Static outliers for Witton Street 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 Witton Street Surgery is higher than most

BNF Chemical	Chemical Items	BNF Subparagraph	Subparagraph Items	Ratio	Mean	std	Z_Score	Plots
Quinidine sulfate☰	5	Drugs for arrhythmias	37	0.14	0.00	0.00	235.36
Quinidine sulfate 200mg tablets : 5
Tiaprofenic acid☰	6	Non-steroidal anti-inflammatory drugs	499	0.01	0.00	0.00	17.23
Tiaprofenic acid 300mg tablets : 6
Spironolactone with loop diuretics☰	5	Potassium sparing diuretics and compounds	5	1.00	0.01	0.08	12.90
Lasilactone 20mg/50mg capsules : 5
Sodium zirconium cyclosilicate☰	1	Oral potassium	3	0.33	0.01	0.07	4.98
Lokelma 5g oral powder sachets : 1
Amisulpride☰	122	Antipsychotic drugs	625	0.20	0.03	0.04	4.35
Amisulpride 50mg tablets : 31 Amisulpride 100mg tablets : 43 Amisulpride 400mg tablets : 22 Amisulpride 200mg tablets : 26

Prescribing where Witton Street Surgery is lower than most

BNF Chemical	Chemical Items	BNF Subparagraph	Subparagraph Items	Ratio	Mean	std	Z_Score	Plots
Trimethoprim☰	29	Sulfonamides and trimethoprim	60	0.48	0.86	0.13	-2.95
Trimethoprim 50mg/5ml oral suspension sugar free : 4 Trimethoprim 200mg tablets : 18 Trimethoprim 100mg tablets : 7
Procyclidine hydrochloride☰	11	Antimuscarinic drugs used in parkinsonism	38	0.29	0.84	0.21	-2.65
Kemadrin 5mg tablets : 6 Procyclidine 5mg tablets : 5
Potassium chloride☰	2	Oral potassium	3	0.67	0.98	0.12	-2.62
Sando-K effervescent tablets : 2
Tramadol hydrochloride☰	29	Opioid analgesics	661	0.04	0.27	0.09	-2.47
Marol 100mg modified-release tablets (Teva) : 1 Tramadol 50mg capsules : 23 Tramadol 50mg modified-release tablets : 5
Budesonide☰	0	Corticosteroids	2	0.00	0.70	0.34	-2.08