Presenting pathology data to patients - a graphical representation of a haemoglobin result

Traditional pathology results, based on numerical values and strict reference ranges, maybe hard for both patients and doctors to understand. A lot of activity and worry is generated by tests that fall outside reference ranges. We need better ways of representing the 'normality' or otherwise of a result, so that we can have more honest dialogues with patients about meaning.

We recently saw a patient with an incidental finding of a haemoglobin of 108, with the lower end of the reference at 115. This 'low' result has caused anxiety to the GP, who must decide whether to follow guidelines for investigation of anaemia; but prinicipally to the patient, who now worries they may have cancer. 

We assumed that most haemoglobins measured in primary care are in patients with no underlying pathology. We plotted sequential results from women aged 65-75 (the demographic of our patient), to show the context of results we would be expecting. We then plotted the patients result, and used a large data point to represent the uncertainty that is inherent in any result. We added a line showing 2 standard deviations from the mean.

We think that this shows a result in a way that is instantly understandable in context. By showing the population variation as data points rather than in relation to a static mean, or between confidence limits, may give a feel for the dynamic nature of a test which is perhaps lost in traditional reports. Other background 'normal' data sets might be used if available - and this would be essential if there was a high proportion of data from patients with significant pathology.

An alternative way of presenting the data. My feeling is that this does not display the uncertainty of a test in a way that is as meaningful - it still emphasises the abnormality of the result. This may also be beacuse it uses set 'normal' ranges that may not be entirely appropriate for the popultation