Static outliers for St James' 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 St James' Surgery is higher than most

BNF Chemical	Chemical Items	BNF Subparagraph	Subparagraph Items	Ratio	Mean	std	Z_Score
Dibrompropamidine isetionate	1	Antibacterials	54	0.02	0.00	0.00	12.55
Golden Eye 0.15% ointment : 1
Propamidine isetionate	3	Antibacterials	54	0.06	0.00	0.01	9.79
Golden Eye 0.1% drops : 3
Sodium fusidate	12	Antibacterial preparations also used systemically	35	0.34	0.02	0.05	5.90
Fucidin 20mg/g ointment : 12
Tiaprofenic acid	3	Non-steroidal anti-inflammatory drugs	836	0.00	0.00	0.00	5.07
Surgam 300mg tablets : 3
Fluocortolone	1	Copound haemorrhoidal preparations with corticosteroid	39	0.03	0.00	0.01	4.86
Ultraproct ointment : 1

Prescribing where St James' Surgery is lower than most

BNF Chemical	Chemical Items	BNF Subparagraph	Subparagraph Items	Ratio	Mean	std	Z_Score
Amlodipine	683	Calcium-channel blockers	1638	0.42	0.75	0.11	-2.98
Amlodipine 5mg tablets : 409 Amlodipine 10mg tablets : 272 Amlodipine 2.5mg tablets : 2
Gliclazide	106	Sulfonylureas	199	0.53	0.92	0.14	-2.89
Gliclazide 80mg tablets : 74 Gliclazide 40mg tablets : 30 Gliclazide 60mg modified-release tablets : 2
Fusidic acid	11	Antibacterial preparations also used systemically	35	0.31	0.72	0.15	-2.67
Fucidin 20mg/g cream : 1 Fusidic acid 2% cream : 10
Ramipril	597	Angiotensin-converting enzyme inhibitors	1890	0.32	0.69	0.17	-2.24
Ramipril 1.25mg capsules : 88 Ramipril 2.5mg capsules : 151 Ramipril 5mg capsules : 181 Ramipril 10mg capsules : 155 Ramipril 1.25mg tablets : 7 Ramipril 2.5mg tablets : 10 Ramipril 5mg tablets : 5
Warfarin sodium	0	Oral anticoagulants	583	0.00	0.24	0.11	-2.19