Coblation versus other surgical techniques for tonsillectomy

Patient or population: patients requiring tonsillectomy (any diagnosis)
Setting: hospitals
Intervention: coblation
Comparison: alternative tonsillectomy techniques (including 'cold' and 'hot' techniques)

Pain postoperative day 1
№ of participants: 538
(6 studies)

—

Pain score was lower by a standardised mean difference (SMD) of 0.79 (1.38 lower to 0.19 lower) in the coblation group

⊕⊝⊝⊝
very low

There seems to be less pain with coblation (a small effect) but it is unclear whether this difference is important to patients. There is very little research on the minimal clinically important difference for acute post‐surgical pain to support interpretation.

Our confidence in the estimate is very low because of high risk of bias within studies, statistical heterogeneity, imprecision of the estimate and reporting bias.

Pain postoperative day 3
№ of participants: 401
(5 studies)

—

Pain score was lower by a SMD of 0.44 (0.97 lower to 0.09 higher)

⊕⊝⊝⊝
very low

There seems to be slightly less pain with coblation (a very small effect). There is very little research on the minimal clinically important difference for acute post‐surgical pain to support interpretation.

Our confidence in the estimate is very low because of high risk of bias within studies, statistical heterogeneity, imprecision of the estimate and reporting bias.

Pain postoperative day 7
№ of participants: 420
(5 studies)

—

Pain score was lower by a SMD of 0.01 (0.22 lower to 0.19 higher)

⊕⊕⊝⊝
low

There seems to be no clinically significant difference in pain with coblation, but our confidence in the estimate is low because of high risk of bias within studies and reporting bias, based on the small proportion of studies that reported data in a manner that permitted meta‐analysis. However, unlike the data on postoperative day 1 and postoperative day 3, there was no heterogeneity or inconsistency observed in the data.

Intraoperative blood loss
№ of participants: 781
(9 studies)

—

Not estimable

⊕⊝⊝⊝
very low

Only 9 studies reported sufficient information for meta‐analysis. However, these could not be pooled because different methods and parameters were used. Of these studies, 7 showed lower bleeding in the coblation group but the importance of this was difficult to interpret.

Primary bleeding
№ of participants: 2055
(25 studies)

⊕⊕⊝⊝
low

There seems to be no clinically significant difference in the risk of primary bleeding with coblation but our confidence in the evidence is low because of high risk of bias within studies and imprecision of the estimate.

1.1%
(0.5 to 2.2)

0.0% fewer (0.6 fewer to 1.1 more per 100 people)

Secondary bleeding
№ of participants: 2118
(25 studies)

⊕⊕⊝⊝
low

There seems to be a slightly higher risk of secondary bleeding with coblation, but our confidence in the evidence is low because of high risk of bias within studies and imprecision of the estimate.

5.0%
(3.5 to 7.1)

1.3% higher (0.2 lower to 3.5 higher per 100 people)

*The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).

CI: confidence interval; SMD: standardised mean difference

GRADE Working Group grades of evidence
High quality: We are very confident that the true effect lies close to that of the estimate of the effect
Moderate quality: We are moderately confident in the effect estimate: The true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different
Low quality: Our confidence in the effect estimate is limited: The true effect may be substantially different from the estimate of the effect
Very low quality: We have very little confidence in the effect estimate: The true effect is likely to be substantially different from the estimate of effect