EXPRESS: Over-the-Counter Drug Consumption: How Consumers Deviate from Label Instructions

Product consumption is an important yet understudied aspect of marketing. Over-the-counter (OTC) medicines present a unique consumption context because consumers are expected to follow product label instructions. For acetaminophen, a widely consumed OTC drug, we study which consumers tend to label deviate, why, and the interventions that are most promising to mitigate such deviations. We develop a dynamic structural model of consumption which allows us to investigate the probability of different types of label deviations (e.g., >4g per day) and drivers of such behaviors. Label deviations are infrequent “tail area” behaviors, and the model uncovers them well. Our analysis is based on a unique online consumption diary in which consumers select from two classes of acetaminophen products (single ingredient or combo) to treat their pain or non-pain related symptoms. Consumers have a higher probability of taking>4g of acetaminophen when they have multiple symptoms, and a variety of observable factors explain the individual propensity to label-deviate. We propose two interventions—a new label instruction and consumer education—to mitigate the observed label deviations and assess the expected impact of each.