Static outliers for Horfield Hc

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 Horfield Hc is higher than most

BNF Chemical Chemical Items BNF Subparagraph Subparagraph Items Ratio Mean std Z_Score Plots
Bambuterol hydrochloride 23 Selective beta(2)-agonists 2279 0.01 0.00 0.00 14.76
Diclofenac sodium 5 Ocular diagnostic & peri-operative prepn & photodynamic tt 6 0.83 0.03 0.13 6.38
Ibuprofen lysine 9 Non-steroidal anti-inflammatory drugs 1346 0.01 0.00 0.00 6.27
Azilsartan medoxomil 3 Angiotensin-II receptor antagonists 1800 0.00 0.00 0.00 4.45
Almotriptan 20 Treatment of acute migraine 217 0.09 0.01 0.02 3.42

Prescribing where Horfield Hc is lower than most

BNF Chemical Chemical Items BNF Subparagraph Subparagraph Items Ratio Mean std Z_Score Plots
Glycopyrronium bromide 0 Antimuscarinic drugs 1 0.00 0.82 0.36 -2.30
Alfentanil hydrochloride 0 Opioid analgesics 1 0.00 0.82 0.37 -2.21
Betahistine hydrochloride 42 Drugs used in nausea and vertigo 584 0.07 0.27 0.11 -1.80
Tiotropium bromide 105 Antimuscarinic bronchodilators 272 0.39 0.71 0.18 -1.77
Mesalazine (Systemic) 110 Aminosalicylates 288 0.38 0.64 0.15 -1.76
Pentasa 2g modified-release granules sachets : 2
Salofalk 2g/59ml enema : 2
Salofalk 1g/application foam enema : 2
Salofalk 500mg gast res MR gran sachets : 2
Salofalk 1g suppositories : 2
Salofalk 500mg gastro-resistant tablets : 2
Mesalazine 1g suppositories : 1
Mesalazine 1g/application foam enema : 1
Mesalazine 800mg gastro-resistant tablets : 1
Pentasa Mesalazine 1g/100ml enema : 1
Salofalk 500mg suppositories : 1
Pentasa 500mg modified-release tablets : 9
Pentasa 1g suppositories : 4
Mesalazine 1g modified-release tablets : 3
Pentasa 1g modified-release tablets : 3
Asacol 800mg MR gastro-resistant tablets : 17
Mesalazine 500mg modified-release tablets : 7
Asacol 400mg MR gastro-resistant tablets : 7
Mezavant XL 1200mg tablets : 7
Octasa 800mg MR gastro-resistant tablets : 16
Octasa 400mg MR gastro-resistant tablets : 15
Salofalk 1.5g gastro-resistant modified-release gran sachets : 5