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Endgames Statistical Question

Randomised controlled trials: understanding confounding

BMJ 2015; 351 doi: (Published 25 September 2015) Cite this as: BMJ 2015;351:h5119

Re: Randomised controlled trials: understanding confounding

Dr. Sedgwick gave four ways of tackling the confounding, viz.:

1. Random allocation
2. Stratifying the random allocation
3. Intention to treat analysis
4. Multiple regressions

Here we would like to add:

1. Strict subject selection criteria: Inclusion and exclusion criteria, where confounders are eliminated or made as selection elligibility criteria

2. Matching for confounders like, same socio-ecnomic status in the two groups, especially in the observational studies.

The above two methods as well will tackle the confounders.

Competing interests: No competing interests

02 November 2015
Neeru Gupta
Scientist F
Jugal Kishore.
Indian Council of Medical Research
Ansari Nagar, New Delhi-110029.