Randomisation is necessary to disentangle intrinsic patient risk from effects of care

Papers p 1274

Intensive care in the United Kingdom is certainly underprovided relative to many developed counties. The United States spends over 1% of its gross national product on providing intensive care, while Britain spends around 0.05%—possibly twentyfold less.1 But intensive care remains largely outside the evidence based paradigm—apparently for ethical reasons. Judging the appropriateness of intensive care provision still depends solely on apparent unmet need and observed associations of prognostic indicators with mortality. This week's BMJ sees another such study.2

It seems too easy to claim benefit in intensive care on the basis of biological plausibility and observational comparison alone. For example, a recent Cochrane overview of 30 trials on the effect of intravenous albumin for acute renal failure,3 which showed significant harm, was dismissed by some enthusiasts.4 The writings of respected and dispassionate authors who have held intensive care to be immune from randomisation do not help this apparent impasse. 5 6 In the absence of any rigorous measurement of attributable effect, intensive care will continue to be provided on the basis of evidence that is unacceptable in other areas of health enhancement. With 21st century medical technology …