Patient non-adherence to medications functions as a key mediator between medical practice and patient outcomes, occurring in 20–50% of patients.1 One point of intervention is the medical encounter.2 However, providers are hesitant to ask about non-adherence, which leads to poor prescribing decisions and missed opportunities for addressing non-adherence.3 Direct questions about non-adherence are not ideal, as they elicit “socially desirable” responses and are subject to poor recall.4

We explore the potential benefit of asking about patients’ medication-taking routines/habits for estimating adherence. This approach may avoid problems associated with direct questions—patients may not be able to accurately reflect on or want to report specific instances of forgetting a pill, but could describe a “typical daily routine.” Further, patients’ behavioral habit strength (automaticity in taking medication) predicts adherence more strongly than commonly assessed cognitive predictors (e.g., beliefs5). Therefore, if providers get a sense of the stability of a patient’s routine, they may be able to predict that patient’s adherence.

We present data from prescribing medical providers, who used real patients’ direct reports of non-adherence and descriptions of their medication-taking routines to estimate patients’ objective adherence. We hypothesized that providers’ adherence estimates based on patients’ medication-taking routines would be equally or more accurate than their adherence estimates based on patients’ direct reports of non-adherence.