Table 4.
Direct, Indirect, Total and Overall effect of PCV10 on VT carriage (0 dose vs 3 doses).
| Year | 2014–2015 | 2015–2016 | 2016–2017 | 2017–2018 | 2014–2018 |
|---|---|---|---|---|---|
| VT carriage (3 doses) % (95% CI) * | 11.4 (8.1–15.4) |
12.4 (9.5–16.0) |
8.9 (6.6–11.8) |
8.1 (6.0–10.7) |
9.9 (8.6–11.4) |
| VT carriage in 2 doses % (95% CI) β | 20.0 (12.7–29.2) |
12.1 (6.2–20.6) |
7.4 (3–14.7) |
12.3 (6.7–20.1) |
13.0 (9.9–16.8) |
| VT carriage in 1 dose % (95% CI) α |
24.7 (16.0–35.3) |
14.8 (8.7–22.9) |
14.1 (7.5–23.4) |
16.4 (8.8–27.0) |
17.4 (13.6–21.8) |
| VT carriage (0 doses) % (95% CI)∞ | 17.4 (13.1–22.5) |
14.2 (9.1–20.7) |
11.6 (5.7–20.3) |
10.4 (4.6–19.4) |
14.8 (12.0–17.9) |
| Direct Effect (95% CI) | 34.6 (2.1–56.2) |
12.3 (-39.1–44.8) |
23.0 (-46.6–59.60) |
21.8 (-59.5–61.68) |
32.8 (14.7 – 47.0) |
| Indirect effect (95% CI) | 34.8 (29.1–40.5) |
46.8 (39.0–54.7) |
56.4 (46.0–66.9) |
61.1 (50.2–72.0) |
44.6 (40.6–48.6) |
| Total effect (95% CI) | 57.3 (51.9–62.8) |
53.4 (48.7–58.1) |
66.5 (62.4–70.6) |
69.6 (65.7–73.4) |
62.8 (60.5–65.0) |
| Overall effect (95% CI) | 39.8 (36.3–43.2) |
51.0 (47.5–54.5) |
63.9 (60.6–67.2) |
63.9 (60.6–67.2) |
54.8 (53.1–56.5) |
VT carriage prior to PCV10 introduction was taken as 26.7% *p-value for trend 0.031, α p-value for trend 0.172, β p-value for trend 0.068, ∞p-value for trend 0.003.
Direct effect was calculated as 1– (VT carriage rate in children who received all three doses /VT carriage rate in children who received zero dose), indirect effect was defined as 1- (VT carriage rate in children who received zero dose /26.7%), total effect was defined as 1-(VT carriage rate in children who received all three doses/26.7%) and overall effect was defined as 1- (carriage rate in the study population / 26.7%).