Objectives: To systematically review studies designed to increase advance directive completion in the primary care setting and employ meta-analytic techniques to quantify their effects.
Design: Extensive bibliographic searches of English-language literature published from January 1991 through July 2005 were conducted. Investigators abstracted prespecified information (e.g., design, study duration, types of interventions employed) and advance directive completion rates for intervention and control arms in each investigation and calculated absolute rate differences (i.e., difference in completion rates between the two groups) for each study. Individual study and pooled-effect sizes were also calculated, along with 95% confidence intervals (CIs).
Setting: Literature review.
Results: Eighteen studies were retained in the final sample. Most studies employed multimodal interventions. The most common approach consisted of educational materials directed at patients (through mailing or at visit) coupled with a patient-healthcare provider interaction in a group or individual setting (n=7). Absolute differences in completion rates varied from a high of 44% (favors intervention) to a low of -2% (favors control). Effect sizes could be calculated for 15 of the 18 studies. The pooled effect size was 0.50 (95% CI=0.17-0.83), indicating a moderate overall effect in favor of the intervention.
Conclusion: The majority of studies demonstrated statistically significant effects associated with the advance directive intervention. The most successful interventions incorporated direct patient-healthcare professional interactions over multiple visits. Passive education of patients using written materials (without direct counseling) was a relatively ineffective method for increasing advance directive completion rates in the primary care setting.