Table 3:
Multivariable linear regression model predicting the number of tests ordered for a fever.
| Variable | Estimate (SE) | p-Value |
|---|---|---|
| Hospital | 0.02 | |
| Community | Reference | |
| Academic | 1.10 (0.46) | |
| Age | 0.00 (0.01) | 0.68 |
| Charlson comorbidity index | 0.08 (0.05) | 0.11 |
| Organ transplant recipient | −0.49 (0.51) | 0.34 |
| Immunosuppressed statusa | 0.51 | |
| None | Reference | |
| Low | 0.43 (0.49) | |
| High | 0.30 (0.29) | |
| Met at least two of four SIRS criteriab | 0.30 (0.30) | 0.33 |
| Met at least two qSOFA criteriac | 0.41 (0.68) | 0.55 |
| Last time blood cultures drawn | <0.001 | |
| Never | Reference | |
| < 24 | −2.05 (0.46) | |
| 24–48 h | −1.82 (0.47) | |
| 49–72 h | −0.77 (0.53) | |
| >72 | −0.47 (0.52) | |
| Resident level of training | 0.04 | |
| PGY-1 | Reference | |
| PGY-2 | 1.11 (0.42) | |
| PGY-3 | 0.92 (0.64) | |
| Note written by cross-cover resident | 1.35 (0.86) | 0.12 |
| Indication that cross-cover resident saw patient | 1.42 (0.56) | 0.02 |
| Patient transferred to higher level of care | 4.03 (1.06) | <0.001 |
| Sign-out instructed to perform an FFWU | 1.48 (0.27) | <0.001 |
FFWU, full fever work-up; PGY, post-graduate year; qSOFA, quick sepsis-related organ failure assessment; SE, standard error; SIRS, systemic inflammatory response syndrome.
Patients with high-level immunosuppression included those with combined primary immunodeficiency disorder, receiving cancer chemotherapy, within 2 months after solid organ transplantation, with HIV infection and a CD4 T-lymphocyte count < 200 cells/mm3, receiving daily corticosteroid therapy with a dose ≥ 20 mg of prednisone or equivalent for ≥ 14 days, or receiving certain biologic immune modulators, including tumor necrosis factor-α (TNF-α) blockers or rituximab. Patients with low-level immunosuppression include those with asymptomatic HIV and a CD4 T-lymphocyte count of 200–499 cells/mm3, receiving a lower daily dose of systemic corticosteroid than for high-level immunosuppression for ≥14 days or receiving alternate-day corticosteroid therapy or receiving methotrexate ≤ 0.4 mg/kg/week, azathioprine ≤ 3 mg/kg/day, or 6-mercaptopurine ≤ 1.5 mg/kg/day [13].
SIRS consists of temperature > 38° C or < 36° C, heart rate > 90/min, respiratory rate > 20/min or PaCO2 < 32 mmHg, and white blood cell count > 12,000/mm3 or < 4000/mm3 or > 10% immature bands.
qSOFA includes a respiratory rate of 22/min or greater, altered mentation, or systolic blood pressures of 100 mmHg or less. Patients meeting at least two of these criteria are more likely to have poor outcomes [15].