This study reports on the impact of anaemia upon surgical outcome by retrospectively analysing a cohort of 2073 patients operated upon a hospital ship in the low-income settings of the Republic of Congo and Madagascar. The authors observe that the prevalence of anaemia was 38% within this cohort, of whom the mean age was 27.2 (±20.0) years. Beyond demographic data and the surgical speciality, the authors do not include other background data including comorbidities such as haemoglobinopathy and renal disease. Their logistic regression model includes age, gender, surgical speciality, country and anaemia score. It would have been helpful to provide further stratification of comorbidity, e.g. ASA score, and incorporated this into the regression model to help quantify the impact of anaemia and reduce the confounding upon their findings.
The authors found a significantly higher complication rate in those with severe anaemia. Those patients with mild anaemia showed no difference in risk of complications compared to non-anaemic patients. The authors discuss this finding in the context of low-income countries in contrast to the association between anaemia and increasing age and comorbidity in high-income countries. The authors conclude that in this young population, there may better tolerance of the demands of surgery with mild anaemia when compared to the older, frailer patients of high-income countries. From this the authors caution against the mandatory treatment of mild anaemia in the low-income healthcare setting.
This article reminds us of the potential challenges when interpreting evidence from different population groups and applying this to others. It also demonstrates the challenges of distinguishing the direct effect of anaemia upon outcome and its relation to other comorbidities and risk factors and their influence upon outcome in retrospective studies.
– Ben Clevenger