I'm working with two different measures of PTSD symptoms, the Acute Stress Disorder Scale (ASDS) and PTSD Checklist (PCL) in an LGMM model in MPlus. The model uses four time points of PTSD symptoms (T1 = ASDS, T2 = PCL, T3 = PCL, T4 = PCL). For clinical interpretability, I would like to use raw scores in the model rather that standardizing the scales and presenting z-scores. Does anyone know of a way to transform the ASDS to make it comparable to/on the same scale as the PCL?
Below are some details on both measures (as used in my current study):
ASDS_T1: 14 items, score range 14-70, M=24.30, SD=10.38
PCL_T2: 17 items, score range 17-85, M=24.60, SD=11.03
PCL_T3: 17 items, score range 17-85, M=24.80, SD=12.09
PCL_T4: 17 items, score range 17-85, M=24.04, SD=11.20