Static outliers for Barn Close 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 Barn Close Surgery is higher than most

BNF Chemical	Chemical Items	BNF Subparagraph	Subparagraph Items	Ratio	Mean	std	Z_Score	Plots
Epinastine hydrochloride☰	34	Other anti-inflammatory preparations	105	0.32	0.00	0.01	27.69
Relestat 500micrograms/ml eye drops : 34
Paliperidone☰	20	Antipsychotic drugs	398	0.05	0.00	0.00	27.43
Invega 3mg modified-release tablets : 20
Levocetirizine☰	103	Antihistamines	702	0.15	0.00	0.01	16.84
Levocetirizine 5mg tablets : 103
Escitalopram☰	1097	Selective serotonin re-uptake inhibitors	3444	0.32	0.04	0.04	7.90
Escitalopram 10mg tablets : 581 Escitalopram 20mg tablets : 346 Escitalopram 5mg tablets : 168 Cipralex 10mg tablets : 2
Rabeprazole sodium☰	327	Proton pump inhibitors	6567	0.05	0.00	0.01	6.94
Rabeprazole 20mg gastro-resistant tablets : 306 Rabeprazole 10mg gastro-resistant tablets : 14 Pariet 10mg gastro-resistant tablets : 7

Prescribing where Barn Close Surgery is lower than most

BNF Chemical	Chemical Items	BNF Subparagraph	Subparagraph Items	Ratio	Mean	std	Z_Score	Plots
Procyclidine hydrochloride☰	0	Antimuscarinic drugs used in parkinsonism	4	0.00	0.84	0.21	-4.04
Glucose☰	0	Treatment of hypoglycaemia	6	0.00	0.75	0.21	-3.62
Amlodipine☰	1791	Calcium-channel blockers	4814	0.37	0.75	0.11	-3.37
Amlodipine 5mg tablets : 1220 Amlodipine 10mg tablets : 571
Emollient bath and shower preparations☰	0	Emollient bath and shower preparations	1	0.00	0.61	0.21	-2.88
Glycopyrronium bromide☰	0	Antimuscarinic drugs	9	0.00	0.82	0.36	-2.30