Table 4. Distribution of estimated percentage reductions in sample concentration by aliquot number 1.
| Aliquot
Number |
Number of
samples |
Estimated percentage reduction in serum sample concentration | |||||||
|---|---|---|---|---|---|---|---|---|---|
| ≤-2% 2 | >-2% to
≤-1% 2 |
>-1% to
<-1% |
≥1% to
<3% |
≥3% to
<5% |
≥5% to
<10% |
≥10% 3 | Mean | ||
| Manual | 9,086 | - | - | 100% | - | - | - | - | - |
| 1 | 418,170 | 0.00% | 0.21% | 98.54% | 1.25% | - | - | - | 0.1% |
| 2 | 29,050 | - | 0.01% | 20.55% | 77.88% | 1.56% | - | - | 1.4% |
| 3 | 10,230 | 0.01% | - | - | 0.02% | 1.94% | 97.97% | 0.07% | 6.4% |
| Total | 466,536 | 0.00% | 0.19% | 91.55% | 5.97% | 0.14% | 2.15% | 0.00% | 0.3% |
1 Assays excluded from the dilution estimation included those with a high biological coefficient of variation (CV) (lipoprotein (a), gamma glutamyltransferase, C-reactive protein, rheumatoid factor) plus vitamin D, where seasonal variation masked any dilution effects related to time of sample acquisition, leaving 24 assays included. Also excluded from this table were participant samples where the aliquot number used varied between assays (see the Extended Data for further details).
2 A small number of samples had estimated concentrations higher than the theoretical true result (i.e. derived from perfect aliquoting).
3 Results for serum assays with estimated percentage reduction in sample concentration ≥10% were set to missing.