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Prototype Prescribing Outlier Dashboard for Chiswick PCN

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. These pilot results are provided for the interest of advanced users, although we don't know how relevant they are in practice. 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.

The DataLab is keen to hear your feedback on the results. You can do this by completing the following survey or emailing us at [email protected]. Please DO NOT INCLUDE IDENTIFIABLE PATIENT information in your feedback. All feedback is helpful, you can send short or detailed feedback.

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, the count of all prescriptions within that chemical's BNF subparagraph, for prescriptions dispensed between June 2021 and December 2021. We then calculate the ratio of these counts along with the mean and standard deviation of those ratios across all PCNs. From this we can calculate the “z-score”, which is a measure of how many standard deviations a given PCN is from the population mean. We then rank your “z-scores” to find the top 10 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.

For each outlier chemical, a kernel density estimation plot of all PCN's chemical:subparagraph ratios is provided, with this PCN's ratio overlaid in red.

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, to inform research on this topic. Our full analytical method code is openly available on GitHub here.

This is a new, experimental feature. We'd love to .

Prescribing where Chiswick PCN is higher than most

BNF Chemical Chemical Items BNF Subparagraph Subparagraph Items Ratio Mean std Z_Score Plots
Pridinol mesilate 21 Skeletal muscle relaxants 279 0.08 0.00 0.00 17.75
Calcium carbonate 42 Compound Alginates and proprietary indigestion preparations 645 0.07 0.00 0.01 11.79
Evolocumab 3 Lipid-regulating drugs 23,528 0.00 0.00 0.00 9.89
Dexamethasone sodium phosphate 3 Use of corticosteroids 1,742 0.00 0.00 0.00 8.55
Ketamine hydrochloride 8 Drugs used in nausea and vertigo 1,445 0.01 0.00 0.00 6.68
Patiromer calcium 6 Oral potassium 29 0.21 0.01 0.03 6.61
Ketotifen fumarate 33 Antihistamines 4,036 0.01 0.00 0.00 6.48
Tretinoin 1 Topical preparations for acne 620 0.00 0.00 0.00 6.24
Pimozide 28 Antipsychotic drugs 4,246 0.01 0.00 0.00 6.11
Inclisiran 1 Lipid-regulating drugs 23,528 0.00 0.00 0.00 6.06

Prescribing where Chiswick PCN is lower than most

BNF Chemical Chemical Items BNF Subparagraph Subparagraph Items Ratio Mean std Z_Score Plots
Alginic acid compound preparations 603 Compound Alginates and proprietary indigestion preparations 645 0.93 1.00 0.01 -10.31
Desmopressin acetate 100 Posterior pituitary hormones and antagonists 103 0.97 1.00 0.01 -4.93
Sildenafil (Erectile Dysfunction) 791 Drugs for erectile dysfunction 1,321 0.60 0.76 0.05 -3.08
Sodium chloride 0 Topical nasal decongestants 56 0.00 0.54 0.18 -3.06
    Clotrimazole 145 Vaginal and vulval infections 191 0.76 0.90 0.05 -2.94
    Oral rehydration salts 39 Oral sodium and water 351 0.11 0.65 0.20 -2.74
    Potassium chloride 23 Oral potassium 29 0.79 0.97 0.07 -2.41
    Aluminium chloride 20 Antiperspirants 22 0.91 0.99 0.04 -2.22
    Morphine sulfate 365 Opioid analgesics 4,120 0.09 0.21 0.06 -2.22
    Rifampicin 0 Antituberculosis drugs 5 0.00 0.74 0.34 -2.17