Static outliers for Millbrook Surgery, Castle Cary

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 Millbrook Surgery, Castle Cary is higher than most

BNF Chemical	Chemical Items	BNF Subparagraph	Subparagraph Items	Ratio	Mean	std	Z_Score	Plots
Alirocumab☰	1	Lipid-regulating drugs	2324	0.00	0.00	0.00	30.99
Alirocumab 75mg/1ml inj pre-filled disposable devices : 1
Fondaparinux sodium☰	6	Parenteral anticoagulants	9	0.67	0.00	0.03	19.17
Fondaparinux sodium 2.5mg/0.5ml inj pre-filled syringes : 1 Fondaparinux sodium 5mg/0.4ml inj pre-filled syringes : 1 Fondaparinux sodium 7.5mg/0.6ml inj pre-filled syringes : 4
Ketotifen fumarate☰	6	Antihistamines	362	0.02	0.00	0.00	8.48
Ketotifen 1mg/5ml oral solution sugar free : 6
Ampicillin☰	1	Broad-spectrum penicillins	172	0.01	0.00	0.00	6.74
Ampicillin 250mg capsules : 1
Levomepromazine hydrochloride☰	28	Antipsychotic drugs	335	0.08	0.01	0.02	4.72
Levomepromazine 25mg/1ml solution for injection ampoules : 28

Prescribing where Millbrook Surgery, Castle Cary is lower than most

BNF Chemical	Chemical Items	BNF Subparagraph	Subparagraph Items	Ratio	Mean	std	Z_Score	Plots
Nitrofurantoin☰	132	Urinary-tract infections	159	0.83	0.97	0.06	-2.23
Nitrofurantoin 100mg modified-release capsules : 101 Nitrofurantoin 100mg tablets : 2 Nitrofurantoin 100mg capsules : 3 Nitrofurantoin 50mg tablets : 26
Desogestrel☰	161	Oral progestogen-only contraceptives	196	0.82	0.94	0.05	-2.15
Desogestrel 75microgram tablets : 155 Cerelle 75microgram tablets : 1 Cerazette 75microgram tablets : 5
Fusidic acid☰	18	Antibacterial preparations also used systemically	44	0.41	0.72	0.15	-2.05
Fucidin 20mg/g cream : 1 Fusidic acid 2% cream : 17
Sertraline hydrochloride☰	502	Selective serotonin re-uptake inhibitors	1812	0.28	0.45	0.09	-2.00
Sertraline 50mg tablets : 262 Sertraline 100mg tablets : 236 Sertraline 25mg tablets : 4
Chloramphenicol☰	17	Antibacterials	32	0.53	0.78	0.13	-1.92
Chloramphenicol 1% eye ointment : 7 Chloramphenicol 0.5% eye drops : 10