Static outliers for Modality Lewisham PCN

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 Modality Lewisham PCN is higher than most

BNF Chemical Chemical Items BNF Subparagraph Subparagraph Items Ratio Mean std Z_Score Plots
Co-triamterzide(Triamterene/hydrochlorothiazide) 1 Potassium sparing diuretics and compounds 24 0.04 0.00 0.00 27.44
Wool fat hydrous 1 Vehicles 1 1.00 0.02 0.14 6.74
Lithium citrate 12 Drugs used for mania and hypomania 187 0.06 0.01 0.01 5.68
Rifabutin 1 Antituberculosis drugs 2 0.50 0.01 0.09 5.37
Apomorphine hydrochloride 10 Dopaminergic drugs used in parkinsonism 419 0.02 0.00 0.00 4.99

Prescribing where Modality Lewisham PCN is lower than most

BNF Chemical Chemical Items BNF Subparagraph Subparagraph Items Ratio Mean std Z_Score Plots
Terbinafine hydrochloride 71 Other antifungals 77 0.92 0.99 0.02 -4.07
Isosorbide mononitrate 458 Nitrates 963 0.48 0.73 0.07 -3.84
Cetomacrogol 0 Vehicles 1 0.00 0.93 0.25 -3.76
Desmopressin acetate 45 Posterior pituitary hormones and antagonists 46 0.98 1.00 0.01 -3.58
Water for injection 10 Electrolytes and water 30 0.33 0.81 0.17 -2.85