This audit consisted of the pre-intervention, feedback and post-intervention phases. The patients included were those who were admitted to the neurosurgical ward during the pre- and post-intervention of the audit and received treatment with one of the three commonly used third-generation cephalosporin (ceftriaxone, cefoperazone/sulbactam and ceftazidime).
The sample size required in each phase was estimated based on a previous study, which reported that the proportions of prescriptions showing an appropriate use of empirical antibiotics were, respectively, 61.7% and 83.8% before and after an intervention (15). With the confidence level set at 95% and power at 80%, the calculated sample size was 63 in the pre- and post-intervention phases each. To account for 10% of cases with incomplete information, 70 cases were studied in both phases.
Pre-intervention phase (1st July - 31st October 2019)
A ward pharmacist, who was also the AMS pharmacist, extracted the data from medical records of patients treated with a third-generation cephalosporin between 1st July and 31st October 2019. The data collection and assessment were conducted at the point when the first dose of a cephalosporin was administered prior to any interventions made by the ward pharmacist. The information gathered included the types of antibiotics, their dosage and frequency, duration and the diagnosis of patients. In this context, inappropriate prescribing referred to the use of a cephalosporin not in line with either the NAG or recommendations of the AMS team, in term of drug selection, dose and frequency; and treatment duration. In a case that a condition was not captured by the NAG, the prescriber was expected to seek advices from the AMS team. Also, the prescribers were expected to perform a C&S test right before the first dose of a cephalosporin was given.
The ethics approval for this study was obtained from the Medical Research and Ethics Committee (MREC) under the MOH, Malaysia [(Registration number: NMRR-19-804-47375 (IIR), approval number: KKM/NIHSEC/P19-945(10).
Intervention phase (13th December 2019)
The audit findings were then presented in a 2-hour feedback session, in which all the cases of inappropriate prescribing were discussed. The feedback session was led by the hospital AMS team which consisted of AMS pharmacists, clinical microbiologists and infectious disease physicians. The attendees included neurosurgeons and medical officers from the neurosurgical department. The audit feedback was presented by the ward AMS pharmacist and the discussion emphasized the need to use cephalosporins according to the recommendations of the NAG (Table 1), as well as to perform C&S testing right before empirical treatment was initiated.
Table 1
Summary note of recommended treatment for several common conditions in a neurosurgical ward
(adapted from the National Antibiotics Guidelines 2019).
No.
|
Conditions
|
Recommended treatment
|
1
|
Intracranial trauma and open fracture
|
IV Cefuroxime 1.5g TDS + IV Metronidazole 500mg TDS/PO Metronidazole 400mg TDS
|
2
|
Depressed skull fracture and penetrating craniocerebral injury
|
IV Ceftriaxone 2g BD + IV Metronidazole 500mg TDS/PO Metronidazole 400mg TDS
|
3
|
Aspiration pneumonia
|
IV Amoxycillin/Clavulanic Acid 1.2g TDS
|
4
|
Hospital-acquired pneumonia
i. Early onset
ii. Late onset
|
i. IV Augmentin 1.2 g TDS
ii. IV Piperacillin/Tazobactam 4.5g QID or IV Cefepime 2g TDS
|
Note: IV = intravenous, TDS = three times daily, PO = per os (orally), BD = two times daily, QID = four times daily |
The neurosurgical team agreed to the above recommendations, with an exception given to the use of ceftriaxone at their discretion in patients who had a basilar skull fracture complicated with cerebrospinal fluid (CSF) leak.
Post-intervention phase (15th December 2019 - 31st August 2020)
The post-intervention audit was performed in the same manner as in the pre-intervention phase. No staff change took place throughout the audit period. To minimize the Hawthorne effect [17], only the head of neurosurgical department was informed of the conduct of the audit. Only one ward pharmacist was involved in the data collection and assessment in order to ensure the internal reliability of the assessment.
The statistical analysis was performed using the SPSS for Windows (Version 20.0. Armonk, NY: IBM Corp). The categorical variables were described as frequencies and percentages, and continuous variables as mean with standard deviation (SD). The independent t- and the Pearson’s chi-square tests were used to assess the differences in the patients before and after the intervention. The statistical significance of the test was indicated by a p-value <0.05.