Association between faecal occult bleeding and medicines prescribed for chronic disease: a data linkage study

The presence of detectable faecal haemoglobin (f-Hb) has been shown to be associated with all-cause mortality and with death from a number of chronic diseases not known to cause gastrointestinal blood loss. This effect is independent of taking medicines that increase the risk of bleeding. To further investigate the association of f-Hb with chronic disease, the relationship between f-Hb and prescription of medicines for a variety of conditions was studied.

All subjects (134 192) who participated in guaiac faecal occult blood test (gFOBT) screening in Tayside, Scotland, between March 2000 and March 2016, were studied in a cross-sectional manner by linking their gFOBT result (abnormal or normal) with prescribing data at the time of the test.

The screening participants with an abnormal gFOBT result were more likely to have been being prescribed medicines for heart disease, hypertension, diabetes and depression than those with a normal test result. This association persisted after adjustment for sex, age and deprivation (OR 1.35 (95%CI 1.23 to 1.48), 1.39 (1.27 to 1.52), 1.35 (1.15 to 1.58), 1.36 (1.16 to 1.59), all p<0.0001, for the four medicine categories, respectively).

The results of this study confer further substantial weight to the concept that detectable f-Hb is associated with a range of common chronic conditions that have a systemic inflammatory component; we speculate that f-Hb might have potential in identifying individuals who are high risk of developing chronic conditions or are at an early stage of disease.