A cohort study assessing the impact of small volume blood tubes on diagnostic test quality and iatrogenic blood loss in a cohort of adult haematology patients

Background/Aim To estimate the reduction in blood volume loss and impact on diagnostic test quality associated with introduction of small volume blood tubes in a cohort of haematology inpatients compared to a historical comparator group. Methods Prospective cohort study of haematology inpatients admitted to a tertiary referral hospital in Adelaide. Small volume blood tubes were used in an intervention cohort admitted between 2012 and 2013 and compared to a control cohort admitted between 2009 and 2010 where standard volume blood tubes had been used. The diagnostic test quality, specimen integrity and total reduction in blood loss associated with small volume blood tubes were estimated. Results Small volume blood tubes demonstrated acceptable collinearity on commonly assayed haematological and biochemical parameters. Small volume tubes were associated with a 42% reduction in blood volume loss equating to a saving of 8.5 mL per patient per day or 180 mL of blood loss over a 3‐week admission. Small volume blood tubes were associated with a slight but significantly increased rate of fibrin contamination of ethylenediaminetetraacetic acid samples (0.2–0.5% of specimens). Conclusion Small volume blood tubes are associated with a substantial reduction in total blood volume collected per day in haematology inpatients. They have similar diagnostic validity and sample integrity to that of standard volume containers.