Table 2.
Requirement for analgesia and pain and after surgery in participants assigned to therapeutic suggestions by audiotape during surgery (intervention) or to a blank audiotape (n=385). Values are medians (interquartile ranges) unless stated otherwise
| Intervention group (n=191) | Control group (n=194) | Absolute difference (95% CI) | P value* | Cohen’s d (95% CI) | NNT | |
|---|---|---|---|---|---|---|
| Postoperative opioids: | ||||||
| MME† | 4.0 (0-8) | 5.3 (2-12) | 0.002 | 0.36 (0.2 to 0.6) | ||
| None, No/% (95% CI) | 70/37(30 to 44) | 39/20 (157 to 26) | 16.5 (8 to 25) | <0.001 | 0.46 (0.2 to 0.7) | 6.0 |
| No high dose (MME ≥10), No/% (95% CI) | 153/80 (74 to 86) | 129/66 (59 to 73) | 13.6 (5 to 22) | 0.014 | 0.39 (0.1 to 0.7) | 7.3 |
| Postoperative non-opioids: | ||||||
| % of MDD‡ | 50 (6-100) | 75 (25-100) | 0.0135 | 0.25 (0.1 to 0.5) | ||
| Postoperative pain, NRS (01-10): | ||||||
| Average within 2 hours | 2 (1-3) | 3 (1-4) | <0.001 | 0.40 (0.2 to 0.6) | ||
| Maximum within 24 hours | 4 (3-6) | 5 (4-7) | <0.001 | 0.45 (0.3 to 0.7) | ||
| Patients with NRS <3: | ||||||
| At 0 minutes (admission to PACU), No/% (95% CI) | 145/76 (70 to 82) | 122/63(56 to 70) | 13.4 (4 to 23) | 0.003 | 0.35 (0.1 to 0.6) | 7.7 |
| Average within 2 hours, No/% (95% CI) | 119/62 (55 to 69) | 84/43 (36 to 51) | 19.0 (9 to 29) | <0.001 | 0.43 (0.2 to 0.7) | 5.3 |
| At 24 hours, No/% (95% CI) | 110/57.6 (50.2 to 64.7) | 75/38.7 (31.8 to 45.9) | 18.9 (9.1 to 28.7) | 0.001 | 0.42 (0.2 to 0.7) | 5.3 |
NNT=number needed to treat of pain; MME=morphine milligram equivalents; MDD=maximum daily dose; NRS=numerical rating scale; PACU=post-anaesthesia care unit.
*
Mixed effect.
‡
MDD calculated to correct for different non-opioid analgesics with various half-lives (metamizole=4000 mg, paracetamol=4000 mg, ibuprofen=2400 mg, diclofenac=150 mg, etoricoxib=120 mg, from information provided by manufacturers).