eTable 3. Overview of randomized controlled trials on the effect of waking suggestions in medical treatment procedures*.
| Reference | Type of medical treatment | Type of suggestion Number of patients | Control intervention Number of patients | Result |
|---|---|---|---|---|
| Lang et al. 2000 (20) |
Percutaneous vascular intervention | Structured attention control―; N=80 Structured attention control plus self-relaxation and self-hypnosis; N = 82 |
Standard treatment; N=79 | Increase in pain: significantly greater for standard treatment (mean 0.09 pain score/15 min) and attention control (mean 0.04/15 min) than for hypnosis (no increase) |
| Drug consumption: significantly higher increase in standard treatment group (mean 1.9 units) than in attention control group (mean 0.07) and hypnosis group (mean 0.11) | ||||
| Reduction of anxiety: no significant difference between attention control (mean –0.07) und hypnosis (mean –0.11); significantly lower with standard treatment (mean 0.04) | ||||
| Hemodynamic instability: significantly lower for hypnosis (1.2%) than for attention control (12.5%) and standard treatment (15.2%) | ||||
| Duration of intervention: significantly shorter for hypnosis (mean 61 min) and attention control (mean 67 min) than for standard treatment (mean 78 min) | ||||
| Lang et al. 2006 (21) |
Breast biopsy | Structured attention control**; N=82 Structured attention control plus self-relaxation and self-hypnosis; N = 78 |
Standard treatment; N=76 | Increase in pain: significantly greater for standard treatment (mean 0.53) than for attention control (mean 0.37) and hypnosis (mean 0.34) |
| Drug consumption: significantly higher increase in standard treatment group (mean 0.18) than in attention control group (mean −0.04) and hypnosis group (mean –0.27) | ||||
| Reduction of anxiety: significantly less reduction in standard treatment group (mean 0.18) than in attention control group (mean –0.04) and hypnosis group (mean –0.27) | ||||
| Complications: no significant differences among standard treatment (8.9%). attention control (13.8%). and hypnosis (3.7%) | ||||
| Duration of intervention: no significant differences among hypnosis (mean 39 min). attention control (mean 43 min). and standard treatment (mean 46 min) | ||||
| Lang et al. 2008 (22) |
Radiofrequency ablation or embolization of carcinomas | Structured attention control**; N=65 Structured attention control plus self-relaxation and self-hypnosis; N = 66 |
Standard treatment; N=70 | Increase in pain: significantly greater for standard treatment (median 2.5 units) and attention control (median 2.5 units) than for hypnosis (median 0 units) |
| Reduction of anxiety: no significant differences among standard treatment group (median 2 units). attention control group (median 2 units). and hypnosis group (median 1 unit) | ||||
| Complications: significantly higher rates in attention control group (48%) compared to hypnosis group (12%) and standard treatment group (26%) | ||||
| Duration of intervention: no significant differences among hypnosis (median 110 min). attention control (median 120 min). and standard treatment (median 110 min) | ||||
| Ott et al. 2012 (23) |
Sampling of venous blood | “I’m going to start taking the blood sample now” N=50 | “This will hurt a bit” N=50 | Mean pain intensity. as measured on an 11-point (0–10) numeric rating scale (NRS) was 2.7 in the “This will hurt” group compared with 1.6 in the “I’m going to” group (p = 0.001). 58 % of the probands in the “This will hurt” group but only two probands (4.2 %) in the “I’m going to” group rated the pain intensity of the injection at ≥ 1 on the NRS. the threshold value for mild to moderate pain (p<0.001). |
| Oktay et al. 2014 (25) |
Acute headache | “This drug is a powerful pain killer for your headache. Its analgesic effect peaks at about 20 to 30 minutes. We are expecting that your headache will resolve in 45 minutes” N=50 (group 1) | “A nurse is going to administer you a pain killer called … by intramuscular injection” N=50 (group 2) “If your headache does not resolve in 45 minutes. we can administer you a more potent pain killer” N=53 (group 3) | Pain reduction on a 0–100 visual analog scale 45 min after injection (p=0.49): group 1: 43 ± 30 group 2: 39 ± 29 group 3: 36 ± 24 |
| Varelmann et al. 2010 (24) |
Local anesthesia before creation of access for peridural or spinal anesthesia in pregnant women before delivery | “We are now going to give you a local anesthetic so that it’s comfortable for you when we perform the epidural spinal anesthesia” N=33 | “You will now feel a prick and a burning sensation in your back as though you have been stung by a bee; that’s the worst part of the whole procedure” N=32 | Pain was rated significantly stronger by patients who received the second instruction (median pain intensity 5 versus 3 on an 11-point scale). |
*Trials listed in alphabetical order
**Agreement with the patient’s verbal and non-verbal communication patterns; attentive listening; reinforcement of feeling of autonomy (“Let us know at any time what we can do for you”); swift action in response to the patient’s wishes; avoidance of negative suggestions (“How bad is your pain? “You will now feel a prick and a burning sensation“); positive suggestions (focus on sensations of fullness. coolness. warmth during painful stimuli) Significant. p<0.05