The costs incurred by the NHS in England due to the unnecessary prescribing of dependency-forming medications.

This cross-sectional study estimates the costs incurred by the National Health Service (NHS) in England as a consequence of the unnecessary prescribing (i.e. non-indicated or dispensable) of dependency-forming medicines (antidepressants, opioids, gabapentinoids, benzodiazepines, Z-drugs). It assesses prescribing in primary care from April 2015-March 2018. Analyses were based upon the following data sets: the number of adults continuously prescribed dependency forming medications and the duration of prescriptions (obtained from Public Health England); the Net Ingredient Cost (NIC) and the dispensing costs for each medicine (obtained from the NHS Business Service Authority [NHSBSA]). Consultation costs were calculated based on guideline recommendations and the number of consultations evidenced in prior research for long-term medication monitoring. Across opioids, gabapentinoids, benzodiazepines, Z-drugs the total estimated unnecessary cost over three years (April 2015-March 2018) was £1,367,661,104 to £1,555,234,627. For antidepressants the total estimated unnecessary cost for one year was £37,321,783 to £45,765,504. The data indicate that the NHS in England may incur a significant estimated mean annual loss of £455,887,035 to £518,411,542 for opioids, gabapentinoids, benzodiazepines, Z-drugs and an estimated annual loss of £37,321,783 to £45,765,504 for antidepressants. Combined, this gives an estimated annual loss of £493,208,818 to £564,177,046 as a result of non-indicated or dispensable prescribing of dependency-forming medicines. Estimates are conservative and figures could be higher.