1.4 SUBDIRECCIÓN DE SERVICIOS ADMINISTRATIVOS
1.1.1.1 DIVISIÓN DE CARRERA
Four groups of studies with a wide variation in error rates (which were conducted in the same setting) were identified.
Table 3.1: Studies using the same denominators showing wide variation in error rates classified according to methodology and type of errors
Method Type of medication errors Denominator Number of studies Range of reported errors Number of different settings with wide variation Chart/medical record review
MPEs Of all orders 27 0-90.5% 10 3
Of all errors 6 0.7-89% 6 1 Direct observation MAEs Of all administrations 8 1.2-96.6% 5 1
Mixed methods MEs Per 1000 patient days
6 4-167 * 4 2
* Wang et al. 2007 (106) identified more than one error per admission.
3.4.1.1.Studies using “of all orders” as the denominator and identified prescribing
errors using chart/medical record review
Studies in three different settings (specialist children’s hospital, primary care centres and outpatients) were associated with a wide variation in error rate.
Four studies in specialist children’s hospitals showed error rates of 1.2-82% of all
orders (68). Two of these studies used interventions. The rate of error was very high in only one study looking at controlled substances such as opiate drugs and was 82%
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of all orders. The authors of this study suggested that the cause for the high error rate was because the drugs studied were high risk medications. Another study (96) just looking at sedation medication found the next highest error rate of 25%. The remaining studies looked at all medications. The Senegal study (120) showed a relatively high rate of 17% compared to a UK study (152) that identified a very low error rate both before and after the intervention (introduction of CPOE). The authors of this study suggested that this is because the study only identified dosing prescribing errors.
Four studies were conducted by the same authors in primary care centres in Bahrain. The overall error rate range was between 2.5-90.5% of all orders. In each study specific subsets of prescribing errors were studied with specific types of medications and this accounts for much of the variation. One study (153) identified a very high rate of errors (90.5% of all orders) and involved all medications, unlike the other three studies (154-156) which identified errors with particular drug groups. The authors identified three types of prescribing errors for the study involving all medications, omission, commission and integration errors. They define each type as following:
Minor omission errors: “absence of prescription components such as date of prescription, any parameter of patient’s personal identifiers, physician’s stamp,
and/or direction for use”. Major omission errors: “absence, vague, incomplete
and/or illegibility of any component of body of the prescription”.
Commission errors: “incorrectly written component(s) of body of the prescription”.
Errors of integration or knowledge-based errors in prescribing: “include potential drug-drug interactions or drug allergies which may reflect a failure of the
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According to the study authors; the reason for high error rate is because of the lack of a national drug policy and irrational drug use in primary care centres.
Two studies (157) (57) were conducted in outpatients (error rate between 9.7-62.2% of all orders). Neither study used an intervention and both involved all medications. The Nigerian study (157) relates its high rate of error (62.2%) to irrational prescribing. Under-dosing (38% of all medications) and overdosing (19% of all medications) were identified as common errors as well as inadequate treatment courses (28% of all medications). They emphasised the urgent need for a prescribing monitoring committee. The other study conducted in the US found a far lower error rate of 9.7% (57).
3.4.1.2.Studies using “of all errors” as the denominator and identified prescribing
errors using chart/medical record review
One study showed wide variation in error rate. Jain et al. 2009 (70) from India explained most of the wide variation with an error rate seen. This study identified only prescribing and dispensing errors of which 43 prescribing errors were in the emergency department and 24 prescribing errors in the neonatal unit. Of all medication errors in the emergency department; 79% were prescribing errors (70% of all errors by senior doctors and 9% by junior doctors). Eighty-nine percent of all errors in the neonatal unit were related to prescribing errors by senior doctors. The authors suggested that environmental issues in emergency departments (e.g. stress,
noise and crowding caused by patients’ carers), verbal orders and a shortage of
healthcare professionals could be causes of the high rate of prescribing errors. The reason why senior doctors were involved in more prescribing errors than junior doctors is not explained. However, as this study only identified two types of
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medication errors (prescribing and dispensing) it is clearly an important reason for the high prescribing error rates identified.
3.4.1.3.Studies using “of all administrations” as the denominator and identified
administration errors using direct observation
Three studies in paediatric units in general hospitals showed a wide variation in error rates. The error rate was very high (89.9%) in the study (158) in Ethiopia which identified administration errors by nurses and parents. A wrong time error (delay in administration by more than one hour) was responsible for the highest portion of errors (28%). Conroy, in the UK, showed a very low error rate of 1.2% of all administrations (142) and Chua, in Malaysia, showed 11.7% of all administrations (67). Only doctors and/or nurses were involved in administration in these studies.
3.4.1.4.Studies using “per 1000 patient days” and identified medication errors in
general and using mixed methods
Studies in two different settings (neonatal and paediatric units in general hospitals and paediatric units in general hospitals) showed wide variation in error rates.
Two studies (106, 159) identified the error rate in neonatal and paediatric units in general hospitals in the US. One (159) only identified serious medication errors and therefore had a much lower number of errors identified.
For the two studies (145, 160) that were conducted in paediatric units in general hospitals; the study by Walsh (160) was retrospective and only identified errors related to electronic order entry which is likely to explain the much lower error rate than the prospective study from New Zealand (145).
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