hey, you’re sick? can we know where you live? (simple experiments, complicated designs)

i have been working on a blog for 3ie (*now posted, here!), based on a delhi seminar talk i gave recently, in turn based on this paper and this blog on using text messages to increase completion of anti-malarial treatment. not all of the material i initially wrote will appear in the final blog — which is good, it is more focused now. nevertheless, i thought i would share the excised part that i wrote about the actual experimental set-up. part of the point i made in the seminar — and which i intend to make in this blog — was that as a ‘simple’ and ‘hands-off’ intervention (meaning minimal input from either the surveyors or our hosts, medical vendors, in encouraging or facilitating take-up) can require an all-the-more complicated study design. .

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rainy season!

rainy season!

the study was meant to be a proof-of-concept — it is the first randomized evaluation of a direct-to-patient (rather than to health workers) text messaging program for malaria in sub-saharan africa. as guided by our funder, CHAI (as an operational research project for the Affordable Medicines Facility – malaria (AMFm), we wanted to learn about the minimum of supportive moving parts required to get patients enrolled into a text messaging system of reminders to complete education. a relatively simple mHealth intervention – much of the intervention work was done by a computer, a modem, some lines of code, and occasionally an electric generator – it was the rainy season after all) – required a fairly intricate experimental set-up.

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diligently organizing follow-up

diligently organizing follow-up

it was a deviation for ipa-ghana in terms of not-household-or-firm-based-surveying and it took a lot of logistical coordination (as shown in the photo), attention to timetables, and a willingness on the part of the surveyors to set out without perfectly clear instructions.  .. .

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things worked roughly like this: with participating anti-malarial vendors, we (the research team) worked to maintain a façade of a separate flyer system to invite people to enroll in a mobile health information system, distinct from the surveyor talking to people obtaining an antimalarial medication. during that interview about the medicines purchased and price paid, if the respondent proved willing and eligible, the surveyor asked how we could find them at home. and for their phone number. and for directions to a neighbor’s house. and the neighbor’s phone. (i have written previously about the fun of trying to track people down based on the directions they give.) just in case we decided to follow-up to see how they were doing. and the surveyors were purposefully cagey about whether and when this would be happening and to what end. .

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[i am still amazed that so many people agreed to this (thank you, participants!) — if someone approached me in a drug store while i was sick and asked me to chat and then how to find me at home, even my deepest beliefs in survey karma would probably be abandoned in favor of some fairly unbecoming language.] . .

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but, in fact, we had a very precise purpose and timing in mind: to find the respondent between ~58 and 72 hours after we met them in a drug shop. with some basic assumptions about when they would start their antimalarial medication, we wanted to land up at people’s homes just after they had completed their medication. respondents often didn’t give very precise directions to their homes, resulting in a lot of motorcycle-mounted wild goose chases – but we also achieved a follow-up rate of 99% within our specified time window. phew! . this is really a tribute to the commitment and perseverance of the survey team and our field managers.