The development of nurse prescribing in mental health services: Outcomes from five national surveys 2004–2019

Abstract Aim This study aimed to explore data from national surveys of nurse prescribing in England's National Health Service mental health services. Background Nurse prescribing is increasing worldwide. Reports describing long‐term developments after implementation are rare. Methods Five surveys were distributed to all mental health organisations between 2004 and 2019. Results Response rates increased from 54% (n = 45/83) in 2004 to 79% (n = 42/53) in 2019. The estimated proportion of mental health nurses who were prescribers increased to 4.3% by 2019. Distribution between clinical practice areas did not change significantly over time, with the largest numbers in community mental health teams. The proportion of nurse prescribers actively prescribing increased from 76.4% in 2014 to 87.8% in 2019. Independent prescribing became the predominant approach, with supplementary prescribing rarely used as the sole model within organisations. The scale of implementation varied markedly between organisations. Conclusions Although nurse prescribing in mental health services has grown over time, growth has slowed and is variable at local level. Implications for Nursing Management Organisations considering the introduction or growth of nurse prescribing should note the evidenced preference for an independent prescribing model to date and consider how to avoid unwarranted variation in nurse prescriber role distribution.

The International Council of Nurses (n.d.) estimate that 70 countries have ACP nursing roles currently or are planning to do so. Maier (2019) identified 13 European countries with nurse prescribing powers, 10 introducing this since 2010. Despite frequent opposition from medical lobbies (Day, 2005;Elsom et al., 2009;Lim et al., 2017;Zarzeka et al., 2019), nurse prescribing seems likely to continue to spread, with more countries debating its introduction (Badnapurkar et al., 2018;Ling et al., 2018).
The development of nurse prescribing has taken place in a context of international workforce shortages (Kakuma et al., 2011;Lancet, 2018), large treatment gaps, particularly in lower and middle-income countries (World Health Organization, 2011), growth of neo-liberal and managerialist agendas within health care systems (Hewko & Cummings, 2016) and international evidence that health professionals often perform tasks for which they are overqualified (OECD, 2013).
Systematic reviews have compared the effectiveness of nurse prescribing and medical prescribing. A Cochrane review (Weeks et al., 2016) identified 26 studies and concluded that nurse prescribers practising in a variety of settings can achieve outcomes in the management of chronic disease and preventive health care comparable with those with medical prescribers. Noblet et al. (2018) concluded that the limited evidence available from randomized control trials suggests that nurse prescribing is safe and can provide beneficial clinical outcomes, although did not comment on generalizability of this judgement to specific clinical specialities, such as mental health, with no trials having examined nurse prescribing in general mental health services in the United Kingdom to date.

| Nurse prescribing internationally
Internationally, data regarding distribution and characteristics of NPs in mental health services are mostly reported within wider studies of nurse prescribing across all specialities. In the United States, surveys have taken place of advanced nurse practitioners (ANPs) with prescribing powers. In 2019, 4.2% of ANPs were reported as working predominantly in mental health settings (American Association of Nurse Practitioners [AANP], 2019), with such roles being more numerous in areas with low numbers of psychiatrists (Feldman et al., 2003;Goolsby, 2011). In Australia, surveys have indicated a low proportion of mental health-focused nurse prescribers (Buckley et al., 2013;Fong et al., 2020), whereas in New Zealand, a study identified less than 1% of patients receiving nurse prescribing were mental health/substance misuse service users (Poot et al., 2017).
In the United Kingdom, cross-sectional studies have provided some specific information regarding distribution of nurse prescribers in mental health services, in addition to the five surveys reported herein. A national survey of nurse prescribers in Wales identified only 8 mental health nurses (MHNs) from 321 respondents (Courtenay et al., 2017), whereas Latter et al. (2011) reported that 5.5% of mental health inpatient wards/units and 47.7% of community mental health units in England had a qualified nurse prescriber. A survey of substance misuse services in England and Scotland identified 324 nurse prescribers, some of whom were employed outside the National Health Service (NHS) (Mundt-Leach & Hill, 2014). In relation to advanced practice type roles, a national survey of MHN consultants in England identified 35.7% of respondents as NPs (Brimblecombe et al., 2019).

| Scope of nurse prescribing
There is significant variation in the scope of prescribing authority between countries (Maier, 2019  Author 1 was involved with all five surveys and Author 2 with the latter three.

| AIM
This study aimed to describe the development of nurse prescribing in NHS mental health services in England, including changes in distribution and type.

| METHOD
For each survey, an invitation to participate was sent to the director of nursing of every NHS trust that then provided mental health services. The invitation to participate explained the purpose of the survey and provided a summary of previous survey outcomes.
Directors of nursing were chosen as contacts, as having good awareness of local workforce developments and high degree of influence over nurse prescribing implementation.
Follow-up to non-responders was by email after 3 months and, in the 2014 and 2019 surveys, further contact by phone.

| The questionnaire
The questionnaire was originally designed in 2003 by the National Institute for Mental Health in England Non-Medical Prescribing Advisory Group, in the context of a lack of national data regarding nurse prescribing in mental health services.
The surveys were not originally planned as a time series. Subsequent surveys were largely based on the 2003 questionnaire but were amended to reflect changes in the legal prescribing framework and the structure of mental health services. In 2014 and 2019, additional questions were included regarding governance and planning activities, and a free-text question as to perceived barriers to implementation.
In all surveys, respondents were asked to report the number of   (Table 1), an increase of 810%.  Table 2).

| DISCUSSION
The five surveys provide a unique description of nurse prescribing in a major clinical speciality of a large national health care system over an extended period. To the authors' knowledge, detailed longitudinal quantitative surveys of nurse prescribing have only been reported elsewhere through surveys of ANPs in the United States, for instance, Goolsby (2011). The findings from the surveys described here will allow for comparison with developments in other specialities and/or countries. This is timely, with the continuing expansion of nurse prescribing internationally.
The survey response rate generally increased over time, from 54% in 2004 to 79% in 2019. These response rates are higher than average for organisational surveys (Baruch & Holtom, 2008). The authors hypothesize that the increase in response rates may reflect the overall increase in use of nurse prescribing in health care organisations, with fewer trusts having low numbers of nurse prescribers or little governance in place. Trusts with little nurse prescribing activity may be more reluctant than others to participate in surveys, even where data are anonymised for publication.

| Distribution
The rapid increase rate in nurse prescriber numbers did not persist to   (Brimblecombe & Nolan, 2021;Brimblecombe et al., 2019). Greenhalgh et al. (2004) cite the extent to which a health care innovation becomes integrated into usual practice as depending on the interaction between features of the innovation, the adopters and the context. Innovations that have a demonstrable advantage in either effectiveness or cost-effectiveness are more easily implemented.
However, currently, there is no specific and robust evidence base for nurse prescribing in mental health services to support implementation, nor evidence as to any comparative outcomes in different mental health clinical settings. In this context, introduction of innovations, such as new roles, may be more likely to be influenced by attitudes of individual organisational leads (Brimblecombe et al., 2019).
Adequately powered randomized control trials evaluating clinical and cost-effectiveness are still required to evaluate NMP across clinical specialties, professions and settings (Noblet et al., 2018). Courtenay et al. (2011 comment that nurse prescribing roles are more likely to become embedded where a strategic approach to development is adopted by trusts. The data from the surveys herein imply that the leadership in different mental health trusts may perceive the value of nurse prescribing differently or that unknown local factors produce different workforce requirements. The range of clinical areas where nurse prescribers practise is broad, although there is consistency as to where the largest number is found, that is, community mental health teams (26.5% of prescribers in 2008/2019). There has been no significant change in the proportion of nurse prescribers working in other areas over time.
The question of why nurse prescribing is established in certain clinical areas was not addressed by this study but is important to understand.

| Models of nurse prescribing and area of clinical practice
In 2004  A similar pattern has been identified in non-mental health services (Courtenay & Carey, 2008). Independent prescribing allows greater flexibility and responsiveness in services, for example, in extended hours community teams, where medical cover is often limited. The evidence reporting differential frequency of use between the two prescribing models has implications for other countries. Narrower nurse prescribing powers than those available in England are more typical internationally. However, the above evidence suggests that a restrictive prescribing model, such as supplementary prescribing, is less likely to be the model preferred by clinical services than a less restrictive model, that is, independent prescribing.
There is no evidence available as to the extent of nurse prescribing by advanced clinical practitioners in England's mental health services to date in the studies reported here or elsewhere, excepting that by nurse consultants, who have some similar educational and role requirements (Brimblecombe et al., 2019). The development of ACP roles appeared slow initially in England's mental health services (Brimblecombe & Nolan, 2020); however, national encouragement for developing these roles (NHS England [NHSE], 2019) seems likely to ultimately increase nurse prescribing by default, as prescribing training is part of ACP training requirements. In countries where the route for introduction of nurse prescribing is solely via ACPs, then any spread of ACP roles will create growth in nurse prescribing, but ultimately, this growth may be less than if other routes to prescribing practice were also available.

| Limitations
The lower levels of response in the earlier surveys and changes in the number and boundaries of trusts somewhat limit confidence as to the ability to report change over time. NMP in professions other than nursing is an important issue but was not reported in this paper, as it was not explored in detail in the surveys.

| CONCLUSIONS
This paper provides a unique insight into the development of nurse prescribing over a 15-year period within a major specialty of a largescale national health service. The findings illustrate the importance of the type of nurse prescribing adopted, the challenge of variation in approach between local organisations and the likely implications of lacking a specialty-specific evidence base.
The move away from the use of supplementary prescribing suggests that this approach is largely used as a developmental stage for new nurse prescribers before progressing to independent prescribing status and as such is not recognized as a significant contribution to service delivery in itself. This active choice by services provides countries considering adopting nurse prescribing a useful case study of organisational choice regarding preferred type of nurse prescribing, at least in mental health services.
The surveys suggest that where nurse prescribing is introduced, there will be variable take-up of the role and variability in how it is utilized. The role of senior 'champions' within organisations may play a major role in the level of uptake, as may the attitude of senior medical staff.
Non-prescribing once qualified can be a serious waste of resource and is found in these and other surveys, although here nonprescribing reduced over a period of years. There is reported variation in this regard between countries, so high levels of non-use may not be inevitable.

| IMPLICATIONS FOR NURSING MANAGEMENT
Nurse prescribing is a skill set that potentially allows for service and workforce redesign and enhanced nursing employment pathways. The surveys reported in this paper illustrate that choices made by local organisation management are likely to have a large effect on how and to what extent nurse prescribing is utilized in services, especially in the absence of a robust, speciality-specific evidence base. Managers across multiple organisations will need to consider what level of variation between organisations is justifiable. The lack of change over time as to which clinical areas have most nurse prescribers suggests that managers may need to ensure processes of ongoing evaluation take place to ascertain whether distribution is the most effective possible.
Although relatively rare, some challenges were identified regarding support from medical staff for nurse prescribing roles, which nurse managers may need to proactively address.
The results clearly indicate that independent prescribing is the model of prescribing most used in mental health services. Therefore, nurse managers, where nurse prescribing is being considered for introduction, may consider prioritizing the development of independent prescribing where legally permissible and note that any national plans to introduce a form of nurse prescribing with less scope, for example, a supplementary prescribing model, may be perceived as less able to meet service needs.