Validity of markers for association with disease phenotypes over time in individual patients.

Includes 75 CD subjects with at least four samples per individual patient.Sum of quartiles: Values presented are median (25th percentile, 75th percentile) and P-values correspond to Wilcoxon rank sum tests.Antibody positivity: Values presented are N (%) and P-values correspond to Fisher's Exact test (F) and Pearson's chi-square tests otherwise.Complication: fistula or stenosis.