This study examined performance of the Shared Decision Making (SDM) Process scale in patients with depression, compared alternative wording of two items in the scale, and explored performance in younger adults.
A web-based non-probability panel of respondents with depression aged 18-39 (younger) or 40-75 (older) who talked with a health care provider about starting or stopping treatment for depression in the past year were surveyed. Respondents completed one of two versions of the SDM Process scale that differed in wording of pros and cons items, and completed measures of decisional conflict, decision regret and who made the decision (mainly the respondent, mainly the provider or together). A subset of respondents completed a retest survey at 1 week. We examined how version and age group impacted SDM Process scores and calculated construct validity and re-test reliability. We hypothesized that patients with higher SDM Process scores would show less decisional conflict using the SURE scale (range=0-4); top score=no conflict versus other, and less regret (range 1-4; higher scores indicated more regret).
The sample (N=494) was majority White, non-Hispanic (82%), female (72%), 48% were younger, and 23% had a high school education or less. SDM Process scores did not differ by version (p=.09). SDM Process scores were higher for younger respondents (M=2.6, SD=1.0) than older respondents (M=2.3, SD=1.1; p=0.001). Higher SDM Process scores were also associated with no decisional conflict (M=2.6, SD=0.99 vs. M=2.1, SD=1.2 p<0.001) and less decision regret (r=-0.18, p<.001). Retest reliability was ICC=0.81.
The SDM Process scale demonstrated validity and re-test reliability in younger adults, and changes to item wording did not impact scores. Although younger respondents reported more SDM, there is room for improvement in SDM for depression treatment decisions.