TABLE. Characteristics associated with participation in school SARS-CoV-2 testing among student contacts (N = 594) — 13 elementary schools, Salt Lake County, Utah, December 2020–January 2021*.
| Characteristic | No. (%) |
Prevalence ratio (95% CI) | |
|---|---|---|---|
| Total |
Participants |
||
| (N = 594) | (n = 438) | ||
|
Student characteristic
| |||
|
Race/Ethnicity
| |||
| White, non-Hispanic |
285
|
190 (66.7) |
Ref |
| White, Hispanic/Latino |
213
|
172 (80.8) |
1.21 (1.09–1.35) |
| Racial minority† |
96
|
76 (79.2) |
1.19 (1.04–1.35) |
|
Grade in school
| |||
| Kindergarten–grade 2 |
258
|
197 (76.4) |
Ref |
| Grades 3–4 |
162
|
118 (72.8) |
0.95 (0.85–1.07) |
| Grades 5–6§ |
174
|
123 (70.7) |
0.93 (0.82–1.04) |
|
Identified as a close contact to index patient¶
| |||
| No |
428
|
314 (73.4) |
Ref |
| Yes |
166
|
124 (74.7) |
1.02 (0.92–1.13) |
|
Family member (including nonhousehold) ever received positive SARS-CoV-2 test result
| |||
| No |
534
|
389 (72.8) |
Ref |
| Yes |
60
|
49 (81.7) |
1.12 (0.98–1.28) |
|
School/Investigation characteristic
| |||
|
Cumulative SARS-CoV-2 incidence rate by school
| |||
| ≤51 cases per 1,000 persons** |
305
|
216 (70.8) |
Ref |
| >51 cases per 1,000 persons |
289
|
222 (76.8) |
1.08 (0.99–1.19) |
|
No. of school cases during 14 days before testing date
| |||
| 1–4 |
402
|
300 (74.6) |
Ref |
| >4 |
192
|
138 (71.9) |
0.96 (0.87–1.07) |
|
Days from last school exposure to first time contacted††
| |||
| 2–4 |
142
|
106 (74.6) |
Ref |
| 5–7 |
331
|
245 (74.0) |
0.99 (0.88–1.11) |
| 8–12 |
118
|
85 (72.0) |
0.97 (0.83–1.12) |
|
Days from last school exposure to test date
| |||
| 6–7 |
316
|
231 (73.1) |
Ref |
| 8–10 |
278
|
207 (74.5) |
1.02 (0.93–1.12) |
|
Month of testing
| |||
| December |
227
|
156 (68.7) |
Ref |
| January |
367
|
282 (76.8) |
1.12 (1.01–1.24) |
|
ZIP code–level characteristic††
| |||
|
Cumulative SARS-CoV-2 incidence rate by ZIP code since March 2020
| |||
| ≤11,461 cases per 100,000 persons§§ |
301
|
210 (69.8) |
Ref |
| >11,461 cases per 100,000 persons |
292
|
228 (78.1) |
1.12 (1.02–1.23) |
|
Deprivation level¶¶
| |||
| Very low to average |
315
|
226 (71.7) |
Ref |
| High to very high |
278
|
212 (76.3) |
1.06 (0.97–1.17) |
|
Masking compliance rate by ZIP code since May 2020
| |||
| ≥81.6%*** |
299
|
230 (76.9) |
Ref |
| <81.6% | 294 | 208 (70.7) | 0.92 (0.84–1.01) |
Abbreviations: CI = confidence interval; Ref = Reference group.
* Log-binomial regression was conducted to calculate crude prevalence ratios and 95% CIs to identify correlates of participation. Prevalence ratio estimates that did not include 1.0 were considered statistically significant at p<0.05. Participation was defined as completing in-school specimen collection for reverse transcription–polymerase chain reaction SARS-CoV-2 testing.
† Includes non-Hispanic and Hispanic Asian, non-Hispanic and Hispanic Black/African American, non-Hispanic Native Hawaiian or Other Pacific Islander, non-Hispanic and Hispanic American Indian or Alaska Native, and non-Hispanic and Hispanic Multiracial. Among 96 students who identified as members of a racial minority group, 11 (11%) also identified as Hispanic or Latino.
§ All students in this category were in grades 5 or 6 except for two students who were in grade 7 or higher because they were identified as school contacts of the same index patient.
¶ Close school contacts were defined as persons within 6 ft of the index patient for a cumulative total of ≥15 minutes over a 24-hour period.
** Median SARS-CoV-2 incidence rate across schools included in the analysis.
†† Missing data: ZIP code was missing for one nonparticipating student; days between last exposure date and first time family was contacted was missing for three students.
§§ Median SARS-CoV-2 incidence rate across students’ ZIP codes included in the analysis.
¶¶ This is a composite index calculated using nine indicators from the Utah Behavioral Risk Factor Surveillance System: 1) median family income; 2) income disparity (a logarithmic ratio of households with <$10,000 income to ≥$50,000 income); 3) percentage of home ownership; 4) percentage of unemployment; 5) percentage of families below poverty threshold; 6) percentage of single-parent households with children aged <18 years; 7) percentage of population aged ≥25 years with <9 years of education; 8) percentage of population aged ≥25 years with at least a high school diploma; and 9) percentage of population at <150% of the poverty threshold. The index is divided into quintiles (very low, low, average, high, and very high).
*** Median masking compliance rate among residential ZIP codes of students included in the analysis.