F1000Research F1000Research 2046-1402 F1000 Research Limited London, UK 10.12688/f1000research.149214.1 Research Article Articles Minimal clinically important difference in physical activity in patients with stroke

[version 1; peer review: 1 not approved]

 Hiragami Shogo Conceptualization Formal Analysis Funding Acquisition Investigation Methodology Project Administration Visualization Writing – Original Draft Preparation Writing – Review & Editing https://orcid.org/0000-0002-3491-9547 a 1 Yoshida Keishi Conceptualization Data Curation Formal Analysis Investigation Methodology Writing – Original Draft Preparation Writing – Review & Editing 2 Otsuka Tsunehiro Conceptualization Formal Analysis Methodology Writing – Original Draft Preparation Writing – Review & Editing 1 Inoue Yu Conceptualization Formal Analysis Methodology Writing – Original Draft Preparation Writing – Review & Editing 3 Department of Occupational Therapy, School of Rehabilitation, Hyogo Medical University, 1-3-6 Minatojima, Chuo-ku, Kobe, Hyogo, 650-8530, Japan Department of Rehabilitation, Senri-chuo Hospital, 1-4-3 Shinsenri Higashi-machi, Toyonaka-shi, Osaka, 560-0082, Japan School of Health Science and Social Welfare, Kibi International University, 8 Iga-machi, Takahashi-shi, Okayama, 716-8508, Japan hiragami@hyo-med.ac.jp

No competing interests were disclosed.

 12 4 2024 2024 13 263 28 3 2024 Copyright: © 2024 Hiragami S et al. 2024 This is an open access article distributed under the terms of the Creative Commons Attribution Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Background

Estimates of the minimal clinically important difference (MCID) for stroke-related outcomes are needed, but the MCID for physical activity is unknown.

 Objective

To provide an anchor-based estimate of the MCID for physical activity in patients with stroke.

 Methods

This study included 31 patients with stroke admitted to a hospital and discharged home. Physical activity, including the daily number of steps and metabolic equivalents (METs), was evaluated shortly after informed consent was obtained following admission (baseline) and discharge using an Active-style Pro HJA-750C with a triaxial accelerometer. We calculated the number of steps and time rate (%) of sedentary behavior (SB), light-intensity physical activity (LPA), and moderate-to-vigorous physical activity (MVPA) per day. After discharge, the physical therapist rated each participant’s perceived amount of physical activity recovery on the Global Rating of Change scale (GRC). The mean change in each physical activity data point from baseline to after discharge in the group of participants who answered “a little better, meaningful” in the GRC was considered the MCID.

 Results

Eighteen participants were included in the analysis. Participants’ physical function improved from baseline to at discharge during hospitalization, although mild motor paralysis persisted. MCID values for the step activity, SB, LPA, and MVPA were 1828 steps, -11.2%, 6.9%, 4.3% per day, respectively.

 Conclusion

For researchers and clinicians, this study’s MCIDs provide a benchmark for interpreting changes in the effects of intervention studies, and specific guidelines for interventions in clinical practice. Further research with larger sample sizes is required to confirm these findings.

 stroke minimal clinically important difference physical activity global rating of change scale rehabilitation JSPS KAKENHI JP17K12875 This work was supported by the JSPS KAKENHI under the grant number 17K12875. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Introduction

The number of people living with stroke worldwide has increased by 84% between 1990 and 2010. Stroke is the third leading cause of disability ( Feigin et al., 2015). Notably, 50% of patients with ischemic stroke continually have hemiplegia for 6 months after onset ( Kelly-Hayes et al., 2003), and a significant number of patients have activity limitations due to impaired extremities ( Flynn, MacWalter and Doney, 2008). A low level of physical activity, often resulting from activity limitations, poses a significant risk factor for stroke ( McDonnell et al., 2014). Engaging in regular physical activity and exercise, as recommended to enhance overall health, functionality, and daily independence ( Belfiore, Miele, Gallè, and Liguori, 2018; Gordon et al., 2004; Lynch et al., 2018), is crucial for individuals recovering from stroke. However, it is observed that patients with stroke often lead sedentary lifestyles across various post-stroke stages ( Bernhardt, Dewey, Thrift and Donnan, 2004; Field et al., 2013; Fini et al., 2017; Lacroix et al., 2016). Therefore, promoting physical activity stands as a critical intervention for patients with stroke.

Several longitudinal observational studies have examined changes in patients’ physical activity after stroke onset. These studies have revealed that the number of steps, walking time, and standing time in patients with stroke increase over time after stroke onset with decreasing sitting/lying time ( Kerr, Rowe, Esson and Barber, 2016; Kunkel, Fitton, Burnett and Ashburn, 2015; Moore et al., 2013; Simpson et al., 2018). Interventional studies on physical activity in patients with stroke have examined the effects of step activity ( Danks, Pohlig and Reisman, 2016; Lynch et al., 2018), activity intensity ( Askim et al. Stroke, 2018), and sitting time ( English et al, 2016b). Notably, the results of these studies are crucial when considering interventions in clinical practice; however, it is also necessary to interpret data on changes in physical activity regarding patient-centered outcomes based on minimally clinically important differences (MCID), defined as “the smallest difference in scores in the domain of interest which patients perceive as beneficial” ( Jaeschke, Singer and Guyatt, 1989). For researchers and clinicians, understanding MCID of physical activity in patients with stroke can help determine whether a change in outcome scores due to an intervention is clinically important ( Revicki, Hays, Cella and Sloan, 2008). However, there is no knowledge of the MCID in physical activity, such as the number of steps and activity intensity, in patients with stroke. Therefore, this study aimed to estimate the anchor-based MCID for physical activity in patients with stroke.

 Methods Ethics

This study was approved by the Institutional Review Board of Hyogo Medical University (approval number: 4311), and all procedures followed the ethical standards of the Declaration of Helsinki. Written informed consent was obtained from all the participants.

 Participants

This prospective observational study included 31 patients with stroke who were admitted to a hospital in Japan and discharged home between April 2019 and December 2022. No studies exist on the MCID in physical activity in patients with stroke; therefore, this study’s sample size was set at the minimum number of participants based on previous studies that examined the MCID in stroke-related outcomes ( Bohannon, Andrews and Glenney, 2013; See et al., 2013). The inclusion criteria were 1) first stroke (ischemic or hemorrhagic) and stable medical condition after stroke onset, 2) no significant cognitive impairments and ability to have daily conversations to provide informed consent, and 3) no other disease influencing the physical activity. The participants underwent a rehabilitation program during hospitalization, including conventional physiotherapy, occupational therapy, and speech therapy (if needed) for approximately 150 min/day.

 Data collection

Information about participant characteristics such as age, sex, time since stroke onset, stroke type, side of paralysis, the severity of paralysis (assessed using the Brunnstrom recovery stage [BRS]), and functional performance (assessed using the Functional Independence Measure [FIM]) was extracted from each participant’s medical records after informed consent (baseline) and at discharge.

Gait ability and physical activity of the participants, including the number of steps and energy expenditure, were evaluated at baseline and after discharge from the hospital (average 42.1 ± 9.7 days, range: 32–62 days).

A physical therapist assessed gait ability using the Functional Ambulation Category (FAC); the assessment after discharge was conducted through a telephone interview. Based on the physical support required, the FAC classifies walking ability into six categories, with score ranging from 0 (nonfunctional ambulator) to 5 (ambulator, independent) ( Holden et al., 1984).

Physical activity was evaluated at baseline and after discharge using an Active-style Pro HJA-750C with a triaxial accelerometer (OMRON, Kyoto, Japan). The device can estimate step counts and metabolic equivalents (METs) every 10 seconds. The validity and accuracy of the device have been confirmed ( Ohkawara et al., 2011; Oshima et al., 2010; Shimizu, Hashidate, Ota and Saito, 2018), and the device was used in a recent intervention study ( Matsushita et al., 2022). The measurement method using this device was based on a previous study ( Fini, Burge, Bernhardt and Holland, 2019; Troiano et al., 2008). All participants wore the device on a waist belt on their paretic side for 7 consecutive days. The participants were blinded to their step counts or activity intensity during the collection period by setting the device to avoid displaying step counts or activity intensity on the device screen. Participants were instructed to perform their usual physical activities. We extracted 12 hours of collected activity data between 8:00 am and 8:00 pm to analyze the data. An individual’s data were considered if there were ≥2 days of data with >10 h (600 min) of device-wearing time. Non-wearing of the device was defined as no counts for over 60 consecutive min in the daily measurement data. Sedentary behavior (SB) was defined as ≤1.5 estimated METs, light-intensity physical activity (LPA) as 1.6–2.9 estimated METs, and moderate-to-vigorous physical activity (MVPA) as ≥3 estimated METs ( Ainsworth et al., 2011; Strath et al., 2013). We calculated the average number of steps and time rate (%) of SB, LPA, and MVPA (time for each intensity of physical activity divided by the wearing time of the device) daily for each participant. For measurement after discharge, the device was mailed to the participants’ homes. Subsequently, participants were asked by the physical therapist via telephone to wear the device and return it after the measurements were completed.

In a telephone interview conducted by the physical therapist after discharge, participants were asked about the extent to which they subjectively perceived a significant change in their physical activity from baseline to after discharge (at the time of the interview). For the assessment, we used the 7-point Global Rating of Change Scale (GRC) ( Copay et al., 2007; Lang, Edwards, Birkenmeier and Dromerick, 2008). The participants were asked to answer the following question: “How much did your daily physical activity change compared with the time in the hospital?” using the GRC. Participants responded based on the following scores: 1 = much better; 2 = a little better, meaningful; 3 = a little better, not meaningful; 4 = approximately the same; 5 = a little worse, not meaningful; 6 = a little worse, meaningful; and 7 = much worse. The criterion validity and test-retest reliability of the GRC assessment has been confirmed in patients with stroke ( Hiragami et al., 2012).

 Statistical analysis

For the analysis, we first confirmed the participants’ cognitive function during hospitalization, using the mini-mental state examination scores ≥21 ( Folstein, Folstein and McHugh, 1975) or FIM-cognitive scores ≥25 ( Manuel et al., 2002; Tokunaga et al., 2014), and participants who did not meet these criteria were excluded from the analysis. Data were reported as mean and standard deviation (SD) or median and frequency (percentage). Two-sample t-tests or Wilcoxon rank tests were used to compare the participants’ characteristics between baseline and at discharge or after discharge. ANOVA or Kruskal–Wallis tests and Fisher’s exact tests were performed to compare the participants’ characteristics between the groups, classified by GRC score.

The MCID was calculated using anchor-based approaches. Following previous studies ( Copay et al., 2007; Lang, Edwards, Birkenmeier and Dromerick, 2008), participants with a GRC score of 2 (a little better, meaningful) were assigned to the MCID group. The mean changes in the average number of steps and time rate (%) of SB, LPA, and MVPA per day in the MCID group between baseline and after discharge were considered the estimated MCID values. Two-sample t-tests or Wilcoxon rank tests, along with effect size calculations, were used to compare the average number of steps and the time rate (%) of SB, LPA, and MVPA at baseline and after discharge. The effect size (r) was calculated using the following formula: r = Z √ N

The effect size values were interpreted as 0.1 for small, 0.3 for medium, and 0.5 for large ( Cohen, 1992). Statistical significance was set at p < 0.05. All statistical analyses were conducted using IBM SPSS Statistics software (version 27).

 Results

Thirty-one participants consented to participate in this study. Eleven subjects had insufficient physical activity data for analysis (2, urgent discharge; 3, incomplete physical activity data after discharge; 1, refusal of measurements; and 5, no response to phone calls after discharge). Two participants had physical activity data for <2 days. Therefore, 18 participants were included in the analysis ( Figure 1). Participants wore the device for an average of 5.4 ± 2.1 days at baseline and 4.2 ± 1.8 days after discharge. Participants’ average daily device wearing time was 706.3 ± 26.4 min/day at baseline and 682.3 ± 32.0 min/day after discharge. Four participants had missing step-count data at baseline or after discharge; these participants were excluded from the analysis of step-count data.

Flowchart of participants.

Of 31 enrolled participants, 13 were excluded from the analysis and 18 were included in the final analysis.

The participants’ characteristics are summarized in Table 1. The average participant age was 72.8 ± 8.6 years, and the average number of days since stroke onset was 41.9 ± 19.2 days at baseline and 146.9 ± 49.1 days after discharge. The participants’ physical function, gait ability, and functional performance improved from baseline to at discharge during hospitalization, although mild motor paralysis remained.

Participant characteristics.
Total (N = 18) P-value *
Baseline At discharge After discharge
Time since stroke onset, mean (SD), days 41.9 ± 19.2 104.8 ± 50.7 146.9 ± 49.1 -
Sex, males/females (n) 8/10 -
Age, mean ± SD (years) 72.8 ± 8.6 -
Type of stroke, ischemic/hemorrhage, n 14/4 -
Side of lesions, right/left/bilateral, n 11/6/1 -
Brunnstrom stage (UE) (median) 5.0 5.5 0.014
Brunnstrom stage (LE) (median) 5.5 6.0 0.059
FAC (median), 1/2/3/4/5, n 3.0 2/3/5/7/1 5.0 0/1/1/5/11 <0.001
FIM (motor) score, mean ± SD 59.4 ± 14.3 83.4 ± 5.9 <0.001
FIM (cognitive) score, mean ± SD 29.9 ± 4.3 32.6 ± 2.9 0.005

Values are presented as mean ± standard deviation (SD), median, or n. UE: upper extremity, LE: lower extremity, FAC: Functional ambulation category, FIM: Functional independence measure.

Wilcoxon rank test.

Table 2 summarizes participant characteristics based on GRC scores. The GRC response distribution was as follows: 1 (much better), n = 5; 2 (a little better, meaningful), n = 8; 4 (approximately the same), n = 5, 3, and 5-7: n = 0. There were no significant differences in participant characteristics, gait ability, and functional performance between the GRC score-classified groups except for physical function. There were significant differences in BRS; motor paralysis of upper and lower limb was more severe in the group with a GRC score of 4.

Characteristics of participants according to the GRC score.
GRC score P-value
1(n = 5) 2(n = 8) 4(n = 5)
Time since stroke onset (baseline), mean (SD), days 39.8 ± 18.4 40.1 ± 24.9 46.8 ± 9.9 0.326 a
Time since stroke onset (at discharge), mean (SD), days 93.6 ± 42.3 83.8 ± 45.1 149.8 ± 44.6 0.073 a
Time since stroke onset (after discharge), mean (SD), days 133.6 ± 47.6 130.6 ± 41.7 186.2 ± 47.3 0.101 a
Sex, males/females, n 2/3 3/5 3/2 0.840 b
Age, mean ± SD, years 75.2 ± 4.8 73.0 ± 10.1 70.2 ± 10.0 0.522 a
Type of stroke, ischemic/hemorrhage, n 3/2 7/1 4/1 0.771 b
Side of lesions, right/left/bilateral, n 4/1/0 4/3/1 3/2/0 0.925 b
Brunnstrom stage (UE) (at discharge), median 6.0 6.0 3.0 0.049 a
Brunnstrom stage (LE) (at discharge), median 6.0 6.0 4.0 0.029 a
FAC (after discharge), median 5.0 5.0 4.0 0.389 a
FIM (motor) score (at discharge), mean ± SD 83.2 ± 5.5 85.0 ± 6.5 81.0 ± 5.6 0.439 a
FIM (cognitive) score (at discharge), mean ± SD 30.8 ± 2.6 32.5 ± 3.2 34.6 ± 0.9 0.073 a

Values are presented as mean ± standard deviations (SD), median, or n. GRC: global rating of change scale, UE: upper extremity, LE: lower extremity, FAC: Functional ambulation category, FIM: Functional independence measure.

Kruskal–Wallis test.

Fisher’s exact test.

Table 3 summarizes the average number of steps and time rate (%) of SB, LPA, and MVPA and their changes from baseline to after discharge. For all participants and MCID group, MVPA% increased significantly after discharge compared to baseline, and there were no significant changes in other indicators of physical activity.

Changes in physical activity from baseline to after discharge.
Parameter Baseline After discharge Δ P-Value * Effect size (r)
All participants (n = 18)
Step (n = 14) 1706.9 3697.6 1990.7 0.074 0.48
SB (%) 74.1% 70.3% -3.8% 0.408 -0.20
LPA (%) 23.6% 25.4% 1.9% 0.647 0.11
MVPA (%) 1.5% 4.3% 2.7% 0.001 0.75
GRC = 1 (n = 5)
step (n = 4) 2024.7 5670.6 3645.9 0.273 0.55
SB (%) 73.6% 70.9% -2.7% 0.500 -0.30
LPA (%) 23.8% 24.0% 0.2% 0.893 0.06
MVPA (%) 2.6% 5.1% 2.5% 0.080 0.78
GRC = 2 (n = 8): MCID group
step (n = 7) 2189.9 4018.1 1828.2 0.176 0.51
SB (%) 75.0% 63.7% -11.2% 0.069 -0.64
LPA (%) 24.0% 30.8% 6.9% 0.208 0.45
MVPA (%) 1.1% 5.4% 4.3% 0.017 0.84
GRC = 4 (n = 5)
step (n = 3) 156.3 319.2 162.9 0.593 0.31
SB (%) 73.1% 80.2% 7.1% 0.138 0.66
LPA (%) 22.7% 18.2% -4.5% 0.500 -0.30
MVPA (%) 1.1% 1.6% 0.5% 0.273 0.49

Values are presented as means. GRC: global rating of change scale, SB: sedentary behavior, LPA: light-intensity physical activity, MVPA: Moderate-to-Vigorous physical activity, Δ: mean change after discharge from baseline.

r = Z/√N.

Wilcoxon rank test.

The mean changes in the average number of steps and time rate (%) of SB, LPA, and MVPA in the MCID group (GRC=2) between baseline and after discharge were 1828 steps/day, -11.2%/day, 6.9%/day, and 4.3%/day, respectively.

 Discussion

A novel finding of our study was that the MCIDs of physical activity were estimated using the stroke patient-centered outcome measure (GRC) as an anchor. We evaluated the physical activity of patients with stroke during hospitalization and after discharge to estimate the MCID. MVPA% increased significantly after discharge compared to baseline in all participants and MCID group, and there were no significant changes in the number of steps, SB%, and LPA%. As the results of these statistical analyses may have been influenced by the small sample size, we examined the changes using effect sizes. The effect sizes for changes in the number of steps and time rate (%) of SB, LPA, and MVPA from baseline to after discharge ranged from small to large for all participants. These results are consistent with those of previous studies. A previous study that investigated changes in the number of steps in patients with stroke with a similar number of days since stroke onset and walking ability as our study participants found a significant increase (at hospital: average 1872 steps/day and at home after discharge: 2596 steps/day; mean difference: 725 steps/day) ( Simpson et al., 2018). The study also reported that sitting time decreased significantly (at the hospital: average 648 min/day; at home after discharge: 624 min/day, Mean Difference: - 45 min/day). Our study also showed a decrease in SB%/day; the SB time from baseline to after discharge, calculated using the average daily wearing time of the device after discharge (682 min), had reduced from 505 min/day to 480 min/day, with a difference of -26 min.

Based on the data from previous studies, the physical activity levels of patients with stroke in our study remained low even after returning to the community. A systematic review of physical activity in people with stroke living in the community showed that the number of steps ranged from 1389 to 7379 steps/day, compared with 6294 to 14730 steps/day in healthy older adults ( English, Manns, Tucak and Bernhardt, 2014). Community-dwelling patients with stroke spent 206 min in LPA and 5 min in MVPA and had significantly lower levels of LPA and MVPA than healthy controls ( English et al, 2016a).

To our knowledge, this is the first study to estimate the MCID for physical activity in patients with stroke. Therefore, there are no data to compare with our results. The validity of the MCID estimated in our study can be examined using effect size as an external criterion ( Copay et al., 2007). In this study, SB% decreased and the step activity, LPA%, and MVPA% increased; and the effect sizes of these changes were medium to large in the MCID group (GRC=2). Therefore, it was appropriate to use data from the group to estimate the MCID. The MCID is a more appropriate benchmark than statistical significance for determining the importance or effectiveness of change scores ( Hsieh et al., 2007). The P-value is influenced by the magnitude of change and the study’s sample size and group variance ( Crosby, Kolotkin and Williams et al., 2003). Therefore, if the physical activity data in a group of patients with stroke similar to those in our study exceeded the MCID, the change could be interpreted as meaningful. Conversely, if the physical activity is lower than the MCID, the change should not be regarded as meaningful, even if the amount of change reaches a statistically significant level. We believe that for researchers and clinicians, this study’s MCID provides a benchmark for interpreting changes in longitudinal studies, the effects of intervention studies, and specific guidelines for interventions for patients with stroke during hospitalization and after discharge to promote physical activity in patients.

According to Tudor-Locke et al. (2011), the recommended number of steps for patients with chronic diseases, including stroke, is between 6,500 and 8,500 steps daily. Physical activity to prevent recurrent mild ischemic stroke is also aimed at achieving 6025 steps/day ( Kono et al., 2015). Regarding the physical activity intensity, according to the World Health Organization ( De Camargo and Añez, 2020), adults living with disabilities should engage in at least 150-300 min of moderate-intensity aerobic physical activity, or at least 75-150 min of vigorous-intensity aerobic physical activity throughout the week, or a combination of both, to achieve substantial health benefits. In our study, the duration of MVPA was calculated using the average daily wearing time of the device (682 min) after discharge in the MCID group (GRC=2), and MVPA was 37 min/day. Comparing our data with the indices presented in previous studies ( De Camargo and Añez, 2020; Kono et al., 2015; Tudor-Locke et al., 2011), the number of steps taken in our study were considerably lower in the MCID group after discharge. Therefore, if health aspects are the main outcomes, changes in the number of steps taken in patients with stroke may need to be well above our study’s MCID.

This study has some limitations. First, the MCID estimation method was limited. The estimation of MCID for a specific patient-reported outcome measure should be based on multiple approaches (e.g., receiver operating characteristic curves) ( Arya, Verma and Garg, 2011; Page, Fulk and Boyne, 2012). This study could not use the method due to its small sample size. Second, this study could not robustly align the time since the stroke onset, the degree of paralysis, walking ability, or individual factors of the participant. Third, during the survey period of our study, participants’ physical activities could have been altered due to the coronavirus 2019 pandemic. The MCID may vary by population and context. Therefore, future studies with a larger sample size should analyze MCID by including participants’ functional levels and individual factors.

 Conclusions

The MCID values for the step activity, SB, LPA, and MVPA were 1828 steps/day, -11.2%/day, 6.9%/day, and 4.3%/day for patients with stroke with mild motor paralysis who were hospitalized and discharged home. These findings may be useful for clinical interpretation of physical activity data. Further research with larger sample sizes is required to confirm these estimates.

 Data availability Underlying data

Figshare: Dataset of minimal clinically important difference in physical activity in patients with stroke. https://doi.org/10.6084/m9.figshare.25471156.v1 ( Hiragami, 2024).

This project contains the following underlying data:

Dataset of minimal clinically important difference in physical activity in patients with stroke.csv

Data are available under the terms of the Creative Commons Attribution 4.0 International license (CC-BY 4.0).

 Acknowledgements

We are grateful to all individuals who gave their time to participate in this study.

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Competing interests: No competing interests were disclosed.

 6 8 2024 Copyright: © 2024 Liepert J 2024 This is an open access peer review report distributed under the terms of the Creative Commons Attribution Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. recommendation reject

This paper attempts to identify the minimal clinically important difference in physical activity in stroke patients by assessing the number of steps and time rates of 3 different behaviors (sedentary behavior, light-intensity physical activity, and moderate-to-vigorous physical activity) and attributing them to results obtained from the Global Rating of Change Scale (GRC).

According to the GRC results, 18 stroke patients could be assigned to 3 groups (“much better“ (n=5), “a little better, meaningful“ (n=8) and “approximately the same“ (n=5)). The patients that evaluated their change as “a little better, meaningful“ (n=8) were chosen as those that represent the minimal clinically important difference. Changes in the number of steps and behavioral time rates were calculated and presented.

The idea of this study is highly important and clinically relevant.

However, I have several concerns and questions.

My main concern relates to the number of subjects on which the data is based. Eight stroke patients do not seem to be a representative number on which conclusions and recommendations can be based. I am aware of the fact that the prerequisites for a power analysis are not fulfilled due to lack of pre-existing data on this topic. Nevertheless, eight patients are not sufficient to establish cut off values.

Another concern relates to the question the patients were asked (“How much did your daily physical activity change compared with the time in the hospital“). As far as I understood the protocol, patients stayed in the rehab hospital for about 7 weeks. During this time, physical activity should have changed considerably. However, the question does not specify whether patients should consider the beginning or the end of their inpatient stay. As mentioned above, it is most unlikely that patients can estimate a “mean value“ because of the changes in performance and activity level that usually occur during rehabilitation.

Please provide a more detailed description of how “metabolic equivalents“ (page 4) are calculated.

Please provide information about the time patients had already spent at home when they were asked to wear the Active-style Pro HJA-750C device.

Please define more precisely when the baseline evaluation was done – how many days after admission to the hospital?

Please provide explanations for the letters “Z“ and “N“ used in the formula (page 4).

To my knowledge, Cohen´s d is interpreted as being large if it exceeds 0.8  (and not 0.5, as stated in the manuscript on page 4).

Why was the FAC not assessed at discharge?

In conclusion, I acknowledge that the authors have listed the limitations of their study (page 7) and agree on this paragraph. However, my concern regarding the group size still persists.

Is the work clearly and accurately presented and does it cite the current literature?

Yes

If applicable, is the statistical analysis and its interpretation appropriate?

Yes

Are all the source data underlying the results available to ensure full reproducibility?

Partly

Is the study design appropriate and is the work technically sound?

Partly

Are the conclusions drawn adequately supported by the results?

Partly

Are sufficient details of methods and analysis provided to allow replication by others?

Partly

Reviewer Expertise:

Neurorehabilitation, plasticity, motor functions

I confirm that I have read this submission and believe that I have an appropriate level of expertise to state that I do not consider it to be of an acceptable scientific standard, for reasons outlined above.