health Survey; VAS, visual analogue scale.