Use of dementia care mapping in the care for older people with intellectual disabilities: A mixed‐method study

Abstract Background The ageing of people with intellectual disabilities, with associated morbidity like dementia, calls for new types of care. Person‐centred methods may support care staff in providing this, an example being Dementia Care Mapping (DCM). DCM has been shown to be feasible in ID‐care. We examined the experiences of ID‐professionals in using DCM. Methods We performed a mixed‐methods study, using quantitative data from care staff (N = 136) and qualitative data (focus‐groups, individual interviews) from care staff, group home managers and DCM‐in‐intellectual disabilities mappers (N = 53). Results DCM provided new insights into the behaviours of clients, enabled professional reflection and gave new knowledge and skills regarding dementia and person‐centred care. Appreciation of DCM further increased after the second cycle of application. Conclusion DCM is perceived as valuable in ID‐care. Further assessment is needed of its effectiveness in ID‐care with respect to quality of care, staff‐client interactions and job performance.

In caring for older people with intellectual disabilities, person-centred methods are promising and may contribute to the shift from task-focused to more supportive care (Brown et al., 2016;Cleary & Doody, 2017a, 2017bOuellette-Kuntz et al., 2019;Van der Meer, Nieboer, Finkenflügel, & Cramm, 2017). Person-centred care puts the person at the centre of care services, rather than the disease (WHO, 2020). Person-centred care evolved from the field of dementia care and is strongly connected to Tom Kitwood's concept of personhood in dementia (Kadri et al., 2018;Kitwood, 1998). Personhood refers to the relational aspects of being human, and the importance of being in an inclusive psychosocial environment where people are recognized as a person with a unique personality and life history who need a unique approach (Brooker, 2003;Brooker, Woolley, & Lee, 2007;Edvardsson, Winblad, & Sandman, 2008;Kitwood, 1992Kitwood, , 1998). Kitwood's view model highlights the relational components of personhood, engaging both the "cared for" and the "carer" in its construction and maintenance (Kadri et al., 2018). Kitwood stressed that the nature of cognitive and functional impairments associated with dementia (e.g., language and executive function) makes it difficult for people with dementia to meet their own needs (Kitwood, 1992(Kitwood, , 1997Willemse et al., 2015). To meet these psychological needs, person-centred care provided by professional staff should comply with four major elements summarized in Brooker's VIPS framework: (a) an assertion of the absolute value of all human lives, regardless of age or cognitive ability; (b) an individualized approach, recognizing uniqueness of the person; (c) an understanding of the world from the perspective of the person; (d) a positive social psychology, enabling the person to experience relative well-being (Brooker et al., 2007;Røsvik, Brooker, Mjorud, & Kirkevold, 2013;Røsvik, Kirkevold, Engedal, Brooker, & Kirkevold, 2011). Person-centred care can yield more effective interactions between clients and care professionals (Brownie & Nancarrow, 2013;Tay et al., 2018;Van der Meer et al., 2017), and better collaboration of staff in coordination of care (Edvardsson et al., 2008;Rathert, Wyrwich, & Boren, 2013). In ID-care, however, person-centred methods, usually derived directly from regular dementia care, are often used in an unsystematic way (Fokkens, IJsbrandij, & Jansen, 2016;Schaap, Finnema, Stewart, Dijkstra, & Reijneveld, 2019a), even though previous research has strongly indicated that they should be customized to be successful (Hodes, Meppelder, Schuengel, & Kef, 2014;Vlaskamp, Hiemstra, & Wiersma, 2007).
One such person-centred method, Dementia Care Mapping (DCM), designed to support staff in their daily care for people with dementia, has also been adapted to ID-care Schaap, Fokkens, et al., 2018). DCM has characteristics that enhance innovation in ID-care; it is a structured psychosocial method, based on the principles of person-centred care, aimed at increasing the quality of care (Finnamore & Lord, 2007;Jaycock, Persaud, & Johnson, 2006;Persaud & Jaycock, 2001;Van de Ven et al., 2013). DCM is an intensive observational tool. It is used within a cycle of practice development for staff care settings, and is simultaneously an approach to achieve and embed person-centred care for people with dementia (Surr et al., 2016). DCM is a cyclic method, consisting of a structured observation of six hours, followed by feedback to the whole care-team, and action planning (see Box 1). This helps staff to reflect on their routine behaviour and interactions in daily care, thereby improving care from a client-centred perspective. In small-scale, qualitative studies, DCM has shown to be feasible and promising in supporting staff in caring for older people with intellectual disabilities, whether or not with dementia, in the United Kingdom and the Netherlands (Finnamore & Lord, 2007;Jaycock et al., 2006;Persaud & Jaycock, 2001;Schaap, Fokkens, et al., 2018).
Quantitative findings on the effects of DCM in ID-care are, however, conflicting. On the one hand, studies did not show positive effects of DCM, neither on the quality of life of older people with intellectual disabilities (Schaap et al., 2019a) nor on the job satisfaction of ID-care staff (Schaap, Finnema, Stewart, Dijkstra, & Reijneveld, 2019b). On the other hand, staff reported that DCM provided adequate psychosocial methods and approaches to care for older people with intellectual disabilities Schaap, Fokkens, et al., 2018). Such contradictory findings regarding the use of DCM have also been reported for dementia care (Barbosa, Lord, Blighe, & Mountain, 2017;Chenoweth et al., 2009;Dichter et al., 2015;Rokstad et al., 2013;Van de Ven et al., 2013).
Further assessment of the reasons underlying these contradictory findings may contribute to a better understanding of DCM and its use in ID-care. The aim of this study is therefore to examine the experiences and opinions of staff and group home managers in the use of DCM in ID-care.

| Study design
To obtain information from ID-care professionals on their experiences in using DCM-in-ID, we used quantitative and qualitative methods after each of two DCM-cycles. The quantitative method involved collecting data on the opinions of staff members after each application of DCM, via questions in a follow-up questionnaire for a quasi-experimental study on DCM. The qualitative method involved collecting in-depth data from all ID-care staff after each DCMcycle, using focus-group discussions and face-to-face interviews.
We performed the design, analysis and reporting according to the COREQ checklist (Tong, Sainsbury, & Craig, 2007).
The study was performed in accordance with the Helsinki Declaration, and informed consent was obtained from all participants (World Medical Association, 2013

| Dementia care mapping in intellectual disability-care
DCM-in-ID consists of a structured observation of six hours, followed by feedback of this observation to the whole care-team, and then action planning (see Box 1). First, based on the findings of a feasibility study of DCM in ID-care, in each group home four older clients were mapped simultaneously by a mapper not affiliated with the group home, for a total of six hours distributed across two or three separate periods (Schaap, Fokkens, et al., 2018).
Second, the mapper presented the results to all available staff and the manager of the group home in a report and in a feedback session focused on dementia and person-centred care. Third, as part of the feedback, staff wrote up an action plan to improve support of their clients in daily practice. The action plans were explicitly discussed by the mapper in the feedback session after the next cycle.
This provided opportunity for staff to reflect on their planned action in routine daily care (see Box 1 and Figure 1).

| Procedure and sample
First, we approached all six major ID-care organizations which had at least four group homes for older clients in the north of

Box 1 Dementia Care Mapping in people with intellectual disabilities: person-centred care in action
Dementia Care Mapping (DCM) is an intervention developed by the Dementia Research Group at Bradford University to improve the quality and effectiveness of care from the perspective of people with dementia (Brooker & Surr, 2005). It is based on Kitwood's social-psychological theory of personhood in dementia. (Kitwood, 1992) DCM was designed as observational tool to develop personcentred care for people with dementia in nursing homes (Van de Ven et al., 2013). Person-centred dementia care can be specified as: valuing people with dementia (V); using an individual approach that recognises the uniqueness of the person (I); making an effort to understand the world from the perspective of the person (P); and providing a supportive social environment (S) (Brooker et al., 2007).
DCM has three main components:

A: Mappers' training in DCM
A staff member receives training to become a certified DCM mapper. A basic DCM mapping course includes 4 days of basic concepts and skills. To participate in research, a mapper must achieve the level of advanced mapper. Required for this is a three-day course focused on the background and theory of DCM, and person-centred care. An advanced DCM mapper can observe (map) care with an inter-reliability score of ≥0.8, report the observation, provide feedback and instruct staff in drawing up action plans ( Van de Ven et al., 2013).

B: Organizational introductory briefing
Before the mapping (systematic observation of the actual care) takes place, the basic principles of DCM and person-centred care are explained to the complete staff of a group home, to ensure endorsement and appropriate implementation (Van de Ven et al., 2013).

C: DCM cycle: observations-feedback-action plan
The introductory DCM organizational briefing day is followed by a DCM-cycle, consisting of: Observation, analysis and report. A mapper observes four to six residents in communal areas for 4 to 6 hr. For each 5-min time frame, a code is noted to record what happened with each resident and the associated behaviour of the staff. The DCM coding protocol contains 23 behavioural category codes (BCCs), well/ill-being (WIB) values of clients, and personal detractions (PDs) and personal enhancers (PEs) in staff-client interactions (Brooker & Surr, 2005). PDs and PEs refer to staff behaviour and are often related to the WIB values in the interpretation of observations. After analysis the observations are included in a written report.
Feedback. The results of the mapping are communicated verbally to the staff. The purpose of this feedback is to discuss and gain insight into residents' behaviour in the context of both their lives and the care (Brooker & Surr, 2005). The feedback is complemented with knowledge of dementia and person-centred care. Feedback is presented in a non-threatening way and is intended to enhance staff awareness of their own and residents' behaviour and of staff-resident interactions, thereby motivating them to improve their competencies, performance and interactions (Van de Ven et al., 2013). The feedback is supported by the written report.
Action plans. Based on observation and feedback, the staff draw up action plans to improve care at individual and group levels. Action plans are tools to implement theoretical knowledge of dementia and the principles of person-centred care in daily practice, and to increase uniformity of care.
the Netherlands. Second, each organization provided four group homes for the study. A group home houses a small number (range 4-12) of older people with intellectual disabilities in need of care, support and supervision by care staff are living together. All participants were clients living in such small-scaled group homes. The possibilities for using DCM determined our inclusion criteria for the group homes; we needed the possibility to observe four people simultaneously in a shared area (e.g., a living room) for at least two consecutive hours, the presence of at least three older people with (a strong suspicion of) dementia and a stable team not anticipating reorganization.
A complete cycle of DCM-in-ID was carried out twice in all group homes, with an interval of seven months, along with a quasi-experimental study. To guarantee intervention adherence, the DCM trainers strictly monitored the intervention and supported the newly trained mappers in following the DCM-in-ID implementation protocol (Bradford Dementia Group, 2014). This protocol includes a description of all DCM-preconditions and of every step needed to implement DCM in ID-care (Bradford Dementia Group, 2014). This monitoring ensured that DCM was implemented and applied in all group homes in a similar way. We collected both quantitative and qualitative data among ID-care staff from twelve group homes for older people. In each group home live a small number (range 6-12) of people with intellectual disabilities in need of care and support. Of these residents, 21% had a mild intellectual disability, 49% a moderate and 31% a severe or profound one. Regarding dementia, 46% had a diagnosis or a strong suspicion of dementia, and 18% showed some signs of dementia. The care and support deal with all aspects of everyday life, including activities of daily living (ADL) and day care activities.
The quantitative data regarded responses to questionnaires by care staff in each of the twelve group homes. From each group home, we included all staff with regular employment and excluded students doing an internship. Staff could fill in the questionnaire either on-line or on paper. Data were anonymized by giving each staff member an identification number.
Qualitative data were obtained from two staff members per care facility (N = 24), as well as from all group home managers (N = 10), all behavioural specialists involved (N = 7) and all DCM-ID mappers (N = 12). We conducted a total of eight focus-group discussions, four after the first application of DCM and four after the second (Table 1).
Staff members were invited at random for both time points. The discussions were categorized according to staff function: two regarded staff members from various group homes, one regarded managers and behavioural specialists, and one regarded all DCM mappers. The focus-group discussions and individual interviews were semi-structured, led by a discussion leader (FDS, GJD or EJF) accompanied by an observer (FDS, GJD and ASF), and by an interviewer (FDS), respectively.
Individual interviews were held with participants who could not attend a focus-group, four after the first cycle and two after the second cycle.
The interviews and focus-groups lasted approximately 1.5 hr, and were audio recorded and then transcribed in full.

| Topics and measures
The quantitative data were derived from self-developed open and closed questions for evaluating the use of DCM in daily ID-care.
We asked whether and to what extent DCM was a usable and practical addition to care. These questions were incorporated in follow-up questionnaires in a quasi-experimental trial. The qualitative data were gathered using the empathy map, derived from the methodology of the design-thinking theory (Curedale, 2013).
The empathy map facilitated tracing of the "pains and gains" of the participants, allowing them to discuss what they "think and feel," "say and do," "hear" and "see" about the first use of DCM in IDcare. This method was developed to provide in-depth information regarding opinions and experiences of participants.

| Data analysis and reporting
We analysed and reported the data in three steps. We first described the background of the sample. We then reported on experiences and opinions of staff regarding the use of DCM in ID-care after each DCM-cycle. We finally reported on which factors influenced the evaluation of this method by staff, group home managers and DCM-in-ID mappers. We performed separate analyses for quantitative and qualitative data.
We analysed the questionnaire data on experiences and opinions of staff in response to the closed questions using descriptive statistics, with IBM SPSS statistics (version 25). We tested the differences between both measurements using Pearson's chi-square tests. We analysed the qualitative data and open questions following the principles of conventional content analysis (Hsieh & Shannon, 2005) and thematic analysis (Braun & Clarke, 2006

| Background characteristics
Of the 167 approached staff members, 136 (81%) have returned a questionnaire at both time points.  Schrijnemaekers et al., 2002) and/or Gentle Care (Buijssen, 1991). b Training in methods named above or a self-developed training by the organization.

SCHAAP et Al.
mostly (senior) daily care professionals (95%) with secondary vocational training (80%). All were relatively experienced staff (69% had over 11 years of experience) and most (84%) reported they received training in person-centred care and in caring for older people with intellectual disabilities, respectively, 84% and 76%.

| Opinions and experiences regarding DCM in ID-care
The quantitative data indicated that the majority of all participants in the group homes (61% to 84%) agreed in both measurements with the statement that DCM is a good way to map clients' behaviour, and provides new cues and insights for giving support to their clients (

| Underlying factors
The factors underlying staff experiences and opinions were derived from the qualitative data and the open questions in the questionnaire. Table 3 describes participants in the focus-group discussions and personal interviews. The results of staff experiences in the use of DCM in ID-care from a professional perspective were reported per theme as derived from the qualitative data: information about clients, professional reflection, knowledge and skills, organization of care and use in daily care. The following paragraph will elaborate on these topics.

| Information about clients
We found the most dominant underlying factor for the experiences with and opinions on DCM to be the degree of insight which DCM provided regarding the causes of specific client behaviours. Examples were behaviour caused by over-or under-responsiveness, physical discomfort (cold, inappropriate furniture and aids) and (behavioural) consequences of dementia.
Especially, the under-responsiveness of and the lesser attention to quiet and non-demanding clients were striking to some staff.  Yes, more consciously. That you focus on one client and take the time for it. Do not fly past, things like that… just walk, don't fly by, but adjust your pace.
What they told me in the team was that it was so helpful that an external person came to observe, who could also comment on the blind spots of staff.  Group home managers *,a 5 5 7

TA B L E 3 Participants in focus-group discussions (FGD) and individual interviews (IV)
Behavioural specialists *,a 2 5 a Participants took part in both measurements, whether in a focus-group discussion or an interview.

| Knowledge and skills
In general, DCM provided more knowledge and skills on ageing and dementia, and on person-centred care. Staff indicated that they knew better what they were doing in their work, and why.
According to staff, managers and mappers, this resulted in more person-centred, deliberate and in-depth care, which was highly appreciated. DCM gave them more ground in providing care; they were able to relate care to the needs of the client, based on the theory of person-centred care, as well as to the consequences of ageing and dementia. Staff reported that by making the needs of the clients visible using Kitwood's five dimensions of personhood (Kitwood, 1992) improved the interpretation and explanation of clients' behaviour. This was reflected in the action plans; the proposed actions had a theoretical basis in person-centred care and knowledge of dementia. However, staff experienced a conflict between person-centred working and the task-oriented organization of care and the registration systems.

| Use of DCM in daily care
Staff, managers and mappers reported that they found DCM very practical and applicable. In the qualitative data and open questions, they almost unanimously agreed that they would like to con- For us it works well: the staff member reports the things indicated by DCM. That may be that someone is always very lonely, or someone who seems very easy gets a bit neglected. A goal-oriented report was made by the personal coach; at least three times a day an attention moment was given, besides the regular care moments. And then you could score whether you had done that… If you see that your colleague has done a certain thing, then you think 'Oh, that is actually very nice', but you also notice yourself thinking, 'I also can't say I did nothing'. It encourages you to do something yourself. It strikes me that at our location, DCM really has been an eye-opener; we have to do much more with policies regarding care for older people; it has to be much more structured in the organisation. And many more DCM-mappings, many more things need to be developed in terms of the policy to provide good care for older people. DCM is a great part of that; that you can see.

| Comparison of results of both measurements
Comparison of the data from both measurements showed that after the second cycle of DCM staff were even more positive about the benefits of DCM (Table 2). We found both in the quantitative and qualitative data that the answers of staff given after the first cycle were aimed mostly at the clients and their behaviour. After the second DCM-cycle, staff spoke more about their own professional reflection. This was also the case regarding the provision of personcentred care. After the first cycle, staff were quite convinced that they worked in a person-centred way. After the second cycle, staff agreed even more that this could be improved. They reported having become more aware that DCM is not an instant solution, but that they had to contribute themselves. They remarked that provision of care became more in line with the well-being and needs of the clients, rather than task-driven or habitual. However, this is not yet compliant with the organization of daily care, according to staff. Next, the multi-organizational focus-groups we observed that care staff found it inspiring and helpful to hear about and learn from each other's experiences. Furthermore, we found that in group homes with staff experienced in person-centred care (f.i. using method Urlings), DCM was more successful. Finally, we found that staff belonging to one group home did not find DCM to have added value next to existing methods because of the mapper's way of providing feedback.

| D ISCUSS I ON
With this mixed-method study, we examined the experiences and opinions of staff and group home managers on the use of DCM in IDcare. In general, we found that professionals valued DCM positively in the care for older people with intellectual disabilities, with or without dementia. The method provided insights into the behaviour of clients, enabled professional reflection, provided new knowledge and skills regarding dementia and person-centred care, and helped to apply this theoretical knowledge in practice. However, we found that not all group homes completely fulfilled the DCM-preconditions which had previously been found to be successful . Finally, we found that staff appreciated DCM even more after the second cycle than after the first.
The quantitative data indicated that the majority of participants found DCM a usable and valuable addition to daily care. It provided new insights into clients' behaviour and into their own professional behaviour, and gave new cues for organization of care.
Furthermore, almost the half of the staff reported having gained more knowledge and skills for dementia-and person-centred care which had slightly increased after the second DCM-cycle. This indicates that staff, who in majority stated to have had previous training in dementia and in person-centred methods, were enabled by DCM to apply this knowledge better. Moreover, DCM was applied for a relatively short time, a longer follow-up period may be useful, as a transition to more person-centred care may require more time than provided by the follow-up of our study (see also Schaap et al., 2019b). However, staff stated that DCM did not influence their job satisfaction, a result also found in previous research: feedback as provided showed DCM to be helpful and possibly leading to enhanced job performance (Visscher, Peters, & Staman, 2010), but showed job performance hardly to have affected job satisfaction (Bartlett, 2001;Squires et al., 2015).
We found, first of all, that the most frequently mentioned underlying factors for positive experiences with DCM in ID-care were that DCM increased insights both into the behaviour of both clients and professionals. The insight into clients, related to new knowledge regarding dementia and person-centred care, led to more understanding of the causes of their behaviour and ideas for more tailored care. Furthermore, DCM improved professional behaviour; the method enabled professional reflection and provided guidance in ID-care, which we found had been uncommon for daily ID-care staff. These factors may contribute to coping with challenges in long-term care. Our study and previous ones indicated that long-term care relationships are important for understanding the behaviour of clients, but can also cause blind spots and impede a critical look at one's own professional behaviour (Bekkema, de Veer, Hertogh, & Francke, 2015;Donaldson & Grant-Vallone, 2002;Finkelstein, Bachner, Greenberger, Brooks, & Tenenbaum, 2018;Iacono et al., 2014;Janssen & Van der Vegt, 2011;Murray, 2005).
Previous research showed that strong bonds with clients and high engagement with work may lead to ID-care staff taking on overly demanding responsibilities and refusing to admit mistakes in daily work (Donaldson & Grant-Vallone, 2002;Janssen & Van der Vegt, 2011;Murray, 2005). Moreover, previous studies found that professional reflection and understanding are important to overcome this habitual professional behaviour and these blind spots; such reflection could lead to improved job performance Potthoff et al., 2018;Presseau et al., 2014;Visscher et al., 2010). We found that DCM helped to achieve this because it provides recurring feedback and reflection on job performance, in combination with greater knowledge regarding dementia and person-centred care: factors not yet common in ID-care (Fokkens et al., 2016).
A second value of DCM seems to be its provision of new knowledge and skills regarding dementia like person-centred care, cues to coordinate care and a methodical tool to apply knowledge in practice; these have not been reported for any other method in IDcare. This report by professionals contradicts the large number of existing approaches for providing care and support to people with intellectual disabilities (Singh, 2016a(Singh, , 2016bTwint & Bruijn, 2014), which often lack either a theoretical, scientific or methodical base (Fokkens et al., 2016;Maaskant, Balsters, & Kersten, 2017). We found that DCM provided an underlying, person-centred, theory for staff in daily care provision by relating the needs of clients to Kitwood's five dimensions of personhood. This led to more deliberation of individual staff in daily care, which are factors associated with improved job performance (Chiniara & Bentein, 2016;Maurits, de Veer, Groenewegen, & Francke, 2017;Squires et al., 2015). Staff reported that the methodical cycle helped them to sustain the application of theoretical knowledge on person-centred care, ageing and dementia in practice, and to bridge the gap between knowing and doing, as also shown in previous research (Grimshaw, Eccles, Lavis, Hill, & Squires, 2012;Slaughter et al., 2018). Furthermore, the improved coordination and conformity of care provided by DCM created in staff a feeling of being a team, which previous research has also shown to be an enabling factor for providing good care (Fyffe, McCubbery, & Reid, 2008;Kersten, Taminiau, Schuurman, Weggeman, & Embregts, 2018). DCM thus provides an applicable theory for the provision of daily care.
Third, staff reported that DCM helped to apply a more person-centred approach, which was perceived as helpful to fulfil the individual clients' needs. However, staff experienced a conflict between person-centred working and the task-oriented organization of care and registration system. This conflict was also noted in previous studies on use of DCM in nursing homes and was identified as an important barrier for its implementation (Kadri et al., 2018;Griffiths et al., 2019;Van de Ven et al., 2014). Several studies have shown that a person-centred point of view should be the guiding principle in providing high-quality care for older people with intellectual disabilities, but most ID-care organizations have a task-oriented organization of care (Cleary & Doody, 2017a, 2017bHolst et al., 2018;Ouellette-Kuntz et al., 2019).
To be successful, DCM requires fulfilment of preconditions, which we found were not always present, such as a strong base of person-centred care throughout the organization. Previous research on DCM indicated that to reach optimal results the fulfilling of these preconditions is of major importance Schaap, Fokkens, et al., 2018;Van de Ven et al., 2014). For future implementation of DCM, adequate compliance to the preconditions should be maximized.
Finally, we found that staff were more positive about DCM after the second cycle. This has also been shown in previous research regarding its use in dementia care Van de Ven et al., 2014). This could be for several reasons: first, the DCM-in-intellectual disabilities mappers had become more experienced in carrying out DCM and were therefore able to provide better feedback. Second, staff had become more aware of what DCM entails: not instant solutions, but reflection on professional behaviour and finding solutions themselves. Previous research showed that this mechanism is common after implementing a new intervention; participants have to become used to working with it (Grilo, Santos, Rita, & Gomes, 2014;Kersten et al., 2018;Slaughter et al., 2018;Wood et al., 2014). Related to this is that the answers of staff after the first DCM-cycle were aimed mostly at (the behaviour of) clients, but after the second cycle they were aimed at reflection on their own professional behaviour. Previous research showed that when not in control, staff are inclined to attribute problems in daily care to the clients' behaviour (Farrell, Shafiei, & Salmon, 2010;Squires et al., 2015). This suggests that after the second DCM-cycle, staff are used to doing more professional reflection and are more in control of their daily work, which may lead to improved job performance.

| Strengths and limitations
A key strength of this study was our use of a multi-informant and multi/mixed-method design to examine the opinions of care staff and managers on DCM in ID-care settings. Moreover, we examined the use of DCM in practice in 12 group homes from six organizations for people with intellectual disabilities, each home having its own vision, culture, team characteristics and habits in care; this enhances the validity of our results for routine ID-care practice.
A first limitation of this study is that we rely fully on reports by professionals. These reports may be biased due to social desirability and a Hawthorne effect, related to the additional attention to professionals as part of the study. However, this is not very likely because the methods used in the interviews and focus-groups enabled staff to perform critical reflection and take part in in-depth discussion. This makes a Hawthorne effect not very plausible, although it cannot be ruled out. Second, we used a self-developed questionnaire which had not been validated. Third, another limitation might be that the observation, report and feedback were carried out by a DCM-in-ID mapper from an external organization. However, a feasibility study of DCM in ID-care and this study showed that the fresh look of an external person improved independence and led to avoidance of interpretation bias due to familiarity with habits, clients and colleagues (Schaap, Fokkens, et al., 2018). Finally, regarding performance quality, that is the mappers' skills: despite finishing the basic and advanced mappers' trainings, the newly trained mappers were not always fully experienced in providing feedback. This may have caused a lower quality of the feedback and the further results.

| Implications
Our finding that DCM provides new knowledge and skills for staff caring for older people with intellectual disabilities could bridge the gap in the changing approach to care for this group (Chapman, Lacey, & Jervis, 2018). The method was perceived as useful for applying theoretical knowledge in practice, also knowledge gained from previous training and courses. However, for a routine application of DCM a broader (theoretical) knowledge on the part of staff in person-centred care should be considered. Moreover, to enable staff to provide more person-centred care, a shift would be advisable towards person-centred care throughout the whole organization, a shift from a task-oriented way of working to a person-centred compliant vision.
Although we found that staff valued DCM in daily care practices and that indications that it might improve job performance and quality of (person-centred) care for older people with intellectual disabilities, previous research has found no evidence on the quality of life of people with intellectual disabilities nor on job satisfaction of care staff (Schaap et al., 2019a(Schaap et al., , 2019b. The effectiveness of DCM should thus be assessed in a study aimed at outcomes in the direct care process, such as job performance, quality of (person-centred) care and quality of staff-client interactions.

| CON CLUS ION
Staff considered the use of DCM in ID-care to be a valuable additional method to support them in their work with ageing clients. We found that DCM gave insights and consciousness, new knowledge and skills, a (person-centred) theoretical base and a methodical cycle to sustain knowledge in practice. This indicated that DCM could improve the quality of care and job performance of staff. However, the implementation and maintenance of DCM need further attention, as does compliance to the action plans.
Future research should follow-up on the effects of DCM in IDcare on quality of care, quality of staff-client interactions and job performance.