Static outliers for Carden 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 Carden Surgery is higher than most

BNF Chemical	Chemical Items	BNF Subparagraph	Subparagraph Items	Ratio	Mean	std	Z_Score	Plots
Xipamide☰	36	Thiazides and related diuretics	569	0.06	0.00	0.00	49.97
Xipamide 20mg tablets : 34 Diurexan 20mg tablets : 2
Paraffin soft yellow☰	10	Tear deficiency, eye lubricant/astringent	85	0.12	0.01	0.02	6.46
Simple eye ointment : 10
Tizanidine hydrochloride☰	23	Skeletal muscle relaxants	34	0.68	0.07	0.10	5.92
Tizanidine 2mg tablets : 23
Telmisartan☰	111	Angiotensin-II receptor antagonists	823	0.13	0.01	0.02	5.33
Telmisartan 40mg tablets : 67 Telmisartan 80mg tablets : 30 Telmisartan 20mg tablets : 14
Reboxetine☰	24	Other antidepressant drugs	1346	0.02	0.00	0.00	4.72
Reboxetine 4mg tablets : 24

Prescribing where Carden Surgery is lower than most

BNF Chemical	Chemical Items	BNF Subparagraph	Subparagraph Items	Ratio	Mean	std	Z_Score	Plots
Other multivitamin preparations☰	34	Multivitamin preparations	172	0.20	0.81	0.21	-2.94
Dalivit oral drops : 2 Ketovite tablets : 2 Valupak Multivitamin One A Day tablets : 2 Abidec Multivitamin drops : 1 Forceval Soluble tablets : 1 Renavit tablets : 1 Healthy Start Children's Vitamin drops : 1 Forceval capsules : 24
Clotrimazole☰	31	Vaginal and vulval infections	49	0.63	0.90	0.10	-2.78
Clotrimazole 200mg pessaries : 2 Canesten 500mg pessaries/vaginal pessaries : 2 Fluconazole 150mg capsule and Clotrimazole 2% cream : 1 Canesten Combi 500mg pessary and 2% cream : 1 Clotrimazole 500mg pessary and Clotrimazole 2% cream : 12 Clotrimazole 2% cream : 7 Canesten Oral & Cream Duo : 6
Baclofen☰	11	Skeletal muscle relaxants	34	0.32	0.83	0.18	-2.73
Baclofen 5mg/5ml oral solution sugar free : 4 Baclofen 10mg tablets : 7
Urea hydrogen peroxide☰	0	Removal of ear wax and other substances	1	0.00	0.83	0.34	-2.47
Hydralazine hydrochloride☰	4	Vasodilator antihypertensive drugs	24	0.17	0.85	0.28	-2.42
Hydralazine 50mg tablets : 4