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.
BNF Chemical | Chemical Items | BNF Subparagraph | Subparagraph Items | Ratio | Mean | std | Z_Score | Plots |
---|---|---|---|---|---|---|---|---|
Hydrogen peroxide | 1 | Otitis externa | 811 | 0.00 | 0.00 | 0.00 | 35.41 | |
Flupentixol hydrochloride | 1214 | Other antidepressant drugs | 16857 | 0.07 | 0.01 | 0.01 | 9.60 | |
Pridinol mesilate | 50 | Skeletal muscle relaxants | 1729 | 0.03 | 0.00 | 0.00 | 8.89 | |
Pericyazine | 1168 | Antipsychotic drugs | 12013 | 0.10 | 0.00 | 0.02 | 5.72 | |
Promethazine hydrochloride | 4530 | Antihistamines | 9489 | 0.48 | 0.12 | 0.08 | 4.43 | |
Promethazine 25mg/1ml solution for injection ampoules : 1 Promethazine hydrochloride 10mg tablets : 1223 Promethazine hydrochloride 20mg tablets : 54 Promethazine hydrochloride 25mg tablets : 3089 Promethazine 5mg/5ml oral solution sugar free : 98 Phenergan 10mg tablets : 11 Phenergan 25mg tablets : 40 Phenergan Nightime 25mg tablets : 2 Phenergan 5mg/5ml elixir : 12 |
BNF Chemical | Chemical Items | BNF Subparagraph | Subparagraph Items | Ratio | Mean | std | Z_Score | Plots |
---|---|---|---|---|---|---|---|---|
Apixaban | 970 | Oral anticoagulants | 10873 | 0.09 | 0.40 | 0.12 | -2.55 | |
Quinine sulfate | 1025 | Antimalarials | 1451 | 0.71 | 0.89 | 0.08 | -2.41 | |
Cetirizine hydrochloride | 874 | Antihistamines | 9489 | 0.09 | 0.28 | 0.08 | -2.40 | |
Amlodipine | 13373 | Calcium-channel blockers | 23369 | 0.57 | 0.75 | 0.08 | -2.12 | |
Donepezil hydrochloride | 471 | Drugs for dementia | 1903 | 0.25 | 0.49 | 0.11 | -2.12 | |