TABLE 2.
Index ED Visit Clinically Ordered (ie, Not Part of Research) Laboratory Investigations and Diagnostic Imaging
| Country | Difference, %a (95% Wald CIs) | ||
|---|---|---|---|
| Canada PERC Study; n (%) (N = 827) | US PECARN Study; n (%) (N = 588) | ||
| Urine dipstick or urinalysis | 78 (9.4) | 56 (9.5) | 0.1 (−3 to 3.2) |
| Urine culture | 51 (6.2) | 41 (7.0) | 0.8 (−1.8 to 3.4) |
| Serum electrolytes | 84 (10.2) | 75 (12.8) | 2.6 (−0.8 to 6) |
| Blood gas | 51 (6.2) | 31 (5.3) | −0.9 (−3.3 to 1.5) |
| Complete blood count | 81 (9.8) | 37 (6.3) | −3.5 (−6.3 to −0.7) |
| Blood culture | 31 (3.7) | 10 (1.7) | −2 (−3.7 to −0.4) |
| Stool viral studiesa | Not collected | 16 (2.7) | — |
| Stool bacterial culturea | 81 (9.9) | 45 (7.7) | −2.2 (−5.2 to 0.7) |
| Chest radiograph | 24 (2.9) | 15 (2.6) | −0.4 (−2.1 to 1.4) |
| Abdominal radiograph | 1 (0.1) | 17 (2.9) | 2.8 (1.4 to 4.1) |
| Abdominal ultrasound | 4 (0.5) | 19 (3.2) | 2.7 (1.2 to 4.3) |
Missing values are as follows (Canada and US): stool culture (7 and 0). —, not applicable.
a
Does not include stool testing performed as part of the research protocols.