Table 2.
Change in cf-DNA content of study units with storage
| Storage period (days) | Change in cf-DNA |
|||
|---|---|---|---|---|
| change in content µg, | rate of change, μg/day | percent change, % | ||
| BC-PRBC | ||||
| Initial period (0–7) | M | 9.08 | 1.30 | 76.19 |
| (n = 31) | R | 45.44 | 6.49 | 1,333.26 |
| IQR | 11.56 | 1.65 | 176.43 | |
| 1Q–3Q | 3.04 to 14.60 | 0.43 to 2.09 | 30.39 to 206.82 | |
| Later period (7–21) | M | 217.67* (0.000) | 15.55* (0.000) | 1,175.59* (0.000) |
| (n = 33) | R | 1,418.73 | 101.34 | 7,841.49 |
| IQR | 159.17 | 11.37 | 1,103.32 | |
| 1Q–3Q | 166.06 to 335.46 | 11.10 to 22.47 | 669.23 to 1,772.55 | |
| Total period (0–21) | M | 220.52f(0.000) | 10.50f(0.000) | 2,815.66* (0.000) |
| (n = 31) | R | 1,420.22 | 67.63 | 20,638.26 |
| IQR | 167.41 | 8.07 | 4,706.94 | |
| 1Q–3Q | 155.44 to 314.60 | 7.91 to 15.97 | 1,408.33 to 6,115.28 | |
| LP-PRBC | ||||
| Initial period (0–7) | M | −1.92 | −0.27 | −16.89 |
| (n = 28) | R | 22.72 | 3.25 | 377.83 |
| IQR | 2.88 | 0.41 | 36.03 | |
| 1Q–3Q | −2.92 to −0.04 | −0.42 to −0.005 | −37.04 to −1.07 | |
| Later period (7–21) | M | −0.25 | −0.02 | −3.25 |
| (n = 29) | R | 1,117.13 | 79.80 | 43,310 |
| IQR | 3.20 | 0.23 | 68.11 | |
| 1Q–3Q | −1.35 to 1.85 | −0.10 to 0.13 | −24.59 to 43.53 | |
| Total period (0–21) | M | −0.50 | −0.02 | −4.31 |
| (n = 28) | R | 1,113.89 | 53.04 | 2,056.28 |
| IQR | 6.31 | 0.36 | 94.42 | |
| 1Q–3Q | −3.27 to 3.05 | −0.16 to 0.15 | −48.52 to 45.90 | |
| IR-PRBC | ||||
| Initial period (0–7) | M | 9.20 | 1.31 | 131.21 |
| (n = 34) | R | 52.15 | 7.45 | 1,747.75 |
| IQR | 11.30 | 1.61 | 322.69 | |
| 1Q–3Q | 5.17 to 16.46 | 0.74 to 2.35 | 42.68 to 365.38 | |
| Later period (7–21) | M | 225.49* (0.000) | 16.11* (0.000) | 1,086.34* (0.000) |
| (n = 34) | R | 768.43 | 54.89 | 6,322.03 |
| IQR | 242.55 | 17.33 | 1,173.06 | |
| 1Q–3Q | 129.73 to 372.28 | 9.27 to 26.59 | 650.29 to 1,823.34 | |
| Total period (0–21) | M | 233.72* (0.000) | 11.13* (0.000) | 4,106.16* (0.000) |
| (n = 34) | R | 776.74 | 36.99 | 19,512.64 |
| IQR | 250.06 | 11.91 | 5,199.13 | |
| 1Q–3Q | 134.29 to 384.35 | 6.39 to 18.30 | 1,235.19 to 6,434.32 | |
M, median; R, range; IQR, interquartile range; 1Q–3Q, 25th–75th percentile values. Intragroup comparison: * shows significant difference between initial and later storage periods (day 0–7 vs. day 7–21) within one study group. Change in cf-DNA content, rate of change, and percent change were significantly higher (Wilcoxon signed-rank test) in the BC-PRBC and IR-PRBC groups during the later period (day 7–21) of storage compared to the initial period (day 0–7). There was no statistically significant difference in the LP-PRBC group for all three parameters during the later period compared to the initial period of storage. Intergroup comparison: p values were assessed across various groups for changes in cf-DNA over the total storage duration (day 0–21) only (Mann-Whitney U Test): †shows significant difference between BC-PRBC and LP-PRBC groups; ‡shows significant difference between LP-PRBC and IR-PRBC groups. There was no statistically significant difference between the BC-PRBC and IR-PRBC groups for change in content (p = 1.000), rate of change (p = 0.670), or percent change (p = 0.743). Values in parentheses beside the symbols indicating significant differences indicate the respective p values.