Staff experience of team case formulation to address challenging behaviour on acute psychiatric wards: a mixed-methods study

Abstract Background Team case formulation on acute psychiatric wards aims to support staff to manage significant levels of challenging behaviour. However, there is limited research on staff experience of case formulation in this setting. Aim This study aimed to investigate staff experience of team case formulation sessions on acute psychiatric wards and their impact on staff wellbeing. Methods Eighteen multidisciplinary staff (nurses, doctors, occupational therapists, support workers, activities coordinators) from five acute wards at a South London psychiatric hospital completed a semi-structured interview and visual analogue scales on their experience of attending case formulation. Thematic analysis was employed to analyse qualitative data. Results Participants reported that case formulation supported staff to develop a holistic understanding of service users, provided a safe space for staff to discuss the impact of challenging behaviour and improved teamwork and communication. Participants reported that these benefits increased their ability to identify and support the needs of service users and improved therapeutic relationships. Challenges with establishing continuity of care were highlighted. Conclusion Team case formulation is an important intervention to support ward staff and has significant benefits to staff wellbeing and quality of care. Greater integration with existing ward practices may benefit both staff and service users.


Introduction
Acute inpatient care aims to provide a safe and therapeutic environment for service users in the most vulnerable stages of mental illness and who may pose a risk to themselves or others (Department of Health, 2002). However, concerns have been raised regarding the quality of care provided in inpatient settings, including limited availability of nursing staff, limited access to psychological interventions and service users describing wards as 'untherapeutic' and 'frightening' (Mind, 2011;Rose et al., 2015). Significant reductions of UK hospital beds have led to a higher threshold for admission, increasing the proportion of service users who are formally detained and presenting with high levels of challenging behaviour (DCP, 2011). Behaviour can be described as challenging "when it is of such an intensity, frequency or duration as to threaten the quality of life and/or the physical safety of the individual or others" (Royal College of Psychiatrists, 2007) and includes aggressive and violent behaviour, verbal aggression, self-harm and absconding (Bowers et al., 2015). Assaults on staff are most prevalent in the mental healthcare sector, accounting for 70% of reported assaults in the NHS (NHS Protect, 2016). According to the NHS 2017 Staff Survey for England, 33% of mental health nurses have experienced physical violence in the previous 12 months and 47% have experienced harassment, bullying or abuse (NHS, 2018).
Exposure to high levels of challenging behaviour, working in a highly pressured environment, and treating service users who are acutely unwell and often admitted to hospital against their will contributes to high levels of burnout among mental healthcare staff (Letvak & Buck, 2008;Pina et al., 2020). This has significant costs for the NHS, where staff turnover is high, absence rates of mental healthcare staff exceed that of other healthcare sectors and a higher proportion of absences is attributed to anxiety, stress and depression (Johnson et al., 2018). Meta-analyses indicate that staff burnout has negative consequences for service user care and satisfaction (Dreison et al., 2018;Morse et al., 2012). A qualitative investigation of staff morale on inpatient psychiatric wards in England indicated that the most valued positive influences by staff were good relationships and communication within the team, a culture where one's voice is heard regardless of seniority and the availability of support following violent incidents (Totman et al., 2011).
Psychological formulation is an evidence-based approach that aims to provide high-quality and person-centred care (DCP, 2011). Team case formulationthe process of a group of clinicians creating a shared understanding of service users' difficulties and developing evidence-based interventionsis a key competency for clinical psychologists Johnstone, 2018). Formulating within teams offers numerous benefits, including shifting teams towards a more psychologically minded culture, building relationships, improving team communication and providing learning opportunities through drawing on expertise of multidisciplinary professionals (DCP, 2011). Team formulation is recommended for management of challenging behaviour, where a collaborative approach is considered essential in designing effective interventions (NHS Protect, 2014).
An influential approach suggests that challenging behaviour is the manifestation of a person's unmet needs and distress. According to NHS Protect (2014), effective prevention of challenging behaviour involves developing a unified multidisciplinary understanding of the reasons for service users' behaviour and developing personalised strategies to meet needs and minimise distress. Similarly, the Newcastle Model (James, 2011), originally developed in the context of dementia care, encourages staff to conceptualise challenging behaviour in terms of service users' unmet needs, and in the context of wider psychosocial factors, to inform effective, person-centred care. Team formulation is viewed as one of the key recommendations for best practice in acute inpatient settings and commonly implemented, however, approaches vary widely in terms of theoretical models used, frequency of meetings and their structure Raphael et al., 2021). A randomised-controlled trial of a cognitive-behavioural team case formulation intervention on psychiatric rehabilitation wards indicated that, post-intervention, service users reported better relationships with staff, who also reported increased optimism and lower depersonalisation (a known component of burnout) .
Team case formulation has potential to offer benefits to staff wellbeing and team communication (DCP, 2011). In the current study, team formulation aimed to support staff in their work through offering a space to reflect and develop psychologically informed care plans. There are innovative approaches to support staff in acute settings , but there is limited research investigating staff experience of using team case formulation on acute psychiatric wards. This study used predominantly qualitative methodology to explore acute ward staff experience of using team case formulation to understand challenging behaviour of service users, its impact on staff wellbeing and staff recommendations to improve team case formulation.

Design
This was a mixed-methods study using semi-structured interviews and visual analogue scales (VAS) of staff experience.

Procedure
This study was approved by the South London and Maudsley NHS Foundation Trust. Participants provided informed consent. EK conducted interviews with staff (25-45 min) under regular supervision from SR. Participants self-reported demographic characteristics and VAS. Participants were interviewed individually in private rooms in the hospital, always off the wards. Interviews were audiorecorded, anonymised and transcribed. Data was collected alongside other research (Kramarz et al., 2021).

Participants
Participants were recruited from staff from five acute wards (two male, two female and one male psychiatric intensive unit) at a South London psychiatric hospital. Emails advertising the study were sent to ward staff. Participants were deemed eligible for inclusion if they had attended at least three team case formulation sessions to ensure sufficient familiarity with their content.
Case formulation sessions were 1-h staff meetings, which occurred fortnightly for each ward and focused on a service user who had been nominated by staff as most challenging for the team. Service users were not directly involved in sessions because sessions were typically carried out for service users who were engaging in highly challenging and aggressive behaviour and not engaging with ward interventions. Service users' perspectives, views, and wishes were incorporated throughout the discussion through information from healthcare records and staff observations. Sessions were open to all ward staff. An integrated formulation model was used, drawing on the Newcastle model, cognitive behavioural theory and third-wave approaches. The Newcastle model was used to understand challenging behaviour as communication of unmet needs; a cognitive behavioural approach emphasised how interactions between thoughts, emotions and behaviour maintain service users' difficulties (Beck, 2011); and third-wave approaches, e.g. dialectical behaviour therapy and acceptance and commitment therapy, provided emphasis on emotional regulation, personal strengths, goals, and values (Hayes & Hofmann, 2017). All sessions were facilitated by a clinical psychologist (SR). In session, staff were invited to consider multiple factors potentially related to the challenging behaviour. The model was displayed on a large computer screen, and notes were typed by an assistant psychologist on to the model so that this was visible to the staff team. After the session, a two-page Psychology Care Plan was written up for ward staff, which outlined a case history, a description of the current challenging behaviour, a formulation of the behaviour and a set of interventions or strategies for ward staff to carry out that aimed to meet the service user's needs in more functional ways. The psychology team then followed up the Psychology Care Plan and its implementation by ward staff a week later. The interview was developed by EK and SR based on clinical  experience and research literature and comprised of openended and non-leading questions, to prevent imposing  researchers' assumptions. Participants were asked about their experience of working on acute wards (e.g. "Why were you interested in working on acute wards?"); their general experience of case formulation, including its impact on their wellbeing and work (e.g. "What was your experience of case formulation like?"; "Was case formulation supportive to your emotional wellbeing?"); relationships with service users and colleagues (e.g. "Did case formulation have an impact on your relationships with patients? In what ways?"); implementation of the Psychology Care Plan (e.g. "Can you tell me about your experience of implementing interventions?"); and future recommendations. Participants were invited to consider the topics that had guided discussion in case formulation sessions they had attended (e.g. "How helpful did you find the discussion of this topic in understanding patients' challenging behaviour?"; "Were there any difficulties when discussing this topic?"). Topics included (but were not limited to) the identification of the behaviour, consequences of the behaviour, physical health, medication, cognitive and functional abilities, physical and social environment, mental health, personality, life story, relationships, current thoughts and feelings, reasons for the behaviour, service users' needs, recommendations, interventions and strategies and care planning.

Semi-structured interview
Visual analogue scales (VAS) VAS evaluated staff experience of case formulation.
Participants were asked to mark on a line "how helpful you found case formulation in understanding patients' challenging behaviour," "how helpful it was to identify psychology care plan strategies based on case formulation" and "to what extent the psychology care plan strategies identified during case formulation felt achievable." Five VAS were adapted from a validated burnout measure, the Oldenburg Burnout Inventory (OLBI) (Demerouti & Bakker, 2008): participants were asked to mark on the line "how supportive you found case formulation for your emotional wellbeing" and to what extent "case formulation has helped you to feel more engaged with your work," "case formulation has helped you to tolerate the pressure of your work," "case formulation has helped you to feel more energised at work," "case formulation has helped you to manage the amount of work you do." In two VAS, participants were asked to mark on a line "to what extent you felt your voice was heard during case formulation," based on research regarding staff morale (Totman et al., 2011) and "to what extent case formulation has improved communication between you and your colleagues," based on case formulation research . VAS format was adapted from research on clinician experience (Riches et al., 2019). All VAS scores were on a scale from 0 ("not at all") to 10 ("very much").

Analysis
Interviews were transcribed, anonymised and uploaded to the software programme NVivo12. Thematic analysis (TA), a systematic method for identifying and organising patterns of meaning and content in qualitative data (Willig, 2013), was employed to analyse data. Analysis was conducted according to Braun and Clarke's (2006) six stages of TA. Analysis was divided into, first, impact of team case formulation on staff, and second, staff views on important topics and recommendations for team case formulation. Data was independently coded by two researchers (EK, CLMM). Analysis was regularly discussed between researchers (EK, CLMM, SR) to examine different interpretations of the data and possible ways of grouping codes into themes. Data was analysed with an inductive approach, without attempting to fit data into pre-existing theories (Braun & Clarke, 2006). Analysis was conducted within a critical realist and experiential framework, focusing on capturing participants' views, meanings, and experiences (Clarke & Braun, 2013). Researchers reflected on how their own views and perspectives influenced data collection and interpretation. All researchers were psychology professionals (EK, CLMM and MW were Assistant Psychologists and SR was a Clinical Psychologist) who were involved in facilitating team formulation sessions and had an interest in psychologically informed approaches on acute wards. Mean (SD) VAS scores were calculated using Microsoft Excel software.

Sample
Eighteen acute ward staff of various professional backgrounds participated, including six nurses (two of whom were ward managers), five occupational therapists, three doctors, two support workers and two activities coordinators. Most participants were female, aged 26-35 and of White British or Black/Black British ethnicities. See Table 1 for staff demographics.

Thematic analysis
Impact on staff There were nine themes: Wish for improved continuity of care (N ¼ 17), Safe supportive space (N ¼ 15), Holistic understanding (N ¼ 14), Shared understanding of behavioural patterns (N ¼ 13), Improved clinical confidence (N ¼ 12), Improved therapeutic alliance (N ¼ 11), Improved team relationships and communication (N ¼ 11) Increased job satisfaction (N ¼ 10), and Reflective practice (N ¼ 9). See Table 2 for full details of themes with illustrative quotes.
Nearly all staff reported a wish for improved continuity of care and felt that it was difficult to ensure that care plan strategies were put into action by the entire team. They suggested that this could be improved through integrating the care plan into existing practices such as handover, allocating strategies to groups of professionals and having an ongoing team discussion about how the strategies are being implemented.
Participants highly valued having a safe supportive space, where staff could acknowledge how challenging behaviour has affected them emotionally, feel understood and supported by colleagues. Some staff described the pressure of having to uphold a professional demeanour and staff feeling ashamed to discuss the emotional impact, and therefore appreciated having a confidential space where they could show vulnerability. Team formulation also enabled staff to develop a holistic understanding of service users. Drawing on the knowledge and perspectives of professionals from different disciplines was described as a key benefit, allowing staff to develop an understanding of the service user beyond their mental health condition. This encouraged them to develop more individualised and holistic care plans, which considered multiple aspects related to an individual's care, such as their interests, background and cognitive abilities. Developing an informed care plan improved clinical confidence and made staff feel less "lost" in challenging situations. Participants described increased job satisfaction, reporting that case formulation contributed to the sense of meaning they derived from their work and allowed them to feel heard and valued for their contributions. The discussion was enriched by team members' observations during different shift patterns and in different professional contexts, which allowed them to develop a shared understanding of behavioural patterns rather than viewing behaviours in isolation. This increased their ability to identify triggers, predict and manage challenging behaviour. Another valued aspect of team formulation was having protected time to engage in reflective practice, as there was rarely time for this outside case formulation due to the fast-paced nature of the work. As challenging behaviour can be highly upsetting and frustrating for staff, staff reported that assumptions can be made about the reasons for service user's behaviour, for instance that it is deliberate. Engaging in reflective practice allowed staff to step back and think more deeply about what the service users may be feeling, including loneliness or fear, which in turn reduced blame-based thinking. Participants reported feeling increased motivation to approach service users and understanding of how to communicate with and support them, resulting in improved therapeutic alliance. Case formulation led to improved team relationships and communication, enabling teams to develop a more unified approach to care and a sense of team "togetherness." Staff views on important factors to discuss in team case formulation There were eight themes: Life Story (N ¼ 18), Service users' needs and perspectives (N ¼ 16), Awareness of cognitive and functional abilities (N ¼ 13), Impact on others (N ¼ 11), Physical health (N ¼ 11), Social relationships (N ¼ 10), Maintenance factors (N ¼ 8) and Distressing ward environment (N ¼ 8). See Table 3 for full details of themes with illustrative quotes.
Learning about service users' life story was seen as key in generating insight into what may have led to their current difficulties. All participants highly valued this, as they rarely had the opportunity to find out more about service users' backgrounds outside case formulation sessions. Participants expressed that learning about service users' traumatic histories increased their empathy, ability to provide traumainformed care, and allowed them to be more understanding of challenging behaviour. Participants valued discussing service users' needs and perspectives as a team, as this encouraged them to consider different perspectives and think more deeply about what service users may be feeling, creating more understanding and compassion. While staff felt that this was important, they acknowledged that it can be difficult to put themselves in someone else's shoes, due to the subjective nature of interpreting behaviour. Another topic which participants considered important was raising awareness of cognitive and functional abilities, as staff were not always aware of service users' additional needs, including learning disabilities, autism or inability to read or write. This allowed the team to consider alternative explanations for service users' behaviours, for instance an inability to understand a situation and encouraged them to consider alternative approaches for communication (e.g. sign posting). Participants reported that it was important to discuss impact on others, including staff, other service users and families. They reported that physical health was often overlooked on psychiatric wards, and the impact of physical conditions and medication side-effects on behaviour may be missed. Some participants found it helpful to discuss social relationships, enabling them to reflect on service users' complex social networks during their various stages of recovery. Discussing maintenance factors allowed participants to reflect on how they may be inadvertently reinforcing behaviours and how this could be addressed. Some staff found it helpful to discuss the distressing ward environment, which   (83) Participants reported that they appreciated having a confidential space to acknowledge that they may be feeling stressed and where they are able to support each other.
"It does allow you … an opportunity to just say 'this person stresses me out' … showing vulnerability is rarely something you're capable of doing … so to have the opportunity to do that in a way that is just socially sanctioned can be helpful, because otherwise you have to just uphold a very professional demeanour and that can be quite exhausting." (#7) "There is actually only certain kinds of safe environments, like when we do the case-based discussion, where it's purely MDT, it's … your choice to go … and I think people enjoy that sort of safe hour, you know it's uninterrupted, and it's a good time for me to realise that someone else was really stressed by that." (#6) "It does have a lot of impact on staff, whether it's physical, emotional, and being stressed … it's like it gives permission to be thinking about and acknowledging that it is really hard on you and if you've been … getting someone shouting at you or saying things that are unkind to you, that it's quite normal to be feeling that way. (#10) "You find that you're not alone, because everyone is going through the same thing. And that's why it's good that it's done as a group." (#1) "The ward is so fast-paced and a highly intensive environment, sometimes you just need that space to just, let yourself be heard, because it can be frustrating." (#17) "I think we should maybe encourage people to talk a little more on that point, because it would be nice for staff to really have a good think about, talking out loud about how actually it makes them feel and not feel … embarrassed to say 'oh I felt really upset about that.'" (#6) Holistic understanding 14 (78) Participants reported that they valued developing a broad understanding of service users, which was difficult to do outside of case formulation due to the busy working environment of the ward. They reported that this helped them to understand the contextual factors that have contributed to the service user's current presentation, rather than looking at their behaviour in isolation.
"A lot of the time these guys on the ward will have a lot of, a lot to tell you about their life … and I think that probably does play a big part … into why they are here now, so it's definitely a good idea to look back at that and obviously, it … helps to get … a broad understanding of the person … like their background and who they are." (#3) It gives you time to sit down and really get … that in-depth background in the patient that you might not have time to do when on the ward, you're quite busy, so you'll get a snapshot, so you might not be able to delve into [medical records]." (#17) "Sometimes, if we are not careful, we will end up using one aspect, which is mental health, to decide on what sort of care plan we're going to create for the patient, whereas if we sit down to do case formulation we put everything else into context, we consider all the factors that concerns the patient and then we use that to create a care plan, which at the end of the day, looks at the holistic person … that is why case formulation is different and beneficial." (#12) "Because everyone's got different experiences and different sort of professions that they've come from, everyone's got different contributions to make to that discussion, so it does feel like we have a good picture of the person afterwards." (#10) "It's nice that there is space for the [psychology] interventions or recommendations but also … nursing interventions or OT interventions are also included in that, it's … more … wellrounded, which is really nice for us to think in that way." (#5) "On this template, you have everything, all on one page and it's good to just see it all in one go and put it all together and that's quite hard to do by myself and it's good to have that in that sense, so we can all sort of feed into it and build a big picture rather than a small one." (#14) Shared understanding of behavioural patterns 13 (72) Participants reported that formulating as a team helped to develop a shared understanding of service users' behaviour. They reported that this was useful for bringing information together from different professionals, who may have different relationships with service users and may notice different aspects of behaviour on their shifts.
"I think it's quite good to identify the behaviour in the first instance and highlight what's happening because it helps you think 'is there a pattern to it?' … having a think about what happened before, is there anything that caused it." (#14) "If you see a pattern, you can almost predict if some behaviour is going to come up, so you can look at ways of managing it." (#4) "The good thing is, because different staff work around with the patients, everybody may have experienced different aspects of (continued)  (67) Participants reported that generating an informed care plan which addressed patient needs allowed them to feel more in control and confident to assist with their care.
"It helps because you come in and it works, it makes you happy, that means that you're working along with patient's needs and that's it, that solves the problem … so … coming up with that, it does help … it gives a better understanding to manage the patient on the ward." (#9) "Before I was a bit lost, working out how to deal with this person, or I found them a bit dangerous, or a bit intimidating … I felt more confident afterwards to be able to interact with that patient and more confident in how I can assist with their care." (#8) "When you come out with the recommendations, you kind of know more how you should try and respond to them, maybe you should try and engage them with activities or get them to go to groups and things like that so I think it definitely does impact how you engage with them." (#3) "You … come at a time when we have really difficult patients to manage, where we're probably thinking 'I don't know what else we can do to manage them,' … We were able to use some of the strategies that we identified which we wouldn't have thought of … on our own … so it's a good standing board."(#17) Improved team relationships and communication 11 (61) Participants reported that listening to their colleagues' perspectives has brought them closer together, made them feel less alone and more like part of a team. Participants reported that agreeing upon a single care plan has improved consistency of care delivery.
"Because of this stress you rarely get to see the sensitivity of others … because the only time you are really interacting [is] when it's … a crisis … so to have a moment where people show this side of themselves … it can really make you feel very close to them, you think 'oh no you do, you really care about this person' … it gives you … a lot of faith in your colleagues." (#7) "We are all in this together and let's see, let's try to understand all together what's going on and how we can help each other in this." (#15) "It gave people structure that they could follow and I think it … unified the staff approach to caring for the patient." (#18)"It just … makes everyone … on the same page and … we understand the client more and understand our own roles … our own recommendations as well." (#5) "I think it improves the communication because we are all sharing and it doesn't really matter what your role is, everyone has an opportunity to give their perspective and their views so I think it brings us closer together." (#10) Improved therapeutic alliance 11 (61) Participants reported that case formulation improved their ability to connect with service users, through gaining a better understanding of how to engage with them and support them. They reported that case discussion increased their motivation to approach service users and take extra steps to help them.
"I think from the patient's perspective … we can be more caring about them and we show interest about their situation, I think that they feel more listened to and that we are here to help as well." (#2) "After you do a case formulation you find that you speak to that person a lot more because you want to find out what's going on in their heads … So it's definitely important, because something switches in your brain and you think, maybe I should try a bit more with that particular patient right now because they are actually being really challenging and see if you can possibly help them overcome that." (#1) "I had no idea that [this is] something that they are really interested in and … it gives me something I can then try and introduce to them or you know, have a further discussion about." (#10) "I think it just helps us understand in what way to approach them and how to help them manage their needs and … get them to achieve their needs … because some of their behaviours might be because we're not understanding what they've been through and that could result in a negative or challenging behaviour but then if we just sort of change the way we approach them and how we deal with things with them [this] could lead to more positive behaviour." (#14) "It does help us to connect better with the patient because the person feels well supported and this is one of the bases … when the patient recognises that they feel well supported by the team, why would they want to be aggressive." (#12) Increased job satisfaction 10 (56) Participants reported that they felt more valued as a result of case formulation. They reported feeling heard and able to make important contributions to the discussion, regardless of seniority. Participants also reported finding more meaning "I feel like everyone is heard in that … group, it's really nice … some people think that because they are like a level 3 compared to a really high up level … that there is some sort of hierarchy, but … everybody … contributes evenly to it, which is really nice." (#5) "Especially when you've got something to contribute to the discussion and it could be new information (continued) that you realise other people didn't know, it makes you feel a bit more valued … like you are actually making a really important contribution." (#10) "It gives more meaning to my job because obviously you've got this new information that helps you to see the person … behind the illness." (#15) "It motivates you to go that extra step, to try a bit more, so it drives you and motivates you." (#17) "She's doing really well, and you know, through activities, engaging her, it's made me think 'oh we're getting somewhere'. It makes you even more interested because it makes you try to find out more and sort of like keep chipping away at the wall." (#1) Reflective practice 9 (50) Participants reported that they appreciated a space to slow down and think about service users in more depth, which can be difficult in a fast-paced environment of the ward. They reported that discussing service users with the MDT encouraged them to reflect on their practice and consider different points of views.
"When … you've got a patient who maybe is displaying some challenging behaviour, it's easy to become frustrated and to … really struggle to think about … what are they trying to tell me … So it's easy to get lost in that, but … in those sessions you just … get to sit down and just get to think and I really appreciate that." (#3) "It just gives you a bit of a nice, sort of protected space to actually think about the patient in a nonrushed, sort of, I often might see patients on call and you're really rushed and you're stressed and you don't get the time to sort of stop and think about it in detail." (#6)"Developing an approach that we can all agree with … that is appropriate for this patient, and is empathetic and … curious and I think … that is rarely achieved in a very fast-paced environment." (#7) "It gives us a link with the psychology team and it makes us think a little bit deeper about our patients and not just kind of in, out, in treat, out." (#6) "I think that's the beauty of having so many people in there and I think sometimes, especially when you've got a … quite an unwell patient and it can be quite draining on you sometimes, and then to look at it from another point of view and you think 'oh actually, I do feel quite bad for them, or I might change that' so it's a really good way to reflect on your own practice." (#4)  perspective and allowed them to see that service users' behaviour may not be deliberate. They reported that it was difficult to think in this way outside of case formulation, due to work demands and staff burnout.
they are getting annoyed. So I think that is really important, so we know how they are feeling, we think about it in more depth." (#1) "I think, we have to understand it from their perspective, it's their recovery and it's their journey and we're here to help them, I think if we're not thinking about what they're thinking, then we're not doing it right, but it can be hard." (#14) "Staff can be burned out … it's hard and you … get into … the routine of the ward, but it's nice to put yourself in someone else's shoes." (#5) "Through the case formulation, what comes out, is another aspect behind the behaviour that is not immediately obvious." (#15) "It's … making us think, at the end of the day, what are they trying to communicate … If they are being aggressive towards staff and patients, is there something else?" (#8) "I think this is the hardest one. Out of all of them, because it's just so … subjective isn't it. Because it's not just observations." (#4) "Quite often, we're thinking about the behaviour and how it's presenting us with a challenge and that gets us to stop and think, why is this person doing this and are they trying to tell us that they are frustrated, are they just really unwell … I think it gets us to stop and put ourselves into their perspective for a minute and think about … how this must feel just as bad for them as it might be feeling for us." (#10) "I think sometimes you can get a little bit presumptuous, but it's good to, because sometimes we'll say completely different things and that's quite interesting, sometimes things you just never even thought that they might be thinking or feeling." (#6) Awareness of cognitive and functional abilities 13 (72) Participants reported that the discussion made the whole team more aware of possible cognitive or functional dysfunctions and reduced blame-based thinking through realising that service users' behaviour is often unintentional. Participants reported that it was useful to identify alternative approaches to engage and communicate with service users who have additional needs.
"It can be quite hard to recognise cognitive dysfunction … [it is] easy to assume it with lots of our patients, that they are just doing things deliberately, and I think it could be important to try and take people away from that blame-based thinking." (#7) "I think it gives people that reminder … or … a better understanding of why someone might be acting a certain way. And quite often it's easy to just think 'oh someone is being aggressive' and we might not have thought about that they maybe, this is their way of communicating or they haven't understood a situation … I might know something from an assessment that somebody has autism or a learning disability or maybe has issues reading and writing, and … the nurses may not have known that, and it might help to piece pieces together if they realised, oh if I'm giving him something written, he's not understanding it and I need to make sure I've done it a different way." (#10) "I think if we establish what are the cognitive abilities we might use alternative approaches with the patient to facilitate the communication and for the patient to be more engaged with us." (#2) Impact on others 11 (61) Participants reported that it was useful to consider the impact of challenging behaviour on staff members, service users' families and other service users on the ward.
"It gets us to think about consequences we haven't thought about … the impact that it has on the staff member … or what it has for the relationships they have got with their family or the other patients who have observed it … and being asked that question gets us to think a bit wider about what is the real issue with this behaviour and who else is it possibly affecting." (#10) Physical health 11 (61) Participants reported that physical health is often overlooked on psychiatric wards and it can provide an important link to behaviour. Participants reported that it was useful to consider medication side-effects, noncompliance and how it may affect service users' daily routines.
"I think it's good that we're focusing on that as well because a lot of the time, because we're working in mental health, physical health can sort of be put to one side, but it's also as important … to see how that can influence their behaviour." (#8) "They might be over-sedated … some medications … can actually cause [a] patient to go a little bit high or manic, sometimes we give patients medications that they have tolerance of or even have dependence on and so their behaviour can be a way of trying to get those medications." (#11) Social relationships 10 (56) Participants reported that it was helpful to reflect on service users' social networks inside and outside the hospital, which may positively or negatively impact their mental state.
"A lot of them discuss a lot of things … which is nice and it benefits them a lot … at other times, it can be really detrimental and [there are] interactions between 17 different patients, so you have, quite a complex network of things going on." (#6) "The ward is like a small society, so … the way patient behaves, we can definitely reflect how it's going to be on the outside world and how they will behave with their families, with their friends, in the community." (#2) Maintenance factors 8 (44) (continued) highlighted loss of freedom experienced by service users and the power imbalance in staff-service-user relationships.

Visual analogue scales
Highest mean VAS scores (>8) indicated that case formulation was most helpful in providing an opportunity for staff to feel heard, increasing understanding of challenging behaviour, offering support to staff emotional wellbeing, helping staff to feel more energised at work and identifying care plan strategies. All mean VAS scores were >7, apart from the extent to which case formulation has helped participants in work management, which was 5.33. Table 4 reports all VAS.

Discussion
This study investigated staff experience of using team case formulation to address challenging behaviour on acute psychiatric wards. Qualitative and VAS data indicate that team case formulation is an important source of support for acute ward staff and improves clinical care. Participants reported that it provided a safe space to support their wellbeing, improved their clinical confidence, supported them in their work and increased their job satisfaction. Participants highlighted that case formulation supported them in developing improved therapeutic relationships, which may have been facilitated by thinking more deeply about service users' needs, life stories and developing an informed care plan. Positive effects of case formulation on the therapeutic alliance have important implications, due to strong associations with service user satisfaction and recovery (Sweeney et al., 2014). Benefits such as providing a safe space for staff to discuss and contextualise their emotional reactions to the behaviour, inadvertent reinforcement of certain behaviours, and staff feeling heard and supported are likely to be critical to good service provision for service users, and thus indirectly improve care. These benefits to staff and service users are consistent with formulation research in acute rehabilitation, forensic learning disability and community mental health settings (Berry et al., 2009;Hollingworth & Johnstone, 2014;Summers, 2006;Whitton et al., 2016) and they extend previous findings through a detailed analysis of the way in which team formulation offers support to staff. Participants reported that it was helpful to reflect on factors, including staff behaviour, which could be inadvertently reinforcing challenging behaviour.
"They've learnt different ways of … getting their needs met, and it depends on the consequences that they get and so they learn either to, it perpetuates the behaviour or to refrain from it completely … So in our discussions we explore all these areas as to whether we are reinforcing the behaviour." (#12) "It is quite helpful when you're thinking about the behavioural conditioning with the consequences for the patient, they do this … and then we tell them to go outside and that's what they really like and so essentially we are reinforcing it. " (#11) Distressing ward environment 8 (44) Participants reported that it was helpful to consider how the environment of the ward may be contributing to challenging behaviour. They reported that loss of power and freedom and the behaviour of other acutely unwell service users are contributing factors. Participants reported that the discussion encouraged them to think about possible adaptations to improve service users' wellbeing on the ward.
"Environment plays a crucial part in patients' treatment on the ward … there's only so many areas they can access at the time, this is not a normal, homely environment, so it's very difficult to get everything you need at all times … your bedrooms, staff members need to open the door before you can access it, because nobody is allowed a key on the ward, so you've got so many … compromises … your privacy." (#12) "We have other patients who are very unwell and … people who are not able to sleep and they are constantly distressed, pressing the alarms, constantly a lot of commotion on the ward, and it will have definite impact on people's behaviour and this we try to also identify." (#12) "There are some solutions that we can look at and it could be whether it's moving someone's room, or … thinking about the level of activities that they are engaging in, or if there's certain people, they get on better with others and maybe we need to involve their family a bit more." (#10) The findings highlight the importance of providing a safe space and encouraging MDTs to reflect on how challenging behaviour has affected them personally, moving away from a culture where staff feel ashamed to show vulnerability. Staff support provided by team case formulation is particularly important in acute psychiatric settings, where staff are regularly exposed to intense emotional distress and challenging behaviour (Johnson et al., 2018). Neverthless, issues like management of workload and continuity of care remain a challenge. The findings highlight the importance of traumainformed care, which recognises the impact of trauma on individuals' responses to their environment and the role of mental health services in providing sensitive care to avoid re-traumatisation (Bloomfield et al., 2020;Sweeney et al., 2018). Staff experience also aligns with the Power Threat Meaning Framework , which recognises that emotional distress and associated coping strategies are understandable responses to past circumstances and threats. This is particularly significant in acute psychiatric settings, as it is estimated that 47% of individuals with severe mental health conditions have experienced physical abuse and 37% sexual abuse (Mauritz et al., 2013). This may be exacerbated by the restrictive and potentially distressing acute ward environment, which is intended to provide safety, but may trigger feelings of being trapped, coerced, or in danger among individuals with trauma histories (Wampole & Bressi, 2019).
Strengths of this study include the development of a detailed and rich understanding of staff views regarding team case formulation. To our knowledge, this is the first study to investigate staff views on important factors to discuss in team case formulation on acute psychiatric wards. Limitations include the fact that all staff were recruited from one hospital, where wards are likely to share a particular ethos, and therefore may reduce generalisability to other settings; that VAS items, although adapted from a validated burnout questionnaire (OLBI) (Demerouti & Bakker, 2008), were brief and untested and participants were potentially more predisposed to have strong views on case formulation, either positive or negative, by virtue of being a self-selecting convenience sample. It is arguable that, without direct service user involvement, such formulation can only be speculative and used to develop initial hypotheses about behaviour. As we increasingly recognise the importance of doing "with" and not doing "to," future work and consultation with experts by experience is needed to develop more collaborative ways of working, aiming to reach a shared understanding that helps service users make sense of their mental health and relationships (Johnstone, 2018). The challenge in acute ward settings will be how to do this with service users with highly challenging behaviour and who may not be willing to engage with ward interventions.
This study has important clinical implications for developing an improved approach to case formulation on acute psychiatric wards. It highlights many of the factors that staff value and feel are supportive about team case formulation. However, an important future direction highlighted by this study is improving continuity of care and ensuring that care plan strategies are implemented consistently by staff. This could be achieved through integrating discussions about case formulation within existing practices, such as handover and ward rounds. Information technology systems could play a crucial role. Psychology care plans, which summarise information and recommendations from case formulation, could be uploaded to electronic clinical records in the form of a checklist. This could allow staff to check-off strategies which were implemented, indicate how successful they were, and rerate frequency of challenging behaviour. This could increase clarity about which strategies have been implemented and provide efficacy data (Foley & Woollard, 2019). Further clarity could also be provided through assigning care plan strategies to groups of professionals. Follow-up team discussions could be organised by staff, emphasising that psychological formulation is an ongoing process. Due to the numerous benefits of formulation on acute wards, this should be implemented for more service users, rather than solely focusing on service users that staff find most challenging.
Future research using validated measures of staff wellbeing, teamwork and therapeutic relationships before and after participating in case formulation could allow for a systematic investigation of its impact on staff wellbeing and their work on acute psychiatric wards. Another key research priority is gaining a better understanding of the most suitable way to involve service users in team case formulation and to investigate their subjective experience of this approach (Johnstone, 2018). Future studies could also investigate staff appraisals of case formulation using the recently developed Team Formulation Quality Rating Scale , which could enhance the reliability and validity of the findings and increase potential for comparison between studies. Research with larger numbers of participants from varying professional backgrounds could examine whether there are differences in staff perspectives of team formulation, particularly in relation to psychological mindedness. Research suggests that higher levels of psychological mindedness are associated with greater case formulation skill (Hartley et al., 2016) and greater capacity to form good therapeutic relationships (Berry et al., 2008), and thus, may affect staff perceptions of case formulation and its impact on relationships. More robust research exploring acceptability and effectiveness of team formulation is needed to guide best practice and optimal mode of delivery on acute wards .
In conclusion, team case formulation on acute psychiatric wards appears to be a promising approach, which may improve staff understanding of challenging behaviour, staff wellbeing, teamwork and quality of care.