Static outliers for Rawnsley 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 Rawnsley Surgery is higher than most

BNF Chemical Chemical Items BNF Subparagraph Subparagraph Items Ratio Mean std Z_Score Plots
Asenapine 7 Drugs used for mania and hypomania 64 0.11 0.00 0.00 22.87
Ibuprofen lysine 5 Non-steroidal anti-inflammatory drugs 538 0.01 0.00 0.00 8.76
Insulin glulisine 54 Short-acting insulins 113 0.48 0.03 0.05 8.23
Almotriptan 27 Treatment of acute migraine 167 0.16 0.01 0.02 6.36
Olmesartan medoxomil/amlodipine 23 Angiotensin-II receptor antagonists 1217 0.02 0.00 0.00 5.70

Prescribing where Rawnsley Surgery is lower than most

BNF Chemical Chemical Items BNF Subparagraph Subparagraph Items Ratio Mean std Z_Score Plots
Potassium citrate 0 Drugs used in urological pain 1 0.00 0.93 0.24 -3.87
Insulin aspart 44 Short-acting insulins 113 0.39 0.79 0.12 -3.44
Sumatriptan succinate 56 Treatment of acute migraine 167 0.34 0.67 0.12 -2.72
Sertraline hydrochloride 454 Selective serotonin re-uptake inhibitors 1942 0.23 0.45 0.09 -2.50
Prucalopride 0 Other drugs used in constipation 5 0.00 0.71 0.33 -2.18