Temporal trends in the misdiagnosis rates between Crohn’s disease and intestinal tuberculosis

Table 1 Demographic and clinical characteristics of Crohn’s disease patients misdiagnosed as intestinal tuberculosis (final Crohn’s disease group) and intestinal tuberculosis patients misdiagnosed as Crohn’s disease (final intestinal tuberculosis group) n (%)

	Final CD group (n = 494)	Final ITB group (n = 83)	P value
Male	342 (69.2)	49 (59.0)	0.0661
Age at definite diagnosis4 (yr)	23.4 (19.5-30.3)	35.8 (27.3-46.0)	< 0.0012
Interval from misdiagnosisto definite diagnosis4 (mo)	5.2 (2.3-12.0)	4.0 (1.7-13.2)	0.0822
Presenting symptoms
Abdominal pain	318 (64.4)	46 (55.4)	0.1181
Diarrhea	293 (59.3)	22 (26.5)	< 0.0011
Weight loss	104 (21.1)	12 (14.5)	0.1651
Hematochezia/melena	84 (17.0)	6 (7.2)	0.0231
Constipation	1 (0.2)	2 (2.4)	0.0563
Asymptomatic (incidentally diagnosed at routine health check-up)	8 (1.6)	10 (12.0)	< 0.0013
Fever	28 (5.7)	1 (1.2)	0.1033
Active and/or past perianal fistula	192 (38.9)	7 (8.4 )	< 0.0011
Active pulmonary TB	0 (0.0)5	10 (12.7)6	< 0.0013
Old pulmonary TB in chest X-ray	5/469 (1.1)7	16/66 (24.2)7	< 0.0013
Medical institutions where misdiagnosis was made			0.0151
Primary clinic	44 (8.9)	12 (14.5)
Secondary referral hospital	118 (23.9)	30 (36.1)
Tertiary referral hospital	314 (63.6)8	41 (49.4)9
Unknown	18 (3.6)

¹The P value by the χ² test;

²The P value by the Mann-Whitney U test;

³The P value by the Fisher’s exact test;

⁴The Median (Interquartile range);

⁵Not evaluated in one patient;

⁶Not evaluated in four patients;

⁷Patients who had active pulmonary TB and patients whose chest X-ray film was unavailable were excluded;

⁸Misdiagnoses were made at our institution in 68 patients (13.8%);

⁹Misdiagnoses were made at our institution in 7 patients (8.4%). CD: Crohn’s disease; ITB: Intestinal tuberculosis; TB: Tuberculosis.

Table 2 Characteristics of patients finally diagnosed with intestinal tuberculosis who were initially misdiagnosed as Crohn’s disease; final diagnostic criteria for intestinal tuberculosis and medication for Crohn’s disease before correct diagnosis n (%)

	Final ITB group1 (n = 83)
Diagnostic criteria of ITB
Positive culture of M. Tb alone	40 (48.2)
Positive AFB smear alone	1 (1.2)
Positive culture of M. Tb + Positive AFB smear	1 (1.2)
Caseating granuloma alone	1 (1.2)
Improvement after empirical anti-tuberculosis	40 (48.2)
treatment in patients without the above findings
Medication for CD before definite diagnosis of TB
No medication	21 (25.3)
5-ASA alone	42 (50.6)
5-ASA + Corticosteroids	12 (14.5)
5-ASA + Thiopurines	1 (1.2)
5-ASA + Corticosteroids + Thiopurines	4 (4.8)
Medication given, but unavailable records	3 (3.6)

¹Final ITB group: Intestinal tuberculosis patients initially misdiagnosed as Crohn’s disease. 5-ASA: 5-amino salicylic acids; AFB: Acid-Fast Bacilli; CD: Crohn’s disease; ITB: Intestinal tuberculosis; M. Tb: Mycobacterium tuberculosis; TB: Tuberculosis.