What is a "Discretionary" Health Expense?

With consumer driven health plans like HSAs becoming more popular, consumers need more guidance in determining which medical expenditures are necessary and which are discretionary. The goal is to avoid or minimize discretionary health expenses because with HSAs, you are paying for most of your care out of pocket. Unfortunately, according to this article, more studies need to be done to help consumers make wise health spending decisions. Some health insurance companies, like Kaiser Permanente, have begun offering decision aids which seem to be helpful to consumers, but it remains to be seen how effective they are and whether these decision aids will be adopted by more insurers.