Objectives: to assess the role of four administrative healthcare databases (pathology reports, copayment exemptions, hospital discharge records, gluten-free food prescriptions) for the identification of possible paediatric cases of celiac disease.
Design: population-based observational study with record linkage of administrative healthcare databases. SETTING AND PARTICIPANT S: children born alive in the Friuli Venezia Giulia Region (Northern Italy) to resident mothers in the years 1989-2012, identified using the regional Medical Birth Register.
Main outcome measures: we defined possible celiac disease as having at least one of the following, from 2002 onward: 1. a pathology report of intestinal villous atrophy; 2. a copayment exemption for celiac disease; 3. a hospital discharge record with ICD-9-CM code of celiac disease; 4. a gluten-free food prescription. We evaluated the proportion of subjects identified by each archive and by combinations of archives, and examined the temporal relationship of the different sources in cases identified by more than one source. RESULT S: out of 962 possible cases of celiac disease, 660 (68.6%) had a pathology report, 714 (74.2%) a copayment exemption, 667 (69.3%) a hospital discharge record, and 636 (66.1%) a gluten-free food prescription. The four sources coexisted in 42.2% of subjects, whereas 30.2% were identified by two or three sources and 27.6% by a single source (16.9% by pathology reports, 4.2% by hospital discharge records, 3.9% by copayment exemptions, and 2.6% by gluten-free food prescriptions). Excluding pathology reports, 70.6% of cases were identified by at least two sources. A definition based on copayment exemptions and discharge records traced 80.5% of the 962 possible cases of celiac disease; whereas a definition based on copayment exemptions, discharge records, and gluten-free food prescriptions traced 83.1% of those cases. The temporal relationship of the different sources was compatible with the typical diagnostic pathway of subjects with celiac disease.
Conclusions: the four sources were only partially consistent. A relevant proportion of all possible cases of paediatric celiac disease were identified exclusively by pathology reports.