Do clinicians convey what they intend? Lay interpretation of verbal risk labels used in decision encounters

To assess the numerical probabilities that individuals associate with frequently-used verbal labels relating to treatment outcomes and their association with medical context, age, gender, educational level, health literacy, and numeracy.

Verbal labels (N = 11) were extracted from N = 90 audiotaped decision encounters in oncology. Three hundred Dutch adults, as proxies for newly-diagnosed cancer patients, assigned numerical probabilities to the labels in the context of cancer recurrence or nausea, and completed questions on their socio-demographic characteristics, health literacy and numeracy.

We found considerable variation in how individuals interpreted the verbal labels. Participants' probability estimates of verbal labels was lower in the context of (the more serious) cancer recurrence compared to (less serious) nausea. Lower numerate participants differentiated less between labels. There was no association between participants' estimates and age, gender, educational level or health literacy.

There is considerable variation in how individuals interpret verbal labels frequently-used in decision encounters. Individuals seem to take base rates and severity of outcomes into account. Verbal labels may be less helpful to lower numerate individuals.

To minimize misinterpretation and to improve patient-clinician decision making about health and care, we recommend to avoid the use of verbal labels only.