Summary of all studies

Table 2.17 summarises all results identified and illustrates the number of studies using each denominator to identify each type of errors categorised according to the methods of data collection.

68

Table 2.17: Number of studies providing error rates by denominators and methods

Denominator

Chart/medical record review Direct observation

Medication error incident report review

Mixed methods Simulation Total number of studies MPE s MA E s

MEs _{MTEs MMEs MD}

E s MPE s MA E s MPE s MA E s

MEs _{MTEs MMEs MD}

E s MPE s MA E s

MEs _{MTEs MMEs MD}

E s MPE s MA E s Of all errors 6 2 1 2 4 7 7 5 3 5 2 2 2 1 2 51 Of all orders 27 1 5 2 2 4 1 3 1 1 1 2 50 Of all patients 3 2 3 1 2 2 1 2 16 Of all administrations 1 8 1 3 13

Per 1000 patient days 1 1 1 1 1 6 1 1 13

Of all admissions 1 1 1 1 1 1 3 1 1 11

Of all medications 3 1 1 1 1 7

Mean errors 4 1 5

Per 1000 orders 1 3 1 5

Of all patient visits 2 1 1 4

Of all participants 3 3

Of all medication days 1 1 1 3

Of all doses 1 1 2

Per 1000 administrations 1 1 2

Of all possible errors 1 1 2

Median errors 1 1

Visits per 10,000 individuals per year 1 1

Per 100 patient days 1 1

Of all preparations 1 1

Of all samples 1 1

Per 3.9 hospitalisation days 1 1

Per 1000 doses 1 1

Of all transcriptions 1 1

Of all charts 1 1

Of all ADEs 1 1

Per bed day 1 1

Total number of studies 50 8 18 6 3 6 1 8 11 10 6 5 3 5 10 8 17 2 4 6 1 10 198 Legend: Bold underlined numbers are studies with wide variations (> 50%) in results. These studies will be explored further in Chapter 3.

69

2.5. Discussion

Ghaleb et al’s (2006) systematic review identified 32 relevant studies of medication

errors in children from 1966 to March 2006. In my project, 153 studies have been identified from the five years April 2006 - March 2011. This suggests that the literature on the subject is increasing very quickly.

Many factors in study design can affect the rate of errors determined. These factors make comparing the rates of errors in different studies difficult and often impossible. The following summary of my findings illustrates this:

1. Two hundred and thirty six different definitions of medication errors were used by 78 studies.

2. Many studies did not identify the rate of medication errors (44 studies only identified the number of errors).

3. Five different methods were used to identify errors (chart/medical record review (39.2%), review of incident reports (32.7%), mixed methods (15.1%), simulation (7.8%) and direct observation (5.2%). Lots of US studies seem to rely on reviewing medication error incident reports.

4. The rate of error identified in some studies was for specific types of medication errors and in others was general: prescribing errors (28.8%), several specific types of errors (27.5%), administration errors (23.5%), medication errors in general (18.9%), dispensing errors (0.65%) and monitoring errors (0.65%).

5. Twenty six different denominators were used. The commonest denominators

70

6. Twenty two different settings were used (mostly specialist children’s hospitals followed respectively by neonatal units and paediatric units in general hospitals).

7. Studies were conducted in 30 different countries often using different healthcare systems (mostly the US followed by the UK).

8. Some studies investigated medication errors with all medications (73 studies) while some studies only investigated errors with specific medications such as chemotherapy (seven studies) and antimicrobials (four studies).

9. Some studies investigated errors with only a particular route of administration, e.g. intravenous.

10. Studies used different designs, e.g. prospective or retrospective chart review. 11. Some studies identified the rate of errors in the whole paediatric population

and some identified the rate of errors in specific ages.

12. Some studies focused only on medication errors, while others focused on medical errors in general or adverse drug events (which include medication errors).

13. Fifty-nine out of 153 studies used 65 interventional tools which affected the error rates.

14. Many settings used routine strategies for decreasing the rate of medication error (e.g. electronic prescribing or clinical pharmacy services); therefore, the rate of medication errors may be altered by these strategies.

15. Some studies used simulation rather than collecting data from clinical settings. 16. Chart /medical record review was used to identify prescribing errors more than

other types of errors.

71

18. Review of medication error incident reports was used mostly to identify medication errors in general.

19. Prescribing and administration errors followed by medication errors in general were the commonest errors identified using mixed methods.

20. Simulation studies mostly focused on administration errors.

21. The ranges reported for specific types of errors identified by the same methods are very wide in many cases.

McLeod et al. 2013 (151) identified quantitative observational studies exploring administration error rates in the UK. They aimed to measure the effect of variations in methods on the rate of administration errors identified. They identified 44 administration errors subcategories from 16 UK studies using four different denominators. Different factors were identified to be responsible for the variation in the administration error rates found. These factors include: methods of data collection,

route of administration, patients’ age, definitions used including explicit inclusion and

exclusion criteria, subtypes of errors and denominators. McLeod only studied observational methods measuring administration errors. In my own systematic review of the factors influencing the rate of all medication errors in paediatric patients; the above factors identified by McLeod plus 15 other factors were identified.

72

All of these factors make it very challenging to compare studies and therefore the plan is to study the following in more depth in the next chapter of my thesis:

a) The reasons for the wide variation in reported error rates in studies which used the same methods, the same denominators and identified the same types of medication error.

b) The relationship between the methods used for data collection and the results; i.e. how did specific types of error rates vary between studies using different methods of data collection.

c) The relationship between the clarity of definitions used in studies and their results.

d) The effect of different interventional tools in reducing the rate of medication errors.

e) Studies conducted in the UK identifying the rate of medication errors and different methods used to prevent these errors.

f) Studies describing the time of the day and days of the week mostly associated with errors.

73

Chapter 3: Detailed analysis of papers from