TABLE 3. Timeliness and effectiveness of workplace investigations, by workplace prioritization* — Seattle & King County, Washington, June 15–November 15, 2020.
| Features | Priority, no. (row %) |
p-value† | ||
|---|---|---|---|---|
| Total | High | Medium and low | ||
|
Timeliness
| ||||
| Interval between notification and investigation, days, median (IQR)§ |
2 (1–5) |
2 (1–5) |
3 (1–8) |
0.002 |
| Duration spent on an investigation, minutes, median (IQR)¶ |
60 (40–90) |
60 (45–100) |
50 (30–60) |
<0.001 |
|
Effectiveness
| ||||
|
Exposed contacts not previously elicited during patient interviews
| ||||
| 0–1 |
96 |
60 (62.5) |
36 (37.5) |
0.002 |
| ≥2 |
95 |
79 (83.2) |
16 (16.8) |
|
|
Identified employee cases not previously linked to the workplace
| ||||
| 0–1 |
452 |
335 (74.1) |
117 (25.9) |
0. 001 |
| ≥2 |
55 |
52 (94.5) |
3 (5.5) |
|
|
No. employee cases identified
| ||||
| 0–1 |
450 |
350 (77.8) |
100 (22.2) |
<0.001 |
| ≥2 | 363 | 337 (92.8) | 26 (7.2) | |
Abbreviation: IQR = interquartile range.
* Priority levels were assigned based on workplace features observed to be associated with increased COVID-19 spread, and workforce features associated with severe disease outcomes.
† P-value comparisons using Wilcoxon Rank-Sum test to compare medians and Pearson’s chi-square test or Fisher’s exact test to compare categorical data. Number of workplaces varies by metric because of incomplete data.
§ Total of 1,142 workplaces.
¶ Total of 671 workplaces.