Summary of findings 2. Summary of findings table 2.
| ITNs versus no intervention for preventing leishmaniasis | ||||||
|
Patient or population: People at risk of CL or VL Settings: CL or VL endemic areas Intervention: ITNs Comparison: No intervention | ||||||
| Outcomes | Illustrative comparative risks* (95% CI) | Relative effect (95% CI) | No of participants (trials) | Quality of the evidence (GRADE) | Comments | |
| Assumed risk | Corresponding risk | |||||
| No intervention | ITNs | |||||
| Vector density | ‐ | ‐ | Not pooled | (3 trials) | ⊕⊕⊝⊝ low1,2,3,4 | Two trials found a reduction in vector numbers post‐intervention and one did not. |
|
CL cases > 12 months follow‐up |
52 per 1000 |
16 per 1000 (9 to 28) |
RR 0.31 (0.18 to 0.53) |
10,579 (2 trials) |
⊕⊕⊝⊝ low2,5,6,7,11 | ‐ |
|
VL cases > 2 years follow‐up |
4 per 1000 |
4 per 1000 (2 to 9) |
RR 0.99 (0.46 to 2.15) |
19,810 (1 trial) |
⊕⊕⊕⊝ moderate8,9,10 | ‐ |
| *The basis for the assumed risk is provided in footnotes. The corresponding risk (and its 95% CI) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: confidence interval; RR: risk ratio; CL: cutaneous leishmaniasis; VL: visceral leishmaniasis; ITN: insecticide treated bednet. | ||||||
| GRADE Working Group grades of evidence High quality: Further research is very unlikely to change our confidence in the estimate of effect. Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate. Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate. Very low quality: We are very uncertain about the estimate. | ||||||
1Three RCTs evaluated vector density, but one did not present before and after data and only stated the difference was statistically significant. 2Downgraded by 1 for serious risk of bias: Trials are at high or unclear risk of selection bias and reporting bias. 3Downgraded by 1 for serious inconsistency: Chowdhury 2011 BGD reports a statistically significant difference in total vector numbers over 12 months follow‐up, Emami 2009 IRN reports statistically significant reduction but did not provide data. Joshi 2009 ASIA found no difference in mean number of vectors per household. 4No serious indirectness: Chowdhury 2011 BGD distributed PermaNet® 2.0 to all households in trial sites in Bangladesh, Emami 2009 IRN distributed Olyset® in Iran, and Joshi 2009 distributed PermaNet® to households in India, Bangladesh and Nepal. 5The assumed risk of CL over 12 months follow‐up is taken from Reyburn 2000 AFG which contributed 99.5% of weight to this analysis. This trial was conducted in Afghanistan from 1997 to 1998. 6No serious indirectness: These two trials were conducted in urban areas of Iran (Olyset® nets), and Afghanistan (family size bednets impregnated with 0.5 g/m² of permethrin). The findings would be expected to apply to other endemic areas. 7No serious inconsistency: The two trials found similar effects. However, once adjusted for clustering the result was not statistically significant in the trial from Iran. 8The assumed risk of VL over 2 years months follow‐up is taken from the control group of Picado 2010a ASIA ‐ a study conducted in India and Nepal in 2006/09. 9No serious indirectness: This single trial was conducted in two areas (India and Nepal) using PermaNet® 2.0. 10Downgraded by 1 for serious imprecision: This trial found no difference between ITNs and control areas. However the 95% CI remains wide and includes the possibility of clinically important effects.
11Downgraded by 1 for serious indirectness: There are single trials from particular geographical areas.