Reviewed and revised 26 August 2015
- This page provides a broad overview of the complicated process of conducting a clinical trial
- Conducting a clinical trial can be conceptualised as having 14 key steps
(1) Research question
- is it worth while?
- could it help improve patient outcome?
(2) Define hypothesis
- take an opinion on what the answer to the question is.
(3) Literature review
- make sure no one has already conclusively answered the question
- make sure it’ll benefit patients
(4) Involve statistician, and discuss:
- type of study
- calculate sample size (alpha and beta values, power, effect size , variance of population)
- how to reduce bias:
- -> blinding (single, double or triple)
- -> crossover
- -> randomization
- -> controls
(5) Develop inclusion & exclusion criteria
- stick to them when carrying out study!
(6) Calculate sample size needed
- beta value and power (small sample size is the commonest cause of a false negative result)
- alpha value (e.g. p < 0.05; limits false positive results)
- variance of population
- effect size
- statistical test
(7) Develop methodology
- side effects
- how to collect information
(8) Gain ethical approval
- consider professional virtue of medical loyalty
- autonomy, non-maleficence, beneficence & distributive justice.
Some issues include
- use of placebos when efficacious therapy available
- whether every research participant needs to sign a written consent
- whether informed consent is necessary (ICU patients)
- accepting drug company gifts
- misleading information from the drug reps.
(9) Perform pilot study
- modify protocol based on pilot study
(10) Carry out study
- patient information & informed consent important
- collect data
- measure outcomes
- monitor safety
- using appropriate statistical methods
(12) Compare to null hypothesis
- proven or disproven
- statistically significant difference or not
(13) Consider errors
- sources of bias
- patients lost to follow up
- adverse effects
- surprising benefits
(14) Submit for publication
- survive the peer review process and hope that the article is accepted!
- educate others of the findings so it can be implemented into clinical practice (knowledge translation)