[Communicating test results in a comprehensible manner: A randomized controlled trial of word usage in doctor-patient...

Doctor-patient communication is one of the hallmarks of good medical treatment. Mutual understanding is of foremost importance, in particular when communicating non-numerical test results.

Using a two-step approach, this study analyses the influence of wording on the correct understanding of medical test results by people without a medical background. In a first step, a qualitative analysis of physicians' letters helped to identify adjectives that are frequently used to communicate test results. In a second step, a parallel randomised study was conducted to test the comprehensibility of particularly relevant adjectives, combining the written communication of test results with a subsequent survey. 1,131 participants, representing the population of Germany with regard to age, gender, and educational level, were recruited via an online platform. The participants read a scenario involving the communication of the results of a breath test, whereby non-numerical test results were described as being either "positive" vs. "negative" (n=566) or "abnormal" vs. "normal" (n=565). Participant assignment to one of these groups took place in a randomised way. The outcomes measured included the subjective and objective understanding of test results as well as the participants' subjective comprehension of the physician communicating with them.

People without a medical background can understand medical test results more readily when neutral, descriptive adjectives are used rather than adjectives considered as being judgmental in everyday language. 54 % of the participants who read test results using the adjectives "positive" vs. "negative" and 65 % of the participants who read test results using the adjectives "abnormal" vs. "normal", respectively, understood the results correctly. This relative difference of 20.4 % in the number of participants with a correct understanding is statistically significant (Chi square=13.061; p=0.001). There was also a considerable difference in the subjective understanding (means of 5.04 of "positive" vs. "negative" and 5.47 for "abnormal" vs. "normal" on a 7-point Likert scale; absolute mean difference 0.42 [95 % CI: 0.20; 0.64]) as well as in the subjective comprehension of the communicating physician (means of 4.49 for "positive" vs. "negative" and 4.95 for "abnormal" vs. "normal" on a 7-point Likert scale; absolute mean difference 0.45 [95% CI: 0.23; 0.67]). A higher level of comprehension for the words "abnormal" vs. "normal" was consistent across the overall sample. It is mainly people with no school-leaving certificate and a lower educational level who benefit from the changed wording.

In the process of communicating non-numerical medical test results, people without a medical background understand neutral, descriptive adjectives better than adjectives that are considered judgmental in everyday usage. A corresponding change of written and oral communication can easily be implemented by medical experts in their everyday practice and particularly supports a population group that already suffers disadvantages in the medical system.