Static outliers for Wham PCN

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 Wham PCN is higher than most

BNF Chemical	Chemical Items	BNF Subparagraph	Subparagraph Items	Ratio	Mean	std	Z_Score	Plots
Lidocaine/prilocaine (Premature Ejaculation)☰	1	Drugs for premature ejaculation	1	1.00	0.01	0.08	12.90
Fortacin 150mg/ml / 50mg/ml cutaneous spray (Recorati) : 1
Trientine dihydrochloride☰	2	Drugs used in metabolic disorders	2	1.00	0.02	0.13	7.29
Trientine dihydrochloride 300mg capsules : 2
Fluocortolone☰	7	Copound haemorrhoidal preparations with corticosteroid	341	0.02	0.00	0.00	6.47
Ultraproct ointment : 6 Ultraproct suppositories : 1
Indometacin☰	103	Non-steroidal anti-inflammatory drugs	2128	0.05	0.01	0.01	6.02
Indometacin 25mg capsules : 6 Indometacin 50mg capsules : 92 Indometacin 25mg/5ml oral suspension : 5
Mepivacaine hydrochloride☰	21	Local anaesthetics	286	0.07	0.00	0.01	5.83
Scandonest plain 3% solution for injection 2.2ml cartridges : 21

Prescribing where Wham PCN is lower than most

BNF Chemical	Chemical Items	BNF Subparagraph	Subparagraph Items	Ratio	Mean	std	Z_Score	Plots
Dapoxetine hydrochloride☰	0	Drugs for premature ejaculation	1	0.00	0.99	0.08	-12.90
Metronidazole☰	167	Metronidazole, tinidazole and ornidazole	168	0.99	1.00	0.00	-5.10
Metronidazole 200mg/5ml oral suspension : 2 Metronidazole 200mg tablets : 1 Metronidazole 400mg tablets : 163 Metronidazole 500mg tablets : 1
Sildenafil (Erectile Dysfunction)☰	465	Drugs for erectile dysfunction	803	0.58	0.77	0.05	-3.46
Sildenafil 50mg tablets : 174 Sildenafil 25mg tablets : 27 Sildenafil 100mg tablets : 261 Viagra 100mg tablets : 3
Doxazosin mesilate☰	1017	Alpha-adrenoceptor blocking drugs	1055	0.96	0.99	0.01	-2.44
Doxazosin 1mg tablets : 169 Doxazosin 2mg tablets : 295 Doxazosin 4mg tablets : 448 Doxazosin 4mg modified-release tablets : 44 Doxazosin 8mg modified-release tablets : 52 Doxazosin 8mg tablets : 9
Rifampicin☰	0	Antituberculosis drugs	2	0.00	0.74	0.35	-2.12