Static outliers for Winchmore Hill Practice

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 Winchmore Hill Practice is higher than most

BNF Chemical	Chemical Items	BNF Subparagraph	Subparagraph Items	Ratio	Mean	std	Z_Score
Sodium chloride	11	Tear deficiency, eye lubricant/astringent	56	0.20	0.00	0.01	16.78
Sodium chloride 5% eye ointment : 6 Sodium chloride 0.9% eye dps 0.5ml ud preservative free : 5
Acetylcysteine	9	Tear deficiency, eye lubricant/astringent	56	0.16	0.01	0.02	8.21
Ilube 5% eye drops : 9
Paliperidone	22	Antipsychotic drugs	1879	0.01	0.00	0.00	6.29
Paliperidone 6mg modified-release tablets : 22
Diflucortolone valerate	7	Topical corticosteroids	1118	0.01	0.00	0.00	5.05
Diflucortolone 0.1% cream : 2 Nerisone 0.1% oily cream : 2 Diflucortolone 0.1% oily cream : 1 Diflucortolone 0.3% oily cream : 1 Nerisone 0.1% cream : 1
Paraffin soft yellow	4	Emollients	484	0.01	0.00	0.00	4.48
Yellow soft paraffin solid : 4

Prescribing where Winchmore Hill Practice is lower than most

BNF Chemical	Chemical Items	BNF Subparagraph	Subparagraph Items	Ratio	Mean	std	Z_Score
Medroxyprogesterone acetate	13	Parenteral progestogen-only contraceptives	32	0.41	0.88	0.16	-2.92
Medroxyprogesterone 150mg/1ml inj pre-filled syringes : 7 Depo-Provera 150mg/1ml inj pre-filled syringes : 6
Sodium cromoglicate	25	Other anti-inflammatory preparations	113	0.22	0.67	0.18	-2.44
Opticrom Allergy 2% eye drops : 4 Sodium cromoglicate 2% eye drops : 21
Codeine phosphate	0	Cough suppressants	1	0.00	0.76	0.35	-2.18

Pregabalin	343	Control of epilepsy	3507	0.10	0.27	0.08	-2.17
Pregabalin 25mg capsules : 54 Pregabalin 50mg capsules : 68 Pregabalin 75mg capsules : 72 Pregabalin 100mg capsules : 65 Pregabalin 150mg capsules : 50 Pregabalin 300mg capsules : 22 Pregabalin 200mg capsules : 7 Lyrica 50mg capsules : 5
Co-amilofruse (Amiloride hydrochloride/frusemide)	0	Potassium sparing diuretics and compounds	10	0.00	0.68	0.33	-2.07