Static outliers for Tri-Links Medical Practice

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 Tri-Links Medical Practice is higher than most

BNF Chemical	Chemical Items	BNF Subparagraph	Subparagraph Items	Ratio	Mean	std	Z_Score
Diazoxide	6	Treatment of hypoglycaemia	12	0.50	0.00	0.04	13.79
Diazoxide 50mg tablets : 6
Tiagabine	4	Control of epilepsy	1394	0.00	0.00	0.00	8.21
Tiagabine 10mg tablets : 2 Tiagabine 15mg tablets : 2
Ciprofloxain/dexameth	55	Otitis externa	100	0.55	0.05	0.06	7.97
Ciprofloxacin 0.3% / Dexamethasone 0.1% ear drops : 54 Cilodex ear drops : 1
Sirolimus	3	Corticosteroids and other immunosuppressants	3	1.00	0.03	0.14	6.99
Sirolimus 2mg tablets : 3
Trandolapril	47	Angiotensin-converting enzyme inhibitors	2030	0.02	0.00	0.00	6.75
Trandolapril 1mg capsules : 21 Trandolapril 2mg capsules : 21 Trandolapril 4mg capsules : 5

Prescribing where Tri-Links Medical Practice is lower than most

BNF Chemical	Chemical Items	BNF Subparagraph	Subparagraph Items	Ratio	Mean	std	Z_Score
Dexamethasone	40	Otitis externa	100	0.40	0.78	0.13	-2.90
Otomize ear spray : 40
Aciclovir	33	Herpes simplex and varicella-zoster	43	0.77	0.95	0.07	-2.71
Aciclovir 800mg dispersible tablets : 1 Aciclovir 200mg dispersible tablets : 1 Aciclovir 400mg tablets : 14 Aciclovir 800mg tablets : 11 Aciclovir 200mg tablets : 6
Glucose	3	Treatment of hypoglycaemia	12	0.25	0.75	0.21	-2.42
Rapilose 40% gel : 2 GlucoGel 40% gel original : 1
Donepezil hydrochloride	5	Drugs for dementia	105	0.05	0.49	0.19	-2.39
Donepezil 10mg tablets : 5
Finasteride	37	Male sex hormones and antagonists	64	0.58	0.82	0.12	-2.09
Finasteride 5mg tablets : 37