I have a second question. You compared before/after intervention malaria rates for the treated vs. control districts, and found that the multiplier was 52.5% lower in the treated areas. Do we have information on how this compares to historical data? Also, were the districts randomly selected for the treatment vs. control group, or was it chosen on a convenience basis?
I am thinking about the possibility that the treated and control districts may have significantly different base rates of malarial increase at the seasonal time points chosen for the before and after measurements, since there are only 7 districts and it sounds like they may be ecologically and demographically heterogeneous.
Having looked at the original paper, I found a partial answer in table 3:
Before the intervention, the treatment district had a malaria rate 3.3 times higher than the control district. After the intervention, the treatment district had a malaria rate 1.6 times higher than the control district. There were large differences in the levels of malaria incidence between the two districts before the intervention.
As far as I can tell, there has not been an attempt to rule out the possibility and size of any systematic differences in how malaria fluctuates or how it is measured between the treatment and control districts. To address this, historical data showing the average multiplier in these districts during the same time of year in previous years when the treatment was not applied could be used to compare with the current base rates.
If historical data is available for these districts, it seems like it ought to be possible to examine that historical data prior to rolling out a larger-scale $6 million RCT.
If I am making mistakes in this analysis, please let me know and I will correct my comment. Thank you!
First of all, a small clarification—we are seeking $6M for various purposes; the cost of the RCT should be about $1.5M. To the main point: historical data from the Ministry of Health on Anopheles mosquitoes supports the same conclusions but was not included in the publication (history of malaria data per district has not been shared with us by the government). As highlighted in the paper, the intervention was a pilot and NOT a clustered randomized control trial (cRCT), though it was the Ministry of Health (and not us) who selected the intervention and control areas.
In other words, we do need a cRCT to fully validate our method, but the existing evidence is definitely strong enough to justify spending $1.5M on rolling out such an cRCT.
Hope this answers your questions. Let me know if something is still unclear.
I have a second question. You compared before/after intervention malaria rates for the treated vs. control districts, and found that the multiplier was 52.5% lower in the treated areas. Do we have information on how this compares to historical data? Also, were the districts randomly selected for the treatment vs. control group, or was it chosen on a convenience basis?
I am thinking about the possibility that the treated and control districts may have significantly different base rates of malarial increase at the seasonal time points chosen for the before and after measurements, since there are only 7 districts and it sounds like they may be ecologically and demographically heterogeneous.
Having looked at the original paper, I found a partial answer in table 3:
Before the intervention, the treatment district had a malaria rate 3.3 times higher than the control district. After the intervention, the treatment district had a malaria rate 1.6 times higher than the control district. There were large differences in the levels of malaria incidence between the two districts before the intervention.
As far as I can tell, there has not been an attempt to rule out the possibility and size of any systematic differences in how malaria fluctuates or how it is measured between the treatment and control districts. To address this, historical data showing the average multiplier in these districts during the same time of year in previous years when the treatment was not applied could be used to compare with the current base rates.
If historical data is available for these districts, it seems like it ought to be possible to examine that historical data prior to rolling out a larger-scale $6 million RCT.
If I am making mistakes in this analysis, please let me know and I will correct my comment. Thank you!
Thanks again. This, too, is a good point.
First of all, a small clarification—we are seeking $6M for various purposes; the cost of the RCT should be about $1.5M. To the main point: historical data from the Ministry of Health on Anopheles mosquitoes supports the same conclusions but was not included in the publication (history of malaria data per district has not been shared with us by the government). As highlighted in the paper, the intervention was a pilot and NOT a clustered randomized control trial (cRCT), though it was the Ministry of Health (and not us) who selected the intervention and control areas.
In other words, we do need a cRCT to fully validate our method, but the existing evidence is definitely strong enough to justify spending $1.5M on rolling out such an cRCT.
Hope this answers your questions. Let me know if something is still unclear.
Thanks!
Yes it does, thank you for the added context!