Demographic and clinical characteristics of 508 patients with suspected appendicitis
| True positive (n=103) | True negative (n=181) | False positive (n=12) | False negative (n=12) | Inconclusive (n=200) | All (n=508) | |
| Age (mean (SD)) | 31.8 (12.04) | 30.5 (13.4) | 28.6 (9.76) | 44.9 (24.18) | 31.1 (12.64) | 31.3 (13.24) |
| Sex (M/F) | 58 (56%)/45 (44%) | 55 (30%)/126 (70%) | 3 (25%)/9 (75%) | 6 (50%)/6 (50%) | 77 (39%)/123 (62%) | 199 (39%)/309 (61%) |
| History, n (%) | ||||||
| Abdominal pain | ||||||
| Right lower quadrant (RLQ) | 85 (83) | 112 (62) | 11 (92) | 9 (75) | 155 (78) | 372 (73) |
| Left lower quadrant (LLQ) | 7 (7) | 37 (20) | 2 (17) | 5 (42) | 27 (14) | 78 (15) |
| Epigastric pain | 3 (3) | 22 (12) | 1 (8) | 1 (8) | 16 (8) | 42 (8) |
| Diffuse abdominal pain | 14 (14) | 30 (17) | 1 (8) | 2 (17) | 28 (14) | 75 (15) |
| Flank pain | 3 (3) | 13 (7) | – | 1 (8) | 14 (7) | 31 (6) |
| Start as epigastric pain | 44 (43) | 21 (12) | 7 (58) | 3 (25) | 45 (23) | 120 (24) |
| Nausea | 35 (34) | 65 (36) | 7 (58) | 4 (33) | 62 (31) | 173 (34) |
| Vomiting | 42 (41) | 47 (26) | 3 (25) | 6 (50) | 57 (29) | 155 (31) |
| Diarrhoea | 17 (17) | 46 (25) | 1 (8) | 1 (8) | 38 (19) | 103 (20) |
| Dysuria | 4 (4) | 17 (9) | 3 (25) | 1 (8) | 14 (7) | 39 (8) |
| Medical findings | ||||||
| BMI (mean (SD)) | 23.5 (2.98); n=80 | 22.9 (3.74); n=119 | 23.1 (4.21); n=10 | 23.3 (3.93; n=8 | 23.7 (4.39); n=145 | 23.3 (3.88); n=362 |
| Temperature (mean (SD)) | 37.1 (0.71); n=103 | 36.9 (0.74); n=176 | 37.2 (0.81); n=12 | 37.6 (0.96); n=12 | 37.0 (0.71); n=196 | 37.0 (0.73); n=499 |
| Pain on palpation, n (%) | ||||||
| RLQ | 80 (78) | 99 (55) | 10 (83) | 8 (67) | 138 (69) | 335 (66) |
| LLQ | 9 (9) | 26 (14) | 2 (17) | 1 (8) | 27 (14) | 65 (13) |
| Left upper quadrant/Right upper quadrant | 4 (4) | 23 (13) | 3 (25) | 3 (25) | 20 (10) | 53 (10) |
| Painful flank percussion | 9 (9) | 25 (14) | 2 (17) | 2 (17) | 29 (15) | 67 (13) |
| Rebound tenderness | 63 (61) | 52 (29) | 8 (67) | 6 (50) | 66 (33) | 195 (38) |
| Psoas sign | 15 (15) | 15 (8) | 3 (25) | 2 (17) | 27 (14) | 62 (12) |
| Alvarado Score | 5.6 (1.5) | 3.6 (1.69) | 5.1 (1.93) | 5.1 (2.46) | 4.3 (1.84) | 4.4 (1.89) |
| Laboratory findings | ||||||
| CRP in mg/dL (median,(IQR)) | 14 (51.5) | 3 (16) | 13 (65) | 51 (180) | 5 (37.3) | 6 (33) |
| Leucocyte count in G/l (mean, (SD)) | 13.55 (3.95) | 9.54 (4.09) | 10.63 (3.52) | 13.77 (6.47) | 11.02 (3.98) | 11.08 (4.32) |
| Final diagnosis acute appendicitis after all imaging/follow-up, n (%) | 103 | – | – | 12 | 59 (29) | 174 (34) |
BMI, body mass index; CRP, C reactive protein.