Table 2.
Standardised mean differences reported in reviews and calculated from pooled data for pain intensity for continuous data.
| Reference | Title | Condition | Comparison | No. Pooled Studies | Number of Participants Pooled TENS | Number of Participants Pooled Comparison | SMD | Lower CI | Upper CI | Comment |
|---|---|---|---|---|---|---|---|---|---|---|
| Standardised Mean Difference during or post TENS relative to baseline | ||||||||||
| Wu et al., 2018 [14] | Literature Review and Meta-Analysis of Transcutaneous Electrical Nerve Stimulation in Treating Chronic Back Pain | Chronic low back pain | Control | 9 | TENS = 238 | Control = 159 | −0.2 | −0.58 | 0.18 | NOTE: Data also presented for SMD TENS vs. other nerve stimulation therapies = 0.86 (95%CI 0.15, 1.57), TENS = 122 NST = 105, 5 trials |
| Keller et al., 2007 [63] | Effect sizes of non-surgical treatments of non-specific low-back pain | Chronic low back pain | Placebo | 2 | Not reported Total sample = 114 |
Not reported Total sample = 114 |
−0.19 | −0.51 | 0.13 | NOTE: of the 2 studies one recorded improvement of pain on a 6 point Likert scale and the other pain intensity VAS |
| Philadelphia Panel 2001 [64] | Philadelphia Panel Evidence-Based Clinical Practice Guidelines on Selected Rehabilitation Interventions for Low Back Pain | Chronic low back pain | Unclear | 3 | Not reported | Not Reported | −0,2 | −0,4 | 0.1 | NOTE: MA for chronic back pain only. SMD reported but not trial arm sample sizes |
| Brosseau et al., 2002 [62] | Efficacy of the transcutaneous electrical nerve stimulation for the treatment of chronic low back pain—A meta-analysis. | Chronic low back pain | Placebo | 3 | TENS = 89 | Placebo = 82 | −4.32 | −10.36 | −1.72 | NOTE: We used data from Figure 1 of the report at 1 month |
| Stein et al., 2013 [65] | Electrical stimulation and electromagnetic field use in patients with diabetic neuropathy: systematic review and meta-analysis | Diabetic neuropathy | Sham | 5 | TENS = 76 | Sham TENS = 57 | −0.44 | −0.79 | −0.09 | |
| Jin et al., 2010 [66] | Effect of transcutaneous electrical nerve stimulation on symptomatic diabetic peripheral neuropathy: A meta-analysis of randomized controlled trials | Diabetic neuropathy | Sham | 2 | TENS = 26 | Sham TENS = 16 | −1.65 | −4.02 | 0.73 | NOTE: Forest plot has multiple counts from the same study. Figure within the report calculated an overall SMD with data extracted from different time points from the same study. We have extracted data at 12 weeks because other SMDs represented 1 study e.g., at 4 weeks SMD TENS vs. sham = −5.37 (95%CI −6.97, −3.77) pain intensity TENS = 18 sham = 13 |
| Almeida et al., 2018 [67] | Transcutaneous electrical nerve stimulation and interferential current demonstrate similar effects in relieving acute and chronic pain: a systematic review with meta-analysis | Acute and chronic pain—various | IFT | 8 | TENS = 249 | IFT = 243 | 0.36 | −0.56 | 1.27 | NOTE: Pain intensity VAS relative to baseline VAS, values pre-and post-intervention and results |
| Johnson and Martinson 2007 [10] | Efficacy of electrical nerve stimulation for chronic musculoskeletal pain: A meta-analysis of randomized controlled trials | Chronic musculoskeletal pain | Placebo | 28 | TENS/ES = 869 | Placebo = 823 | −0.99 | −1.25 | −0.74 | NOTE: Forest plot has multiple counts from the same study. Figure 2 within the report estimated overall SMD using data extracted from different time points from the same study. Also includes PENS interventions and data duplicates in analysis |
| Corbett et al., 2013 [68] | Acupuncture and other physical treatments for the relief of pain due to osteoarthritis of the knee: network meta-analysis | Osteoarthritis—knee pain | Standard care | 12 | Nor reported | Not reported | −0.65 | −1.06 | −0.25 | |
| Philadelphia Panel 2001 [69] | Clinical practice guidelines on selected rehabilitation interventions for knee pain | Osteoarthritis—knee pain | Placebo | 5 | TENS = 113 | Placebo = 111 | Not reported | Not reported | Not reported | NOTE: There is a forest plot but SMD not reported |
| Arik et al., 2021 [70] | The effect of TENS for pain relief in women with primary dysmenorrhea: A systematic review and meta-analysis | Dysmenorrhoea | Sham | 2 | TENS = 143 | Sham TENS = 156 | −1.38 | −2.26 | −0.5 | |
| Cottrell et al., 2014 [71] | Benefits and Harms of Electrical Neuromodulation for Chronic Pelvic Pain: A Systematic Review | Chronic pelvic pain | Control |
|
Not reported
|
Not reported
|
Not reported | Not reported | Not reported | NOTE: Figure 2a from the report is a forest plot that provides pain scores in RCTs and (c) and Forest plot provides pain scores in non-RCTs. Neither states overall effect size for the TENS trials as overall effect size calculated from data pooled with other neuromodulation techniques |
| Price and Pandyan 2000 [72] | Electrical stimulation for preventing and treating post-stroke shoulder pain | Post-stroke—shoulder | Control | 2 | TENS = 46 | Control = 38 | −0.1 | −0.54 | 0.34 | NOTE: Extracted Electrical Stimulation (Functional electrical stimulation or TENS) vs. sham. There was only 1 SMD TENS vs. control = −0.44 (CI −1.05, −0.16), TENS = 26, control = 18 |
| Standardised Mean Difference during or post TENS (absolute difference) | ||||||||||
| Zimpel et al., 2020 [73] | Complementary and alternative therapies for post-caesarean pain | Postoperative pain—caesarean | Placebo | 3 | TENS = 119 | Control = 119 | −1.1 | −1.37 | −0.82 | SMD TENS (+ analgesia) vs. placebo (+ analgesia) = −1.10 (CI −1.37, −0.82) |
| Li and Song 2021 [74] | Transcutaneous electrical nerve stimulation for postoperative pain control after total knee arthroplasty: A meta-analysis of randomized controlled trials | Postoperative pain—knee arthroplasty | Control | 5 | TENS = 136 | Control = 131 | −0.26 | −0.44 | −0.08 | |
| Zhu et al., 2017 [75] | Effect of Transcutaneous Electrical Nerve Stimulation for Pain Control after Total Knee Arthroplasty: A Systematic Review and Meta-Analysis | Postoperative pain—knee arthroplasty | Control | 2 | TENS = 51 | Control = 51 | −0.47 | −0.87 | −0.08 | |
| Zeng et al., 2015 [76] | Electrical stimulation for pain relief in knee osteoarthritis systematic review and network meta-analysis | Osteoarthritis—knee pain | Control | 9 | Not reported Total sample = 329 | Not reported Total sample = 329 | −0.78 | −1.34 | −0.22 | NOTE: Used data for SMD h-TENS vs. control; Also reported: h-TENS vs. IFC = −0.14 (CI −1, 0.74), total sample = 56, 1 trial; h-TENS vs. l-TENS = −0.64 (CI −1.53, 0.32), total sample = 75. 2 trials; l-TENS vs. control = −0.14 (CI −1.03, 0.78), total sample = 123, 3 trials. This was a network meta-analysis. |
| Dowswell et al., 2009 [22] | Transcutaneous electrical nerve stimulation (TENS) for pain management in labour (Review) | Labour pain | Placebo/routine care | 2 | TENS = 143 | Placebo/routine care = 156 | −1.01 | −3.0 | 0.97 | NOTE: This is using the same study data as (Bedwell et al., 2011) but gets a different SMD. This used a random effects model |
| Standardised Mean Difference—Unclear whether absolute difference or difference relative to baseline | ||||||||||
| Chen et al., 2016 [77] | Transcutaneous Electrical Nerve Stimulation in Patients with Knee Osteoarthritis Evidence from Randomized-controlled Trials | Osteoarthritis—knee pain | Control | 12 | Not reported | Not reported | −0.79 | −1.31 | −0.27 | NOTE: Needed to manually calculate sample sizes. Exact time points for data extracted was unclear |
| Rutjes et al., 2009 [78] | Transcutaneous electrostimulation for osteoarthritis of the knee (Review) | Osteoarthritis—knee pain | Sham or no treatment | 11 | TENS = 275 | Control = 190 | −0.85 | −1.36 | −0.34 | NOTE: Post, but when post was not available, they pooled DRB |
| Sawant et al., 2015 [79] | Systematic review of efficacy of TENS for management of central pain in people with multiple sclerosis | Multiple sclerosis—central pain | Control | 4 | TENS = 109 | Control = 110 | −0.35 | −0.61 | −0.09 | |
| Standardised Mean Difference—No comparator (i.e., pre-post only) | ||||||||||
| Jauregui et al., 2016 [52] | A Meta-Analysis of Transcutaneous Electrical Nerve Stimulation for Chronic Low Back Pain | Chronic low back pain | None | 12 | Not reported | No control | 0.84 | 0.44 | 1.24 | |
| Cherian et al., 2016 [80] | The effects of various physical non-operative modalities on the pain in osteoarthritis of the knee | Osteoarthritis—knee pain | None | 7 | TENS = 107 | No control | 1.702 | 1.17 | 2.23 | |
Key: IFT = interferential therapy; CI = 95% Confidence Interval DRB = difference relative to baseline, DAbs = absolute difference.