Letters Section Editor: Stephen J. Lurie, MD, PhD, Senior Editor.
To the Editor: Dr Mehta and colleagues1
reported that patients in the intensive care unit who received diuretics for acute renal failure (ARF) had a higher risk of
dying and nonrecovery of renal function than those who did not.
I am concerned that the authors' use of the odds ratios may misrepresent
the difference in risk of death between the 2 groups, which would be better
expressed with risk ratios. Odds ratios are not analogous to risk ratios,
particularly when the outcome in question occurs commonly. The authors state
that "diuretic use was associated with a 68% (95% confidence interval [CI],
6%-164%) increase in in-hospital mortality and a 77% (95% CI, 14%-176%) increase
in the odds of death or nonrecovery of renal function." This statement is
misleading and suggests a much larger increased risk from diuretics than was
actually observed. The risk of dying with or without diuretics is very high
and the actual increase in risk of death associated with diuretics was more
on the order of 20% to 25%.
Emmett M. Diuretics in Critically Ill Patients With Acute Renal Failure—Reply. JAMA. 2003;289(11):1379-1381. doi:10.1001/jama.289.11.1379-a