The lever is a powerful tool |
Thinking about calcium levels and causation and repletion, one cannot help but think about all sorts of other levels we check in the ICU - potassium, magnesium, phosphate - and may other things we routinely do but about which we have no real inkling of an idea as to whether we're doing any patients any good. (Arterial lines are another example.) Are we just wasting our time with many of the things we do? This question becomes more urgent as evidence mounts that much of what we do (in the ICU and elsewhere) is useless, wasteful, or downright harmful. But who or what agency is going to fund a trial of potassium or calcium replacement in the ICU? It certainly seems unglamorous. Don't we have other disease-specific priorities that are paramount in importance to such a trial?
I then realized that a good businessman, wanting to maximize the "profit" from a large, randomized controlled trial (and the dollars "invested" in it), would take advantage of economies of scale. For those who are not business savvy (I do not imply that I am), business costs can be roughly divided into fixed costs and variable costs. If you have a factory making widgets you have certain costs such as the rent, advertising, widget making machines. These costs are "fixed" meaning that they are invariable whether you make 100 widgets or 10,000 widgets. Variable costs are the costs of materials, electricity, and human resources which must be scaled up as you make more widgets. In general, the cost of making each widget goes down as the fixed costs are spread out over more widget units. Additionally, if you can leverage your infrastructure to make wadgets, a product similar to a widget, you likewise increase profits by lowering costs per unit.