Best Evidence Topics

Survey (including pre-test probabilities)

Juan Gutitkrez- Cebollada et al.
Psychotropic drug consumption and other factors associated with heroin overdose.
Drug and alcohol Dependence
35 (1994) 169-174
  • Submitted by:Jenifer Barrie - Student
  • Institution:University of Manchester
  • Date submitted:17th 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, briefly in the abstract and in more detail in the introduction.
2 Design
2.1 Is the study design suitable for the objectives
2.2 Who / what was studied?
  76 heroin addicts who were admitted to the emergency room because of opiate overdose or unrelated conditions wher opiates were detected.
2.3 Was this the right sample to answer the objectives?
2.4 Did the subject represent the full spectrum of the population of interest?
2.5 Is the study large enough to achieve its objectives? Have sample size estimates been performed?
  Sample size was fairly small. There is no mention of sample size estimates.
2.6 Were all subjects accounted for?
2.7 Were all appropriate outcomes considered?
  Yes all variables relating to increased risk of overdose were asked about in the interview.
2.8 Has ethical approval been obtained if appropriate?
  No mention of ethical approval or informed consent.
2.9 What measures were made to contact non-responders?
  No non responders.
2.10 What was the response rate?
  see above
3 Measurement and observation
3.1 Is it clear what was measured, how it was measured and what the outcomes were?
  Yes, subjects and methods section explains what variables were tested for.
3.2 Are the measurements valid?
3.3 Are the measurements reliable?
  Yes as toxicological analysis was performed to determine concomitant drug use. However the interviewed relied upon good recall and honesty from subjects.
3.4 Are the measurements reproducible?
4 Presentation of results
4.1 Are the basic data adequately described?
4.2 Are the results presented clearly, objectively and in sufficient detail to enable readers to make their own judgement?
  Yes, three tables display the results comparing overdose group and non overdose group.
4.3 Are the results internally consistent, i.e. do the numbers add up properly?
5 Analysis
5.1 Are the data suitable for analysis?
5.2 Are the methods appropriate to the data?
Quantitative variables by wilcoxon and Mann-Whitney tests.
Chi squared for comparisons of proportions.
Multivariate analysis with log-linear regression as a risk factor for severity.
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, population used was similar to other studies.Findings are consistant with other studies.
6.2 Is the discussion biased?
6.3 Can the results be generalised?
7 Interpretation
7.1 Are the authors' conclusions justified by the data?
  Measurements of plasma benzodiazepines indicated that they aren't relevant for overdose.
7.2 What level of evidence has this paper presented? (using CEBM levels)
  Survey-level 3
7.3 Does this paper help me answer my problem?
  yes, it shows that alcohol and benzodiazepine levels are significant contributers to outcome in overdose.
After CA, i rated this paper: 7/10
8 Implementation
8.1 Can any necessary change be implemented in practice?
  Polydrug use should be discouraged.
8.2 What aids to implementation exist?
  Health professionals who come into contact with drug users who can provide education on avoiding overdose and minimising damage.
8.3 What barriers to implementation exist?
  Many drug users may not be in regular contact with health professionals.