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The effectiveness of an accelerometer-based physical activity enhancement intervention for patients undergoing lung resection - A pilot randomized controlled trial
Corresponding author. Department of Physical Therapy, School of Rehabilitation, Hyogo Medical University, 1-3-6 Minatozima, chuo-ku, Kobe-shi, Hyogo, 650-8530, Japan.
Increasing physical activity after lung resection is important for maintaining quality of life. It is unclear whether accelerometer-based exercise instruction contributes to increasing daily physical activity after lung resection. We examine whether accelerometer-based exercise instruction will lead to increased physical activity in patients undergoing lung resection.
Materials and methods
Forty-six patients undergoing lung resection were randomly assigned to either the intervention group (n = 22) or the control group (n = 24). Twelve participants dropped out. Ultimately, 16 participants in the intervention group and 18 participants in the control group were eligible for analysis. Each group allocation was only known to the person in charge of allocation. The physiotherapists and assessors were not blinded in this study. The intervention group participated in a postoperative rehabilitation program and received physical activity instruction preoperatively and at discharge. The control group participated in a postoperative rehabilitation program only. The primary outcomes was physical activity such as the number of daily steps, light intensity physical activity (LPA) and moderate-vigorous intensity physical activity (MVPA) at the two month postoperative follow-up.
Results
Thirty-four participants were enrolled in this study. Sixteen participants in the intervention group and 18 participants in the control group were included for analysis. Although there was no significant difference in physical activity at baseline, the number of daily steps in the intervention group at the two month postoperative follow-up was significantly higher than that in the control group (8039.2 ± 3480.8 vs. 4887.0 ± 2376.5 steps/day, p = 0.004). Compared to the control group, the intervention group also had greater increases in LPA (63.8 ± 25.1 vs. 44.5 ± 24.5 min/day, p = 0.030) and MVPA (20.2 ± 19.6 vs. 9.6 ± 8.6 min/day, p = 0.022).
Conclusions
This study showed that accelerometer-based exercise instruction led to an increase in physical activity after lung resection in an unsupervised setting.
Clinical trial registration
The University Hospital Medical Information Network (UMIN) Clinical Trials Registry (UMIN trial No. UMIN000039369).
]. In Japan, more than 75,000 people die of lung cancer each year, and the 5-year survival rate of lung cancer patients is markedly lower than that of patients with other cancers. In recent years, due to advances in diagnostic imaging technology and routine lung cancer screening, it has become possible to detect lung cancer at an early stage. As a result, an increasing number of lung cancer patients are eligible for surgical resection, which has a high cure rate [
Committee for Scientific Affairs, The Japanese Association for Thoracic Surgery Thoracic and cardiovascular surgery in Japan in 2016: annual report by the Japanese Association for Thoracic Surgery.
]. In a survey report published in the Japanese Joint Committee of Lung Cancer Registry in 2019, it was reported that the 5-year survival rate of patients who underwent lung resection increased to 74.7% [
Demographics, safety and quality, and prognostic information in both the seventh and eighth editions of the TNM classification in 18,973 surgical cases of the Japanese Joint Committee of Lung Cancer Registry Database in 2010.
]. Treatment outcomes for lung cancer patients undergoing surgery have improved dramatically.
On the other hand, the quality of life (QoL) of patients undergoing lung resection is lower than that of healthy people of the same age and other cancer survivors [
]. Daily physical activity is one of the most important factors in the QoL of lung cancer patients. Several previous studies have reported that adequate physical activity is associated with better control of cancer-related symptoms, improved health-related QoL, and increased life expectancy [
]. However, physical activity in patients undergoing lung resection is significantly lower than that preoperatively and in healthy people of the same age [
Deterioration in physical activity and function differs according to treatment type in non-small cell lung cancer - future directions for physiotherapy management.
] because of physical factors, including postoperative physical deconditioning and decreased respiratory function, and psychosocial factors, including fear of worse symptoms due to increased physical activity, lack of confidence, absence of exercise supporters and poor supervision in achieving a physical activity goal [
]. The influence of psychosocial factors can be reduced, and it is essential that patients receive exercise instruction to enhance physical activity and maintain QoL after lung resection.
Accelerometer-based exercise instruction has been shown to increase physical activity in patients suffering from other diseases [
]. It is possible that accelerometer-based exercise instruction contributes to increasing daily physical activity after lung resection; however, the efficacy of the intervention is unclear in this patient population. We conducted a pilot randomized controlled trial to examine the effect of accelerometer-based exercise instruction on daily physical activity in patients undergoing lung resection.
2. Material and methods
2.1 Study design
This prospective, participant-blinded, pilot randomized controlled trial was designed in accordance with the Consort guidelines [
]. The study protocol was approved by the Meiwa General Hospital Ethics Committee (approval No. 30-09) and conducted in accordance with the principles of the Declaration of Helsinki. All study participants provided written informed consent. Furthermore, this study was registered in the University Hospital Medical Information Network (UMIN) Clinical Trials Registry (UMIN trial No. UMIN000039369).
2.2 Participants and randomization procedure
The inclusion criteria were as follows: adult patients aged 20 years or older who were diagnosed with lung tumors and who underwent lung resection at the Meiwa General Hospital between September 2018 and December 2019. The exclusion criteria were as follows: patients who were unable to provide written consent, patients with low levels of physical and cognitive function (short physical performance battery <10 and Mini-Cog <4), patients who were unable to complete the set evaluation, patients who were diagnosed with nonneoplastic lung tumors after surgery, or patients who experienced difficulty increasing physical activity due to postoperative complications. Baseline measurements were performed one week before surgery, and participants were randomly assigned to either the intervention group or the control group. Participants were allocated to the groups by randomization using a computer-generated 1:1 allocation sequence and permuted block size of 4. Group allocation and block size were managed so that only the person in charge of allocation could identify them. The allocator was independent of the research team and was not involved in outcome measurement or intervention. The physiotherapists and ward stuff, assessors were not blinded in this study.
2.3 Postoperative exercise program
Both groups underwent a postoperative exercise program once a day for 20 min, 5 times a week. The postoperative exercise program was only implemented during the hospitalization period and provided by three physiotherapists. Patients were encouraged to leave the bed as early as possible the day after surgery. Before the chest drain was removed, conditioning, such as assistance to remove sputum, active exercise of the lower limbs in bed and walking in the ward, was performed. After the chest drain was removed, we started body weight resistance exercise and treadmill walking or bicycle ergometer exercise in the exercise therapy room. The upper limit of exercise intensity during walking exercise was the pulse rate calculated by the Karvonen formula (k = 0.4–0.6) or an intensity of 3–4 on the modified Borg scale. In addition, percutaneous oxygen saturation during exercise was monitored to ensure that it stayed above 90%.
2.4 Intervention
The intervention group received instructions twice on promoting physical activity during the hospitalization period (preoperatively and at discharge) in addition to the postoperative exercise program. Each instruction session lasted 20 min and was provided by the same single physiotherapist. In preoperative instruction, information was provided on the physical and psychological benefits of increased physical activity. In addition, participants received a lecture on how to operate an accelerometer (e.g., checking the number of daily steps taken in the last week) and were asked to record their daily physical activity, as calculated by an accelerometer, from the first postoperative day to two months on a sheet. In the instructions at discharge, the physiotherapist collaborated with participants to formulate an action plan that included the setting of a physical activity goal after discharge and a specific activity plan. Individual physical activity goals during hospitalization were set in consideration of the participant's general condition and physical function by each physiotherapist in charge of the postoperative exercise program. If participants achieved their physical activity goal, the physiotherapist praised the participants and set a higher physical activity goal. On the other hand, if the participants did not achieve their physical activity goal, the physiotherapist discussed the reason why the physical activity goal was not achieved with the participants and reset the physical activity goal [
The control group was asked only to wear an accelerometer. Although an accelerometer display was not blinded, they were not instructed to collect data on the number of daily steps taken and to perform a physical activity. After this study was completed, feedback was provided regarding the performance of physical activity during the study period.
2.5 Outcome measures
2.5.1 Physical activity
The primary outcome was physical activity at the two month postoperative follow-up measured using an accelerometer (Lifecoda GS, SUZUKEN Co Ltd., Nagoya, Japan). The accelerometer retrospectively displays the number of daily steps taken in a week and records the number of daily steps taken for up to 200 days. In addition, the accelerometer records physical activity levels every 2 min and calculates activity time by exercise intensity. The reliability and validity of this accelerometer-based physical activity measurement have been confirmed [
]. Based on previous studies, physical activity of 1.8–2.9 METs were defined as light physical activity (LPA) and physical activity of 3.0–8.2 METs were defined as moderate-vigorous physical activity (MVPA) [
The use of uniaxial accelerometry for the assessment of physical-activity-related energy expenditure: a validation study against whole-body indirect calorimetry.
]. Participants were asked to wear the accelerometer on their waist and to wear it as much as possible from waking to bedtime, except when bathing. Physical activity data were obtained from the accelerometer for at least 480 min/day of activity and at least three consecutive weekdays [
]. The same accelerometer was used to record the number of daily steps in the intervention group and to assess outcomes in both groups. These outcomes were evaluated at baseline, during hospitalization, and at two months postoperatively.
Secondary outcomes were exercise tolerance, health-related QoL, and cancer-related symptoms. Exercise tolerance was measured using a 6-min walking distance test (6MWD) administered in accordance with published guidelines [
]. The walking path was a 25-m flat, straight course with a return path. Participants were instructed to walk as long a distance as possible in 6 min. The assessor was in position and called out a set description every minute. Health-related QoL was measured using the 36-Item Short Form Health Survey version 2 (SF-36v2). The SF-36v2 consists of 36 questions to measure eight health concepts: (1) physical functioning, (2) daily role functioning of the body, (3) body pain, (4) overall sense of health, (5) vitality, (6) social life functioning, (7) daily role functioning of the mind, and (8) mental health. Based on this, three components are calculated from the eight subscales using the three-component scoring method: “QoL summary score for physical dimension,” “QoL summary score for mental dimension,” and “QoL summary score for role/social dimension” [
]. To evaluate cancer-related symptoms, anxiety and depression were measured using the Hospital Anxiety and Depression Scale (HADS). The HADS consists of 14 questions (42 points) on anxiety and depression. Higher scores indicate greater anxiety and depression, and the cutoff value of the HADS for cancer patients is 11 points [
]. Cancer-related fatigue was measured using the Cancer Fatigue Scale (CFS). The CFS consists of three subscales, physical malaise, mental malaise, and cognitive malaise, with a total of 15 questions (60 points). Higher scores indicate greater general fatigue, and the cutoff value is 19 points [
]. Cancer-related dyspnea was measured using the Cancer Dyspnea Scale (CDS). The CDS consists of three subscales: respiratory effort, respiratory discomfort, and respiratory anxiety, with a total of 12 questions (48 points). Higher scores indicate more severe dyspnea [
]. These assessments were performed at baseline and at the two month postoperative follow-up.
2.6 Sample size
Based on physical activity, sample size was calculated using G-power 3.1 with alpha 0.05, power 80%, and effect size 0.25. As a result, 15 participants were required for each group. Considering the potential for dropout, 45 participants were planned to be recruited. Ultimately, 46 participants were recruited.
2.7 Statistical analysis
Continuous variables are expressed as the mean (SD) or median [IQR], and categorical variables are expressed as counts and corresponding percentages. We defined physical activity at baseline and the two month follow-up as the average of three to five consecutive days. We also defined physical activity during hospitalization as the average from the day participants became independent in walking to the day before discharge. Analysis of variance for split-plot factorial design was used to compare the physical activity levels. The within-participants factor was term (baseline vs. hospitalization vs. follow-up), and the between-participants factor was group (intervention group vs. control group). Post-hoc tests were performed using Shaffer's correction. Changes from baseline to follow-up in exercise tolerance, health-related QoL, and incidence of cancer-related symptoms were compared between groups using the Mann-Whitney U test. A p value < 0.05 was considered statistically significant. All statistical analyses were performed using R 3.6.3 software (R Foundation for Statistical Computing, Vienna, Austria).
3. Results
3.1 Participant flow and clinical characteristics
Of the 81 participants who underwent lung resection during this study period, 46 participants who met the inclusion criteria were randomly assigned to either the intervention group (n = 22) or the control group (n = 24). Twelve participants dropped out. Ultimately, 16 participants in the intervention group and 18 participants in the control group were eligible for analysis (Fig. 1).
The clinical characteristics of the 46 participants who met the inclusion criteria are shown in Table 1. The median age was 71 years old, there were more males than females, and there was no marked decline in preoperative physical, cognitive, or pulmonary function. Thirty-one participants (67.4%) had primary lung cancer, and most underwent lobectomy. Postoperative chemotherapy was administered to 23 participants (50.0%). Baseline participant characteristics of the 34 participants included in the analysis and the 12 who dropped out showed a significant difference in FEV1.0%, but this difference was not clinically meaningful. No other significant differences were found.
The changes over time in physical activity are shown in Table 2. Regarding the number of daily steps, there was an interaction between factors in the intervention group and the control group and a significant main effect only for the duration factor. Although there was no significant difference in the number of daily steps between the intervention and control groups at baseline or during hospitalization, the number of daily steps in the intervention group were significantly higher than in the control group at the two month postoperative follow-up. Both LPA and MVPA showed similar increases in daily steps (Table 2). In the intervention group, the number of daily steps at the two month postoperative follow-up increased significantly compared to baseline, whereas in the control group, the number of daily steps at the two month postoperative follow-up was significantly less than baseline.
Table 2Change in physical activity over time.
Intervention group (n = 16)
Control group (n = 18)
p value
ES (r)
Interaction
p value
ES (η2)
Number of steps/day
<0.001
0.065
Baseline
6383.6 (2959.3)
6313.6 (3130.4)
0.918
0.01
Hospitalization
3962.5 (1237.4) a
3454.0 (2181.7) a
0.084
0.29
Follow-up
8039.2 (3480.8) a,b
4887.0 (2376.5) a,b
0.004
0.48
LPA (min/day)
0.007
0.044
Baseline
53.1 (21.7)
51.9 (22.4)
0.920
0.02
Hospitalization
32.6 (8.1) a
29.5 (16.8) a
0.509
0.12
Follow-up
63.8 (25.1) a,b
44.5 (24.5) b
0.030
0.37
MVPA (min/day)
0.016
0.032
Baseline
13.9 (12.4)
13.7 (13.2)
0.730
0.06
Hospitalization
8.7 (8.3) a
7.2 (7.5) a
0.343
0.16
Follow-up
20.2 (19.6) b
9.6 (8.6)
0.022
0.26
Mean (SD), ap<0.05 (vs. baseline), bp < 0.05 (vs. during hospitalization).
Table 3 shows the results for exercise tolerance, health-related QoL, and cancer-related symptoms. There were significant differences between the intervention and control groups in the amount of change from baseline to two month postoperative follow-up in 6MWD, HADS, and CFS. However, there were no significant differences between the two groups in the amount of change in SF-36 component summary score and CDS.
Table 3Exercise tolerance, health-related quality of life and cancer-related symptoms.
Outcome measures
Baseline
Follow-up
Amount of change from baseline to follow-up
p value
ES (r)
Intervention group (n = 16)
Control group (n = 18)
Intervention group (n = 16)
Control group (n = 18)
6MWD, m
500.0 [467.5–530.0]
517.5 [437.5–541.3]
10.0 [-8.3-46.3]
−17.5 [-31.5–6.5]
0.034
0.36
SF-36v2
PCS
46.9 [34.5–52.4]
49.2 [37.4–54.8]
−1.0 [-6.8-7.6]
−3.3 [-11.2–3.2]
0.401
0.14
MCS
55.7 [48.2–61.7]
52.4 [44.6–54.4]
−2.2 [-10.6–4.4]
0.8 [-6.3-6.7]
0.417
0.14
RCS
46.7 [28.3–54.2]
44.6 [32.9–56.4]
6.1 [-9.0-11.0]
−10.0 [-12.3–0.4]
0.055
0.33
HADS, point
10.5 [6.5–17.0]
10.0 [7.0–14.0]
−2.0 [-5.0–1.0]
0 [-1.8-3.5]
0.004
0.50
CDS, point
4.0 [0.8–9.8]
4.0 [0–8.3]
4.0 [-3.0-7.0]
3.0 [0–5.0]
0.972
0.01
CFS, point
20.5 [12.5–30.3]
18.0 [12.0–23.8]
−2.5 [-5.0–0.8]
0.3 [-7.0-6.0]
0.011
0.44
Median [IQR].
ES, effect size; 6MWD, 6-min walk distance; PCS, physical component summary; MCS, mental component summary; RCS, role/social component summary; HADS, Hospital Anxiety and Depression scale; CDS, Cancer Dyspnea Scale; CFS, Cancer Fatigue Scale.
The results of this study showed that accelerometer-based exercise instructions increased physical activity in the early postoperative period after lung resection in an unsupervised setting. Furthermore, this intervention not only increased physical activity but also reduced cancer-related symptoms and prevented a decline in exercise tolerance. Although increased physical activity has been reported to potentially improve postoperative outcomes such as exercise tolerance, cancer-related symptoms, self-efficacy, and health-related QoL in patients undergoing lung resection [
], to the best of our knowledge, this study is the first report to show the significant effect of accelerometer-based exercise instruction on physical activity in an unsupervised setting for patients undergoing lung resection.
In the present study, there was no significant difference in the preoperative physical activity in both groups, and the number of daily steps was similar to or lower than that in the previous study [
]. Physical activity decreased during the postoperative hospitalization period and began to increase after discharge in both groups. In the intervention group, there was a significant increase in physical activity after discharge compared to the control group. Previous studies have shown that self-monitoring of physical activity, self-regulation in the development of action plans and evaluation of their implementation are only important to increasing physical activity [
]. In this study, the adapted intervention method included self-management education, in which participants recorded their daily physical activity, and participants and physiotherapists worked together to set activity goals and develop specific action plans at the time of discharge. This intervention effectively increased post-discharge physical activity in an unsupervised setting. In Japan, the implementation of an outpatient exercise program for patients with cancer is not widespread [
], and most patients undergoing lung resection do not undergo an exercise intervention after discharge due to insurance. Unsupervised exercise is a highly feasible intervention in real-world clinical practice. This study is a clinically relevant intervention trial in which researchers successfully increased physical activity in patients undergoing lung resection.
However, although the proportion of patients performing MVPA in the intervention group was significantly higher than that in the control group, only 31.3% met the 150 min/week recommended in the exercise guidelines for cancer survivors [
]. Previous studies have also shown that in the early postoperative phase after lung resection, the percentage of those who performed MVPA for more than 150 min/week was very low, ranging from 12 to 26% [
]. In the early postoperative phase, it is difficult to increase MVPA in lung resection patients with severe residual physical and respiratory dysfunction [
]. Thus, in patients with relatively mild symptoms and few physical limitations, an action plan should be planned to increase MVPA. On the other hand, it may be important to understand the physical activity patterns in patients with severe residual symptoms to develop a treatment strategy that aims to increase LPA and decrease sedentary time.
Postoperative lung cancer survivors often have cancer-related symptoms such as fatigue, general malaise, anxiety/depression, and low exercise tolerance. These symptoms are often problematic in daily life. It has been reported that a home-based exercise program reduced cancer-related symptoms and improved exercise tolerance [
Short and long-term effects of supervised versus unsupervised exercise training on health-related quality of life and functional outcomes following lung cancer surgery - a randomized controlled trial.
]. The aim of the intervention in this study was to increase physical activity through self-management education, reduce cancer-related symptoms and improve exercise tolerance. The results indicate that increasing physical activity through self-management education may lead to faster postoperative relief of cancer-related symptoms and recovery of the 6MWD. However, recovery of the 6MWD was not greater than the minimal clinically important difference (MCID) among patients with lung cancer [
Short and long-term effects of supervised versus unsupervised exercise training on health-related quality of life and functional outcomes following lung cancer surgery - a randomized controlled trial.
] reported that unsupervised exercise training during the first 4 months postoperatively resulted in an improvement of +61 m over the MCID of 6MWD. This study reflects a relatively early recovery phase of two months postoperatively, and intervention during the first three-four months postoperatively would be necessary to improve the 6MWD above the MCID.
This study has several limitations. First, this study was conducted at a single institution and included only Japanese subjects. There is a possibility of bias in the characteristics of participants. Second, participants had relatively high level of physical function at baseline - 6MWD of over 500 m, ECOG-PS 0, and taking over 6000 steps/day. They may not be representative of the broader population. Third, the physiotherapists and ward stuff, assessor were not blinded. Although blinding the physiotherapists and ward stuff would have been difficult due to the nature of the study, blinding of assessor would have been necessary to ensure the quality of the study. Finally, short-term outcomes are reported in this study. It is unclear whether the interventions in this study have a long-term effect on increasing physical activity. A regular follow-up system may need to be established. In addition, we did not examine the effects of increased postoperative physical activity on long-term QoL or life expectancy.
5. Conclusions
This study showed that accelerometer-based exercise instruction increased physical activity in patients in the early postoperative period after lung resection in an unsupervised setting. This increase in physical activity may improve exercise tolerance and reduce cancer-related symptoms.
Funding
This work was supported by research funding from Hyogo Medical University Graduate School of Health Science, Japan.
Role of the funding source
None.
Data availability statement
The data that support the findings of this study are available from the corresponding author upon reasonable request.
Demographics, safety and quality, and prognostic information in both the seventh and eighth editions of the TNM classification in 18,973 surgical cases of the Japanese Joint Committee of Lung Cancer Registry Database in 2010.
Deterioration in physical activity and function differs according to treatment type in non-small cell lung cancer - future directions for physiotherapy management.
The use of uniaxial accelerometry for the assessment of physical-activity-related energy expenditure: a validation study against whole-body indirect calorimetry.
Short and long-term effects of supervised versus unsupervised exercise training on health-related quality of life and functional outcomes following lung cancer surgery - a randomized controlled trial.
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