Cost-effectiveness analysis applied to the veterinary medicine: The economic value of packed cell value in the prognosis of horse surgical colic

Techniques of cost-effectiveness analyses were applied to determine whether or not it is economically efficient to measure the packed cell volume (PCV) on a colic horse before deciding on abdominal surgery. The effects of this decision of uncertainty on the estimated values of the parameters (probability of survival after surgery, surgery costs, PCV positive predictive value, and length of survival after surgery) were considered along with the monetary values of collecting additional information on those parameters. The effects of uncertainty on
the incremental net benefits of each alternative were depicted by tornado diagrams,
cost-effectiveness acceptability curves, and posterior probability distributions. The worth of additional information was computed as the expected values of perfect and sampling information. Given previously published results, the best PCV cut-off point to distinguish between survivors and nonsurvivors was at 44%. At this threshold, the most economically effective alternative is to measure PCV before surgery providing the owner is willing to pay less than €672 for each year the horse survives. Uncertainty on probability of survival after surgery largely influenced the decision whether or not to measure the PCV, but one should spend at most €381 in research to reduce this uncertainty. A study of postoperative survival of
500 colic horses would ensure an expected gain of €370 associated with a reduction in
uncertainty.