Examining Validity and Reliability of the Shared Decision Making Process Survey in Adults With Depression

The purpose of this study is to test two differently worded versions of the Shared Decision Making Process scale in a sample of adults who have recently made a decision about treatment of depression. The main goals are to gather evidence of psychometric performance of the scale, compare performance of different wording for items, and to extend generalizability of the findings to younger adults.

Subjects are randomly assigned to one of the two versions of the Shared Decision Making Process scale and complete a set of measures regarding their experiences with decision making for depression, demographics, and health status. A subset of respondents will complete the Shared Decision Making Process scale and selected other items again 1 week later to examine short term test-retest reliability.

Staff will work with a national sampling firm to recruit subjects and obtain 500 responses to the baseline survey (n=250 for each version) and a subset will complete a retest survey (n=200; 50 from each age and survey type group). Eligible subjects are adults aged 18-75 who talked with a health care provider about treatment for depression in the preceding 12 months. The sample is not a national probability sample; however, the recruitment efforts will ensure about 50% of respondents aged 18-39 and 50% aged 40-75, and to ensure at least 25% of the sample is racial/ethnic minorities (Black or African American, Asian, Hispanic or Latino).

The investigators will examine validity and reliability of the different versions. The sample size was determined to ensure sufficient power to detect differences in key subgroups, including age (younger adults vs. older adults) and version (A vs. B). To detect a difference of about 0.33 standard deviations at 0.05 significance with 80% power would require 125 per group.