One hundred and seventy-one patients had appendectomies during the study period. Among the 171 patients, 160 had a preoperative CT scan, and all patients had a pathology report. Thirty-four patients had a fecalith in CT scans, 18 patients had a fecalith in pathology reports, 21 patients had a fecalith in both CT scans and pathology reports. One hundred and one patients were operated in the summer months, 70 patients were operated in non-summer months. In summer, 34 patients had a fecalith, and 26 had perf/abs. In non-summer, 39 patients had a fecalith, and 25 had perf/abs (Table 2).
Table 2. The patient data in summer and non-summer.
|
Summer
|
Non-summer
|
p value
|
Patient number
|
101
|
70
|
|
Age (year)
|
12.2±3.7
|
11.4±4.2
|
0.290#
|
Male: female
|
70:31 (2.3:1)
|
45:25 (1.8:1)
|
0.363*
|
With fecalith
|
34 (33.6%)
|
39(55.7%)
|
0.004*
|
Perforation/abscess
|
26
|
25
|
0.161*
|
CRP (mg/dL)
|
6.64±7.78
|
9.06±9.61
|
0.087#
|
WBC*1000
|
16.1±5.0
|
15.4±4.9
|
0.392#
|
Neutrophil (%)
|
81.46±9.67
|
81.57±7.96
|
0.938#
|
Lymphocyte (%)
|
10.97±7.47
|
10.44±6.59
|
0.643#
|
Monocyte (%)
|
6.53±2.73
|
7.23±2.80
|
0.115#
|
*Chi-square test; # t-test
The numbers of AA and AA patients with a fecalith in each month were shown in Figure 1. The number of AA patients increased obviously in summer, mainly due to more patients without a fecalith in summer. The patients with a fecalith remained relative stable in numbers throughout the year. The % of AA patients with a fecalith is significantly higher in the non-summer months (55.7%) than summer (33.6%) (Table 3) because of fewer total AA patients in that period.
Table 3. The number of patients with and without fecaliths in summer and non-summer months.
|
Summer
|
Non-summer
|
Total
|
With fecalith
|
34 (33.6%)
|
39 (55.7%)
|
73 (42.7%)
|
Without fecalith
|
67 (66.4%)
|
31 (44.3%)
|
98 (57.3%)
|
Total
|
101 (100%)
|
70 (100%)
|
171 (100%)
|
The chi-square statistic is 8.2171. The p-value is 0.00415. This result is significant at p < .05
The presence of a fecalith had an association with appendiceal perf/abs (Table 4, p=0.000036), however, the incidence of perf/abs had no significant difference between the summer and the non-summer months (Table 5, p=0.161056).
Table 4. The correlation of appendiceal perforation/abscess with fecaliths.
|
With fecalith
|
Without fecalith
|
Total
|
Perf/abs
|
34
|
17
|
51
|
No perf/abs
|
39
|
81
|
120
|
Total
|
73
|
98
|
171
|
The chi-square statistic is 17.0767. The p-value is 0.000036. This result is significant at p < .05
Table 5. The number of appendiceal perforation/abscess in summer and non-summer months.
|
Summer
|
Non-summer
|
Total
|
Perf/abs
|
26 (25.7%)
|
25 (35.7%)
|
51 (29.8%)
|
No perf/abs
|
75 (74.3%)
|
45 (64.3)
|
120 (70.2%)
|
Total
|
101 (100%)
|
70 (100%)
|
171 (100%)
|
The chi-square statistic is 1.9643. The p-value is 0.161056. This result is not significant at p < .05
There is no significant difference in age, gender between the summer and the non-summer months.
The average CRP level was higher in the non-summer months, but the difference was not statistically significant when compared with summer (Table 2). There was also no significant difference in other laboratory results between the summer and the non-summer months.