Dr Naismith and colleagues determined the degree of this intrapersonal variability in the context of quiescent Crohn's disease.
A single-centre prospective study was undertaken in 143 Crohn's disease patients in clinical remission.
The research team analyzed 3 fecal calprotectin levels from stool samples on consecutive days.
Consistency of fecal calprotectin levels was determined by measuring the intraclass correlation (ICC).
The reliability of detecting a ‘case’ of active inflammation as defined for specific concentrations of fecal calprotectin was measured by the kappa statistic.
|The kappa statistic for the reliability of detecting a case as defined by an FC level of 50 μg/g was 0.65|
|Alimentary Pharmacology & Therapeutics|
The research team obtained 98 complete sets of results.
The ICC was 0.8, which represents low variability across samples.
The doctors reported the kappa statistic for the reliability of detecting a case as defined by an FC level of 50 μg/g was substantial at 0.65.
Dr Naismith's team concluded, "Day to day variability of fecal calprotectin is low in our cohort of quiescent Crohn's disease patients and the reliability of defining a ‘case’ is moderately good."
"These data provide reassurance to clinicians using a single calprotectin sample to inform therapeutic strategies in this cohort."