Frequency and Distribution of Significant Aberrations (Signals) by Threshold Level and Site
| Percentage of Days With Significant Aberrations* in the Number of Observed Cases, by Syndrome | ||||
|---|---|---|---|---|
| Threshold for Dayspring Clinic | Threshold for Emergency Department, UNC Hospitals | |||
| Syndrome | 2 SD | 3 SD | 2 SD | 3 SD |
| ICD-9 = International Classification of Diseases, Ninth Revision. | ||||
| * A significant aberration (signal) occurs when the number of cases recorded for that day exceeds the statistically determined threshold, based on observed cases from the previous week. | ||||
| Botulism-like | 0 | 0 | 12.6 | 6.2 |
| Hemorrhagic illness | 0.9 | 0.9 | 13.2 | 6.2 |
| Lymphadenitis | 11.3 | 5.6 | 7.6 | 3.7 |
| Cutaneous lesion | 3.0 | 2.6 | 9.0 | 5.6 |
| Gastrointestinal | 6.1 | 3.5 | 8.7 | 2.8 |
| Respiratory | 6.9 | 2.2 | 9.0 | 1.7 |
| Neurological | 2.2 | 2.2 | 11.8 | 5.9 |
| Rash | 11.3 | 7.4 | 10.7 | 5.1 |
| Fever | 11.3 | 5.6 | 7.6 | 3.9 |
| Severe illness/death | 0 | 0 | 8.7 | 5.3 |
| Any of the above syndromes | 40.0 | 24.3 | 63.5 | 36.5 |
| Average ICD-9 codes per day | 244 | 641 | ||