Best Evidence Topics

Randomised control trial

Howe RW, Millar MR, Coast J et al
A randomized controlled trial of antibiotics on symptom resolution in patients presenting to their general practitioner with a sore throat
British Journal of General Practice
1997, 47 280-4
  • Submitted by:Helen Slee - Medical student
  • Institution:Manchester University
  • Date submitted:15th July 2005
Before CA, i rated this paper: 7/10
1 Objectives and hypotheses
1.1 Are the objectives of the study clearly stated?
  Yes, to compare in an RCT the effectiveness of penicillin, cefixime and placebo on symptom resolution in patients presenting with sore throat in general practice
2 Design
2.1 Is the study design suitable for the objectives
2.2 Who / what was studied?
  154 patients were recruited from 39 GP's in 22 practices. Patients aged 16-60 presenting to the GP with sore throat, for whom the GP would normally prescribe an antibiotic were included.
2.3 Was this the right sample to answer the objectives?
  Yes, although not all eligible patients were included
2.4 Is the study large enough to achieve its objectives? Have sample size estimates been performed?
  No the study had to be cut short with 40, 29 and 34 in each arm of the study. The authors estimate 60 people would be needed in each arm to achieve statistical significance.
2.5 Were all subjects accounted for?
  Yes, of the 154 recruited for the trial 51 patients did not return a symptom diary. However 3 throat culture results were missing of non-responders and 6 patients stopped taking their medication because of adverse symptoms
2.6 Were all appropriate outcomes considered?
  Yes, symptom diary, GABHS present on throat culture, use of analgesia, relapse
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 blocks of 6, 2 penicillin, 3 cefixime,2 placebo.
2.10 Are the outcomes clinically relevant?
  Yes, the outcome may influence prescribing.
3 Measurement and observation
3.1 Is it clear what was measured, how it was measured and what the outcomes were?
  Yes, symptom scores from patient questionnaires, the actual scores and the mean were reported
A throat swab was performed on everyone to measure eradication of GABHS
Use of analgesia was recorded by the patients in the questionnaire.
Relapse was based on returning to the GP within the 14 days and if the GP prescribed antibiotics.
3.2 Are the measurements valid?
  Yes, symptom scores based on Likert scales.
3.3 Are the measurements reliable?
  Yes however symptom scores are subjective and based on patient interpretation.
3.4 Are the measurements reproducible?
3.5 Were the patients and the investigators blinded?
  Yes, apart from 2 patients who relapsed and were prescribed different antibiotics.
4 Presentation of results
4.1 Are the basic data adequately described?
4.2 Were groups comparable at baseline?
  Difference between 3 groups not described. Responders and non-responders of the symptom diary were compared and no statistical significance was found. Eligible patients included and not included in the trial were not compared.
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?
  No there are missing values, this is acknowledged in the study.
4.5 Were side effects reported?
5 Analysis
5.1 Are the data suitable for analysis?
  The difference in symptom score was not analysed for p values as the numbers were too small.
5.2 Are the methods appropriate to the data?
  Yes, the difference and confidence intervals between the groups were given. The proportion of patients recording use of analgesia was analysed using Chi squared and a p value given.
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?
7 Interpretation
7.1 Are the authors' conclusions justified by the data?
  Yes because although the fact the results are not statistically significant conclusions can still be drawn.
7.2 What level of evidence has this paper presented? (using CEBM levels)
  Level 1, a RCT
7.3 Does this paper help me answer my problem?
  It is moderately useful because although it is of no statistical significance, conclusions can be drawn.
After CA, i rated this paper: 5/10
8 Implementation
8.1 Can any necessary change be implemented in practice?
  No because the evidence is not strong enough to base a recommendation on.
8.2 What aids to implementation exist?
8.3 What barriers to implementation exist?
  Extra cost of cephalosporins compared to penicillin.