Static outliers for Oak Tree 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 Oak Tree Surgery is higher than most

BNF Chemical	Chemical Items	BNF Subparagraph	Subparagraph Items	Ratio	Mean	std	Z_Score	Plots
Prilocaine hydrochloride☰	20	Local anaesthetics	217	0.09	0.0	0.00	128.05
Citanest 3% with Octapressin Dental 0.066units/2.2ml inj : 20
Tolvaptan☰	3	Posterior pituitary hormones and antagonists	29	0.10	0.0	0.01	12.38
Samsca 15mg tablets : 3
Perphenazine☰	3	Antipsychotic drugs	1430	0.00	0.0	0.00	9.68
Perphenazine 2mg tablets : 2 Perphenazine 4mg tablets : 1
Co-triamterzide(Triamterene/hydrochlorothiazide)☰	1	Potassium sparing diuretics and compounds	99	0.01	0.0	0.00	8.63
Co-triamterzide 50mg/25mg tablets : 1
Tolcapone☰	4	Dopaminergic drugs used in parkinsonism	792	0.01	0.0	0.00	8.41
Tasmar 100mg tablets : 4

Prescribing where Oak Tree Surgery is lower than most

BNF Chemical	Chemical Items	BNF Subparagraph	Subparagraph Items	Ratio	Mean	std	Z_Score	Plots
Desmopressin acetate☰	26	Posterior pituitary hormones and antagonists	29	0.90	1.00	0.01	-12.38
Desmopressin 25microgram oral lyophilisates sugar free : 1 Desmopressin 50microgram oral lyophilisates sugar free : 4 DesmoMelt 120microgram oral lyophilisates : 4 DesmoMelt 240microgram oral lyophilisates : 7 Desmopressin 120microgram oral lyophilisates sugar free : 10
Glycopyrronium bromide☰	0	Antimuscarinic drugs	27	0.00	0.82	0.36	-2.30
Ciprofloxacin☰	25	Quinolones	46	0.54	0.86	0.15	-2.12
Ciprofloxacin 250mg tablets : 2 Ciprofloxacin 500mg tablets : 23
Levothyroxine sodium☰	6623	Thyroid hormones	6674	0.99	1.00	0.00	-2.07
Levothyroxine sodium 25microgram tablets : 1706 Levothyroxine sodium 50microgram tablets : 1355 Levothyroxine sodium 75microgram tablets : 623 Levothyroxine sodium 100microgram tablets : 2923 Levothyroxine sodium 50microgram capsules : 1 Levothyroxine sodium 12.5microgram tablets : 15
Atropine sulfate☰	0	Mydriatics and cycloplegics	2	0.00	0.72	0.38	-1.91