Table 2.
Small-Vessel Microvascular Variables in Study Participants With Confirmed Dengue Versus OFI, by Disease Phase
| Variable by Illness Phase or Day of Illness Groupa | OFI |
Dengue |
OR (95% CI)c | P Value | ||
|---|---|---|---|---|---|---|
| Participants, No.; Measurements, No. | Median (IQR)b | Participants, No.; Measurements, No. | Median (IQR)b | |||
| TVD, mm/mm3 | ||||||
| Overall | 15; 20 | 14.2 (12.6–15.5) | 59; 143 | 14.1 (12.6–15.4) | 0.92 (.74–1.16) | .49 |
| Day 1–3 | 9; 10 | 14.0 (13.1–15.3) | 43; 58 | 13.4 (12.2–15.3) | 0.92 (.69–1.22) | .55 |
| Day 4–6 | 9; 10 | 14.3 (12.6–15.6) | 48; 65 | 14.1 (12.0–15.3) | 0.96 (.68–1.36) | .81 |
| Day 7–13 | 0; 0 | … | 20; 20 | 15.3 (14.3–16.0) | … | … |
| Day >13 | 7; 7 | 14.6 (13.0–16.4) | 20; 20 | 15.8 (14.5–17.4) | 1.22 (.70–2.12) | .48 |
| PPV, % | ||||||
| Overall | 15; 20 | 90.3 (83.2–95.5) | 59; 143 | 92.4 (87.9–95.5) | 1.08 (.99–1.17) | .08 |
| Day 1–3 | 9; 10 | 91.3 (85.5–94.6) | 43; 58 | 93.7 (90.2–96.1) | 1.07 (.94–1.22) | .30 |
| Day 4–6 | 9; 10 | 89.0 (82.0–94.2) | 48; 65 | 92.2 (88.5–95.5) | 1.11 (.98–1.27) | .10 |
| Day 7–13 | 0; 0 | … | 20; 20 | 85.3 (82.5–88.9) | … | … |
| Day >13 | 7; 7 | 98.3 (93.5–98.7) | 20; 20 | 96.9 (96.0–97.5) | 1.12 (.74–1.70) | .60 |
| MFI | ||||||
| Overall | 15; 20 | 2.6 (2.1–2.7) | 59; 142 | 2.6 (2.3–2.8) | 1.27 (.98–1.64) | .07 |
| Day 1–3 | 9; 10 | 2.6 (2.2–2.7) | 42; 57 | 2.6 (2.3–2.8) | 1.16 (.70–1.92) | .57 |
| Day 4–6 | 9; 10 | 2.4 (2.0–2.7) | 48; 65 | 2.6 (2.4–2.8) | 1.69 (1.01–2.84) | .04 |
| Day 7–13 | 0; 0 | … | 20; 20 | 2.3 (2.1–2.7) | … | … |
| Day >13 | 7; 7 | 2.7 (2.6–2.8) | 20; 20 | 2.8 (2.8–3.0) | 2.45 (.54–11.07) | .25 |
| HI | ||||||
| Overall | 14; 19 | 0.1 (0.1–0.2) | 59; 138 | 0.2 (0.1–0.3) | 1.04 (.80–1.36) | .77 |
| Day 1–3 | 8; 9 | 0.2 (0.1–0.3) | 41; 56 | 0.2 (0.1–0.3) | 1.00 (.68–1.46) | .98 |
| Day 4–6 | 9; 10 | 0.1 (0.1–0.2) | 48; 65 | 0.2 (0.1–0.3) | 1.01 (.65–1.58) | .96 |
| Day 7–13 | 0; 0 | … | 17; 17 | 0.2 (0.1–0.4) | … | … |
| Day >13 | 6; 6 | 0.1 (0.0–0.2) | 19; 19 | 0.1 (0.0–0.1) | 0.35 (.10–1.22) | .10 |
| eRBC score >0, No. (%) | ||||||
| Overall | 14; 20 | 3 (15) | 59; 141 | 33 (23) | 1.60 (.31–8.28) | .58 |
| Day 1–3 | 9; 10 | 2 (20) | 42; 56 | 13 (23) | 1.24 (.22–7.18) | .81 |
| Day 4–6 | 8; 9 | 1 (11) | 48; 65 | 13 (20) | 1.95 (.24–16.06) | .54 |
| Day 7–13 | 1; 1 | 0 (0) | 20; 20 | 7 (35) | … | … |
| Day >13 | 6; 6 | 1 (17) | 20; 20 | 0 (0) | … | … |
Abbreviations: CI, confidence interval; eRBC, extravasated red blood cell; HI, heterogeneity index; IQR, interquartile range; MFI, mean flow index; OFI, other febrile illness; OR, odds ratio; PPV, proportion of perfused vessels; TVD, total vessel density.
a For each variable, “Overall” corresponds to the overall comparison, which included all values except for those on day of illness >13, adjusted for age, sex, and day of illness. Other rows present comparisons for each day-of-illness category, with adjustment for age and sex. All comparisons were based on generalized estimating equations with independence covariance structure to take into account multiple measurements per patient.
b Data represent median (IQR) except where otherwise indicated (eRBC score).
c The ORs represent the predicted change in the odds of a dengue diagnosis corresponding to increases of 1 mm/mm3 in TVD, 1% in PPV, 0.25 unit in MFI (or 1 unit in the total flow MFI from all 4 quadrants), and 0.1 unit in HI and to having a positive eRBC score.