Estimating the Effectiveness of Health-Risk Communications with Propensity-Score Matching: Application to Arsenic Groundwater Contamination in Four US Locations
This paper provides a demonstration of propensity-score matching estimation methods to evaluate the effectiveness of health-risk communication efforts. This study develops a two-stage regression model to investigate household and respondent characteristics as they contribute to aversion behavior to reduce exposure to arsenic-contaminated groundwater. The aversion activity under study is a household-level point-of-use filtration device. Since the acquisition of arsenic contamination information and the engagement in an aversion activity may be codetermined, a two-stage propensity-score model is developed. In the first stage, the propensity for households to acquire arsenic contamination information is estimated. Then, the propensity scores are used to weight observations in a probit regression on the decision to avert the arsenic-related health risk. Of four potential sources of information, utility, media, friend, or others, information received from a friend appears to be the source of information most associated with aversion behavior. Other statistically significant covariates in the household’s decision to avert contamination include reported household income, the presence of children in household, and region-level indicator variables. These findings are primarily illustrative and demonstrate the usefulness of propensity-score methods to estimate health-risk communication effectiveness. They may also be suggestive of areas for future research. 1. Introduction The provision of high quality drinking water is a priority for many regions of the globe [1–3]. In particular, arsenic contamination of drinking water supplies is a public health issue of growing importance. In some of the rural parts of Bangladesh, arsenic contamination has been an ongoing public health scourge [4], causing economic harm in the form of reduced supply of household labor [5]. Bangladeshis are exposed to arsenic by consuming water from wells which tap into contaminated aquifers [6]. In addition to Bangladesh, arsenic-contaminated aquifers exist in many parts of the globe, including China [7], Sri Lanka [8], Argentina [9], and several regions in the US [10]. In the US, the growing awareness and concern over arsenic contamination have prompted regional water leaders and water managers to investigate this issue and identify strategies that may be effective in reducing risks to public health [11–14]. The health-related harms associated with arsenic exposure include increased risks of a wide variety of diseases and outcomes [15], including skin lesions [16], cancers [17], and
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