Static outliers for Bradworthy 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 Bradworthy Surgery is higher than most

BNF Chemical	Chemical Items	BNF Subparagraph	Subparagraph Items	Ratio	Mean	std	Z_Score	Plots
Perindopril arginine☰	153	Angiotensin-converting enzyme inhibitors	1459	0.10	0.00	0.00	51.18
Perindopril arginine 5mg tablets : 50 Perindopril arginine 10mg tablets : 86 Perindopril arginine 2.5mg tablets : 17
Telmisartan☰	441	Angiotensin-II receptor antagonists	877	0.50	0.01	0.02	21.61
Telmisartan 40mg tablets : 183 Telmisartan 80mg tablets : 104 Telmisartan 20mg tablets : 154
Valproic acid☰	18	Control of epilepsy	532	0.03	0.00	0.00	18.12
Valproic acid 500mg gastro-resistant capsules : 18
Triamcinolone acetonide☰	26	Drugs used in nasal allergy	148	0.18	0.01	0.02	10.60
Nasacort 55micrograms/dose nasal spray : 9 Triamcinolone 55micrograms/dose nasal spray : 17
Diamorphine hydrochloride (Systemic)☰	13	Opioid analgesics	627	0.02	0.00	0.00	8.85
Diamorphine 10mg powder for solution for injection ampoules : 2 Diamorphine 30mg powder for solution for injection ampoules : 4 Diamorphine 5mg powder for solution for injection ampoules : 7

Prescribing where Bradworthy Surgery is lower than most

BNF Chemical	Chemical Items	BNF Subparagraph	Subparagraph Items	Ratio	Mean	std	Z_Score	Plots
Methylphenidate hydrochloride☰	0	CNS Stimulants and drugs used for ADHD	16	0.00	0.65	0.21	-3.15
Doxycycline hyclate☰	18	Tetracyclines	80	0.22	0.63	0.14	-3.00
Doxycycline 100mg capsules : 18
Benzoyl peroxide and clindamycin phosphate☰	0	Topical preparations for acne	20	0.00	0.38	0.14	-2.73
Senna☰	29	Stimulant laxatives	160	0.18	0.55	0.14	-2.67
Senna 7.5mg tablets : 29
Donepezil hydrochloride☰	0	Drugs for dementia	34	0.00	0.49	0.19	-2.65