Reasons Persons with COPD Do Not Walk and Relationship with Daily Step Count

Abstract

Background: Physical activity (PA) is significantly reduced in persons with COPD. Assessing reasons why persons with COPD do not engage in PA can guide development of effective interventions to promote PA. Methods: We queried 102 participants with stable COPD about disease-related and general reasons why they do not walk more. The StepWatch Activity Monitor (Orthocare Innovations, Mountlake Terrace, WA, USA) assessed daily step count, a direct measure of PA. Regression models assessed daily step count by response categories, adjusting for age and FEV₁ % predicted. Results: Subjects had mean age 72 ± 8 years and mean FEV₁ 1.48 ± 0.55 L (52 ± 19% predicted). COPD-related worries of becoming short of breath (SOB), needing to use inhalers, or oxygen level becoming low were endorsed by 31, 14, and 12 subjects, respectively. Controlling for age and FEV₁% predicted, those who worried about becoming SOB walked an average of 1,329 fewer steps per day than those who did not worry (p = 0.020). Those who worried about needing to use inhalers walked an average of 1,806 fewer steps per day than those who did not worry (p = 0.016). Subjects who were the most motivated and confident walked significantly more than those who were the least motivated and confident. Conclusions: Presence of COPD-related reasons and lower motivation and confidence are associated with lower daily step count. Management of dyspnea and education about medication use during exercise, and strategies to increase motivation and confidence could facilitate walking in COPD.

Keywords :

• exercise
• pulmonary disease
• accelerometer
• physical activity
• step count

Introduction

Chronic obstructive pulmonary disease (COPD) is the fourth-leading cause of death in the United States, and is projected by 2020 to rank fifth in burden of disease worldwide (1,2). The benefits of physical activity (PA) have been well documented in persons with COPD (3–6). In COPD, a higher daily step count is associated with better health-related quality of life (HRQL), lower risk of acute exacerbations and COPD-related hospitalizations, and decreased mortality, independent of lung function (4,6–8). Steps walked per day is a simple metric of PA that is meaningful to persons trying to increase their activity (9–12).

Despite these benefits, persons with COPD are physically inactive (8,13). Starting and maintaining a PA regimen in the home environment is challenging to persons with COPD. Even in a supervised setting such as pulmonary rehabilitation programs, non-completion rates are as high as 20 to 40% (14,15). In addition, participants often do not continue to engage in PA after completing a structured program. In one study, only 41% of persons described themselves as regular walkers during the year after completing a supervised pulmonary rehabilitation program (16). An understanding of the reasons why persons with COPD do not walk more would aid the design of effective strategies to promote PA.

Although a few studies have examined barriers to completing clinic-based pulmonary rehabilitation programs (14,17–19), none have examined reasons why persons with COPD do not engage in walking in the community. In addition, studies of barriers to exercise in populations other than those with COPD have relied on self-report of PA (20–27), while few studies have directly measured exercise behavior (28–30). In the current study, our primary aim was to examine the COPD-related reasons for not walking and their relationship with directly measured step counts. As a secondary aim, we examined general reasons for not walking and their relationship with daily step count.

Methods

Study population

From January 2009 through February 2011, we studied 127 participants with COPD recruited from the VA Boston Healthcare System pulmonary clinics and enrolled in an observational research study to characterize daily step count (7). The current analysis includes 102 of those 127 participants who returned for a second study visit at which time reasons for not walking were assessed. These 102 participants did not differ significantly from the 127 persons in terms of age, average daily step count, forced expiratory volume in 1 second % (FEV₁%) predicted, 6-minute walk test (6MWT) distance, modified Medical Research Council (MMRC) dyspnea score, or St. George's Respiratory Questionnaire (SGRQ) Total Score (7). In addition, there was no significant difference in age, daily step count, FEV₁% predicted, 6MWT distance, MMRC dyspnea score, and SGRQ Total Score between the 25 subjects with one assessment and 102 subjects with two assessments (7).

Eligible participants were over 40 years of age, could ambulate with or without an assistive device, and had a diagnosis of COPD defined as a smoking history of >10 pack-years and a ratio of FEV₁ to forced vital capacity of <0.70 or evidence of emphysema on chest computed tomography. All assessments were conducted with subjects in stable clinical condition when at least one month had elapsed from the time of any treatment for a COPD exacerbation. The protocol was approved by the Institutional Committee on Human Research, and written informed consent was obtained from all subjects.

Clinical assessments

At the study visit, we measured weight and height to calculate body-mass index (BMI). We obtained a medical history of co-morbidities, cigarette smoking, medication use, current oxygen use, and prior participation in pulmonary rehabilitation. The FEV₁, measured with an Eaglet spirometer (nSpire Health, Inc.), and the 6MWT were performed following American Thoracic Society guidelines (31,32). Dyspnea at rest was assessed using the MMRC dyspnea scale (responses 0-4 with 4 being the most dyspneic) (33). HRQL was assessed with the SGRQ, with the Total Score (SGRQ-TS) ranging from 0–100 and lower scores indicating better HRQL (34).

Daily step count assessment

The StepWatch Activity Monitor (SAM) (Orthocare Innovations, Mountlake Terrace, WA, USA), an ankle-worn accelerometer, accurately measures step counts from all walking—as part of exercise and daily activities in persons with COPD (7). In this study, participants wore the SAM for 14 consecutive days and were instructed to perform their usual activities and exercise. The SAM does not provide on-instrument feedback of steps walked. Subjects returned the SAM by mail, and staff downloaded the date and time stamped step counts via a docking station. No-wear days, defined as days with <200 steps recorded and <8 hours of wear time, were excluded from the analysis (7,35).

Reasons for not walking

Based on our clinical experience with persons with COPD, we formulated disease-related reasons for not walking more (Appendix A). The COPD-related reasons included worries of becoming short of breath (SOB), needing to use inhalers, or oxygen level becoming low. We assessed whether patients were limited by back or leg symptoms before they were limited by shortness of breath. We also compiled general reasons for not walking which have been commonly used in studies of barriers to PA in the general population, the elderly, and adults with chronic disease (14,20,23–27,36–40). For examples, the general reasons included lack of motivation, lack of confidence, bad weather, low energy level, lack of time, and fear of getting hurt. Social support and aspects of the physical environment such as safety, sidewalks, and location of stores were also assessed (28–30).

COPD-related reasons were assessed with true or false responses. For the general reasons of motivation and confidence, subjects were asked, “Overall, how motivated are you to walk each day?” and “How confident are you that you can walk each day?” with responses ranging 1–10 with higher scores reflecting greater motivation and confidence. Motivation and confidence were further characterized in the context of assessing reasons to walk and confidence to exercise under different situations, including health reasons, bad weather, low energy, lack of time, and fear of getting hurt. Responses were on a 7-point scale from “not important at all” to “very important” for motivation-related questions and from “not at all confident” to “extremely confident” for confidence-related questions. For questions about the physical environment where they could engage in walking, subjects responded using a 4-point scale from “strongly disagree” to “strongly agree.” Social support questions were assessed with true or false responses.

Statistical analysis

Analyses were performed with the SAS statistical software package (9.3, SAS Institute; Cary, NC). We averaged daily step count over 14 days. The frequency of positive responses for each COPD-related reason by Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage was assessed with the Cochran-Armitage two-sided exact test for trend. Responses on 4-point, 7-point, and 10-point scales were dichotomized at the median (Table 1). For each reason, daily step count among subjects with responses above the median response was compared to daily step count among subjects with responses below the median response. ­Generalized linear regression models (PROC GLM) assessed daily step count by response categories, controlling for age and FEV₁% predicted. We present the least-squares (LS) means that are the within-group means adjusted for the effects of age and FEV₁% predicted.

Table 1.  Median cutoffs for reasons for not walking and number of subjects above and below median

Reason	Likert scale range	Median cutoff*	Number below median	Number above median
Motivation:
Overall motivation	1–10	5	42	60
Prevent future health problems	1–7	6	46	56
Take responsibility for my own health	1–7	6	46	56
Improve my physical health	1–7	7	51	51
My doctor told me to exercise more	1–7	6	58	44
I believe it is a good thing	1–7	6	48	54
Manage my weight	1–7	4	49	53
Improve my ability to do daily activities	1–7	6	50	52
Increase my energy levels	1–7	6	49	53
Control an existing health problem	1–7	6	52	50
Feel less tension and stress	1–7	5	50	52
Confidence:
Overall confidence	1–10	9	53	49
Feel you don't have the time to exercise?	1–7	4	50	52
The weather is hot?	1–7	4	48	53
The weather is cold?	1–7	4	51	51
Health issues make it difficult?	1–7	5	60	42
You are afraid of getting hurt?	1–7	3	49	53
It takes too much effort?^†	1–7	4	48	54
Do not have a safe place to exercise?	1–7	5	54	48
Do not have anyone to exercise with?	1–7	4	54	48
You do not have energy?	1–7	5	57	45
You feel tired?	1–7	4	46	56
Physical environment:
Can do most shopping at local stores	1–4	3	49	53
Stores are within easy walking distance	1–4	2	53	49
Parking is difficult in local shopping areas^†	1–4	2	64	37
Many places within easy walking distance	1–4	2	45	57
Easy to walk to a bus/subway/train stop	1–4	2	46	56
Streets in my neighborhood are hilly	1–4	2	43	59
There are sidewalks or walking paths	1–4	4	48	54
Feel safe walking during the day	1–4	4	30	72
Feel safe walking at night	1–4	4	50	52

*Values < the median cutoff are “below median”; values ≥ median cutoff are “above median.”

^†N = 101.

Results

Subject characteristics

One-hundred of the 102 subjects (98%) were males, with mean age 72 ± 8 years and mean FEV₁ 1.48 ± 0.55 L (52 ± 19% predicted) (Table 2) (41). All four GOLD stages were represented, with the most subjects in GOLD II (49%) and GOLD III (31%) (2). Mean daily step count was 5,233 ± 2,822 steps. Of 1,428 total monitored days, only 48 (3%) were no-wear days. Fifty-one subjects had a MMRC dyspnea score of 3 or 4. Twelve subjects had previously participated in a pulmonary rehabilitation program and 34 currently used supplemental oxygen. Co-morbidities included diabetes mellitus (n = 28), coronary artery disease (n = 40), and depression (n = 27).

Table 2.  Subject characteristics*

Characteristic	Number (%) or Mean [sd]
Age (years)	72.2 [8.2]
Male	100 (98.0)
Non-Hispanic White	94 (92.2)
Pack-years	67.5 [36.2]
BMI	28.9 [5.8]
Use of ≥ 1 bronchodilator	98 (96.1)
Regular oxygen use	34 (33.3)
Prior pulmonary rehabilitation	12 (11.8)
FEV1 (Liters)	1.48 [0.55]
FEV1% Predicted	51.9 [18.7]
GOLD StageI II III IV	6 (5.9)50 (49.0)32 (31.4)14 (13.7)
6MWT distance (m)	366 [108]
MMRC Dyspnea Scale0 1 2 3 4	13 (12.8)28 (27.5)10 (9.8)30 (29.4)21 (20.6)
SGRQ-TS	43.8 [17.2]
Diabetes Mellitus	28 (27.5)
Coronary Artery Disease	40 (39.2)
Depression	27 (26.5)
Average daily step countMean [SD] Minimum Quartile 1 Median Quartile 3 Maximum	5,233 [2,822]7283,5694,7596,26017,255

*N = 102. BMI: body-mass index; FEV₁: forced expiratory volume in 1 second; GOLD: Global Initiative for Chronic Obstructive Lung Disease; 6MWT: 6-minute walk test; MMRC: Modified Medical Research Council; and SGRQ-TS: St. George's Respiratory Questionnaire Total Score.

COPD-Related Reasons

Worries of becoming SOB, needing to use inhalers, or oxygen level becoming low were endorsed as reasons for not walking more in 31, 14, and 12 subjects, respectively (Figure 1). Thirty-three subjects (32%) reported at least one of these three COPD-related reasons. There was a significant trend of increasing frequency of each COPD-related reason with increasing GOLD stage (Table 3).

Figure 1.  Frequency of responses to COPD-related reasons for not walking more. N = 102. Values in bars represent absolute response counts.

Table 3.  Frequency of “true” responses to COPD-related reasons to not walk more by GOLD stage, N (%)

I do not walk more than I currently walk because…	GOLD I N = 6	GOLD II N = 50	GOLD III N = 32	GOLD IV N = 14	p-value for trend
I am worried that I will become short of breath	1(17%)	10(20%)	13(41%)	7(50%)	0.011
I am worried that I will need to use my inhalers	0(0%)	5(10%)	4(13%)	5 (36%)	0.020
I am worried my oxygen level will become low	0(0%)	2(4%)	5(16%)	5 (36%)	0.0011
My back or legs stop me from walking before my breathing does	1(17%)	22(44%)	7(22%)	8(57%)	0.70

COPD-related reasons were significantly related to daily step count. Those who worried about becoming SOB walked an average of 1,329 fewer steps per day than those who did not worry, after adjusting for age and FEV₁% predicted, p = 0.020 (Table 4). Those who worried about needing to use inhalers walked an average of 1,806 fewer steps per day than those who did not worry (p = 0.016). Although worry about oxygen level becoming low was present in the fewest number of participants (n = 12), persons who endorsed this reason walked an average of 1,596 fewer steps per day than those who did not (p = 0.054). The 38 subjects who endorsed back or leg discomfort as a limitation to walking walked an average of 998 fewer daily steps than those who did not (p = 0.058) (Table 4).

Table 4.  Relationship between COPD-related reasons and daily step count

I do not walk more than I currently walk because…	True	False	p-value
I am worried that I will become short of breath	4,308	5,637	0.020
I am worried that I will need to use my inhalers	3,675	5,481	0.016
I am worried my oxygen level will become low	3,825	5,421	0.054
My back or legs stop me from walking before my breathing does	4,607	5,605	0.058

Total N = 102; N in each cell varies as shown in Figure 1.

Models adjust for age and % predicted FEV₁, and values presented are least-squares means for daily step count.

General reasons

Subjects reported a wide range of responses to the overall motivation question (Figure 2). Subjects who were most motivated to walk each day (answered above the median response) walked 1,093 steps more than those who were least motivated (answered below the median response), p = 0.033, adjusting for age and FEV₁% predicted (Table 5). Reasons that were most frequently endorsed as “very important” (response = 7) included 1) preventing future health problems (43%), 2) taking responsibility for own health (44%), and 3) improving physical health (50%). In addition, over one-third of participants endorsed the following as “very important” reasons to walk: my doctor told me to exercise more, believing it is a good thing, improve ability to do daily activities, increase energy levels, and control an existing health problem. Despite these reasons being endorsed as very important motivators to walk, only the reasons to prevent future health problems and to feel less tension and stress were significantly related to daily step count (Table 5). Subjects who were most motivated for these reasons (answered at or above the median response) walked 1,047 to 1,134 steps more per day than those were least motivated for these reasons (answered below the median response), after adjusting for age and FEV₁% predicted. One-third of subjects responded that managing weight was not at all an important reason to walk (response = 1).

Figure 2.  Distribution of responses to overall motivation and confidence questions. N = 102.

Table 5.  Relationship between motivation reasons and daily step count

Motivation	< median response	≥ median response	p-value
Overall motivation	4,665	5,758	0.033
How important is each reason for you when deciding to walk?
To prevent future health problems	4,658	5,705	0.045
To take responsibility for my own health	5,026	5,403	0.47
To improve my physical health	4,792	5,673	0.088
My doctor told me to exercise more	5,075	5,441	0.48
I believe it is a good thing	4,705	5,702	0.051
To manage my weight	5,316	5,156	0.76
To improve my ability to do daily activities	4,791	5,658	0.095
To increase my energy levels	4,841	5,596	0.15
To control an existing health problem	5,101	5,370	0.61
To feel less tension and stress	4,655	5,789	0.035

Total N = 102; Models adjust for age and % predicted FEV₁, and values presented are least-squares means for daily step count.

Forty-two subjects said they were extremely confident they could walk every day (response = 10, Figure 2). Adjusting for age and FEV₁% predicted, subjects who were most confident to walk each day (answered at or above the median response) walked 1,417 steps more than those who were least confident (answered below the median response), p = 0.0049 (Table 6). Forty percent or more of subjects were not at all confident (response = 1) they could exercise in situations where they were afraid of getting hurt, when they did not have anyone to exercise with, or when they were in a bad mood. Confidence to exercise when health issues make it difficult was significantly related to step count (Table 6). Subjects who were most confident for this reason (answered at or above the median response) walked 1,359 steps more per day than those were least confident for this reason (answered below the median response), after adjusting for age and FEV₁% predicted.

Table 6.  Relationship between confidence reasons and daily step count

Confidence	< median response	≥ median response	p-value
Overall confidence	4,552	5,969	0.0049
How confident are you that you can exercise when…
You feel you don't have the time to exercise?	4,954	5,501	0.29
The weather is hot?	5,051	5,395	0.50
The weather is cold?	4,913	5,553	0.21
Health issues make it difficult?	4,673	6,032	0.0081
You are afraid of getting hurt?	5,237	5,229	0.99
It takes too much effort?*	5,091	5,390	0.57
You do not feel you have a safe place to exercise?	5,116	5,365	0.63
You do not have anyone to exercise with?	5,018	5,474	0.38
You do not have energy?	4,907	5,646	0.15
You feel tired?	4,954	5,462	0.32
You are in a bad mood?	5,208	5,256	0.93

Total N = 102; *N = 101.

Models adjust for age and % predicted FEV₁, and values presented are least-squares means for daily step count.

Seventy-one percent of the participants strongly agreed that they felt safe walking in their neighborhood; however, perceived safety in walking in one's own ­neighborhood was not related to daily step count. Adjusting for age and FEV₁ % predicted, physical environment factors were not significantly related to daily step count. Sixty-seven percent of participants answered that they received support from family or friends in getting enough PA, while 47% said they wanted support. Presence of and desire for support were not associated with daily step count.

Discussion

We examined disease-related reasons why persons with COPD do not walk more, and showed that persons who endorsed these reasons walked significantly fewer steps per day than those who did not. To date, studies have examined barriers to exercise in COPD mainly by assessing class attendance and completion of structured, clinic-based exercise programs (14,17–19). We extend this literature by examining reasons why persons with COPD do not walk in the community. Although worries of becoming SOB, needing to use inhalers, or oxygen level becoming low were present in less than one-third of subjects, persons with these reasons walked 1,300 to 1,800 fewer steps per day, compared to persons without these reasons.

Reassurance that dyspnea is a normal symptom during walking, education about use of inhalers before and during exercise, and reassurance that patients will not become hypoxemic during exercise may enhance patients’ sense of safety while walking in the community. In addition, over one-third of subjects stated that their back or legs stopped them from walking before their breathing stops them. Attention to back and lower extremity problems could also increase walking in persons with COPD.

Our results highlight the complex relationships between endorsed reasons and physical activity behavior. To date, the majority of studies examining barriers to exercise have assessed PA by self-report (20–27), while few have directly measured PA (28–30). It has been assumed that persons who endorsed a barrier would have lower PA than those who did not endorse the barrier (17). We show that PA needs to be directly measured to understand whether barriers impact behavior. In our study, subjects frequently endorsed reasons related to health expectations as being very important motivators to walk, but this endorsement was not necessarily associated with higher daily step counts. We speculate that COPD-related reasons may predominate in this population, making it difficult to detect differences in daily step count related to general reasons that were endorsed as being important.

The general reasons for not walking more endorsed by our COPD cohort are similar to reasons present in the general population (20,21,23,26) and persons with chronic disease (24,25,27). These general reasons include fear of injury, health problems, lack of time, lack of motivation, fatigue, and lack of exercise partner. In a COPD cohort, O'Shea et al. found that health and weather were major barriers to both short- and long-term adherence to a structured exercise program (19). Confidence to walk in cold or hot weather was not related to daily step count in our study. It is possible that some people endorsed particular reasons as being highly important to them, but they did not encounter those reasons during the activity monitoring period. In other words, bad weather can be a barrier, but if the weather was good during the step count assessment, it would not impact PA.

Novel interventions aimed at enhancing motivation and confidence, such as individualized goal setting and iterative, immediate feedback on attainment of walking goals with pedometers and accelerometers, may promote PA (10,11). Our results suggest that emphasizing the benefits of walking to prevent future health problems and to decrease stress, and improving self-efficacy to exercise in the presence of health issues may increase walking in persons with COPD.

The strengths of our study include the objective monitoring of exercise behavior using a validated device to measure daily step count in a well characterized cohort of persons with COPD. Additionally, enrollment from a general pulmonary clinic makes our results more generalizable than those from previous studies that enrolled only from pulmonary rehabilitation programs.

Some limitations warrant discussion. Our cohort was 98% male and all participants were Veterans, which may limit generalizability. Nevertheless, although our cohort is slightly older and includes persons with GOLD I, it is comparable to subjects enrolled in large COPD clinical trials such as ECLIPSE, TORCH, and UPLIFT in terms of lung function, pack-years, 6MWT distance, MMRC dyspnea score, and HRQL (42–44). Furthermore, the similarity between our average daily step count of 5,233 and those from other studies of US persons with COPD is striking. For examples, persons with COPD in Seattle, WA walked an average 5,646 steps per day (45) and persons with COPD in Pittsburgh, PA walked an average of 5,115 steps per day (46). A cohort of patients in Germany had a slightly higher average daily step count of 6,359, which may be explained by the fact that we have an older group and fewer people in GOLD I (8).

Given the lack of validated questionnaires that measure barriers to PA in the COPD population, the COPD-related reasons for not walking used in this study are preliminary and chosen based on face validity from clinical experience. Nevertheless, we demonstrate concurrent validity of the COPD-related reasons by showing a significant increase in endorsement of the reasons with increasing GOLD stage. It was beyond the scope of our study to conduct focus groups or use patient advocates, but we believe that our findings provide the rationale for future studies to comprehensively identify other reasons for not walking using focus groups, patient advocates, or pilot studies.

We believe our results provide important insight into factors that should be included in the future assessment of barriers to exercise in COPD. Although 30% of the subjects said they participated in regular exercise, we did not assess stage of behavior change, and cannot exclude the possibility that we would have seen greater differences in daily step count if we had limited our study to subjects who were ready to start an exercise program. The findings from our observational study need to be confirmed in other COPD populations in future research. Also, the effect of interventions to increase motivation and confidence, and address COPD-related reasons for not walking on PA behavior needs to be studied.

Conclusions

Presence of COPD-related reasons for not walking is associated with lower daily step count. Management of dyspnea and education about medication use during exercise could facilitate walking in persons with COPD. Directly measured PA is needed to understand the complex relationships between barriers and exercise behavior. Persons who endorse barriers do not necessarily have lower daily step counts compared to persons who do not endorse them. Identifying reasons for not walking and understanding their impact on exercise behavior can aid the design of interventions to promote and sustain PA in persons with COPD.

Appendix A

Questions of Reasons for Not Walking

I. COPD-Related:

I do not walk more than I currently walk because I am worried that I will become short of breath.

  True or False

I do not walk more than I currently walk because I am worried that I will need to use my inhalers more.

  True or False

I do not walk more than I currently walk because I am worried my oxygen level will become low.

  True or False

I do not walk more than I currently walk because my back or legs stop me from walking before my breathing does.

  True or False

II. Personal: Motivation and Confidence

Overall, how MOTIVATED are you to walk each day? Use the scale below.

 (Please choose one number.)

There are many REASONS people decide to walk. Please tell us how important each reason is for YOU. (Choose only one number in each row.)

Overall, how CONFIDENT are you that you can walk each day?

Use the scale below. (Choose only one of the following.)

Listed below are issues that can make it DIFFICULT for people to exercise.

How confident are you that you can exercise when:

III. Environmental: Physical Environment and Social Support

Please choose the answer that best applies to you and your neighborhood. Both “local” and “within walking distance” mean within a 20 minute walk or less from your home.

Do you currently GET support from your family or friends in getting enough physical activity? (Choose only one of the following.)

Yes

No

Do you WANT support from your family or friends in getting enough physical activity? (Choose only one of the following.)

◯ Yes

◯ No

Declaration of Interests Statement

The research reported here was supported by the Department of Veteran Affairs, Veterans Health Administration, Rehabilitation Research and Development Service through a VA Career Development Award to Dr. Moy. Dr. Moy was supported in part by CIMIT: ­Center for Integration of Medicine and Innovative Technology, Boston, MA. The authors report no conflicts of interest.

This study was initiated by the investigators. The results of the present study do not constitute endorsement of the StepWatch Activity Monitor by the authors. Orthocare Innovations had no involvement in the study design, the collection, analysis, and interpretation of data, in the writing of the report, or in the decision to submit the paper for publication. The authors alone are responsible for the content and writing of the paper.