Static outliers for Silverdale Family Practice

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 Silverdale Family Practice is higher than most

BNF Chemical	Chemical Items	BNF Subparagraph	Subparagraph Items	Ratio	Mean	std	Z_Score	Plots
Bambuterol hydrochloride☰	30	Selective beta(2)-agonists	1694	0.02	0.00	0.00	25.99
Bambuterol 10mg tablets : 30
Lixisenatide☰	48	Other antidiabetic drugs	850	0.06	0.00	0.01	8.85
Lixisenatide 20micrograms/0.2ml inj 3ml pf dispos dev : 41 Lixisenatide 10microg/0.2ml and 20microg/0.2ml inj : 2 Lyxumia 20micrograms/0.2ml inj 3ml pre-filled pens : 5
Estradiol and estriol with progestogen☰	3	Oestrogens and Hormone Replacement Therapy	96	0.03	0.00	0.01	4.74
Trisequens tablets : 3
Reboxetine☰	45	Other antidepressant drugs	2518	0.02	0.00	0.00	4.73
Reboxetine 4mg tablets : 45
Empagliflozin☰	507	Other antidiabetic drugs	850	0.60	0.15	0.10	4.47
Empagliflozin 10mg tablets : 53 Empagliflozin 25mg tablets : 454

Prescribing where Silverdale Family Practice is lower than most

BNF Chemical	Chemical Items	BNF Subparagraph	Subparagraph Items	Ratio	Mean	std	Z_Score	Plots
Ramipril☰	783	Angiotensin-converting enzyme inhibitors	2961	0.26	0.69	0.17	-2.55
Ramipril 1.25mg capsules : 137 Ramipril 2.5mg capsules : 234 Ramipril 5mg capsules : 154 Ramipril 10mg capsules : 213 Ramipril 2.5mg tablets : 25 Ramipril 5mg tablets : 10 Ramipril 10mg tablets : 10
Gliclazide☰	373	Sulfonylureas	643	0.58	0.92	0.14	-2.54
Gliclazide 80mg tablets : 295 Gliclazide 40mg tablets : 78
Nitrofurantoin☰	198	Urinary-tract infections	240	0.82	0.97	0.06	-2.32
Nitrofurantoin 100mg modified-release capsules : 146 Nitrofurantoin 50mg capsules : 23 Nitrofurantoin 50mg tablets : 23 Nitrofurantoin 100mg tablets : 6
Dexamethasone☰	1	Corticosteroids	45	0.02	0.50	0.23	-2.09
Dexamethasone 0.1% eye dps 0.5ml unit dose preservative free : 1
Estradiol☰	17	Oestrogens and Hormone Replacement Therapy	96	0.18	0.46	0.14	-2.00
Estradiol 2mg tablets : 1 Evorel 75 patches : 1 Elleste Solo 2mg tablets : 1 Estradot 25micrograms/24hours patches : 4 Estradiol 1mg tablets : 10