Doctors who appeared empathetic and conveyed high expectations of treatment success during pain procedures influenced the way patients felt about outcomes in a new study, published October 21 in Nature Human Behaviour.
Clinicians' beliefs about treatment effectiveness can be passed on to patients during brief social interactions, highlighting the importance of healthcare providers' behavior and cognitive mindset when communicating with patients, according to the researchers.
"Our study provides additional empirical support that interpersonal expectancies substantially affect patients' treatment outcomes," wrote the authors, led by Pin-Hao Chen, PhD, of the department of psychological and brain sciences at Dartmouth College in Hanover, NH.
Treatments often occur following a short social interaction between providers and patients. Though research shows that patients' expectations overwhelmingly affect treatment outcomes, little evidence shows how providers' expectations influence them, the authors noted.
The researchers of the current study systematically tested for interpersonal expectancy effect by creating a simulated clinical interaction involving the administration of thermal pain treatment creams.
Nearly 200 undergraduate students enrolled in introductory psychology and neuroscience at Dartmouth College participated in the study. The researchers randomly assigned the students to play the role of either doctor or patient, and they told the "doctors" that they would be applying thermedol, a transient receptor potential channel blocker with analgesic effects for thermal pain, and an ineffective control cream to patients as a treatment to mitigate the effects of noxious heat stimulation. However, both creams were placebos.
The researchers examined whether the doctors' beliefs affected patients' subjective reports of pain experience, their autonomic arousal measured through skin conductance responses, and their pain behavior communicated through facial expressions.
The team found subtle changes in doctors' facial expressions in response to treatment based on prior beliefs.
"Doctors appeared to convey more information relating to facial displays of pain when administering the control treatment, which they believed was ineffective," the authors wrote. "We speculate that there are at least two possible mechanisms underlying the socially transmitted placebo effect. One possibility is that the doctors send some nonverbal information that communicates their beliefs about which treatment is more likely to be the active treatment. Alternatively, the doctor might be more attentive to the patient and develop a more empathetic connection which ultimately makes the patient feel better when they are receiving pain stimulations. The patient may then incorrectly attribute this analgesic effect to the thermedol treatment."
Though the study findings offer insight into how clinicians' behaviors may affect health outcomes, the authors acknowledged a limitation in that the participants were college students and not real providers or patients.
Other studies that take place in clinical environments with real providers and patients also should look at how verbal suggestions and environmental cues influence perceptions, they noted.
The authors concluded that providers' expectations about the efficacy of treatments can substantially affect patients' treatment outcomes via implicit social cues.
"This finding has important implications for virtually all clinical interactions between patients and providers and highlights the importance of explicit training in bedside manner when delivering information and interventions," they wrote.