Using choice modelling to identify popular and affordable alternative interventions for schistosomiasis in Uganda
Schistosomiasis is a neglected tropical disease (NTD) caused by a vector-borne parasite, commonly found in low- and middle-income countries. People become infected by direct contact with contaminated water, through activities such as bathing, swimming and fishing. Water becomes contaminated when human waste is not adequately contained. Our paper elicits community preferences towards alternative water access, sanitation and hygiene (WASH) interventions that would reduce individuals’ risk of contracting, or transmitting, Schistosoma mansoni, in three rural communities in Eastern Uganda. We administered an economic discrete choice experiment (DCE) to understand community preferences for improved WASH interventions. We compared interventions that target behaviour that puts oneself at higher risk (e.g. contact with contaminated water) with interventions that target behaviours that mainly put others at risk (e.g. open defaecation). DCE help to identify preferences for hypothetical future interventions, for which no market exists in order to elicit its value, and potential uptake, in a community.
DCEs elicit community preferences by presenting participants with a series of hypothetical interventions and asking them to select their most preferred, from the discrete set of alternatives. Typical to these surveys, each intervention bundle comes at a cost to the individual. As such, we are able to elicit how respondents make trade-offs between the interventions’ presented benefits and the associated incurred cost. However, our survey was unique in that interventions came at a monthly monetary cost and weekly labour contribution. As such we elicited both willingness to pay (WTP) and willingness to work (WTW) values for the different intervention characteristics.
Additionally, we administered two separate DCEs to all individuals, in order to quantify what individuals are willing to give up to reduce risk of Schistosomiasis to themselves as well as what they are willing to give up to reduce the risk to others. We also quantify the compensating surplus arising from different packages of interventions, which can help policy makers identify the most preferred intervention types. Key findings indicate that new sources of potable water are the highest valued risk-to-self (RTS) interventions, whilst fines on open defection are the highest valued risk-to-others (RTO) intervention. However, a large portion of our sample ignored the payment vehicles, suggesting overwhelming support for any kind of improvement to the severe health risks that individuals currently face in these communities, and the current lack of suitable sanitation.