Static outliers for The Doc'S 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 Doc'S Surgery is higher than most

BNF Chemical	Chemical Items	BNF Subparagraph	Subparagraph Items	Ratio	Mean	std	Z_Score	Plots
Ceftriaxone sodium☰	18	Cephalosporins	27	0.67	0.0	0.01	87.23
Ceftriaxone 1g powder for solution for injection vials : 18
Human papillomavirus (Type 6,11,16,18)☰	27	Vaccines and antisera	77	0.35	0.0	0.01	23.32
Gardasil vacc inj 0.5ml pre-filled syringes : 27
Pentosan polysulfate sodium☰	2	Oral anticoagulants	223	0.01	0.0	0.00	22.70
Elmiron 100mg capsules (Consilient Health) : 2
Gemfibrozil☰	5	Lipid-regulating drugs	1345	0.00	0.0	0.00	10.12
Gemfibrozil 300mg capsules : 5
Erythromycin stearate☰	5	Macrolides	54	0.09	0.0	0.01	10.03
Erythromycin stearate 500mg tablets : 5

Prescribing where The Doc'S Surgery is lower than most

BNF Chemical	Chemical Items	BNF Subparagraph	Subparagraph Items	Ratio	Mean	std	Z_Score	Plots
Cefalexin☰	9	Cephalosporins	27	0.33	0.96	0.10	-6.13
Cefalexin 250mg tablets : 1 Cefalexin 500mg tablets : 1 Cefalexin 250mg capsules : 4 Cefalexin 500mg capsules : 3
Doxazosin mesilate☰	91	Alpha-adrenoceptor blocking drugs	99	0.92	0.99	0.02	-3.62
Doxazosin 4mg tablets : 32 Doxazosin 8mg tablets : 3 Doxazosin 2mg tablets : 17 Doxazosin 4mg modified-release tablets : 10 Doxazosin 1mg tablets : 24 Doxazosin 8mg modified-release tablets : 5
Ivermectin☰	2	Topical preparation for rosacea	9	0.22	0.88	0.24	-2.78
Ivermectin 10mg/g cream : 2
Methylphenidate hydrochloride☰	10	CNS Stimulants and drugs used for ADHD	78	0.13	0.65	0.21	-2.53
Methylphenidate 10mg modified-release capsules : 2 Concerta XL 54mg tablets : 2 Methylphenidate 27mg modified-release tablets : 6
Fluconazole☰	14	Triazole antifungals	29	0.48	0.85	0.15	-2.50
Fluconazole 50mg capsules : 2 Fluconazole 150mg capsules : 12