The question of developing an effective intervention for advance care planning rests on several assumptions. On a general level, the assumption is that advance care planning is a good thing, that we should want more people to perform it. On a more specific level, the question assumes that an advance care plan, whether documented in a written advance directive or made in less formal ways, will accurately reflect an individual's wishes, will be updated periodically as needed, will be activated or put into play,, at the appropriate time, and will be interpreted and followed in the manner in which the individual intended it to be used. In other words, one must assume that advance care planning actually makes a difference and improves the decisionmaking process for patients who have lost decisional capacity. In this paper, I also assume that advance care planning remains an optional endeavor, rather than something required, for example, as a condition of obtaining health insurance. Having explicitly stated these assumptions, I do believe that there are interventions that can increase the use of advance care planning. There are a number of published studies examining such interventions that can provide insight into how best to accomplish this task. As of this writing, ten of these studies have been published,[1] as was one study that recommended executing an advance directive as part of a comprehensive social and safety evaluation for older patients.[2] In addition, there is one published study of the early effects of the Patient Self-determination Act on advance care planning.[3] These studies have been conducted in a variety of settings including hospital-based clinics, geriatric assessment clinics, nursing homes and other senior housing sites, and home care services for the frail elderly. All but two of the studies (High and Emanuel et al.) used subjects drawn from a single institution. Most studies have been limited to either elderly patients (aged sixty-five or older) or very seriously ill patients. The interventions have ranged from written materials provided through the mail or in person, to discussions held on a single occasion, to repeated conversations with health care providers over weeks to months. Although subjects may have been followed for some length of time, as in the study by Schneiderman et al., even the most intensive interventions did not continue for longer than four months. Almost all of these studies used completion of a written advance directive document as the primary outcome measure. Several studies also touched on advance care planning to the extent that subjects were asked whether they had discussed their wishes with someone else, such as family members and physicians. Only three studies - High, Rubin et al., and Emanuel et al. - employed more than 120 subjects in the intervention group. Given the range of settings, subjects, and interventions, it is not surprising that these studies found a wide range of positive responses, with anywhere from percent to 81 percent of subjects having written advance directives postintervention.[4] The lowest response rates (less than 20%) were obtained in studies involving unselected subjects drawn from outpatient clinics and people over the age of sixty-five recently dip charged from a hospital.[5] The highest response rates (greater than 60% were seen when interventions targeted very seriously ill patients or frail elderly people.[6] Although not found uniformly across all studies, several characteristics appear to be associated with the type of person who executes an advance directive in response to an intervention (or who has a directive in the first place in other, descriptive studies). Individuals more likely to have advance directives or to plan care in advance are older, white, well-educated, and tend generally to plan for the future, as evidenced by a greater proportion of estate wills than the general public. In a few studies, women were more likely than men to draw up advance directives. …