Static outliers for Ashley 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 Ashley Surgery is higher than most

BNF Chemical	Chemical Items	BNF Subparagraph	Subparagraph Items	Ratio	Mean	std	Z_Score	Plots
Fluorescein sodium☰	5	Ocular diagnostic & peri-operative prepn & photodynamic tt	11	0.45	0.00	0.05	9.03
Fluorescein 1% eye drops 0.5ml unit dose preservative free : 1 Minims fluorescein sodium 1% eye drops 0.5ml unit dose : 4
Levothyroxine sodium and liothyronine☰	4	Thyroid hormones	1431	0.00	0.00	0.00	6.59
Armour Thyroid 60mg (1 grain) tablets : 4
Ciprofloxacin☰	11	Otitis externa	60	0.18	0.01	0.03	6.12
Ciprofloxacin 2mg/ml ear dps 0.25ml ud preservative free : 11
Fenofibrate☰	214	Lipid-regulating drugs	4425	0.05	0.01	0.01	5.95
Fenofibrate micronised 200mg capsules : 175 Fenofibrate micronised 267mg capsules : 10 Fenofibrate micronised 67mg capsules : 24 Fenofibrate micronised 160mg tablets : 5
Meloxicam☰	94	Non-steroidal anti-inflammatory drugs	372	0.25	0.03	0.04	4.93
Meloxicam 7.5mg tablets : 73 Meloxicam 15mg tablets : 21

Prescribing where Ashley Surgery is lower than most

BNF Chemical	Chemical Items	BNF Subparagraph	Subparagraph Items	Ratio	Mean	std	Z_Score	Plots
Tiotropium bromide☰	11	Antimuscarinic bronchodilators	80	0.14	0.71	0.18	-3.14
Tiotropium bromide 18microgram inhalation powder capsules : 4 Spiriva 18microgram inhalation powder capsules : 4 Spiriva Respimat 2.5microg/dose inhalation soln refill cart : 3
Fusidic acid☰	13	Antibacterial preparations also used systemically	41	0.32	0.72	0.15	-2.65
Fusidic acid 2% cream : 13
Lithium carbonate☰	0	Drugs used for mania and hypomania	5	0.00	0.61	0.28	-2.19
Coal tar☰	2	Shampoos and some other scalp preparations	22	0.09	0.41	0.16	-2.00
Capasal Therapeutic shampoo : 2
Amlodipine☰	1459	Calcium-channel blockers	2740	0.53	0.75	0.11	-1.96
Amlodipine 5mg tablets : 840 Amlodipine 10mg tablets : 619