. 2024 Aug 28;12(10):e00691-24. doi: 10.1128/spectrum.00691-24

TABLE 3.

Permutation test results for sensitivity analysis

	Full mask (N = 2,673)			No mask (N = 841)			P value^b (permutation)
	Model estimated seroprevalence^c		Estimated population seroconversion^a	Model estimated seroprevalence		Estimated population seroconversion^a
	September	December	Estimated population seroconversion^a	September	December	Estimated population seroconversion^a
Overall	36.61%	49.77%	20.76%	40.19%	54.64%	24.16%	0.061
5–11 yrs	38.02%	45.02%	11.29%	43.89%	51.97%	14.39%	0.082
12–17 yrs	40.63%	56.43%	26.62%	43.03%	59.76%	29.37%	0.339

^{^a}

Estimated population seroconversion was calculated by formula (1). The proportion of seronegative kids in September was calculated as one minus the seroprevalence.

^{^b}

Permutation test evaluated whether the difference of estimated population seroconversion between full and no mask groups is significant.

^{^c}

Robust Poisson regression was applied to estimate marginal means of seroprevalence by full and no mask groups in two time periods. The list of variables used in the model is described in Tables 4 to 6.