Discussion

The total number of items prescribed each year by NMIPs in Wales and dispensed in community pharmacy increased over the study period. In the financial year 2020–2021, total NMIP prescribing was 430% greater than in 2011–2012, with the largest annual increases seen after April 2016. The study identified that over the whole period from April 2011 to March 2021 prescribing in seven BNF chapters equated to approximately 80% of total items prescribed by NMIPs in Wales, with cardiovascular system the most prescribed chapter. From 2011–2012 to 2019–2020, there was a year-on-year increase in prescribed items across the majority of BNF chapters, with the exception of vaccines, (and from 2016– 2017 to 2017–2018 infection). From 2019–2020 to 2020–2021, prescribing fell in five chapters, but with the exception of vaccines, remained higher than in 2011–2012. In the financial year 2011–2012, the BNF chapters with the greatest items prescribed were infection and respiratory system, while in 2020–2021, the BNF chapters with the greatest items prescribed were cardiovascular and nervous system. The number of items prescribed in each LHB in Wales varied, however, the BNF chapters contributing the largest percentages of items to the LHB totals were broadly comparable.

Prior to 2015–2016, infection was the BNF chapter with the greatest number of items prescribed. A study of nurse prescribing in England with data from 2006 to 2010, similarly identified penicillins as the most prescribed drug category by this professional group.20 A year-on-year increase in prescribing of anti-infectives was observed across most years in the current study, consistent with an earlier study of antibiotic prescribing trends in England.21 However, over the whole 10-year period of this study, the greatest prescribing was seen in the cardiovascular and nervous system chapters. This was mainly due to large increases in prescribing in these chapters after 2015–2016. The volume of prescribing indicates that these were the predominant therapeutic areas in which NMIPs were using their qualification after 2015–2016, and indicates a shift in the focus of prescribing compared with the earlier years included in the study. The smaller observed increase in anti-infective prescribing (compared with cardiovascular and nervous system) over the study period may also reflect the role of NMIPs in promoting antimicrobial stewardship and the appropriate prescribing of these medicines.22 23

The observed increase in prescribing volume in cardiovascular and nervous system chapters, and the smaller increase in anti-infective prescribing coincided with the introduction of primary care clusters in Wales. This change to the organisational structure of healthcare delivery in Wales has been a driver for the creation of additional pharmacist and advanced nurse practitioner posts within general practices. Funding has been made available in Wales to provide prescribing training for these healthcare professionals,13 and the number of NMIPs working in primary care increased over the period from 2011 to 2018.15 In this context, the role that pharmacists have in the management of patients with complex, chronic conditions, has been noted.12 The increase in the volume of prescribing from the cardiovascular chapter in particular, (along with somewhat smaller increases in prescribing from other chapters associated with of long-term illness such as the endocrine chapter), suggests that a move towards chronic disease management has been realised in practice. The increase in prescribing from the nervous system chapter adds some further support to this. However, in addition to containing medicines for the management of chronic mental illness and neurological disorders, the nervous system chapter also contains medicines for analgesia, which might have been prescribed for acute pain and minor illness (eg, paracetamol for fever). The proportion of non-analgesic prescribing as a percentage of total nervous system chapter items increased from 50% to 66% during the study period, providing further evidence in support of an increase in primary care NMIP prescribing for long-term psychological and neurological conditions. An additional complication is the classification of certain medicines within the nervous system chapter. Amitriptyline and the gabapentinoids (gabapentin and pregabalin) are used in the management of depression and epilepsy, respectively, and some of this prescribing is recorded in those sections of CASPA. However, these medicines may also be prescribed for the management of neuropathic pain,24 and some formulations of each medicine are recorded in the analgesia section of CASPA, despite the indication not necessarily being specific to the formulation. Adjusting the categorisation of these medicines to analgesics from 2015 to 2016 onwards (when the greatest increases in prescribing were seen) results in prescribing for long-term (non-analgesic) psychological and neurological conditions accounting for 50% of items in 2015–2016, increasing to 57% in 2020–2021. While lower than the unadjusted percentages, there still appears to be an increase in prescribing for these long-term conditions. Consistent with the findings of our study, a survey of pharmacy professionals working in UK General Practice conducted in 2018/2019, identified that over 80% of pharmacist respondents provided clinical services including chronic disease management.25 It should be noted that the sample size was relatively small, with 81 pharmacists, of whom, approximately 75% were prescribers. A change in prescribing from items for acute to chronic illness was also observed in a study of nurse practitioners prescribing in Ontario (Canada) from 2000 to 2010.26 In contrast, a study examining more recent non-medical prescribing trends in New Zealand identified antibiotics and analgesics as the most commonly prescribed items.27 However, it should be noted that this study included practitioners able to prescribe from a limited formulary, in addition to NMIPs, which may have influenced the findings. These changes suggest that those responsible for delivering NMIP education should ensure that chronic disease management forms part of the programme of learning.

Over the whole study period, the total number of items prescribed by NMIPs in each of the seven LHBs in Wales varied significantly, with the lowest prescribing in Powys, and the highest in Betsi Cadwaladr. Although the number of items varied, the chapters contributing the greatest number of prescribed items were relatively consistent across the LHBs. Infection accounted for the most items in five of the seven LHBs in 2011–2012, while cardiovascular and nervous system were the two most prescribed chapters across all seven LHBs in 2020–2021. There was a relatively weak correlation between items prescribed and population, which reflected the previous observation that LHBs with larger populations employed greater numbers of NMIPs.15 The COVID-19 pandemic appeared to have a variable impact across the LHBs based on the difference in NMIP prescribing between 2019–2020 and 2020–2021. Overall, NMIP prescribing was 5% higher in Wales in 2020–2021 compared with the previous year, although this was a much smaller increase than the 16% seen from 2018–2019 to 2019–2020. Across Wales as a whole, NMIP prescribing from respiratory, infection, ear, nose and throat, vaccines, and anaesthesia chapters was lower in 2020–2021 than in the previous year. In the individual LHBs, prescribing in two (Hywel Dda and Cwm Taf Morgannwg) was lower, prescribing in one (Betsi Cadwaladr) remained relatively constant, and prescribing in the other four LHBs was higher than the previous year. Prescribing of antibiotics decreased in LHBs compared with 2019–2020, consistent with other studies examining primary care usage of these drugs during the COVID-19 pandemic.28 29 This COVID-19-related effect contributed to infection being the sixth ranked BNF chapter in 2020–2021, compared with the third ranked chapter in 2019–2020. However, the percentage contribution of the infection chapter to total NMIP prescribing was similar in both years (8% and 10%, respectively). Other chapters in which there was a reduction in items prescribed across all LHBs were vaccines, and ear, nose and throat. Nevertheless, the data indicate that NMIPs were still actively prescribing as part of their roles during the pandemic.

This study has some limitations. As a result of the retrospective secondary data design, confounding factors that may have influenced prescribing trends could not be identified and explored.30 For example, while the introduction of primary care clusters may have been a driver for the apparent change towards more chronic disease management in Wales (as well as the overall increase in prescribing), a causal association could not be determined. CASPA does not provide patient level data, nor data relating to indication, which limits conclusions that can be drawn. While the increase in prescribing from the cardiovascular chapter suggested an increase in chronic disease management, it was not possible to determine whether NMIPs were prescribing ongoing items for the same patient on a long-term basis, or whether they were prescribing occasional items for multiple patients. Similarly, as noted above, indications for the gabapentinoids and amitriptyline could not be determined. The prescribing measure chosen for this study was items, as it was felt that this best reflects a single prescribing interaction. However, it should be noted that the quantity supplied on each prescription may vary. If a prescription were issued with a 3-month supply, the number of items would be smaller. In particular, this may have influenced the number of oral contraceptive items prescribed as part of the genitourinary chapter, as these are typically provided as a longer supply.

In summary, the BNF chapter with the most prescribed items changed from infection to cardiovascular during the study period. This, along with increases in prescribing from other chapters associated with long-term illness, suggested an increase in chronic disease management by NMIPs over time. There was little regional variation in the therapeutic areas most commonly prescribed, indicating a similar approach to NMIP implementation across the LHBs in Wales. The COVID-19 pandemic had variable impact on prescribing both in terms of therapeutic area, and regional variation. However, prescribing by NMIPs continued to increase, and the impact of this on the delivery of primary care services is a focus for future work.