Repeated assessments of depressive symptoms in randomized psychosocial intervention trials: best practice for analyzing symptom change over time.

ABSTRACT:

Objective

Psychotherapy randomized trials rarely have tested for the best fitting model for time effects. We examined the fit of different statistical models for examining time when repeated assessments of depressive symptoms are the primary outcome.

Method

We used data from three studies comparing psychotherapy treatments for major depressive disorder. Outcome measures were self-report ratings for Study 1 (N = 237) and Study 2 (N = 100) and clinician ratings for Study 3 (N = 120) of depressive symptoms measured at every session (Studies 1 and 2) or monthly (Study 3). We examined the fit of the following time patterns: linear, quadratic, cubic, log transformation of time, piece-wise linear, and unstructured.

Results

In Study 1, a log-linear model

SUBMITTER: Crits-Christoph P 

PROVIDER: S-EPMC9649835 | biostudies-literature | 2023 Feb

REPOSITORIES: biostudies-literature