Table 2.

Adjusted Likelihood of Meeting Criteria for Items on the AMHART

Measure	Adjusted Odds Ratio	95% CI	P-Value
Model
ChatGPT-5	Ref	Ref	Ref
ChatGPT-4	0.69	0.53, 0.90	0.006
Gemini 2.5 Flash	0.81	0.62, 1.05	0.107
Claude Sonnet 4.5	0.27	0.21, 0.35	< 0.001
Vignette
Anxiety	Ref	Ref	Ref
Depression	0.25	0.21, 0.30	< 0.001
Symptom Severity
Moderate	Ref	Ref	Ref
Severe	0.51	0.42, 0.61	< 0.001

Table Notes: “Ref” denotes the regression comparison category used to parameterize a predictor; it does not indicate evaluator weighting or a reference standard for AMHART scoring. Values reported from item-level mixed-effects logistic regression. The binary outcome was whether a given item passed or failed for a particular chatbot-persona-conversation combination, with fixed effects for chatbot, diagnostic category, symptom severity, and sex, and random effects for item and conversation (i.e., run index).