Baseline characteristics
| Requesting dates | 6 September 2016– 1 November 2017 | 3 November 2017– 2 January 2019 | 6 September 2016– 2 January 2019 | p value (MT vs DBS) |
| 5670 Datasets | EDTA MT kit (1515), n (%)* | DBS kit (4155), n (%)* | Combined kits (5670), n (%)* | |
| Sex | ||||
| Male | 460 (30.4) | 1357 (32.6) | 1817 (32.0) | 0.100 |
| Female | 1051 (69.4) | 2788 (67.1) | 3839 (67.7) | 0.110 |
| Transgender | 0 (0.0) | 2 (0.05)† | 2 (0.04)† | 1.000 |
| Other gender identity | 4 (0.2) | 8 (0.2) | 12 (0.2) | 0.540 |
| Age (years), mean (95% CI) | 27.4 (27.1 to 27.8) | 27.3 (27.1 to 27.5) | 27.3 (27.1 to 27.5) | – |
| Age (years), median (IQR) | 26 (22–31) | 26 (22–31) | 26 (22–31) | – |
| Ethnicity | ||||
| Any other Asian background | 2 (0.1) | 5 (0.1) | 7 (0.1) | 1.000 |
| Any other black background | 6 (0.4) | 21 (0.5) | 27 (0.5) | 0.600 |
| Any other mixed background | 11 (0.7) | 30 (0.7) | 41 (0.7) | 0.990 |
| Any other white background | 41 (2.7) | 105 (2.5) | 146 (2.6) | 0.710 |
| Bangladeshi | 6 (0.4) | 12 (0.3) | 18 (0.3) | 0.530 |
| Black African | 25 (1.6) | 104 (2.5) | 129 (2.3) | 0.570 |
| Black Caribbean | 81 (5.3) | 246 (5.9) | 327 (5.7) | 0.410 |
| Chinese | 1 (0.06)† | 7 (0.2) | 8 (0.1) | 0.690 |
| Indian | 51 (3.4) | 111 (2.7) | 162 (2.9) | 0.160 |
| Pakistani | 13 (0.9) | 45 (1.1) | 58 (1.0) | 0.460 |
| Unknown/not specified | 26 (1.7) | 78 (1.9) | 104 (1.8) | 0.690 |
| White and Asian | 17 (1.1) | 51 (1.2) | 68 (1.2) | 0.750 |
| White and black African | 2 (0.1) | 9 (0.2) | 11 (0.2) | 0.740 |
| White and black Caribbean | 79 (5.2) | 271 (6.5) | 350 (6.2) | 0.700 |
| White British | 1147 (75.7) | 3044 (73.2) | 4191 (74.0) | 0.630 |
| White Irish | 7 (0.5) | 16 (0.4) | 23 (0.4) | 0.690 |
| Sexuality | ||||
| Heterosexual man | 353 (23.3) | 1012 (24.3) | 1365 (24.1) | 0.410 |
| Heterosexual woman | 977 (64.5) | 2617 (63.0) | 3594 (63.4) | 0.300 |
| Bisexual man | 20 (1.3) | 67 (1.6) | 87 (1.5) | 0.430 |
| Bisexual woman Percentage difference (95% CI)* | 18 (1.2) | 95 (2.3) | 113 (2.0) | 0.009 1.1 (0.4 to 1.8) |
| MSM exclusive | 87 (5.7) | 278 (6.7) | 365 (6.4) | 0.200 |
| WSW exclusive Percentage difference (95% CI)* | 56 (3.7) | 76 (1.8) | 132 (2.3) | <0.001 −1.9 (−2.9 to −0.8) |
| Heterosexual TG woman | 0 (0.0) | 2 (0.05)† | 2 (0.04)† | 1.000 |
| Unknown/not specified | 4 (0.2) | 8 (0.2) | 12 (0.2) | 0.600 |
p values in bold typeface denote statistical significance; p values rounded to three decimal places.
For proportion percentage differences with 95% CI; negative values favour MT, positive values favour DBS.
*Rounded to one decimal place.
†Rounded to two decimal places for representation.
DBS, dried blood spot; MSM, men who have sex with men; MT, mini tube; TG, transgender; WSW, women who have sex with women.