Static outliers for The Garden Surgery

There is substantial variation in prescribing behaviours, across various different areas of medicine. Some variation can be explained by demographic changes, or local policies or guidelines, but much of the remaining variation is less easy to explain. At OpenPrescribing we are piloting a number of data-driven approaches to identify unusual prescribing and collect feedback on this prescribing to inform development of new tools to support prescribers and organisations to audit and review prescribing.

This report has been developed to automatically identify prescribing patterns at a chemical level which are furthest away from “typical prescribing” and can be classified as an “outlier”. We calculate the number of prescriptions for each chemical in the BNF coding system using the BNF subparagraph as a denominator, for prescriptions dispensed between April 2021 and August 2021. We then calculate the mean and standard deviation for each numerator and denominator pair across all practices/CCGs/PCNs/STPs. From this we can calculate the “z-score”, which is a measure of how many standard deviations a given practice/CCG/PCN/STP is from the population mean. We then rank your “z-scores” to find the top 5 results where prescribing is an outlier for prescribing higher than its peers and those where it is an outlier for prescribing lower than its peers.

It is important to remember that this information was generated automatically and it is therefore likely that some of the behaviour is warranted. This report seeks only to collect information about where this variation may be warranted and where it might not. Our full analytical method code is openly available on GitHub here.

The DataLab is keen to hear your feedback on the results. You can do this by completing the following survey or emailing us at ebmdatalab@phc.ox.ac.uk. Please DO NOT INCLUDE IDENTIFIABLE PATIENT information in your feedback. All feedback is helpful, you can send short or detailed feedback.

Prescribing where The Garden Surgery is higher than most

BNF Chemical	Chemical Items	BNF Subparagraph	Subparagraph Items	Ratio	Mean	std	Z_Score	Plots
Penciclovir☰	1	Antiviral preparations	2	0.50	0.00	0.00	124.94
Penciclovir 1% cream : 1
Measles, mumps and rubella vaccine☰	1	Vaccines and antisera	8	0.12	0.00	0.01	18.09
M-M-RVAXPRO vacc inj 0.5ml pre-filled syringes : 1
Oxazepam☰	55	Anxiolytics	271	0.20	0.01	0.02	8.11
Oxazepam 10mg tablets : 55
Zuclopenthixol hydrochloride☰	72	Antipsychotic drugs	758	0.09	0.01	0.01	6.30
Zuclopenthixol 2mg tablets : 51 Zuclopenthixol 10mg tablets : 16 Zuclopenthixol 25mg tablets : 5
Fluticasone furoate (Inhalation)☰	844	Corticosteroids (respiratory)	1616	0.52	0.09	0.08	5.29
Relvar Ellipta 184microg/dose / 22microg/dose dry pdr inh : 66 Relvar Ellipta 92microg/dose / 22microg/dose dry pdr inh : 157 Trelegy Ellipta 92microg/55microg/22microg/dose dry pdr inh : 616 Fluticasone furoate 92microg/Vilanterol 22microg/dose : 5

Prescribing where The Garden Surgery is lower than most

BNF Chemical	Chemical Items	BNF Subparagraph	Subparagraph Items	Ratio	Mean	std	Z_Score	Plots
Aciclovir☰	1	Antiviral preparations	2	0.50	1.00	0.01	-87.72
Aciclovir 5% cream : 1
Carbimazole☰	28	Antithyroid drugs	49	0.57	0.93	0.11	-3.39
Carbimazole 10mg tablets : 7 Carbimazole 5mg tablets : 16 Carbimazole 20mg tablets : 5
Amitriptyline hydrochloride☰	1355	Tricyclic and related antidepressant drugs	2119	0.64	0.84	0.08	-2.62
Amitriptyline 10mg tablets : 976 Amitriptyline 25mg tablets : 226 Amitriptyline 50mg tablets : 146 Amitriptyline 25mg/5ml oral solution sugar free : 2 Amitriptyline 10mg/5ml oral solution sugar free : 5
Calcium carbonate☰	9	Calcium supplements	14	0.64	0.95	0.13	-2.31
Adcal 1500mg chewable tablets : 2 Calcium carbonate 1.25g chewable tablets sugar free : 4 Calcium carbonate 1.5g chewable tablets sugar free : 3
Estradiol☰	5	Preparations for vaginal/vulval changes	45	0.11	0.55	0.21	-2.05
Estradiol 10microgram pessaries : 2 Vagifem 10microgram vaginal tablets : 3