Static outliers for Lunesdale 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 Lunesdale Surgery is higher than most

BNF Chemical	Chemical Items	BNF Subparagraph	Subparagraph Items	Ratio	Mean	std	Z_Score	Plots
Triamcinolone acetonide☰	69	Drugs used in nasal allergy	566	0.12	0.01	0.02	7.20
Triamcinolone 55micrograms/dose nasal spray : 69
Methenamine hippurate☰	143	Urinary-tract infections	321	0.45	0.03	0.06	6.78
Methenamine hippurate 1g tablets : 90 Hiprex 1g tablets : 53
Darifenacin hydrobromide☰	134	Drugs for urinary frequency enuresis and incontinence	661	0.20	0.01	0.04	5.18
Darifenacin 7.5mg modified-release tablets : 71 Darifenacin 15mg modified-release tablets : 63
Aclidinium bromide☰	47	Antimuscarinic bronchodilators	121	0.39	0.04	0.07	5.02
Aclidinium bromide 375micrograms/dose dry powder inhaler : 42 Eklira 322micrograms/dose Genuair : 5
Bilastine☰	5	Antihistamines	1208	0.00	0.00	0.00	4.91
Bilastine 20mg tablets : 5

Prescribing where Lunesdale Surgery is lower than most

BNF Chemical	Chemical Items	BNF Subparagraph	Subparagraph Items	Ratio	Mean	std	Z_Score	Plots
Nitrofurantoin☰	178	Urinary-tract infections	321	0.55	0.97	0.06	-6.78
Nitrofurantoin 50mg tablets : 33 Nitrofurantoin 100mg modified-release capsules : 136 Nitrofurantoin 100mg capsules : 3 Nitrofurantoin 50mg capsules : 6
Levothyroxine sodium☰	2571	Thyroid hormones	2599	0.99	1.00	0.00	-3.15
Levothyroxine sodium 25microgram tablets : 811 Levothyroxine sodium 50microgram tablets : 863 Levothyroxine sodium 75microgram tablets : 91 Levothyroxine sodium 100microgram tablets : 780 Levothyroxine sodium 100micrograms/5ml soln sugar free : 6 Levothyroxine sodium 12.5microgram tablets : 20
Pizotifen malate☰	0	Prophylaxis of migraine	4	0.00	0.65	0.26	-2.49
Tiotropium bromide☰	34	Antimuscarinic bronchodilators	121	0.28	0.71	0.18	-2.35
Braltus 10microgram inhalation pdr caps with Zonda inhaler : 14 Tiotropium bromide 18microgram inhalation pdr caps with dev : 4 Tiotropium brom 2.5microg/dose soln for inhalation CFCfree : 4 Spiriva Respimat 2.5microg/dose inhalation soln : 12
Mercaptopurine☰	0	Antimetabolites	11	0.00	0.80	0.35	-2.31