| Methods |
Design: five group parallel trial
Purpose: examine the respiratory depressant response of placebo in patients newly treated with opioids |
| Participants |
Patients: lung cancer patients undergoing posterolateral thoracotomy, having repeatedly been treated with buprenorphine for three days, and were 'almost pain‐free'
Baseline comparability: yes (age, gender, weight) |
| Interventions |
Placebo: saline injection (patients told it was continuation of analgesic medication)
Untreated: no injection
Experimental: naloxone injection (open and hidden)
(Co‐intervention: additional doses of buprenorphine were administered and resulted in exclusion of the patient from the study, numbers NS) |
| Outcomes |
Respiratory depression (ventilation per minute) 73 hours after surgery
Pain (11 point numerical scale, 0 to 10) |
| Notes |
The trial investigated the negative effect of placebo (respiratory depression). We included the trial in the review in a separate category (adverse effects), but not in the main analyses. |
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Adequate sequence generation? |
Unclear risk |
NS |
| Allocation concealment? |
Unclear risk |
NS |
| Blinding?
Treatment provider |
Low risk |
'The 60 patients... were investigated according to a randomized double‐blind design' |
| Blinding?
Outcome assessor |
Unclear risk |
NS |
| Incomplete outcome data addressed?
All outcomes |
Low risk |
Drop‐out < 15% |
| Free of selective reporting? |
Unclear risk |
No protocol available |
| Free of other bias? |
High risk |
See notes |
| Trial size > 49? |
High risk |
N = 24 |
| Clearly concealed allocation + trial size > 49 + drop‐out max 15% |
High risk |
Trial size < 49 |
