Short-term interventions on wards fail to reduce preanalytical errors: results of two prospective controlled trials

Preventing laboratory errors promotes patient safety and reduces the cost of unnecessary processing. The aim of this study was to test the effectiveness of two short-term interventions at reducing errors in the preanalytical stage of laboratory testing.

Error data were reviewed from inpatient wards at Bradford Royal Infirmary (BRI), Leeds General Infirmary (LGI) and St James' University Hospital (SJUH) for 22 weeks. Two separate interventions lasted for two weeks. The outcome measures were inadequate tube and form labelling, incorrect tube selection and insufficient sample volume. Posters targeting these errors were created and displayed on inpatient wards in SJUH (n = 48). BRI and LGI were control hospitals. Qualitative interviews were held with clinical staff to raise awareness of common errors, give advice and discuss error reduction (n = 37). Ten weeks later, screensavers warning against labelling errors were displayed (LGI and SJUH). Quantitative error data, routinely collected by the laboratory, were used for analysis.

There was no change in error rate or type at the intervention site(s) compared with the control(s). There were 7058 reported errors across three sites, of which 6623 were errors targeted by the interventions. The overall error rate remained stable on all three sites (analysis of variance, P = 1.0). When interviewing clinical staff, 29% thought that equipment was the main contributing factor to errors while 23% struggled with tube selection.

Despite enthusiasm on the part of the ward-based staff, both short-term interventions had no significant impact on preanalytical error rates. Most errors are due to human factors. These may be reduced with the introduction of an electronic ordering system.