TABLE 1.

All Appendectomy, Appendicitis, and Negative Appendectomy

	All Appendectomy (n = 19,327)	Appendicitis (n = 18193)	Negative Appendectomy (n = 1042)	P-value
Number female patients	47.86%	46.9%	64.0%	P < 0.001*
Mean age (SD)	39.4 (16.6)	39.5 (16.6)	37.4 (15.9)	P < 0.001**
Pre-operative Imaging	91.3%	92.2%	75.3%	p < 0.001*
Negative Appendectomy	5.4%	–	–
Laparoscopy	84.8%	84.9%	83.5%	P = 0.24*
Perforation	15.0%	15.8%	–
Mean WBC (SD)	13.2 (4.3)	13.3 (4.3)	10.4 (4.0)	P < 0.001**
Mean BMI (SD)	27.7 (6.0)	27.8 (6.2)	27 (6.3)	P < 0.001**
Co-morbidity Index:				NS
0	86.5%	86.6%	85.5%
1	10.9%	10.8%	12.6%
2	1.7%	1.7%	1%
≥3	0.9%	0.9%	0.5%

SD = standard deviation

^*= Pearson Chi-squared test

^**= Independent Student’s T-test (two-sided)

P-values reflect results of statistical comparison between patients with appendicitis and patients with NA