Static outliers for Chapel Row 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 Chapel Row Surgery is higher than most

BNF Chemical	Chemical Items	BNF Subparagraph	Subparagraph Items	Ratio	Mean	std	Z_Score	Plots
Lacidipine☰	1222	Calcium-channel blockers	3107	0.39	0.01	0.03	13.98
Lacidipine 2mg tablets : 427 Lacidipine 4mg tablets : 621 Motens 2mg tablets : 99 Motens 4mg tablets : 75
Hepatitis A/hepatitis B☰	4	Vaccines and antisera	7	0.57	0.01	0.05	11.04
Twinrix Adult vacc inj 1ml pre-filled syringes : 2 Ambirix vacc inj 1ml pre-filled syringes : 2
Colestipol hydrochloride☰	9	Lipid-regulating drugs	4363	0.00	0.00	0.00	7.96
Colestipol 5g granules sachets sugar free : 2 Colestid Orange 5g granules sachets : 2 Colestid 5g granules sachets plain : 5
Rabeprazole sodium☰	185	Proton pump inhibitors	3637	0.05	0.00	0.01	7.10
Rabeprazole 20mg gastro-resistant tablets : 175 Rabeprazole 10mg gastro-resistant tablets : 5 Pariet 20mg gastro-resistant tablets : 5
Co-proxamol (Dextropropoxyphene hydrochloride/paracetamol)☰	10	Non-opioid analgesics and compound preparations	1234	0.01	0.00	0.00	6.96
Co-proxamol 32.5mg/325mg tablets : 10

Prescribing where Chapel Row Surgery is lower than most

BNF Chemical	Chemical Items	BNF Subparagraph	Subparagraph Items	Ratio	Mean	std	Z_Score	Plots
Amlodipine☰	813	Calcium-channel blockers	3107	0.26	0.75	0.11	-4.35
Amlodipine 5mg tablets : 94 Amlodipine 10mg tablets : 78 Istin 5mg tablets : 433 Istin 10mg tablets : 204 Amlodipine 2.5mg tablets : 4
Theophylline☰	2	Theophylline	18	0.11	0.83	0.25	-2.93
Uniphyllin Continus 200mg tablets : 2
Doxycycline hyclate☰	94	Tetracyclines	316	0.30	0.63	0.14	-2.47
Doxycycline 100mg capsules : 94
Clopidogrel☰	322	Antiplatelet drugs	1836	0.18	0.32	0.06	-2.33
Clopidogrel 75mg tablets : 322
Naproxen☰	250	Non-steroidal anti-inflammatory drugs	534	0.47	0.69	0.10	-2.17
Naproxen 250mg tablets : 99 Naproxen 500mg tablets : 138 Naproxen 500mg gastro-resistant tablets : 9 Naproxen 250mg gastro-resistant tablets : 4