Table 1.
Input Variables and References
| Item | Baseline Valuea | Rangea | Reference |
|---|---|---|---|
| Probability of contracting malaria without chemoprophylaxis in West Africab | 24.2 cases per 1000 person-mo | 12–70 per 1000 person-mo | [9, 10] |
| Probability of hospitalization for malaria acquired in West Africab,c | 71% | 67%–74% | [7], Unpublished 2009 US malaria surveillance data, CDC |
| Effectiveness of malaria chemoprophylaxis | |||
| Atovaquone/proguanil | 95.8% | 91.5%–97.5% | [11] |
| Doxycycline | 92.6% | 79.9%–97.5% | [12] |
| Mefloquine | 94.5% | 84.0%–98.1% | [13] |
| Probability of chemoprophylaxis-related adverse events requiring medical attention | |||
| Atovaquone/proguanil | 7% | 2%–11% | [14] |
| Doxycycline | 6% | 2%–10% | [14] |
| Mefloquine | 11% | 6%–15% | [14] |
| Percentage adherence with chemoprophylaxis regimend | 100% | 60%; 100% | [15], Assumption |
| Hourly compensation (US$, 2009) | 32.79 | 15.98–48.66 | [16, 17], Supplementary Appendix |
| Lost workdays for malaria treatment | |||
| Ambulatory case | 5 d | 2–7 d | Assumption |
| Hospitalized casee | 10 d | 6–24 d | [18], Assumption |
Abbreviation: CDC, Centers for Disease Control and Prevention.
a Baseline and range values were often taken from different resources. We used expert opinion to determine the most representative baseline values, and thus the baseline values are different from the simple middle or median of the range.
b West Africa included Benin, Burkina Faso, Cape Verde, Côte d'Ivoire, The Gambia, Ghana, Guinea, Guinea-Bissau, Liberia, Mali, Mauritania, Niger, Nigeria, São Tomé and Príncipe, Senegal, Sierra Leone, and Togo [1].
c The probability was estimated by dividing the number of hospitalized malaria cases from West Africa by the number of all malaria cases from West Africa (unpublished 2009 US malaria surveillance data, CDC).
d Reduced adherence rate here is the equivalent of not taking the drug as per recommendations to the point where no effective protection is obtained (eg, traveler obtains prescription but takes no doses). Those who do take the drug are assumed to be fully adherent to the recommended dosages.
e The lost workdays for hospitalized cases included days spent at both hospital and home for recuperation. Because Plasmodium falciparum accounted for 87% of hospitalized malaria cases where the disease was acquired in West Africa (unpublished 2009 US malaria surveillance data, CDC), length of stay at hospital of P. falciparum from Nationwide Impatient Sample data [18] was used as the representative length of stay at hospital.