Best Evidence Topics

Randomised control trial

Chang AK. Schoeman G. Hill M.
A randomized clinical trial to assess the efficacy of the Epley maneuver in the treatment of acute benign positional vertigo
Academic Emergency Medicine
11(9):918-24, 2004 September
  • Submitted by:Jim McGrogan - Emergency Medicine Resident
  • Institution:Grand Rapids, MI; Spectrum Health, MERC
  • Date submitted:24th June 2005
Before CA, i rated this paper: 8/10
1 Objectives and hypotheses
1.1 Are the objectives of the study clearly stated?
2 Design
2.1 Is the study design suitable for the objectives
  Yes, prospective, randomized, placebo-controlled trial
2.2 Who / what was studied?
  Consecutive adult Emergency Department (ED) patients presenting with acute benign positional vertigo (BPV)
2.3 Was this the right sample to answer the objectives?
  Yes, the study used clinical criteria to identify patients with acute BPV
2.4 Is the study large enough to achieve its objectives? Have sample size estimates been performed?
  Yes and yes. The calculated sample size was 30 patients per group however the study was stopped when the null hypotheses was rejected. The effect size was greater than expected.
2.5 Were all subjects accounted for?
2.6 Were all appropriate outcomes considered?
  Yes. The primary outcome was the difference between the two groups in the before and after change in vertigo severity scores. Secondary outcomes included improvement in vertigo scores for patients in the placebo group who received a rescue Epley maneuver.
2.7 Has ethical approval been obtained if appropriate?
2.8 Were the patients randomised between treatments?
2.9 How was randomisation carried out?
  Sealed consecutively numbered opaque envelopes prepared by an independent party and randomized using a computer program were used to allocate patients into the two groups.
2.10 Are the outcomes clinically relevant?
  Likely, although improvement in vertigo scores have not been translated into clinical terms.
3 Measurement and observation
3.1 Is it clear what was measured, how it was measured and what the outcomes were?
  Yes. The study measured patient's symptomatic relief of vertigo using a zero to ten scale after Epley versus placebo maneuver.
3.2 Are the measurements valid?
  The vertigo scale has been used in previously published studies but has not been validated in vertiginous patients.
3.3 Are the measurements reliable?
  Not measured, but the majority of the maneuvers were performed by the two lead authors.
3.4 Are the measurements reproducible?
  Yes, but only after significant training.
3.5 Were the patients and the investigators blinded?
  The patients were blinded , but were informed (by IRB request) that if they did not improve after receiving the placebo maneuver, they would then receive the study maneuver.
4 Presentation of results
4.1 Are the basic data adequately described?
4.2 Were groups comparable at baseline?
  Yes, refer to Table 1 in the article.
4.3 Are the results presented clearly, objectively and in sufficient detail to enable readers to make their own judgement?
  Yes, refer to Figure 3 in the article.
4.4 Are the results internally consistent, i.e. do the numbers add up properly?
4.5 Were side effects reported?
  Not applicable
5 Analysis
5.1 Are the data suitable for analysis?
5.2 Are the methods appropriate to the data?
5.3 Are any statistics correctly performed and interpreted?
  Yes, nonparometric tests were used because of small sample size.
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, study limitations are addressed in the discussion section of the article.
7 Interpretation
7.1 Are the authors' conclusions justified by the data?
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: 9/10
8 Implementation
8.1 Can any necessary change be implemented in practice?
  Yes, the use of the Epley maneuver could bring relief to those suffering from acute BPV. The maneuver is both safe and inexpensive to perform.
8.2 What aids to implementation exist?
  Figure 1 from the New England Journal of Medicine 1999; 341:1590-6
8.3 What barriers to implementation exist?
  Physician's knowledge of and experience with using the Epley maneuver and using it in the properly selected patient population.