Psychometric evaluation of a momentary posttraumatic stress disorder checklist: An ecological momentary assessment study of sexual assault survivors.

The Momentary Posttraumatic Stress Disorder Checklist for DSM-5 (PTSD; mPCL-5) is a 10-item ecological momentary assessment (EMA) version of the PTSD Checklist for DSM-5 designed to capture momentary PTSD symptoms. Prior work supports its reliability and validity but is limited by small samples, short EMA periods, and untested stability across time and participants. The present study examined within- and between-person reliability, convergent and discriminant validity, factor structure, and measurement invariance across time and participants. The sample comprised 64 women who presented to emergency care after sexual assault (Mage = 25.80 years, 54.7% White) who completed EMA surveys over 6 weeks. Total mPCL-5 scores demonstrated good within-person, ω = .88, and excellent between-person, ω = .96, reliability. Moderate-to-strong correlations between mPCL-5 total and subscale scores and negative affect, rs = .41-.88, ps < .001, evidenced convergent validity. Mostly nonsignificant positive affect associations suggested discriminant validity. Confirmatory factor analysis results supported a four-factor structure as the best-fitting model across levels, CFI = .94, TLI = .91, RMSEA = .072, although a one-factor model was also appropriate for between-person analyses. Measurement invariance analyses indicated stable loadings, Bs = 0.41-0.55, and intercepts, Bs = 1.51-2.18, across time and participants, with minimal between-time variance (< .002). Findings support mPCL-5 use in EMA research for monitoring short-term PTSD symptom change, identifying high-risk periods, and evaluating intervention responsiveness.