Best Evidence Topics

Randomised control trial

Herrick AL, MC Coll KE, Moore MR, Cook A, Goldberg A
Controlled trial of haem arginate in acute hepatic porphyria
  • Submitted by:Juliet Murray - Medical student
  • Institution:manchester university
  • Date submitted:20th July 2006
Before CA, i rated this paper: 6/10
1 Objectives and hypotheses
1.1 Are the objectives of the study clearly stated?
  Yes-comparison of placebo and haem arginate in acute hepatic porphyria.
2 Design
2.1 Is the study design suitable for the objectives
2.2 Who / what was studied?
  12 patients with acute intermittent porphyria. 21 attacks were studied.
2.3 Was this the right sample to answer the objectives?
2.4 Is the study large enough to achieve its objectives? Have sample size estimates been performed?
2.5 Were all subjects accounted for?
2.6 Were all appropriate outcomes considered?
  Yes-porphobilinogen excretion, analgesic requirement, pain scores, lenght of hospital stay.
2.7 Has ethical approval been obtained if appropriate?
  Not mentioned
2.8 Were the patients randomised between treatments?
2.9 How was randomisation carried out?
  Randomn number tables.
2.10 Are the outcomes clinically relevant?
3 Measurement and observation
3.1 Is it clear what was measured, how it was measured and what the outcomes were?
3.2 Are the measurements valid?
3.3 Are the measurements reliable?
3.4 Are the measurements reproducible?
3.5 Were the patients and the investigators blinded?
4 Presentation of results
4.1 Are the basic data adequately described?
4.2 Were groups comparable at baseline?
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?
4.5 Were side effects reported?
  Yes, phlebitis in 2 patients in the placebo group and 5 patients in the haem group.
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?
6 Discussion
6.1 Are the results discussed in relation to existing knowledge on the subject and study objectives?
  Yes, they mention the results of uncontrolled reports and comment on the limitations of the study
6.2 Is the discussion biased?
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?
  Yes, although due to the lack of statistical significance reported it is difficult to come to any firm conclusions about the effect of haem arginate on the acute porphyric attack.
After CA, i rated this paper: 7/10
8 Implementation
8.1 Can any necessary change be implemented in practice?
  Yes, if hospitals were to stock haem arginate.
8.2 What aids to implementation exist?
  This study.
8.3 What barriers to implementation exist?
  Lack of evidence for the efficacy of haem arginate and lack of supply of haem arginate.