Table 5.
Description of studies included in the review and main themes.
| Article reference | Study Type | Study area | Main themes | Subthemes | |
|---|---|---|---|---|---|
| 1 | Brim & Franklin [6] 2013 | Position paper | The benefit of the placebo effect in sham-controlled trials | Ethics | Risk-benefit balance, informed consent |
| 2 | Katz et al. [8], 2021 | Consensus recommendations | Research design considerations for randomized controlled trials of spinal cord stimulation for pain | Mitigating bias in sham-controlled trials | Blinding |
| 3 | Dworkin et al. [15], 2010 | Consensus recommendations | Research design considerations for confirmatory chronic pain clinical trials | Type of sham | No perceivable output |
| 4 | Raphael et al. [12], 2011 | Sham- RCT | Percutaneous Electrical Nerve Stimulation in Neuropathic Pain | Type of sham | No perceivable input |
| Design issues relating to sham | Validating the intended sham device | ||||
| 5 | Ghoname et al. [13] 1999 | Sham- RCT | Percutaneous electrical nerve stimulation for low back pain | Type of sham | No perceivable output |
| 6 | Hamza et al. [14], 2000 | Sham- RCT | Percutaneous electrical nerve stimulation for diabetic neuropathy | Type of sham | No perceivable output |
| Design issues relating to sham | Validating the intended sham device | ||||
| 7 | Brunoni et al. [16] 2012 | Systematic review | Transcranial Direct Current Stimulation (tDCS) research recommendations | Type of sham | No perceivable output |
| 8 | White et al. [17], 2001 | Consensus recommendations | Recommendations for optimal treatment, sham controls and blinding of Acupuncture research. | Type of sham | No perceivable output |
| 9 | Boutron et al. [18] 2007 | Systematic review | Reporting methods of blinding in randomized trials assessing nonpharmacological treatments | Type of sham | No perceivable output |
| Mitigating bias in sham-controlled trials | Blinding, assessment of blinding | ||||
| 10 | Gibson et al. [19], 2017 | Systematic review | Transcutaneous nerve stimulation for neuropathic pain | Type of sham | Subtherapeutic dosing |
| Mitigating bias in sham-controlled trials | Blinding | ||||
| 11 | Duarte et al. [21], 2020 | A Systematic Review and Methodological Appraisal | Randomized Placebo-/Sham-Controlled Trials of Spinal Cord Stimulation | Type of sham | Subtherapeutic dosing |
| Mitigating bias in sham-controlled trials | Blinding | ||||
| 12 | Hoffman et al. [22], 2014 | Consensus recommendations | Reporting of interventions: Template for intervention description and replication (TIDieR) | Mitigating bias in sham-controlled trials- | Blinding, Clinical interactions |
| Design issues relating to the sham | Mechanism of action | ||||
| 13 | Birch et al. [27], 2022 | Literature review | Historical perspectives on using sham acupuncture in acupuncture clinical trials | Design issues relating to the sham | Validating the intended sham device |
| 14 | Kim et al. [28], 2022 | Systematic review | Plausible mechanism of Sham Acupuncture Based on Biomarkers | Design issues relating to the sham | Validating the intended sham device |
| 15 | Sheffer et al. [29], 2013 | Single blind study | Evaluation of sham repetitive transcranial Direct Current Stimulation | Design issues relating to sham | Validating the intended sham device |
| 16 | Vetter et al. [31], 2017 | Topical review | Bias, Confounding, and Interaction in research | Mitigating bias in sham-controlled trials | Blinding |
| 17 | Haahr et al. [32], 2006 | Cohort study | Who is blinded in randomized clinical trials? A study of 200 trials and a survey of authors. | Mitigating bias in sham-controlled trials | Blinding |
| 18 | Hróbjartsson et al. [33] 2007 | Cohort study | An analysis of randomized clinical trials that report tests for the success of blinding. | Mitigating bias in sham-controlled trials | Blinding, assessment of blinding |
| 19 | Higgins et al. [35], 2011 | Consensus recommendation and bias tool | Risk of bias tool for RCTs | Mitigating bias in sham-controlled trials | Blinding, assessment of blinding |
| 20 | Boutron et al. [36], 2010 | Systematic review | Reporting and interpretation of randomized controlled trials with statistically nonsignificant results for primary outcomes | Mitigating bias in sham-controlled trials | Blinding |
| 21 | Carroll et al. [37], 2000 | Systematic review | Transcutaneous nerve stimulation for neuropathic pain | Mitigating bias in sham-controlled trials | Blinding |
| 22 | Sterne et al. [38], 2019 | Consensus recommendation and bias tool | Risk of bias tool for RCTs | Mitigating bias in sham-controlled trials | Blinding, assessment of blinding |
| 23 | Chen et al. [39], 2019 | Clinical trial | Socially transmitted placebo effects | Mitigating bias in sham-controlled trials | Clinical interactions |
| 24 | Di Blasi et al. [40], 2001 | Systematic review | Influence of context effects on health outcomes | Mitigating bias in sham-controlled trials | Clinical interactions |
| 25 | Rief et al. [41], 2012 | Randomised experimental study | The hidden effects of blinded, placebo-controlled randomized trials. | Mitigating bias in sham-controlled trials | Clinical interactions |
| 26 | Laferton et al. [44], 2017 | Review | Patients' Expectations Regarding Medical Treatment | Mitigating bias in sham-controlled trials | Expectation |
| 27 | Bingel et al. [42], 2011 | Clinical trial | Treatment expectation on drug efficacy | Mitigating bias in sham-controlled trials | Expectation |
| 28 | Frisaldi et al. [43], 2017 | Commentary article | Patients' Expectations in Clinical Trials | Mitigating bias in sham-controlled trials | Expectation |
| 29 | Dworkin et al. [45], 2010 | Topical review | Placebo and treatment group responses in postherpetic neuralgia vs. painful diabetic peripheral neuropathy | Study population | Placebo |
| 30 | Freeman et al. [46] 2015 | Cohort study | Predictors of placebo response in peripheral neuropathic pain | Study population | Placebo |
| 31 | Arakawa et al. [47], 2015 | Systematic review and meta-analysis | Placebo Response in Clinical Trials in Neuropathic Pain | Study population | Placebo |
| 32 | Skyt et al. [48], 2015 | Review | Placebo effects in chronic pain | Study population | Placebo |
| 33 | Niemansburg et al. [49], 2015 | Review | Ethics of sham-controlled trials | Ethics | Risk-benefit balance, informed consent, deliberate deception |
| 34 | Miller et al. [50], 2004 | Commentary article | Sham procedures and the ethics of clinical trials | Ethics | Risk-benefit balance |
| 35 | Freedman et al. [51] 1987 | Commentary article | Equipoise and the ethics of clinical research. | Ethics | Equipoise |
| 36 | Horng et al. [53], 2003 | Commentary article and proposed framework | Ethical framework for the use of sham procedures in clinical trials. | Ethics | Risk-benefit balance, informed consent, deliberate deception |
| 37 | Miller et al. [65], 2005 | Review | Deception in research on the placebo effect | Ethics | Deliberate deception |