Can the CalproQuest predict a positive Calprotectin test? A prospective diagnostic study

Area of Science:

• Gastroenterology
• Primary Care Medicine
• Diagnostic Test Evaluation

Background:

• Diagnosing inflammatory bowel disease (IBD) in primary care (PC) presents challenges and often leads to significant diagnostic delays.
• The fecal Calprotectin test is a valuable tool, but widespread use in PC for undifferentiated abdominal complaints is cost-prohibitive.
• The CalproQuest questionnaire was developed to identify patients with a higher pre-test probability for elevated fecal Calprotectin levels.

Purpose of the Study:

• To validate the effectiveness of the CalproQuest questionnaire in increasing the pre-test probability for a positive fecal Calprotectin test in a primary care setting.
• To assess the sensitivity and specificity of the CalproQuest for detecting elevated Calprotectin levels and confirming an IBD diagnosis.
• To evaluate the impact of the CalproQuest on patient-reported diagnostic delay.

Main Methods:

• A prospective diagnostic trial was conducted involving 156 patients across 7 study centers.
• Patients completed the 8-item CalproQuest questionnaire, which assesses IBD-suggestive symptoms.
• The primary outcome measured was the sensitivity and specificity of CalproQuest for fecal Calprotectin levels ≥ 50 μg/g and for a confirmed IBD diagnosis upon referral to secondary care.

Main Results:

• The CalproQuest demonstrated low sensitivity (36%) and specificity (57%) for detecting Calprotectin levels ≥ 50 μg/g.
• For predicting a positive IBD diagnosis, the CalproQuest showed a sensitivity of 37% and a specificity of 67%.
• The study observed a substantial patient-reported diagnostic delay, averaging 61 months.

Conclusions:

• The CalproQuest questionnaire exhibited poor performance in terms of sensitivity and specificity for both elevated Calprotectin levels and a confirmed IBD diagnosis in this primary care cohort.
• The findings suggest that the CalproQuest, as used in this study, is not a reliable tool for improving the pre-test probability of IBD in primary care.
• Further prospective research is warranted to determine optimal cut-off values, validate the questionnaire's utility, and assess its cost-effectiveness in conjunction with fecal Calprotectin testing within the primary care setting.