More generally, we show how LLIN programme cost effectiveness varies with bed net price, lifespan, usage and loss rates.
Total programme cost is the sum of main round, replenishment and retreatment costs over 10 years less the value of bed nets with lifespan remaining.
Sensitivity analyses tend to find that bed net price and lifespan have a significant impact on programme cost effectiveness e.g. [ 4, 40].
Moreover, a lifespan-increasing effect in one parameter, such as a decrease in mtROS production, could result in a compensatory change in another, such as the repair proteins of DNA, resulting in no net alteration in lifespan.
The specific aim of the study was to supplement existing data on C. elegans with complete high-resolution life tables and fecundity schedules and to assess the nematode's age at sexual maturity, mean and maximum lifespan, net reproductive rate (R0), total fertility rate (TFR), generation time, population doubling time, and intrinsic rate of increase (rm).
Other issues around programme effect discussed in the literature but excluded from our model because of the relatively small evidence base are the protective efficacy of untreated nets and nets used beyond their lifespan, and the long-term effects of ITN use.
The LLIN is the more cost effective option if LLINs and conventional nets have the same lifespan, unless the LLIN price is above a certain threshold.
Generally, we find that price can increase by USD 1 or more for each one-year increase in lifespan, if nets are of the same type.
Figure 1 illustrates bed nets of different price, lifespan and type which are equally cost effective as the 3-year LLIN at USD 4. In this case, a 4-year LLIN at more than double the price of a 3-year conventional net (USD 5.6 vs. USD 2.4) is equally cost effective, and a 2-year advantage in lifespan can be accompanied by nearly a tripling of the price (USD 7.0).
