Static outliers for The Garden City 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 The Garden City Surgery is higher than most

BNF Chemical	Chemical Items	BNF Subparagraph	Subparagraph Items	Ratio	Mean	std	Z_Score
Hexetidine	2	Mouth-washes, gargles and dentifrices	2	1.00	0.01	0.06	17.05
Hexetidine 0.1% mouthwash sugar free : 2
Other soothing haemorrhoidal preparations	4	Soothing haemorrhoidal preparations	8	0.50	0.00	0.03	14.60
Preparation H ointment : 4
Olmesartan medoxomil/amlodipine	31	Angiotensin-II receptor antagonists	1247	0.02	0.00	0.00	7.57
Sevikar 40mg/5mg tablets : 9 Sevikar 40mg/10mg tablets : 9 Sevikar 20mg/5mg tablets : 8 Olmesartan medoxomil 20mg / Amlodipine 5mg tablets : 5
Betamethasone sodium phosphate	37	Otitis externa	81	0.46	0.03	0.06	7.26
Betamethasone 0.1% / Neomycin 0.5% ear/eye/nose drops : 37
Famciclovir	8	Herpes simplex and varicella-zoster	56	0.14	0.01	0.02	7.05
Famciclovir 500mg tablets : 2 Famciclovir 250mg tablets : 6

Prescribing where The Garden City Surgery is lower than most

BNF Chemical	Chemical Items	BNF Subparagraph	Subparagraph Items	Ratio	Mean	std	Z_Score
Chlorhexidine gluconate	0	Mouth-washes, gargles and dentifrices	2	0.00	0.97	0.11	-9.25

Theophylline	6	Theophylline	60	0.10	0.83	0.25	-2.98
Uniphyllin Continus 300mg tablets : 6
Dexamethasone	32	Otitis externa	81	0.40	0.78	0.13	-2.93
Otomize ear spray : 32
Aciclovir	43	Herpes simplex and varicella-zoster	56	0.77	0.95	0.07	-2.71
Aciclovir 400mg dispersible tablets : 1 Aciclovir 200mg tablets : 8 Aciclovir 800mg tablets : 10 Aciclovir 400mg tablets : 24
Urea hydrogen peroxide	0	Removal of ear wax and other substances	1	0.00	0.83	0.34	-2.47