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Mean, median and mode: tools to enlighten patients

Healthcare professionals can use mean, median and mode observed during studies or trials to explain the expected outcome of treatment to patients in simple language.

To provide answers to patients’ questions, healthcare professionals can sometimes draw on the results of studies and trials on samples of the population.

By looking at the mean, the median and the mode, professionals are better able to answer patients’ questions concerning the anticipated benefits and risks of the proposed treatment.

Clinical trial results can be used to answer patients who ask if a particular medicated plaster will reduce their pain after shingles. In one trial, patients using this plaster found the pain was reduced on average by around 73%. This permits the healthcare professional to inform the patient that with this treatment they can expect the pain to be greatly reduced (by about 75%). In the same trial, the median of the improvement rates was 76%; in other words, half of the patients experienced an improvement of over 76%. This means that the patient can be told there is a 50% chance of their pain being significantly reduced (by at least 75%).

In the same trial, the most frequent value (i.e. the "mode") of the improvement level was 100%, observed in 28% of cases. The patient can thus be told that there is a chance of around one in four of the pain disappearing completely.

And so by translating the results of studies and trials into simple language, healthcare professionals can sometimes give patients important information to help them make a decision.

©Prescrire July 2010

Source: "Moyenne, médiane et mode : utiles pour éclairer certaines questions de patients" Rev Prescrire 2010 ; 30 (320) : 466-469.