Do bots provide correct and adequate guidance regarding acidity: A blinded comparison rated by patients and physicians

Table 8 Readability assessment of responses generated by ChatGPT-5, Gemini-2.5, and Claude-4

Metric	ChatGPT-5			Gemini-2.5			Claude-4			P value
	Score	Grade	Reading difficulty	Score	Grade	Reading difficulty	Score	Grade	Reading difficulty	A vs B	A vs C	B vs C
ARC	12.6 ± 2.2	High school	Moderately difficult	17.4 ± 4.2	Graduate	Very difficult	19.6 ± 1.7	Doctorate	Extremely difficult	0.0001	0.0001	0.0033
ARI	13.5 ± 2.9	College	Fairly difficult	24.5 ± 9.2	Graduate	Very highly difficult	27.8 ± 2.9	Graduate	Extremely difficult	0.0001	0.0001	0.0359
GFI	13.1 ± 6.1	College freshman	Difficult	16. 9 ± 4.1	Early doctorate	Very difficult	18.8 ± 2.9	Doctorate	Very difficult	0.0018	0.0001	0.0207
FRE	34.7 ± 19.5	College level	Difficult	13.9 ± 17.2	Post-graduate	Very difficult	3.9 ± 3.3	Beyond post-graduate	Very difficult	0.0001	0.0001	0.0006
SMOG	10.1 ± 2.7	10th grade	Fairly difficult	16.2 ± 2.7	Graduate	Very highly difficult	18.8 ± 2.7	Doctorate level	Extremely difficult	0.0001	0.0001	0.0001

P < 0.05. P values indicate pairwise comparisons (ChatGPT-5 vs Gemini-2.5, ChatGPT-5 vs Claude-4a, Gemini-2.5 vs Claude-4a). Readability was evaluated using five established indices: Automated Readability Index (ARI), Gunning Fog Index (GFI), Flesch Reading Ease (FRE), Simple Measure of Gobbledygook (SMOG), and Average Reading Level Consensus (ARC). Results are presented as the mean ± SD along with corresponding United States grade levels and qualitative reading difficulty categories. Lower scores and grade levels indicate easier readability. A: ChatGPT-5; B: Gemini-2.5; C: Claude-4a.