Iron deficiency anaemia in general practice: clinical outcomes over three years and factors influencing diagnostic investigations

Abstract

Background: Iron deficiency anaemia (IDA) may be a sign of significant gastrointestinal disease, and delayed diagnosis may result in chronic morbidity. Studies in patients referred to hospital for investigation of their anaemia have shown that 5%–15% have a gastrointestinal cancer but there are few studies of patients presenting to primary care. Factors influencing further investigation in these patients have not previously been identified.

Patients and methods: A cohort of patients presenting to their general practitioners (GPs) with IDA was identified and clinical outcomes recorded. Logistic regression was used to determine which factors influenced GPs to investigate the anaemia.

Results: 43% of patients had investigations within three months and serious pathology was found in 30% of these; 13% of patients were considered unfit for further investigation and 8% refused to have any. Independent predictors of non-investigation were a mild anaemia (odds ratio (OR) 0.38, confidence interval (CI) 0.23 to 0.61, p<0.001), female gender (OR 0.49, CI 0.3 to 0.8, p  =  0.004), a previous history of anaemia (OR 0.39, CI 0.24 to 0.64, p<0.001), and age <65 years (OR 0.44, CI 0.26 to 0.74, p  =  0.002). During the entire study period gastrointestinal cancer was diagnosed in 48 patients (11%); 17% of men had colorectal cancer. Of 263 patients alive at 12 months without a confirmed diagnosis, 113 (43%) had recurrent or persistent anaemia during the study period.

Conclusion: Although the overall prevalence of gastrointestinal cancer in patients presenting to primary care is similar to that seen in secondary care, the diagnosis may be delayed due to lack of appropriate investigations resulting in significant morbidity.