Table 1.

Stability of dry Self-sample brushes stored at 0–32 weeks, measured as relative cellularity using BD Onclarity human Beta-globin (HBB) internal control.

	Time points (weeks)	N Tested	N2 Invalids	HBB Ct Mean	St. dev.	95% CI	P-value3
4 °C 0–8 weeks	0	30	1	28.3	2.4	27.4–29.2	0.95
	2	30	0	27.9	1.9	27.2–28.6
	4	30	0	28.0	1.8	27.3–28.7
	8	30	2	28.0	2.6	27.1–29.0
4 °C 0–32 weeks	01	28	0	28.1	2.6	27.1–29.1	0.54
	16	31	0	28.4	2.3	27.5–29.2
	32	30	1	27.6	3.1	26.5–28.8
RT 0–8 weeks	0	30	0	28.6	1.8	27.9–29.2	0.76
	2	30	3	28.6	2.7	27.6–29.6
	4	30	1	28.9	2.2	28.1–29.8
	8	30	2	28.3	2.8	27.2–29.3
RT 0–32 weeks	0	33	0	28.4	2.3	27.6–29.2	0.39
	16	32	2	28.0	3.3	26.8–29.2
	32	30	1	27.5	2.6	26.5–28.4
30 °C 0–8 weeks	0	30	0	27.7	1.9	26.9–28.4	0.20
	2	30	1	28.4	2.4	27.5–29.3
	4	30	2	28.6	2.9	27.5–29.6
	8	29	0	29.0	2.2	28.2–29.8
30 °C 0–32 weeks	0	32	0	28.2	2.2	27.4–29.0	0.25
	16	29	0	27.5	1.8	26.8–28.3
	32	33	0	27.4	2.1	26.7–28.2

¹Each of the two time studies, 0–8 weeks and 0–32 weeks, had individual baselines (T = 0).

²Invalid outcomes were recorded when the Ct-value of the internal HBB control was above Ct 34.2.

³P-value calculated using the One-way ANOVA test.