Best Evidence Topics

Randomised control trial

S.I.Basha, E McCoy, R.Ullah, J.B. Kinsella
The efficacy of pharyngeal packing during routine nasal surgery- a prospective randomised control study
2006, 61, pages 1161-1165
  • Submitted by:Selvakumar Panchatsharam - Specialty Registrar Year 2
  • Institution:James Cook University Hospital
  • Date submitted:11th November 2007
Before CA, i rated this paper: 8/10
1 Objectives and hypotheses
1.1 Are the objectives of the study clearly stated?
  Yes.Partly in the beginning and partly in the discussion.
2 Design
2.1 Is the study design suitable for the objectives
  Yes. Randomised control trial is the most appropriate study method for this research question.
2.2 Who / what was studied?
  Adult patients scheduled for routine nasal surgery. Studied for the effect of pharyngeal packing on the incidence of sore throat and prevention of PONV.
2.3 Was this the right sample to answer the objectives?
  Unclear. Probably less.
2.4 Is the study large enough to achieve its objectives? Have sample size estimates been performed?
  The author descirbes based on power calculation, total number of patients needed for a 'clinically' significant difference was 80. But it is not mentioned what degree of clinical significance was used to arrive at a sample size of 80.
2.5 Were all subjects accounted for?
  No. Of the 100 patients recruited in the trial 7 cases were omitted due to incomplete data.
2.6 Were all appropriate outcomes considered?
  Probably yes. The main outcomes which were incidence of PONV and post-operative sorethroat were included.
2.7 Has ethical approval been obtained if appropriate?
2.8 Were the patients randomised between treatments?
2.9 How was randomisation carried out?
  By sealed envelope technique. A slight degree of difference existed between the two groups and no statistical analysis was done to prove that there was no significant difference between the groups.
2.10 Are the outcomes clinically relevant?
  Yes. PONV is a significant problem in ENT procedures and a main reason for admission following daycare surgery.
3 Measurement and observation
3.1 Is it clear what was measured, how it was measured and what the outcomes were?
  Yes. Visual analogue scale was used for Pain and PONV.
3.2 Are the measurements valid?
  Yes. The patients and the observers who collected the data were blinded.
3.3 Are the measurements reliable?
3.4 Are the measurements reproducible?
  Probably yes.
3.5 Were the patients and the investigators blinded?
  Although not mentioned, patients are likely to be blinded as they would be unconscious at the time of the intervention (insertion of pharyngeal pack) and was removed prior to extubation but certain degree of awareness is possible during removal of the pack. The person who inserted the throat pack is unlikely to be blinded. The observers where blinded.
4 Presentation of results
4.1 Are the basic data adequately described?
4.2 Were groups comparable at baseline?
  Probably yes. But there where more females in the non-throat pack
(control) group which could have affected the results as incidence of PONV is higher in females.
4.3 Are the results presented clearly, objectively and in sufficient detail to enable readers to make their own judgement?
4.4 Are the results internally consistent, i.e. do the numbers add up properly?
  Mentioned only as percentage and no actual numbers were stated.
4.5 Were side effects reported?
5 Analysis
5.1 Are the data suitable for analysis?
5.2 Are the methods appropriate to the data?
  Mann whitney U test was used which is appropriate because of small numbers in the groups and being ordinal data.
5.3 Are any statistics correctly performed and interpreted?
6 Discussion
6.1 Are the results discussed in relation to existing knowledge on the subject and study objectives?
6.2 Is the discussion biased?
  No. The author accepts that some variables are likely to exist which might have influenced the results but the most significant variable is the pharyngeal pack.
7 Interpretation
7.1 Are the authors' conclusions justified by the data?
  Probably yes. Although power calulation was done it is not elaborated in the paper.
7.2 What level of evidence has this paper presented? (using CEBM levels)
7.3 Does this paper help me answer my problem?
After CA, i rated this paper: 7/10
8 Implementation
8.1 Can any necessary change be implemented in practice?
  Probably yes. But a larger trial is needed with lesser chance of influence by other variables.
8.2 What aids to implementation exist?
  Simple to adopt.
8.3 What barriers to implementation exist?
  Hard to change the conventional practice of throat packing.