Table 3.

Prevalence ratios for the relationship between associated features and ever use of a gluten free diet among children 3–5 years old with autism spectrum disorder in the Study to Explore Early Development

Associated Feature	Ever use N=130 %	Never use N=559 %	Prevalence Ratio	95% CI
Developmental regression
Yes	42.3	25.6	1.70	1.23, 2.36
No	67.7	74.4	–	–
Intellectual disability
Yes	61.5	62.3	0.92	0.77, 1.10
No	38.5	37.7	–	–
ASD severity
>7	49.6	38.6	1.34	0.94, 1.91
<7	50.4	61.4	–	–
Missing (n)	5	10	–	–
Maternal gastrointestinal issues
Yes	16.0	20.3	0.96	0.56, 1.65
No	84.0	79.7	–	–
Missing (n)	1	19	–	–
Child gastrointestinal issues
Yes	78.3	47.0	2.95	2.31, 3.77
No	21.7	53.0	–	–
Missing (n)	1	29	–	–

GFD, gluten free diet; ASD, autism spectrum disorder; CI, confidence interval

Observations with missing data were dropped from the regression model

Adjustment for maternal race/ethnicity, maternal education, and maternal age at clinic visit, child year of birth using inverse probability weights; site adjusted using a random intercept