Table 2. Treatment failure and risk and incidence of recurrent parasitaemia.
| Time point | Outcome measure | CQ (n = 104) | CQ+PQ (n = 102) | AL (n = 100) | AL+PQ (n = 92) |
|---|---|---|---|---|---|
| Day 28 | Lost to follow-up | 6 | 8 | 8 | 6 |
| Early treatment failure | 1 | 0 | 0 | 0 | |
| Late treatment failure | 3 | 0 | 11 | 2 | |
| P. falciparum parasitaemia | 2 | 3 | 0 | 0 | |
| Adequate clinical and parasitological response | 92 | 91 | 81 | 84 | |
| Cumulative risk of P. vivaxa | 4.0 (1.5–10.4) | 0 (0–4.0) | 12.0 (6.8–20.6) | 2.3 (0.6–9.0) | |
| Day 42 | Lost to follow-up | 7 | 12 | 11 | 10 |
| Early treatment failure | 1 | 0 | 0 | 0 | |
| Late treatment failure | 17 | 1 | 27 | 5 | |
| P. falciparum parasitaemia | 2 | 4 | 0 | 0 | |
| Adequate clinical and parasitological response | 77 | 85 | 62 | 77 | |
| Cumulative risk of P. vivaxa | 18.7 (12.2–28.0) | 1.2 (0.2–8.0) | 29.9 (21.6–40.5) | 5.9 (2.4–13.5) | |
| End of follow-up | Lost to follow-up | 15 | 39 | 22 | 28 |
| Early treatment failure | 1 | 0 | 0 | 0 | |
| Late treatment failure | 56 | 14 | 62 | 17 | |
| P. falciparum parasitaemia | 3 | 5 | 0 | 0 | |
| Adequate clinical and parasitological response | 29 | 44 | 16 | 47 | |
| Cumulative risk of P. vivaxa | 61.7 (51.9–71.7) | 20.5 (13–31.5) | 72.4 (62.5–81.6) | 22.0 (14.2–33.1) | |
| Incidence of P. vivax recurrenceb | 2.2 (1.8–2.6) | 0.4 (0.3–0.6) | 2.3 (1.9–2.7) | 0.5 (0.3–0.7) | |
| Adjusted incidence of P. vivax recurrencec | 2.3 (1.9–2.7) | — | 2.2 (1.8–2.6) | — | |
| Incidence of any Plasmodium recurrenceb | 2.2 (1.9–2.7) | 0.5 (0.4–0.7) | 2.3 (1.9–2.7) | 0.5 (0.4–0.7) | |
| Adjusted incidence of any Plasmodium recurrencec | 2.3 (1.9–2.8) | — | 2.2 (1.9–2.7) | — |
aCumulative risk derived from survival analysis, percent (95% CI).
bEpisodes per person-year of observation (95% CI); calculated from the duration of follow-up from first to last visit. Patients receiving antimalarial treatment were assumed to have a period of 28 d of post-treatment prophylaxis after CQ treatment and 14 d of post-treatment prophylaxis after AL treatment, and this period was subtracted from their total period of observation. This analysis included patients not randomized to PQ or no PQ.
cExcluding patients not randomized to PQ or no PQ.
AL, artemether-lumefantrine; AL+PQ, artemether-lumefantrine + primaquine; CQ, chloroquine; CQ+PQ, chloroquine + primaquine.