| Methods |
Design: five group parallel trial
Purpose: examine the effect of ultrasound and placebo on pain and swelling |
| Participants |
Patients: postoperative in‐patients (after removal of impacted third molars)
Baseline comparability: NS |
| Interventions |
Placebo: ultrasound with machine off
Untreated: no ultrasound
Experimental: ultrasound at three levels of intensity
(Co‐intervention: analgesics, fixed ordination scheme) |
| Outcomes |
Pain (VAS) and facial swelling (cubic cm)
Trismus
C‐reactive protein |
| Notes |
|
| 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 |
'... in a double‐blind controlled study...' |
| Blinding?
Outcome assessor |
Unclear risk |
NS |
| Incomplete outcome data addressed?
All outcomes |
High risk |
Drop‐out > 15% or NS |
| Free of selective reporting? |
Unclear risk |
No protocol available |
| Free of other bias? |
Low risk |
|
| No signs of variance inequality or skewness? |
High risk |
Either variance inequality (F‐test statistically significant) or skewness (1.64 standard deviations exceeds the mean) |
| Trial size > 49? |
Low risk |
N = 75 |
| Clearly concealed allocation + trial size > 49 + drop‐out max 15% |
High risk |
Drop‐out > 15% or NS |
