Static outliers for The Dunstan Partnership

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 The Dunstan Partnership is higher than most

BNF Chemical Chemical Items BNF Subparagraph Subparagraph Items Ratio Mean std Z_Score Plots
Promazine hydrochloride 403 Antipsychotic drugs 1508 0.27 0.01 0.04 6.82
Levomepromazine maleate 62 Antipsychotic drugs 1508 0.04 0.00 0.01 5.13
Felodipine 1609 Calcium-channel blockers 3319 0.48 0.08 0.08 4.81
Fluticasone furoate (Inhalation) 1041 Corticosteroids (respiratory) 2193 0.47 0.09 0.08 4.71
Diethylamine salicylate 228 Rubefacients, topical NSAIDS, capsaicin and poultice 740 0.31 0.03 0.06 4.56

Prescribing where The Dunstan Partnership is lower than most

BNF Chemical Chemical Items BNF Subparagraph Subparagraph Items Ratio Mean std Z_Score Plots
Amlodipine 1083 Calcium-channel blockers 3319 0.33 0.75 0.11 -3.78
Gliclazide 202 Sulfonylureas 447 0.45 0.92 0.14 -3.49
Glycopyrronium bromide 0 Antimuscarinic drugs 26 0.00 0.82 0.36 -2.30
Tiotropium bromide 140 Antimuscarinic bronchodilators 475 0.29 0.71 0.18 -2.27
Furosemide 595 Loop diuretics 898 0.66 0.86 0.09 -2.16