What Do Placebo and Nocebo Effects Have to Do With Health Equity? The Hidden Toll of Nocebo Effects on Racial and Ethnic Minority Patients in Clinical Care

Abstract

A placebo effect is a positive clinical response to non-specific elements of treatment with a sham or inert replica of a drug, device, or surgical intervention. There is considerable evidence that placebo effects are driven by expectation of benefit from the intervention. Expectation is shaped by a patient's past experience, observations of the experience of others, and written, verbal, or non-verbal information communicated during treatment. Not surprisingly, expectation in the clinical setting is strongly influenced by the attitude, affect, and communication style of the healthcare provider. While positive expectations can produce beneficial effects, negative information and experiences can lead to negative expectations, and consequently negative or nocebo effects. Key components identified and studied in the placebo and nocebo literature intersect with factors identified as barriers to quality care in the clinical setting for Black patients and other patients of color, including poor patient-clinician communication, medical mistrust, and perceived discrimination. Thus, in the context of discrimination and bias, the absence of placebo and presence of nocebo-generating influences in clinical settings could potentially reinforce racial and ethnic inequities in clinical outcomes and care. Healthcare inequities have consequences that ripple through the medical system, strengthening adverse short- and long-term outcomes. Here, we examine the potential for the presence of nocebo effects and absence of placebo effects to play a role in contributing to negative outcomes related to unequal treatment in the clinical encounter.

Keywords: communication; health inequities; mistrust; perceived discrimination; placebo and nocebo effects.

Figure 1

QOL is quality of life, a measure assessed by many treatment satisfaction surveys. Non-adherence, stress, or poor feelings of quality of life could occur unrelated to these factors. Though there are other mechanisms by which non-verbal and contextual cues and past experiences mediate outcomes, one suggested mechanism is that expectation in part mediates these inputs. For example, experience of racism in a clinical encounter could lead to mistrust of that physician and reduce adherence to the treatment suggested by that physician without the influence of expectations. However, the next time that patient returns to a clinician’s office for a medical problem, they might be wary of the potential for a negative encounter, which could then be mediated by expectations, following the paths in the figure.