Proof-of-concept evaluations: Building evidence for effective scale-ups
I delivered a talk at 3ie’s Delhi Seminar Series on a recently published PLoS ONE paper) and follow-up research. This project was a randomised experiment evaluating the potential for text messages to remind malaria patients to complete their treatment course of antimalarial medication. Specifically, we looked at completion of the only class of drugs fully effective in curing malaria in Sub-Saharan Africa: Artemisinin-based Combination Therapies (ACTs). An individual’s failure to complete treatment can have both private and public harms – parasite resistance to these drugs is already emerging in Southeast Asia and there is no clear alternative treatment in the pipeline.
Several interesting questions arose during the course of the seminar, including from discussant Simon Brooker. Some of these questions about the study also came up in follow-up visits to vendors in Ghana. The main overarching question in all of these was: Why did we design the intervention to be so hands-off?
- Why didn’t we allow the vendors to play a stronger role in educating and enrolling patients into the text messaging system?
- Why didn’t we provide financial support to those for whom phone credit was a barrier to enrolling in the system?
- Why didn’t we use more interactive forms of texting or even voice-calling (including Interactive Voice Response, such as used here)?
- Why didn’t we link our messages to a larger system of messaging the drug vendors themselves to remind them about protocol (as was done here)?
Why this way?
I believe we took this approach for three main reasons.
First, our funder CHAI (as an operational research project for the Affordable Medicines Facility – malaria (AMFm) wanted a proof-of-concept about the minimal supportive moving parts required to get patients enrolled into a text messaging system of reminders to complete their medication. In the context of the AMFm, as well as Ghana’s National Health Insurance Scheme, the availability and affordability of ACTs has been expanding rapidly. But support to encourage appropriate use of those ACTs lagged behind.
So, we wanted to learn what could be scaled up cheaply and easily.
This study is the first randomised evaluation of a direct-to-patient (rather than to health workers) text messaging programme for malaria in Sub-Saharan Africa. We purposefully chose northern Ghana as the site of the study (specifically, in and around Tamale in Northern Region, which falls below the Ghanaian average on most welfare and development indicators). We worried that finding an effect from a text messaging programme in the capital, Accra, wouldn’t go very far in convincing people that a similar programme could work across Ghana. So, we tried to make things a bit difficult to find an impact.
Second, we wanted to isolate the effect of the text message itself. By having the vendors play a stronger role in educating their patients about the need to complete their antimalarial medication, we would find ourselves unable to identify the effect of the text messages alone (without proliferating to an octopus of treatment arms, which budget constraints would not allow).
In this context, we were looking for answers to questions such as: Would the vendors hand out the flyers with minimal encouragement? Would it work if the vendors didn’t tell patients that the point of the messages was to remind them to finish their meds (vendors themselves were kept in the dark about this point until the end of the study)? Would it work if surveyors did not help assist patients in enrolling into the system (by either giving a missed call or sending a text)?
Third, the intervention was a somewhat narrow conception of mHealth-as-text-message, rather than text messages as social interactions embedded within larger social systems of communication and health care. This mHealth intervention, though run through a computer speaking Python and sending messages directly to mobile phones, was still very much embedded in social relationships, such as those between drug vendors and their patients (a point I bring out here).
Which way next?
From this study, we see that text messages can indeed have an effect on treatment completion. Precisely how to interpret the effect size is open to debate but as a proof-of-concept, we now have an idea that even in a purposively tough context, text messages may be part of the arsenal that moves patients towards full completion of malaria medication. This has practical significance as well as statistical significance: it can work. Moreover, there is suggestive evidence that the programme could be scaled up, given the hands-off approach we took and the enthusiasm of the vendors with whom we followed up.
There’s still however a long way to go, as this intervention only gets us to around 70 per cent completion rate of antimalarial medication. A likely way forward is thinking about text messages as one part of a larger, socially embedded intervention with multiple prongs to reach health providers, caregivers and patients through a variety of media and interaction mechanisms. This proof-of-concept evaluation should allow us to build on what works, making this more than a one-off study. It pushes us closer to the ultimate goal of a 100 per cent completion of anti-malarial medication.