Analysis of clinical and demographical differences among participants and non-participants.

<p>IQR, interquartile range.</p><p>^a Systemic lupus erythematosus, rheumatoid arthritis, Sjögren syndrome, vasculitis.</p><p>^b Chronic or acute pancreatitis, inflammatory bowel disease, gastrointestinal hemorrhage, diverticulitis, short bowel syndrome, acute or recurrent cholangitis, benign biliary disease.</p><p>^c Chi-squared test.</p><p>^d t-test.</p><p>Analysis of clinical and demographical differences among participants and non-participants.