Developing clinically relevant and reproducible symptom-defined populations for cancer diagnostic research in general...

In developing cancer diagnostic studies, there is a particular need for the population of patients with symptoms of possible oncological significance who consult the GP in 'real life' to be comparable with the group of individuals with symptoms constructed as part of a research project.

The objective of this study was to seek to assess whether a community-based symptom survey can be harnessed in order to produce clinically relevant and reproducible populations within which studies of more detailed indicants could be undertaken.

A total of 3629 patients registered with a general practice at Winterton, UK, were sent a questionnaire enquiring about 10 symptoms of possible oncological significance together with their consultation intention in relation to these symptoms. Up to 1 month later, an identical questionnaire was applied to all patients reporting at least one symptom, and more detailed information was obtained by research nurses on each symptom.

The overall response rate was 64.4%, and 850 patients reported one or more symptoms. For the majority of symptom reports, there was moderate to substantial agreement between the two applications of the questionnaire. The question on blood in the motions/toilet pan or on the toilet paper demonstrated almost perfect agreement. Slight agreement was found for abdominal pain for longer than 4 weeks and for black/tarry motions. In relation to the reliability of the patient consultation intention, there was substantial/moderate agreement for actions related to the majority of symptoms. For all symptoms, there was also a greater level of agreement for past activity than future intent.

The results of the study provide some support for a community survey as a mechanism to develop 'clinically relevant' populations for the iatrotropic symptoms rectal bleeding or indigestion/heartburn within which studies of more detailed indicants could be undertaken. There is also consistency with the work of others in relation to the numbers and characteristics of patients within the 'clinically relevant' population.