Table 2.

The GRADE “Summary of Findings” table for quality of evidence, magnitude of effect of the interventions at short- and long-term follow-up.

The Analgesic Effect of Transcranial Direct Current Stimulation (tDCS) combined with Physical Therapy on Common Musculoskeletal Conditions
Patient or population: patients with low back pain or fibromyalgia or KOA or myofascial pain diagnosed for at least >3 months
Settings: Outpatient
Intervention: tDCS combined with a form of physical therapy treatment
Comparison: Physical therapy treatment alone or physical therapy combined with sham tDCS
Outcomes	Effect size	Relative and absolute effect (average % improvement (reduction) in pain (95% CIs) in relation to post-treatment score from sham group) * * Where 95%CIs do not cross the line of no effect.	No of participants (studies)	Quality of the evidence (GRADE)
Fibromyalgia
Pain intensity (< 8 weeks from baseline) measured using a visual analog scale or numerical rating scale	MD −12.0; 95%CI (−17.17, −6.83) SMD −1.66; 95%CI (−2.49, −0.82)	This equates to a 12%, 95% CI (17% to 6%) reduction in pain intensity, on a 0 to 100 pain intensity scale	45 (1)	⊕⊕◯◯ low1
Pain intensity (> 8 weeks from baseline) measured using a visual analog scale or numerical rating scale	SMD −1.94; 95%CI (−3.38, −0.49)	This equates to a 13%, 95% CI (16% to 8%) reduction in pain intensity, on a 0 to 100 pain intensity scale	68 (2)	⊕⊕◯◯ low2, 4
Low Back Pain
Pain intensity (< 8 weeks from baseline) measured using a visual analog scale or numerical rating scale	SMD −0.19; 95%CI (−1.13, 0.74)	-	278 (4)	⊕◯◯◯ very low2, 3, 4
Pain intensity (> 8 weeks from baseline) measured using a visual analog scale or numerical rating scale	SMD −0.02; 95%CI (−0.92, 0.95)	-	262 (3)	⊕◯◯◯ very low2, 3, 4
Knee Osteoarthritis
Pain intensity (0 to 8 weeks from baseline) measured using a 0–100 visual analog scale	MD −17.59; 95%CI (−26.31, −8.87)	This equates to a 17%, 95% CI (26% to 8%) reduction in pain intensity, on a 0 to 100 pain intensity scale	90 (2)	⊕⊕◯◯ low2, 4
Myofascial Pain
Pain intensity (< 8 weeks from baseline) measured using a 0–10 visual analog scale	SMD −0.253; 95%CI (−0.96, 0.45)	-	31 (1)	⊕◯◯◯ very low2, 3, 4
GRADE Working Group grades of evidence High quality: we are very conf ident that the true effect lies close to that of the estimate of the effect Moderate quality: we are moderately confident in the effect estimate; the true effect is likely to be close to the estimate of effect, but there is a possibility that it is substantially different Low quality: our confidence in the effect estimate is limited; the true effect may be substantially different from the estimate of the effect Very low quality: we have very little confidence in the effect estimate; the true effect is likely to be substantially different from the estimate of effect

MD: Mean Difference; SMD: Standardized Mean Difference; CI: confidence Interval; KOA: Knee Osteoarthritis

⁴Downgraded once for imprecision due to small sample size

³Downgraded once for study limitation due to high or unclear risk of bias.

²Downgraded once for inconsistency due to heterogeneity.

¹Downgraded twice. Single randomized study (with under 300 participants) were considered inconsistent, imprecise (i.e. wide 95%CI) and with potential publication bias, providing low quality of evidence.