Nearly 70% of all intravenous medications administered had at least one clinical error, and a quarter of these were serious errors likely to result in permanent harm to patients. Few comparative studies are available. Direct observational studies in the UK9
revealed overall error rates of 49% (212/430 intravenous administrations) and 48% (58/122). A more recent study of vancomycin intravenous administrations reported a high rate of 81% (116/143 intravenous administrations) in four wards in a hospital in Brazil.11
An Australian study12
of continuous infusions among surgical patients reported an 18% error rate but excluded infusions such as antibiotics. This drug group was the most frequent in our study and may be one reason for our rate differences. Only two studies9 10
assessed error severity and used a 10-point scale anchored at 0 no harm to 10 death. Severity categories were collapsed into <3 (minor), 3–7 (moderate) and >7 severe. In the UK study9
1% of intravenous errors were rated as severe and 29% moderate; in the German study 3% were severe and 31% moderate. Given the differences in severity scales, our result of 25.5% serious errors appears reasonably consistent with these findings.
A systematic review and Bayesian analysis of nine studies of intravenous administration errors reported an overall probability of at least one error in 73% of intravenous administrations.18
This is similar to our finding of at least one clinical error in 70% of administrations observed. The analysis by McDowell et al18
relied on data from studies published between 1990 and 2006 (more than half reflected data collected over 10 years ago). When no data were available estimates were used. Few of these previous studies collected detailed information about procedural failures. For example, only two studies in McDowell's review collected information about checking patient identification and both reported no errors. McDowell et al18
reported that the reconstitution step was the most error prone and that the checking of patient identification was the least. We found the opposite. Factors such as the increased use of pre-prepared injections, which is recommended practice in New South Wales public hospitals, as part of contemporary medication administration practice may be one reason for our lower error rate in this category.
Wrong administration rate has been shown consistently to be the most significant problem in intravenous medication administration9 12 19 20
consistent with our finding. In an ethnographic study involving direct observations and interviews with nurses, Taxis and Barber21
found wrong rate errors, particularly the fast administration of bolus doses, were most frequently direct violations where nurses reported deliberately deviating from the correct rate. Concerns have also been raised that a proportion of wrong rate errors are due to poor calculation skills.22
Poor supervision of junior colleagues and a general lack of adequate training in intravenous medication administration are further contributors to error.21
While infusion pumps have the potential to reduce errors, their effectiveness in everyday practice is often seriously compromised by a failure to use devices as intended, for example by-passing safety features and ignoring alerts.23 24
We found a low utilisation of pumps especially among less experienced nurses, the group with the highest error rate. However, use of pumps was not associated with reduced errors. The extent to which this was due to incorrect use is unknown.
Few studies have examined the association between nurse experience and intravenous medication errors. We found that as nurses gained experience up to 6 years, their rates and severity of errors declined significantly. This is an important finding and clearly suggests that inexperienced nurses should be a target for training and supervision with a focus on correct intravenous rates. Han et al12
found no relationship between experience and intravenous administration errors, but their sample was vastly more experienced (median 18 years) compared with our study (median 6 years).
We found a significant relationship between failing to check a patient's identification and making an intravenous administration error. While failing this check does not cause a clinical error, we hypothesise that it is an indicator of a general failure to follow correct administration protocols, whether this is because the nurse is under stress, time pressures, or selects to not comply. This finding suggests that this variable could be used as a proxy measure for increased risk of clinical error, and interventions which reinforce compliance with administration protocols may be effective in reducing clinical errors. The poor compliance found with checking patients' identification (47.9%) suggests that this is a routine violation25
performed by a large proportion of nurses.
We used an undisguised observational technique and nurses were aware that our study was investigating problems in medication administration procedures and errors. It is possible that nurses changed their behaviours when observed. The outcomes of this possible bias would be to lead to an underestimation of the ‘true’ error and procedural failure rates. The length of the study, which involved researchers being on the wards for many months, reduces the likelihood of sustained behaviour change by nurses on busy hospital wards. Further, observational studies of clinicians in situ have suggested that the extent of behaviour change is minimal.26 27
For example, Dean Franklin and Barber28
found no difference in the rate of omitted medication doses when nurses in a UK hospital were observed versus those times when they were not. Our sample also only relates to Australian nurses and thus may not be generalisable to countries with very different nursing practice.
Our findings suggest that a significant proportion of IV administration errors reflect knowledge and/or skill deficiencies, with errors reducing in the first few years of clinical experience. A proportion of errors are also associated with routine violations25
which are likely to be learnt workplace behaviours which persist regardless of increased clinical experience. Both areas suggest specific targets for intervention. Such interventions could include more training and supervision of new nurse graduates and consideration of a reduced use of bolus intravenous infusions. Raising nurses' awareness of the high intravenous administration error rate is also likely to be helpful in reinforcing compliance with correct procedures. Nurses receive very limited feedback of outcome data about performance and the nearly total absence of studies on this topic in the last 5 years is likely to have contributed to its low profile as an important safety issue.