Static outliers for Ouse Valley 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 Ouse Valley Practice is higher than most

BNF Chemical	Chemical Items	BNF Subparagraph	Subparagraph Items	Ratio	Mean	std	Z_Score
Arnica montana	1	Rubefacients, topical NSAIDS, capsaicin and poultice	195	0.01	0.00	0.00	12.59
Arnica montana gel : 1
Famciclovir	21	Herpes simplex and varicella-zoster	104	0.20	0.01	0.02	10.08
Famciclovir 250mg tablets : 4 Famciclovir 500mg tablets : 17
Paraffin soft yellow	2	Emollients	161	0.01	0.00	0.00	6.83
Yellow soft paraffin solid : 2
Hydrocortisone sodium succinate	6	Use of corticosteroids	387	0.02	0.00	0.00	5.05
Solu-Cortef 100mg powder for solution for injection vials : 6
Bromfenac	3	Ocular diagnostic & peri-operative prepn & photodynamic tt	3	1.00	0.09	0.23	3.99
Yellox 900micrograms/ml eye drops : 3

Prescribing where Ouse Valley Practice is lower than most

BNF Chemical	Chemical Items	BNF Subparagraph	Subparagraph Items	Ratio	Mean	std	Z_Score
Carbimazole	6	Antithyroid drugs	10	0.60	0.93	0.11	-3.12
Carbimazole 20mg tablets : 2 Carbimazole 5mg tablets : 4
Aciclovir	77	Herpes simplex and varicella-zoster	104	0.74	0.95	0.07	-3.11
Aciclovir 400mg tablets : 37 Aciclovir 800mg dispersible tablets : 2 Aciclovir 200mg tablets : 13 Aciclovir 800mg tablets : 12 Aciclovir 200mg dispersible tablets : 7 Aciclovir 400mg dispersible tablets : 6
Tacrolimus	4	Drugs affecting the immune response	19	0.21	0.81	0.21	-2.89
Tacrolimus 0.1% ointment : 4
Diazepam	93	Anxiolytics	211	0.44	0.75	0.14	-2.31
Diazepam 2mg tablets : 57 Diazepam 10mg/2.5ml rectal solution tube : 2 Diazepam 5mg tablets : 28 Diazepam 10mg tablets : 6
Salicylic acid	0	Preparations for warts and calluses	2	0.00	0.69	0.31	-2.20