Several studies have reported high levels of distress in family members who have made health care decisions for loved ones at the end of life. A method is needed to assess the readiness of family members to take on this important role. Therefore, the purpose of this study was to develop and validate a scale to measure family member confidence in making decisions with (conscious patient scenario) and for (unconscious patient scenario) a terminally ill loved one.

On the basis of a survey of family members of patients with amyotrophic lateral sclerosis (ALS) enriched by in-depth interviews guided by Self-Efficacy Theory, we developed six themes within family decision making self-efficacy. We then created items reflecting these themes that were refined by a panel of end-of-life research experts. With 30 family members of patients in an outpatient ALS and a pancreatic cancer clinic, we tested the tool for internal consistency using Cronbach's alpha and for consistency from one administration to another using the test–retest reliability assessment in a subset of 10 family members. Items with item to total scale score correlations of less than .40 were eliminated.

A 26-item scale with two 13-item scenarios resulted, measuring family self-efficacy in decision making for a conscious or unconscious patient with a Cronbach's alphas of .91 and .95, respectively. Test–retest reliability was r = .96, p = .002 in the conscious senario and r = .92, p = .009 in the unconscious scenario.

The Family Decision-Making Self-Efficacy Scale is valid, reliable, and easily completed in the clinic setting. It may be used in research and clinical care to assess the confidence of family members in their ability to make decisions with or for a terminally ill loved one.

Persons with ALS differ from those with other terminal illnesses in that they commonly retain capacity for decision making close to death. The role patients would opt to have their families play in decision making at the end of life may therefore be unique. This study compared the preferences of patients with ALS for involving family in health care decisions at the end of life with the actual involvement reported by the family after death.

A descriptive correlational design with 16 patient–family member dyads was used. Quantitative findings were enriched with in-depth interviews of a subset of five family members following the patient's death.

Eighty-seven percent of patients had issued an advance directive. Patients who would opt to make health care decisions independently (i.e., according to the patient's preferences alone) were most likely to have their families report that decisions were made in the style that the patient preferred. Those who preferred shared decision making with family or decision making that relied upon the family were more likely to have their families report that decisions were made in a style that was more independent than preferred. When interviewed in depth, some family members described shared decision making although they had reported on the survey that the patient made independent decisions.

The structure of advance directives may suggest to families that independent decision making is the ideal, causing them to avoid or underreport shared decision making. Fear of family recriminations may also cause family members to avoid or underreport shared decision making. Findings from this study might be used to guide clinicians in their discussions of treatments and health care decision making with persons with ALS and their families.