Static outliers for The Mill Hill 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 Mill Hill Surgery is higher than most

BNF Chemical	Chemical Items	BNF Subparagraph	Subparagraph Items	Ratio	Mean	std	Z_Score	Plots
Empagliflozin/linagliptin☰	20	Other antidiabetic drugs	739	0.03	0.00	0.00	22.03
Empagliflozin 25mg / Linagliptin 5mg tablets : 20
Proguanil hydrochloride with atovaquone☰	3	Antimalarials	82	0.04	0.00	0.00	21.12
Proguanil 25mg / Atovaquone 62.5mg tablets : 1 Malarone 250mg/100mg tablets : 1 Malarone Paediatric 62.5mg/25mg tablets : 1
Minocycline hydrochloride☰	17	Tetracyclines	165	0.10	0.01	0.01	7.31
Minocycline 50mg tablets : 17
Fluvastatin sodium☰	48	Lipid-regulating drugs	3483	0.01	0.00	0.00	6.09
Fluvastatin 20mg capsules : 24 Fluvastatin 40mg capsules : 24
Dantrolene sodium☰	17	Skeletal muscle relaxants	55	0.31	0.02	0.06	5.21
Dantrolene 25mg capsules : 17

Prescribing where The Mill Hill Surgery is lower than most

BNF Chemical	Chemical Items	BNF Subparagraph	Subparagraph Items	Ratio	Mean	std	Z_Score	Plots
Calcium carbonate☰	4	Calcium supplements	9	0.44	0.95	0.13	-3.80
Calcichew Forte chewable tablets : 1 Calcichew 500mg chewable tablets : 3
Theophylline☰	2	Theophylline	70	0.03	0.83	0.25	-3.27
Uniphyllin Continus 200mg tablets : 2
Fluconazole☰	9	Triazole antifungals	22	0.41	0.85	0.15	-3.01
Fluconazole 50mg capsules : 2 Fluconazole 150mg capsules : 7
Aciclovir☰	40	Herpes simplex and varicella-zoster	50	0.80	0.95	0.07	-2.24
Aciclovir 200mg dispersible tablets : 1 Aciclovir 400mg tablets : 22 Aciclovir 800mg tablets : 7 Aciclovir 200mg tablets : 10
Salicylic acid☰	0	Preparations for warts and calluses	3	0.00	0.69	0.31	-2.20