Confounding and Simpson's paradox
- 3 December 1994
- Vol. 309 (6967) , 1480-1481
- https://doi.org/10.1136/bmj.309.6967.1480
Abstract
Charig et al undertook a historical comparison of success rates in removing kidney stones.2 Open surgery (1972-80) had a success rate of 78% (273/350) while percutaneous nephrolithotomy (1980-5) had a success rate of 83% (289/350), an improvement over the use of open surgery. However, the success rates looked rather different when stone diameter was taken into account. This showed that, for stones of /=2 cm, success rates of 73% (192/263) and 69% (55/80) were observed for open surgery and percutaneous nephrolithotomy respectively.Keywords
This publication has 2 references indexed in Scilit:
- Comparison of treatment of renal calculi by open surgery, percutaneous nephrolithotomy, and extracorporeal shockwave lithotripsy.BMJ, 1986
- Psychiatric Examples of Simpson's ParadoxThe British Journal of Psychiatry, 1979