Case Control Study
Copyright ©The Author(s) 2017.
World J Gastroenterol. Apr 28, 2017; 23(16): 2948-2956
Published online Apr 28, 2017. doi: 10.3748/wjg.v23.i16.2948
Table 2 Outpatient visits and examination of pyogenic liver abscess cases and controls n (%)
Demographic and clinical characteristicsCases(n = 2135)Controls(n = 10675)Total(n = 12810)P value
Frequency of OPD visits
< 1119 (5.6)2781 (26.1)2900< 0.001
1-2243 (11.4)1989 (18.6)2232
3-7774 (36.3)3403 (31.9)4177
≥ 8999 (46.8)2502 (23.4)3501
Frequency of abdominal ultrasound
01692 (79.3)10329 (96.8)12021< 0.001
1358 (16.8)321 (3.0)679
≥ 285 (4.0)25 (0.2)110
Abdominal ultrasound
with443 (20.8)346 (3.2)789< 0.001
without1692 (79.3)10329 (96.8)12021
ERCP-related procedures
with107 (5.0)9 (0.1)116< 0.001
without2028 (95.0)10666 (99.9)12694
Upper GI panendoscopy
with172 (8.1)131 (1.2)303< 0.001
without1963 (91.9)10544 (98.8)12507
Lower GI endoscopy
with36 (1.7)53 (0.5)89< 0.001
without2099 (98.3)10622 (99.5)12721
Upper or lower GI endoscopy
with189 (8.9)171 (1.6)360< 0.001
without1946 (91.2)10504 (98.4)12450
Upper GI panendoscopy
upper GI only1150 (7.0)130 (1.2)280< 0.001
upper GI with ERCP-related procedures22 (1.0)1 (0.0)23
ERCP without upper GI85 (4.0)8 (0.1)93
None21878 (88.0)10536 (98.7)12414
Lower GI endoscopy
lower GI only134 (1.6)53 (0.5)87< 0.001
lower GI with ERCP-related procedures2 (0.1)0 (0.0)2
ERCP without lower GI105 (4.9)9 (0.1)114
None21994 (93.4)10613 (99.4)12607
Upper or lower GI endoscopy
upper or lower GI only1166 (7.8)170 (1.6)336< 0.001
upper or lower GI with ERCP-related procedures23 (1.1)1 (0.0)24
ERCP without upper or lower GI84 (3.9)8 (0.1)92
None21862 (87.2)10496 (98.3)12450