The fidelity study

To examine the implementation fidelity of the WALK-Cph intervention, a fidelity study performed as an ethnographic study [58] was carried out at the two intervention departments at the same time as the feasibility study, from September 2018 to March 2019 (Table ​(Table1).1). The study was carried out as participant observations of daily practice at the two intervention departments [59]. The observations focused on gathering information about the daily practice concerning the WALK-Cph intervention components that were related to hospitalization (Additional file 1). No observational data were collected on WALK-Cph intervention components to be performed after discharge (i.e., WALK-plan after discharge). Information on this component was collected through patient records.

Data were collected through observations conducted at the two intervention departments during the feasibility periods using a focused observation strategy [60]. The observations followed an observation guide (Table ​(Table2)2) inspired by Hasson’s [61, 62] modification of Carroll’s Conceptual Framework for Implementation Fidelity [63] and was based on the components of the WALK-Cph intervention. All observers were instructed to follow the observation guide and be especially observant towards components of the framework that could be evaluated through observations: adherence (content, frequency, dose), quality of delivery, participant responsiveness, and context [61–63]. Adherence was defined as “how far those responsible for delivering an intervention actually adhere to the intervention as it is outlined by its designers” [63] and related to the delivery of the intended content and dose of the intervention [62, 63]. According to Carroll, adherence is the essential component of implementation fidelity. Obtainment of full adherence can be moderated by factors such as the quality of delivery, participants’ responsiveness [62, 63], and context [61]. The quality of delivery “concerns whether an intervention is delivered in a way appropriate to achieving what was intended” [63] and relates to the quality in delivering the intervention components [62]. Participant responsiveness refers to the engagement of those responsible for delivering the intervention and how they perceive the relevance of the intervention [62, 63]. Context refers to “factors at political, economical, organizational, and workgroup levels that affect the implementation” [62]. The observers could note observations that were not related to the components in the guide if something was deemed interesting or relevant. Observations were carried out as participant observations of the work practices in the departments. Thus, all involved staff and hospitalized patients could be observed as well as their mutual interaction, as this was expected to affect the delivery of the intervention. For example, such an interaction was observed when a health care assistant told a physician, “we need to give a WALK-plan to patient X.” The observer noted how staff and patients acted in relation to the different intervention components. Observations were carried out on weekdays and covered both day and evening shifts in a randomized order. Each session lasted 2–4 h and consisted of the following staff around the department, following physicians around the department, observing in the hallway, and observing in the staff office. All observers were instructed to ask for permission before following a given health care professional and to leave a room or situation if staying felt disturbing or unethical. During the three periods, observations were performed by BSP, JWK, BMG, NTS, RB, MMP, and three research assistants (5 physiotherapists, 2 nurses, 1 medical student, and 1 anthropologist). We chose to use observers with different professional backgrounds to add multidisciplinary breadth to the observations [64]. We used several observers because focused observation can be exhausting and requires full concentration. Field notes were written during and immediately after the observations.

In-hospital observation guide for observers

Do health care staff hand out welcome folders to patients on admission? (S)

 Is the folder introduced with a focus on mobility during and after hospitalization and by whom?

Do health care staff/physicians contact patients regarding WALK-plan and physical activity during hospitalization? (S/P)

Are WALK-plans handed out to patients? By whom? (S/P)

During rounds, do health care staff talk to the patients regarding WALK-plans? (S)

Do patients follow their WALK-plans? (H)

Who attend board meeting at 1 pm? (S/P)

Are WALK-plans mentioned at the board meetings? (P)

At board meetings, do physicians inform about the WALK-Cph intervention and do they follow up on prescriptions? (P) Do physicians express challenges regarding prescription of WALK-plans? (P)

Do those responsible for implementation of the intervention mention the intervention at board meetings? (P)

Do health care staff/physiotherapists contact patients regarding use of the WALK-path? (S)

 How are patients motivated and by whom?

Are patients introduced to the WALK-path and the exercises? (S)

 How are patients introduced and by whom?

Do patients go to the WALK-path/Are patients accompanied to the WALK-path? (S/H)

 How are patients accompanied and by whom?

Do patients exercise independently by the WALK-path? (H)

 If they don’t, why not?

Do health care staff contact patients regarding use of exercises on posters? (S)

 How are the patients motivated and by whom?

Do the patients exercise guided by the posters? (S)

On admission, do health care staff introduce patients to the wardrobes and self-service on clothes on admission and do they show the patients the location of the wardrobes? (S)

Do health care staff contact patients regarding self-service on clothes? (S)

 How are the patients motivated and by whom?

Do patients collect clothes independently/are patients assisted to collect clothes? (S/H)

 Who assist patients and how?

On admission, do health care staff introduce patients to self-service on beverages in refrigerator and by beverage cart and do they show patients the location of the refrigerator / beverage cart? (S)

Do health care staff contact patients regarding self-service on beverages? (S)

 How are the patients motivated and by whom?

Do patients collect beverages independently? (H)

 If patients are assisted, who assists?

^aThis component was not a part of the intervention in department Y; (S) observer follows staff, (H) observer sits in hallway, (P) observer follows physician, and (O) observer is in staff office

Field notes from the fidelity study consisted of 222 pages from the three fidelity periods. The fidelity analysis was performed by BSP, JWK, and BMG. The field notes were read, re-read, and coded in a deductive process structured after Hasson’s [62] modified version of The Conceptual Framework for Implementation Fidelity [63]. All field notes were read individually by all three authors, and the text was coded according to the fidelity components (i.e., adherence, quality of delivery, participant responsiveness, and context). Hereafter, the codes were discussed between the authors until agreement on coding was obtained. For example, when WALK-plans and level of WALK-plans were discussed between different members of the staff, this was coded as “adherence.” After ended coding, five authors (BSP, JWK, RB, NTS, and MMP) carried out consensus discussions to determine an estimated level of fidelity for each of the intervention components. This level of fidelity was based on the five authors’ estimation of the degree of delivery based on the adherence component [63] (content, frequency, dose) throughout all observations: (1) “not delivered as planned,” if the three authors agreed that the overall delivery of the component was considered at the <30% level of the intended delivery (e.g., if two observations show patients collecting clothes and 8 observations show staff collecting clothes); (2) “partly delivered as planned,” if the three authors agreed that the overall delivery of the component was considered at the 30–60% level of the intended delivery; (3) “delivered as planned,” if the three authors agreed that the overall delivery of the component was considered at the >60% level of the intended delivery.

As part of co-designing the WALK-Cph intervention, the research team scored the feasibility of all possible intervention components [36] informed by the Delphi method [65] and rated each component on its ability to enhance the likelihood of mobility on a 1 (yes) to 5 (no) scale. The WALK-plan and the WALK-path were rated as highly able to enhance mobility (score of 1), the welcome folder as moderately able to enhance mobility (score of 2) and the posters, and the self-service and discharge with a WALK-plan as neutral (score of 3). Based on these ratings, the WALK-plan and the WALK-path were considered core components. Therefore, it was decided that these two components needed to be at least partly delivered as planned during phase 2 for the intervention to be sufficiently implemented to be carried forward. This was a pragmatic choice based on an awareness that full implementation cannot be obtained within a month, but likely requires 6 to 12 months [66] and that fidelity of complex interventions is not straightforward and may change over time [30].