Static outliers for Dr Newman

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 Dr Newman is higher than most

BNF Chemical	Chemical Items	BNF Subparagraph	Subparagraph Items	Ratio	Mean	std	Z_Score	Plots
Alclometasone dipropionate☰	1	Topical corticosteroids	421	0.00	0.00	0.00	22.59
Alclometasone 0.05% cream : 1
Metolazone☰	15	Thiazides and related diuretics	236	0.06	0.00	0.01	12.05
Metolazone 5mg tablets : 15
Avanafil☰	7	Drugs for erectile dysfunction	99	0.07	0.00	0.01	9.48
Avanafil 200mg tablets : 7
Ketotifen fumarate☰	5	Antihistamines	328	0.02	0.00	0.00	7.77
Ketotifen 1mg tablets : 5
Diclofenac sodium☰	167	Non-steroidal anti-inflammatory drugs	629	0.27	0.04	0.03	6.66
Diclofenac 100mg suppositories : 151 Diclofenac 50mg suppositories : 2 Diclofenac sodium 75mg modified-release capsules : 2 Diclofenac sodium 50mg gastro-resistant tablets : 4 Diclofenac sodium 75mg modified-release tablets : 8

Prescribing where Dr Newman is lower than most

BNF Chemical	Chemical Items	BNF Subparagraph	Subparagraph Items	Ratio	Mean	std	Z_Score	Plots
Furosemide☰	272	Loop diuretics	460	0.59	0.86	0.09	-2.96
Furosemide 20mg tablets : 95 Furosemide 40mg tablets : 177
Procyclidine hydrochloride☰	3	Antimuscarinic drugs used in parkinsonism	10	0.30	0.84	0.21	-2.60
Procyclidine 5mg tablets : 3
Glycopyrronium bromide☰	0	Antimuscarinic drugs	4	0.00	0.82	0.36	-2.30
Naproxen☰	289	Non-steroidal anti-inflammatory drugs	629	0.46	0.69	0.10	-2.26
Naproxen 250mg tablets : 43 Naproxen 500mg tablets : 213 Naproxen 250mg gastro-resistant tablets : 13 Naproxen 500mg gastro-resistant tablets : 20
Lithium carbonate☰	0	Drugs used for mania and hypomania	4	0.00	0.61	0.28	-2.19