Table A.1.
Model comparison and model building process for PTSD
| Sampling Units | N total observations = 149 | |||||||||
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| N subjects = 77 | ||||||||||
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| Model Specification | Model Name | Nested Model | Fixed Effects | Random Effects | Model fit | LRT Test against nested | ||||
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| AIC | BIC | −2 LL | df | df | X2 | |||||
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| RE only | Null | - | - | intercepts | 407.2 | 416.2 | 401.2 | 3 | - | - |
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| FE main effect | Model 1 | Null | Time | intercepts | 409.1 | 425.2 | 401.1 | 4 | 1 | .1 |
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| FE two-way interactions – cumulative trauma | Model 2 | Model 1 | Time + Age + Gender + Cumulative Trauma + Cumulative Trauma x Time | intercepts | 404.8 | 428.8 | 388.8 | 8 | 8 | 12.3* |
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| FE two-way interactions – trauma subtypes | Model 3 | Model 1 | Time + Age + Gender + Victimization + Death Threat + Accident/Injury + Victimization x Time + Death Threat x Time + Accident/Injury x Time | intercepts | 398.4 | 434.4 | 374.4 | 12 | 8 | 26.7* |
Note. The PTSD variable is operationalized as standardized (Z) scores on the PCL for DSM IV at Time 1 and PCL-5 at Time 2, to allow for comparison across time. Abbreviations: Random effects (RE); Fixed effects (FE); Akaike’s Information Criterion (AIC); Schwarz’s Bayesian Criterion (BIC); −2 Log Likelihood (−2 LL); Likelihood ratio test (LRT)