In practical terms, this can mean hundreds, thousands, or millions of additional deaths due to failure to prioritize. In non-life-saving contexts it means thousands or millions of people with untreated disabling conditions.
Even when other ethical issues in global health are very important in absolute terms, they are typically much smaller than this. For instance, it may be worse on equity grounds to treat a million people in a relatively affluent city than to treat the same number of people spread between the city and the relatively much poorer rural areas. However, it is not vastly worse — not so bad that 99% of the value is lost.
Learning how to correctly factor these other ethical issues into our decision making is an important and challenging problem, but we are currently failing at a much more basic, more obvious, and more important problem: choosing to help more people instead of fewer people, to produce a larger health benefit instead of a smaller one.
Challenges addressed
Some people don't see cost-effectiveness as an ethical issue at all, since it is so cut and dried that it seems like a mere implementation issue. This is misguided. People who decide how to spend health budgets hold the lives or livelihoods of many other people in their hands. They are literally making life-or-death decisions. Most decisions of this sort take dramatically insufficient account of cost-effectiveness. As a result, thousands or millions of people die who otherwise would have lived. The few are saved at the expense of the many. It is typically done out of ignorance about the significance of the cost-effectiveness landscape rather than out of prejudice, but the effects are equally serious.
Some object that consequences are not the only thing that matters. For example, some people think that acting virtuously or avoiding violating rights matters too. However, all plausible ethical theories hold that consequences are an important input into moral decision-making, particularly when considering life or death situations, or those affecting thousands of people. Indeed these are precisely the types of cases in which people think that it may even become permissible to violate rights. However, in the cases under consideration, there is not even a conflict between producing a much greater good and acting virtuously or avoiding violating people's rights. The consequences are thus of great moral importance, with no serious moral factors counting in the opposite direction. Proponents of all ethical theories should therefore agree about the moral importance of funding the most costeffective interventions.
People might also be concerned about the particular choices involved in estimating the benefits of different health interventions. For example, they may disagree about particular disability weights, or about the method for eliciting these weights, or about discounting health benefits, or weighting benefits depending on the age of the recipients, or whether other issues such as equality need to be factored in. However, none of this is in serious disagreement with the thrust of this note. Indeed I personally have many of the same concerns, but as mentioned earlier the practical choices we face often involve factors of ten or more between different interventions, so none of the modifications mentioned here will change the rankings very much. People who are concerned about the details of measuring cost-effectiveness should join with the cost-effectiveness community in improving these measures, rather than throwing out the baby with the bathwater, and leading to thousands of unnecessary deaths.