Feasibility of using the Cognitive Orientation to daily Occupational Performance in a population of Danish stroke survivors: Adaptation and study protocol

Abstract Background A need was identified for an occupational therapy intervention for stroke survivors in a Danish municipal healthcare setting with emphasis on its ability to transfer and generalise what is learned in occupational therapy to everyday life post therapy. Being a possible candidate, the Cognitive Orientation to daily Occupational Performance (CO-OP) approach needed to be adapted to the target group and context, and its feasibility needed examination regarding reach, dose, intervention components, fidelity, perceived value, benefits, harms, and potential outcomes. Aim To adapt the CO-OP to a Danish healthcare setting and present a protocol for examining its feasibility. Material and methods The Adapting interventions to new contexts (ADAPT) guidance was followed to (1) Assess the rationale for intervention and consider intervention-context fit, (2) Plan and undertake adaptations, and (3) Plan a feasibility study. Results Intervention materials and procedures were translated and adapted for home-based occupational therapy with people in the subacute phase of stroke. A protocol was developed to examine feasibility aspects. Quantitative and qualitative evaluations were planned and measurements chosen. Conclusions and significance The planned feasibility study will contribute to further developing and refining the intervention before performing a possible large-scale effectiveness study.


Introduction
Stroke is a leading cause of disabilities worldwide, with millions of people experiencing a stroke each year [1].In 2019 alone, there were over 12 million new cases of stroke globally [2].Stroke appears in all age groups but, starting from around middle age, stroke incidence increases exponentially with ageing [3]; most stroke survivors receiving rehabilitation are therefore within this age group.Stroke survivors often experience changes in their physical, cognitive, and emotional abilities impeding their occupational performance and decreasing their social participation [4][5][6].The majority of stroke recovery occurs through restitution during the first 3 months after stroke, but it can continue up to 6 months or longer [5].Frequently, stroke survivors are referred to stroke rehabilitation, including occupational therapy (OT); the latter is primarily aimed at supporting individuals in achieving health, well-being, and participation in life through engagement in occupation [4].Despite rehabilitation, it has been found that 25% of stroke survivors are still dependent in their occupational performance 6 months post stroke [5].This may indicate that the rehabilitation efforts have not succeeded in effectively solving stroke survivors' performance problems.Another reason behind dependence post stroke may be that achieved improvements in therapy are not consistently transferred or maintained over time; this has been reported within OT as well as multidisciplinary stroke rehabilitation [7,8].
Effectiveness of OT in stroke rehabilitation has been evaluated in an evidence-based review and two systematic reviews [9][10][11]; the included studies vary concerning therapeutic approaches, settings and results.In an evidence-based review from 2015, including 39 trials, Wolf et al. focused on occupation-based OT interventions, understood as interventions supporting performance in activities of daily living (ADL), instrumental activities of daily living (IADL), rest and sleep, education, work, play, leisure, and social participation.They found evidence to support that occupation-based interventions in inpatient, outpatient, community and home settings can improve occupational performance after stroke, however the evidence was limited due to several methodological issues [9].In a Cochrane review from 2017, based on 9 trials, primarily performed in in-home settings, Legg et al. found that OT, focused on remediating impaired capacities and capabilities in ADL and on the use of adaptive techniques or environmental adaptations, can improve occupational performance after stroke.Also, in this review, the included studies were generally reported to be of low quality [10].In a Cochrane review from 2022, based on 24 trials performed in in-and outpatient settings, Gibson et al. focused on possible improvements in ADL through cognitive training and/or ADL training for stroke survivors with cognitive impairments.They concluded that the effectiveness of OT remained unclear [11].Thus, the reviews indicate some, but limited evidence for effectiveness of OT in stroke rehabilitation; little emphasis is, however, put on transfer or maintenance over time.Generally, the content of the OT interventions and how the occupational therapists work therapeutically with their clients (therapeutic approach) is not described in detail.Based on these literature reviews, no unambiguous answer exists to guide the choice of approach to stroke survivors.
The Cognitive Orientation to daily Occupational Performance (CO-OP TM , from now on CO-OP) is described as a client-centered, performance-based and problem-solving approach that enables skill acquisition in order to improve occupational performance within all areas [12].CO-OP is based on learning theory, motor learning theory and cognitive theory.It provides a cognitive approach to skill acquisition and specifically identifies transfer of achieved skills from trained to untrained activities and generalisation from therapy to everyday life as outcome objectives [13,14].It could be hypothesised that transfer and generalisation may lead to better maintenance of occupational performance over time.CO-OP is therefore an approach of interest to further develop OT within stroke rehabilitation.

The CO-OP approach
CO-OP was developed in the late 1990s for use with children with developmental coordination disorders [15,16].Since then, CO-OP has been adapted for use and applied in a variety of populations including adults with neurologic conditions to target a large variety of occupational performance problems.The CO-OP approach has been presented in a number of journal articles [e.g.14, [17][18][19][20][21][22] and in two published textbooks [16,23].The CO-OP consists of five essential elements and two structural elements [23].The five essential elements are the active ingredients that are considered essential for the intervention and therefore not to be changed.They are: (1) client-centred occupational goals set through active engagement of the client, (2) dynamic performance analysis performed by the client and the occupational therapist to identify why the performance is impossible or of too low quality (described in CO-OP terminology as performance breakdowns), (3) cognitive strategy use including the global Goal-Plan-Do-Check strategy and domain specific strategies developed in relation to specific activities, (4) guided discovery where the occupational therapist guides the client to discover strategies that will solve their performance problems, and (5) enabling principles that promote learning, generalisation and transfer [12].The two structural elements are related to (1) intervention format and (2) support person involvement and are described as adaptable to the intervention context [12].
In twelve studies, published between 2009 and 2020, CO-OP has been used among people with stroke (acute, subacute and chronic), traumatic brain injury (chronic), older adults with cognitive complaints and young adults with spina bifida or cerebral palsy [14,[17][18][19][20][21][22][24][25][26][27][28].The intervention settings varied from in-patient to outpatient and home-based environments.In several individual studies, CO-OP has been reported to be effective among adults with neurologic conditions [14,22,[24][25][26][27][28]], yet no systematic reviews have been published.CO-OP has, in several scoping reviews, shown promising results concerning usefulness, efficiency, generalisation and transfer [29][30][31].In a scoping review from 2019, Borujeni et al. identified 15 studies of CO-OP in adult populations.The authors concluded that CO-OP efficiently improved occupational performance and satisfaction in both trained and untrained activities, the latter indicating that transfer can have taken place [29].In a scoping review from 2016, Scammel et al. examined the extent and nature of the literature on CO-OP.Based on the 94 documents, of which 10 reported on research among adults, the authors concluded that CO-OP was, in general, useful although adaptations to the protocol were recommended [30].In a review from 2018, including 25 trials, Houldin et al. focused on effectiveness of CO-OP primarily on transfer among children and adults with various conditions.All articles demonstrated statistically significant and/or clinically meaningful results on at least one and, in many cases, the majority of transfer outcome variables assessed.In the 10 included controlled studies, the CO-OP group demonstrated larger change on more indicators of transfer than the comparison group [31].Hence, CO-OP has shown to be effective in different, yet small studies.
Before conducting a full-scale study to evaluate the effectiveness of CO-OP, adaptation to setting and target group and examination of feasibility is needed [32].Developed and tested interventions may be adapted for and transfer well to new contexts; however, the effectiveness of the intervention may not remain the same.Therefore, according to the Medical Research Council (MRC) framework for developing and evaluating complex interventions, conducting a feasibility study to examine uncertainties is critical in order to ensure a realistic and implementable intervention [32].
The aim of this article is to present a protocol for a feasibility study, including a description of the process of adapting CO-OP to a Danish municipal rehabilitation setting.The goal of the feasibility study presented in this protocol is to examine key uncertainties related to the following feasibility aspects: Reach, dose, intervention components, fidelity, perceived value, benefits, harms, and potential outcomes.

Study design
The feasibility study will be conducted in a single group pre-test-posttest design to examine feasibility aspects.The chosen design allows for examining feasibility of the intervention in its full length without spending resources on a control group.This will provide important information needed before conducting a large-scale effectiveness study in which maintenance over time can also be evaluated.The programme theory behind the CO-OP assumes that learning can be transferred from trained to untrained activities [23].
To possibly deliver support for this theory, transfer from trained to untrained goals will be examined in the feasibility study.
A combination of qualitative and quantitative data will systematically be collected from stroke survivors and occupational therapists during and after the intervention period.

Setting and participants
The feasibility study will be conducted at a neurorehabilitation centre in a Danish municipality of 355,000 inhabitants.The centre receives stroke survivors discharged from hospital and offers multidisciplinary rehabilitation with treatments mainly provided by occupational therapists and physiotherapists and taking place in clients' homes and at the centre.Danish legislation states that people discharged from hospital should be offered tax financed rehabilitation within 7 days when needed.
Middle aged and older stroke survivors (from now on described as clients) will be included in the feasibility study if fulfilling the following criteria: age 45 years or above, home living in the catchment area of the neurorehabilitation centre and referred from acute hospital wards or rehabilitation units to neurorehabilitation. Clients have to present with at least two identified occupational goals, of which at least one will be trained and one left untrained as this will enable measurement of possible transfer.
People with known substance abuse, severe mental illness and/or language barriers causing difficulties participating in CO-OP will be excluded from the study.

Adaptation of CO-OP
The evidence and consensus informed Adapting interventions to new contexts (ADAPT) guidance proposes four steps for adapting and transferring interventions with a previous evidence base to new contexts [33].We followed the guidance through the first two steps in order to Assess the rationale for intervention and consider intervention-context fit (Step 1) and Plan and undertake adaptations (Step 2).The third step, Piloting and evaluation was planned through a protocol for a feasibility study (presented in this article), while the fourth step, Implement and maintain the adapted intervention at scale, is planned to take place in a future study.The adaptation was performed by LMN, TLN and MB at physical meetings.One of the developers of the CO-OP (HP), was involved throughout the adaptation process through online meetings and mail correspondence.

Step 1. Rationale and intervention-context fit
The rationale for selecting CO-OP as candidate intervention to address occupational performance among middle aged and older stroke survivors, including the effectiveness, is described in the introduction of this article.
Concerning the intervention context fit, CO-OP has formerly been used with adults with neurologic conditions primarily in Canada, the United States and Sweden; the settings differ to some degree from a Danish context, e.g. in relation to language (English/ French/Swedish vs. Danish) and in Canada and the US also concerning health-care provision (insurance based, partly insurance-based or tax financed).
In order to consider intervention-context fit within the chosen Danish neurorehabilitation centre and to obtain knowledge about the usual OT practice with the target group, LMN and TLN informally observed four occupational therapists with six individual clients at the neurorehabilitation centre and in the clients' homes.While no formal observation guide was used, two predetermined foci of the observations were therapeutic approach (occupation-based versus conversation-based) and resolvement of performance problems (including how the client was involved).The achieved knowledge of the usual practice served as background knowledge for planning the delivery of the CO-OP.
The observations were followed by group discussions among the authors, occupational therapists and the local coordinator to obtain further insight into usual practices and delivery formats.During three meetings, all conducted at the neurorehabilitation centre, it was discussed how the five essential elements of CO-OP could be incorporated in the usual rehabilitation practice.The usual practice involved initial assessment of occupational performance, using the Canadian Occupational Performance Measure (COPM), followed by goalsetting; this was conducted by occupational and physiotherapists.OT treatment could consist of occupation-based training, as well as training of body functions such as facio oral tract therapy, treatment of shoulder and arm movement or cognitive training through different assignments, the latter often took place at the neurorehabilitation centre.Some of the stroke survivors' occupational performance problems could be directly observed by the occupational therapist, such as dressing or cooking and were addressed through occupation-based training.Other occupational performance problems were not directly observable, such as problems caused by fatigue or problematic social interactions with the family outside the therapy setting.The non-observable occupational performance problems were often addressed through conversations between the occupational therapist and the stroke survivor.CO-OP substituted the usual ways to address observable and non-observable occupational performance problems while other usual OT services could still be delivered, such as training of body function, when relevant.

Step 2. Plan for and undertake adaptations
The structural elements related to intervention format (session number, sequence and length, frequency, duration and materials) were the primary foci of the Danish adaptation, supplemented by specifications of the two further intervention components location and teaching format (see Table 1).
Session number, sequence, length, frequency and duration were decided in cooperation with local occupational therapists and lay within the limits described in previously published literature on using CO-OP with adults with neurologic conditions.Number of sessions was set to 11: three initial sessions for assessment, goal-setting and teaching the Goal-Plan-Do-Check strategy, up to seven training sessions and one session for the final evaluation.Sessions of maximum 60 min each could be delivered once or twice a week.
Adaptation of materials took its starting point in the CO-OP Approach Toolkit from the latest CO-OP textbook [23].The adapted materials consisted of a client's personal CO-OP binder with goal tracking sheets, educational materials and cue cards.The adaptation process was undertaken by the authors of the present article and discussed with occupational therapists at the neurorehabilitation centre.The following adaptation processes were conducted: Modification of the goal tracking sheets, and educational material (Power Point slides) through insertion of pictures and examples of everyday activities culturally valued in Denmark.Abridging and simplification of the goal tracking sheet and the educational materials (Power Point slides) to suit a possible narrow attention span and fatigue among people with stroke.Translation of all included original texts to adult lay language, conducted by a bilingual professional Danish/American speaking translator.The translations were discussed with one of the developers of CO-OP.The adapted material was finally presented to two individual stroke survivors who had received rehabilitation at the neurorehabilitation centre; they gave feed-back on face validity and general layout.
Further intervention components: The home was chosen as primary location for the delivery of CO-OP as the occupational therapists of the neurorehabilitation centre usually delivered OT in the clients' homes and due to the assumption that it would support learning and transfer.Goal setting was based on the COPM as this was also the usual procedure.
Teaching the Goal-Plan-Do-Check was to take place individually.Due to the demand to start rehabilitation within seven days from referral, it was not deemed feasible to wait and collect a group for the educational part of CO-OP.Specific unintended consequences have not previously been reported in relation to CO-OP and were not expected to occur as a product of the planned intervention.Usual safety precautions in relation to treating people with stroke must be applied; this was discussed with the occupational therapists who were to deliver CO-OP [6].Specific extra costs related to the delivery of CO-OP, compared to usual practice, were expected in relation to payment of occupational therapists' CO-OP course and time spent on supervision and group meetings to enhance their CO-OP competences.The extra costs were discussed and agreed upon with the manager of the neurorehabilitation centre, and they were covered through external funding.

Specific procedures of the adapted CO-OP
The adapted CO-OP consists of three initial sessions (assessment and education on CO-OP), up to seven training sessions and one final evaluation.
An initial assessment will be conducted at inclusion (session 1) by the occupational therapist using the COPM [34,35], followed by occupational goal setting.During the COPM interview, the participant will select two to five occupational goals of importance to them; the training sessions will be concentrated on one to three of these goals, leaving one or two goals as untrained.
During the second CO-OP session, the participant will be video-recorded while performing the chosen occupational goal (if observable).Their occupational performance will be scored by the occupational therapist using the Performance Quality Rating Scale (PQRS) [36].The participant will be asked to decide which of the identified goals should become the focus of the CO-OP sessions.
During the third session, the client will be taught the metacognitive Goal-Plan-Do-Check strategy [12], aided by a Power Point presentation.In subsequent sessions, the Goal-Plan-Do-Check strategy will be used iteratively as the main problem-solving framework to facilitate skill acquisition.The participant will work on one or more of the decided goals, the occupational therapist will use guided discovery to help the participant understand performance breakdowns [12] and develop a plan to achieve the goal.Afterwards, the participant will execute the plan and subsequently check to see if the plan is implemented and whether the goal is achieved.If the goal is not achieved, guided discovery will again be used to help the participant analyse performance breakdowns and modify the plan or create a new one.Domain-specific strategies will be developed, through guided discovery to overcome the particular performance problem and achieve the goal [12].Although the focus is on performing the task to be learned, there is no attempt to predetermine the number of iterations to be carried out; this depends on the success of the strategies identified.Once the participant is satisfied with the performance of the particular part of the task being worked on, the next part of the task will be addressed and the next performance breakdown will be identified, followed by a new learning cycle.This will, ideally, be repeated until the goal is achieved.Throughout, the occupational therapist will regularly seek opportunities to promote generalisation and transfer of skills and strategies to other activities and environments.Homework will be planned and encouraged to take place after each CO-OP session and discussed at the following session.For reasons of safety or due to persisting sensorimotor and/or cognitive deficits, the occupational therapist may guide the participant to try out assistive devices (such as mobility devices, special bathroom equipment, kitchen utensils, or memory aids) as part of the client's plans [6].
To ensure uniformity and standardisation of the programme, a manual describes the intervention procedures.It is allowed to supplement CO-OP with more traditional approaches, such as training of body functions when these are considered essential prerequisites to occupational performance.

Training of CO-OP providers
CO-OP will be delivered by three occupational therapists employed at the neurorehabilitation centre.The manager at the neurorehabilitation centre will recruite the occupational therapists on the criteria that they have at least 2 years' experience with the target group and are motivated to participate.As CO-OP has not yet been implemented in a Danish municipal context and is not a part of the curriculum at Danish Bachelor's programmes in OT, the occupational therapists are not expected have prior knowledge and skills in delivering CO-OP.Thus, participation in an established online CO-OP course [37], training and a certificate to practice CO-OP need to be achieved before carrying out the feasibility study.During the intervention period, the occupational therapists will participate in supervision planned by the authors of this article, aiming at clarifying issues related to the CO-OP approach, including how to apply the manual in clinical practice.Questions and problems experienced in practice will be addressed.A collaborative learning process will be facilitated by sharing experiences and reflections.In addition, the occupational therapists will, after each CO-OP training session, fill out a registration form to evaluate their role as a CO-OP therapist, see Supplemental material.
To enhance the occupational therapists' confidence in delivering CO-OP, they will be asked to pre-test the essential elements (primarily the use of dynamic performance analysis, use of the Goal-Plan-Do-Check strategy and domain specific strategies, guided discovery and enabling principles) with their usual clients, before the feasibility study.

Sample size
As this study is a feasibility study aimed at studying processes, not treatment effects, a sample size calculation has not been conducted [38].In order to obtain a sample representative of the target population and large enough to provide information related to the feasibility of the programme, a sample size of 20 clients is planned.

Recruitment
Recruitment of clients will take place in the period March 2022 to March 2023.Personnel at the facility will be responsible for recruitment from a list of people who are referred to rehabilitation.A structured checklist will ensure fulfilment of the inclusion criteria.Written and oral study information will be presented including general information on confidentiality and the right to withdraw.The occupational therapists who deliver CO-OP will obtain written informed consent from the clients before initiating the first CO-OP session.

Outcomes and data collection
As the primary aim is to explore feasibility aspects, the study will gather data about reach, dose (number of sessions, length, frequency and duration), intervention components, fidelity, perceived value, benefits and harms, and potential outcomes (see Table 2).In addition, data concerning client characteristics will be collected.

Client characteristics
At the first assessment session, data on age, gender, diagnosis and self-reported general health will be collected; the latter will be assessed using the Danish translation of the first question (SF1) of the Short Form 36: In general, would you say your health is: (answers: excellent, very good, good, fair or poor) [39].

Quantitative feasibility data
Reach.In the recruitment phase, the reach of the intervention (who accepted and who declined participation) will be registered by an occupational therapist employed as project secretary.Information about reach is considered highly relevant and useful in the planning of a future large-scale study.

Dose.
After each session, the occupational therapist will independently fill out registration forms related to dose of delivered CO-OP (number, length and frequency of sessions, how many minutes were spent on CO-OP and how many on possible other approaches) and factors facilitating or hindering delivery.Number, length and frequency of sessions vary in published CO-OP literature and are needed as an indication of whether the chosen dose in the present feasibility study seems to be sufficient and allowing for differences in needs in the target group.

Intervention components.
Location of each session will be registered by the occupational therapist after each session to see if the component is delivered as planned, or if not, why.Use of the Goal-Plan-Do-Check teaching format and whether it is understandable will be registered by both the occupational therapist and the client after session two.
Fidelity.Use of the five essential elements of CO-OP will be registered by the occupational therapist after each training session.Uncertainties are related to whether it is possible to deliver the essential elements in the training session and whether some of the elements are more difficult to deliver than others.Clients will also register whether they were actively involved.Adherence to delivering the active ingredients of an intervention will be crucial when conducting a large-scale evaluation of the effectiveness of CO-OP.
Perceived value.Meaningfulness of CO-OP from both the clients' and occupational therapists' perspectives will be asked for after each training session.Before conducting a large-scale study, it is important to know what value clients and occupational therapists place on the intervention.Furthermore, the occupational therapists will register how confident they are when delivering CO-OP.Benefits/harms.Will be registered by the occupational therapist after each training session.
Potential outcomes.COPM will be used to measure occupational performance and satisfaction from the client's perspective [34,35].A 10-point visual analog scale is used to obtain these ratings (where 1 indicates low performance and 10 indicates excellent performance).COPM is widely used as an outcome measure for self-reported occupational performance in both clinic and research.It demonstrates moderate to good reliability put poor validity when used for stroke survivors [40].In a systematic review from 2016, the reliability and validity of COPM used with stroke survivors were examined.The authors of the review, reported that COPM showed satisfactory testretest reliability, however, this was only examined in a small sample of 26 stroke survivors [40].In the same review, COPM only demonstrated weak associations with other outcome measures such as Barthel Index and Functional Independence Measure (FIM).This was explained by the client-centered design of COPM as a semi structured guide to explore the clients' needs and by the assumption that COPM provides a different measure of occupational performance [40].This is supported by another study examining the validity of the Danish version of COPM [41].Here the authors suggest, based on a sample of 109 clients, that the construct of the COPM provides data different to those obtained with the standardised measurements: the Occupational Self-Assessment (OSA), the fiveitem World Health Organisation Well-Being Index (WHO-5), and the EuroQol-five domain five level questionnaire (EQ-5D-5L).The Danish version of COPM has also been examined in relation to being sensitive to detect changes.A study from 2022, examining the responsiveness of change in COPM correlated with change in WHO-5 and EQ-5D-5L found only small positive correlations, perhaps because of the assessments' different constructs [42].
Observed performance quality will also be used as potential outcome and measured with the PQRS, [36].PQRS is an observational, video-based tool intended to measure the actual performance of client-selected activities.PQRS was originally developed with a 6-point scale, but modified in 2001 with a 10-point rating scale to better complement the COPM.Although some of the developers of PQRS are the same as the developers of CO-OP, PQRS is not an explicit part of CO-OP, but has been used in some studies of CO-OP.PQRS can be used with either generic scoring, or with specific operational definitions of different rating levels for each client-selected activity.With generic scoring, a rating of '1′ indicates low performance and '10′ indicates excellent performance.For this study, the generic scoring is used.The psychometric properties of PQRS have only been reported in one study examining the reliability and convergent validity [36].Here the authors reported moderate interrater reliability, substantial test-retest reliability, low to moderate convergent validity with the COPM and that PQRS demonstrated ability to detect change.The low convergent validity was explained by the idea that actual performance and perceived performance may be different constructs.The PQRS will be used in the original, English version, since it has not been translated into Danish.
As the PQRS involved video recording of the client's performance, when observable, the occupational therapist may choose (but is not obliged) to use the video recordings with the client during the process of guided discovery in the CO-OP sessions.
The main uncertainties concerning the potential outcomes are related to whether COPM and PQRS are possible to use in combination, their relevance perceived by the occupational therapists and whether the outcome can detect possible changes from baseline to post intervention.Another aspect to examine is whether the COPM can be used to measure transfer of skills from trained to untrained activities.Changes in performance of trained activities may be seen as a direct result of therapist-client interaction during CO-OP, while changes in performance of untrained activities are considered a measure of far transfer, since improvement suggests application of the strategy training applied in a new context [12].

Qualitative feasibility data
Post intervention, to further explore clients' and the occupational therapist's perceptions of reach perceived value as well as possible benefits/harms, qualitative interviews will be conducted using semi-structured interview guides.After the clients' evaluation session, they will be interviewed individually by different members of the research team.The majority of interviews will be performed by research assistants who only have this role in the project.The occupational therapists delivering CO-OP will be engaged in a group interview at the end of the feasibility study.The group interview will be facilitated by a research assistant, who is experienced with conducting group interviews.

Data analyses
Quantitative data concerning client characteristics and feasibility aspects will be processed in STATA 17 [43].Descriptive statistics will include frequencies and proportions for categorical variables.For continuous variables, means and standard deviations (SD) will be used for normally distributed data, while medians and interquartile ranges (IQR) will be used for skewed and ordinal data.Tests for significant differences in occupational performance (COPM and PQRS data) between baseline and post intervention will be performed; alpha levels will be set to 0.05.First and last author of this article will conduct the analyses and be responsible for entry, coding and storage of collected data.

Client characteristics
Age, gender, diagnosis and self-reported health will be presented in a table through means/medians and proportions, as applicable.

Quantitative feasibility data
The recruitment process will be presented in a flow chart to illustrate the steps of inclusion, with numbers and proportions.
Reach.Will be calculated as the proportion of invited stroke survivors that agreed to participate.

Dose.
Aspects related to number, length and frequency of sessions, how many minutes were spent on CO-OP and how many on possible other approaches, will be presented as mean/medians.Factors facilitating or hindering delivery will be categorised.

Intervention component.
The proportion of clients who receive the planned intervention components (location and teaching format concerning the Goal-Plan-Do-Check) will be computed and presented.
Fidelity.Will be computed as the proportion of clients who receive the five essential elements of the CO-OP sessions.
Perceived value and benefits/harms.Will be presented in tables and narrative syntheses.Potential outcomes.Firstly, relevance of the COPM and PQRS, perceived by the occupational therapists will be computed and presented.Secondly, to be able to detect possible significant changes from baseline to post intervention in the COPM performance and satisfaction and the PQRS, median change will be calculated on all occupational goals followed by two-sided nonparametric tests.Finally, to examine indications of transfer, possible differences in COPM performance change scores of trained versus untrained goals will be tested, using a two-sided nonparametric test.

Qualitative feasibility data
Interviews will be transcribed verbatim.Qualitative content analysis will be used deductively to analyse the interviews with a focus on describing aspects of reach, perceived value and benefits/harms of the intervention [44].

Patient and public involvement
As recommended in the ADAPT guidance [33], a reference group was established to bring in expertise of service users and professionals.The group's 13 members were initially involved in the adaptation phase step 2 and 3.The members were: Three stroke survivors (two female and one male), recruited through purposive sampling; they were former clients at the neurorehabilitation centre, and one had been involved in the occupational therapists' pre-test of the CO-OP.One next of kin, the wife of an included stroke survivor.Three occupational therapy practitioners: Two were employed at the neurorehabilitation centre (including one of the authors), the third was an expert in neurorehabilitation at a specialised inpatient stroke rehabilitation unit.Two researchers, experienced in complex interventions and mixed methods research, recruited through the authors' network.The manager of the neurorehabilitation centre was also involved, as well as the two principal researchers (first and last author).Finally, the reference group included a member of the Danish stroke association (former stroke patient).Context specific conditions and beta versions of the adapted CO-OP intervention format and components were presented and discussed at two meetings (online and face to face) with the whole group.Group members were also consulted on individual basis when needed, for instance to try out and give feedback on educational materials (stroke survivors) and to discuss recruitment procedures and choice of outcome measures (occupational therapists and researchers).

Ethics
The Danish Regional Ethics Committee responded that no approval was required as the study was classified as a quality assurance project (J.nr.1-10-72-1-21).The study was approved by the local Ethics Committee at VIA University College, Denmark (#394562).

Discussion
Implementing existing interventions to new contexts might be more efficient than developing a new intervention [32,33].However, there will often be a need for adapting materials and delivery details to a given context.In our process of adapting the CO-OP approach to stroke survivors in a Danish municipal context, the ADAPT guidance was followed.The ADAPT guidance provides a systematic approach to the complex adaptation process as it helps to identify and specify the essential and the structural elements, so that the adapted CO-OP would remain true to the original while at the same time being relevant and useful in the new context.We used multiple methods, such as observations of current practice, informal interviews with clinicians and stroke survivors and a constant feed-back/feed-forward process among the authors to strive for relevance and usability.To fully comprehend the essential elements of the CO-OP and to ensure feasible delivery, the Danish researchers and interventionists followed a certified web-based CO-OP course and discussed the adaptations with a developer of the approach at several occasions.
One of the uncertainties addressed in the feasibility study will be whether the chosen outcome measures COPM and PQRS will be relevant, able to detect change and for the COPM also whether it can be used to asses transfer.The choice of using the COPM and PQRS was primarily based on former CO-OP research.Although the validity and responsiveness of COPM is questioned in some studies, it is the only client-centered measure to capture clients' individual and most important occupational performance problems.Because is it widely recommended within rehabilitation to supplement self-reported occupational performance with performance-based observation, the PQRS was included as an outcome [45].As described earlier, the psychometrics of PQRS are only reported in one study, therefore data from the PQRS in the planned feasibility study will be used to assess reliability and validity, before decisions are made on the possible use of PQRS in a large-scale study.
Involvement of a reference group has served to improve the quality of the adapted intervention.Stakeholders with different experiences have added new perspectives, for instance to the design of the intervention materials and the implementability of the intervention in the given context.It secured democratic representation of end users and increased the quality and integration of the programme into clinical practice [46].
In conclusion, the planned feasibility study will contribute with knowledge about the feasibility of the adapted CO-OP.This knowledge can be used to further develop and refine the programme before a possible large-scale study aimed at examining its effectiveness among stroke survivors in a home-based, Danish municipal healthcare setting.

Table 1 .
adaptation of the intervention format and intervention components.

Table 2 .
data collection related to feasibility aspects.