Variability in Celiac Serology Testing by Provider Type: A Single-Center Experience

To evaluate the ordering practices of celiac disease (CD) serologies by providers at a tertiary, academic, Children’s Hospital and compare them to guidelines and best practices. METHODS: We analyzed celiac serologies ordered in 2018 by provider type (pediatric gastrointestinal (GI) specialists, primary care providers (PCPs), and nonpediatric GI specialists), and identified causes for variability and nonadherence. RESULTS: The antitissue transglutaminase antibody (tTG) IgA was ordered (n = 2504) most frequently by gastroenterologists (43%), endocrinologists (22%), and other (35%). Total IgA was ordered with tTG IgA for screening purposes in 81% of overall cases, but endocrinologists ordered it only 49% of the time. The tTG IgG was ordered infrequently (1.9%) compared with tTG IgA. Antideaminated gliadin peptide (DGP) IgA/IgG levels were also infrequently ordered (5.4%) compared with tTG IgA. The antiendomysial antibody was ordered sparingly (0.9%) compared with tTG IgA, but appropriately by providers with expertise in CD, similar to ordering for celiac genetics (0.8%). Of the celiac genetic tests, 15% were ordered in error. The positivity rate of the tTG IgA ordered by PCPs was 4.4%. CONCLUSIONS: The tTG IgA was appropriately ordered by all types of providers. Endocrinologists inconsistently ordered total IgA levels with screening labs. DGP IgA/IgG tests were not commonly ordered but were inappropriately ordered by one provider. The low number of ordered antiendomysial antibody and celiac genetic tests suggests under-utilization of the nonbiopsy approach. The positive yield of tTG IgA ordered by PCPs was higher compared with previous studies.