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Abstract

  1. Top of page
  2. Abstract
  3. SUBJECTS AND METHODS
  4. RESULTS
  5. DISCUSSION
  6. REFERENCES
  7. APPENDIX A

Objective

To estimate the prevalence of US adults with self-reported, doctor-diagnosed arthritis (without specifying the type of rheumatic disease) who are meeting the US Surgeon General's recommendations for physical activity.

Methods

Using population-based survey data from the 2001 Behavioral Risk Factor Surveillance Survey, we classified respondents according to their arthritis status and their level of physical activity (i.e., physically inactive, insufficiently active, or meeting recommendations). Prevalence data were weighted to take account of the complex sampling design, and were broken down by a variety of demographic characteristics such as race, education, and body weight.

Results

Nearly one-quarter (23%) of US adults reported having doctor-diagnosed arthritis. Among adults with arthritis, 23.8% were physically inactive, 38% reported insufficient levels of physical activity, and 38.3% reported meeting the recommendations for physical activity. The highest prevalence of inactivity in adults with arthritis was found among those subjects with fewer than 8 years of formal education (47.6%), those with 9–11 years of education (35.5%), those who were African American (35.4%), those whose age was ≥65 years (31.1%), and those who were Hispanic (30.4%).

Conclusion

Despite the benefits of physical activity, more than 60% of adults with arthritis do not meet the physical activity recommendations. Efforts should be made to ensure that adults with arthritis are made aware of the benefits of physical activity, and that interventions are prescribed to assist these individuals in becoming more physically active.

Physical activity, specifically that involving traditional exercise regimens, has been shown to be beneficial among persons with arthritis (1, 2). Indeed, a recent work group of the American College of Rheumatology (ACR) concluded that some level of physical activity is “necessary for the maintenance of joint health for both normal and arthritic joints” (3). Apart from arthritis-related benefits, regular physical activity decreases mortality and morbidity related to a number of diseases such as cardiovascular disease, cancer, and diabetes (4, 5). Despite this, the majority of US adults do not get enough physical activity to derive health benefits (5).

In 1996, the US Surgeon General identified physical inactivity as a public health problem and recommended that all US adults participate in regular, moderate-intensity leisure-time physical activity (4). Specifically, the Surgeon General recommends that every adult should accumulate at least 30 minutes of moderate-intensity physical activity (e.g., brisk walking, recreational swimming) at least 5 days per week or 20 minutes of vigorous-intensity physical activity (e.g., jogging, competitive sports) at least 3 days per week. To investigate whether US adults with arthritis are meeting this public health recommendation, we analyzed data from a recent large population-based survey.

SUBJECTS AND METHODS

  1. Top of page
  2. Abstract
  3. SUBJECTS AND METHODS
  4. RESULTS
  5. DISCUSSION
  6. REFERENCES
  7. APPENDIX A

Data collection

The Centers for Disease Control and Prevention's Behavioral Risk Factor Surveillance Survey (BRFSS) is the world's largest ongoing cross-sectional telephone health surveillance survey (6, 7). The BRFSS is a compilation of state-based data on preventive health practices and risk behaviors that are linked to chronic diseases, injuries, and preventable infectious diseases in the noninstitutionalized civilian adult population age ≥18 years. The BRFSS has a multistage cluster design that is based on random-digit dialing methods of sampling to ascertain a representative sample of each state's residents (7). Data collected from each state are pooled to produce a single database. Detailed information on the design and sampling methods used in the BRFSS are reported elsewhere (8). The analyses reported herein are derived from data from the 2001 BRFSS, which contains a total of 212,510 respondents.

Study variables

Self-reported race and ethnicity were used to classify the respondents as white, African American, Hispanic, or other. Age was defined as the age at the time of the household interview, and this was classified into 6 categories: 18–24 years, 25–34 years, 35–44 years, 45–54 years, 55–64 years, and ≥65 years. Self-reported height and weight were used to calculate the body mass index (BMI) (in kg/m2), which was classified into 3 categories: normal weight (<25 kg/m2), overweight (25–29.9 kg/m2), or obese (≥30 kg/m2). Education was classified into 5 categories: ≤8 years, 9–11 years, high school graduate or equivalent, 13–15 years, or >15 years. Smoking status was classified into 3 categories: never smoker, former smoker, or current smoker.

Seven variables comprise the BRFSS Physical Activity Module. These were as follows: physical activity at work (response options included “mostly sitting or standing,” “mostly walking,” and “mostly heavy labor or physically demanding work”; this variable was not used in the calculation of the Physical Activity Recommendation Risk Factor); moderate physical activity (defined as brisk walking, bicycling, vacuuming, gardening, or anything else that causes small increases in breathing or heart rate, performed for at least 10 minutes at a time); number of days per week of moderate physical activity; total time per day spent doing moderate physical activity; vigorous physical activity (defined as running, aerobics, heavy yard work, or anything else that causes large increases in breathing or heart rate, performed for at least 10 minutes at a time); number of days per week of vigorous physical activity; and total time per day spent doing vigorous physical activity.

The Physical Activity Recommendation Risk Factor variable (derived from 6 of the 7 variables in the Physical Activity Module) was used to classify respondents' physical activity into 3 categories. These categories were as follows: physically inactive (defined as no moderate- or vigorous-intensity physical activity, or <10 minutes of either moderate- or vigorous-intensity physical activity per week), insufficiently active (defined as moderate-intensity physical activity <5 days per week or <30 minutes per day or vigorous-intensity physical activity <3 days per week or <20 minutes per day), or meeting recommendations for physical activity (i.e., meeting public health recommendation of at least 30 minutes of moderate-intensity physical activity on 5 or more days per week or at least 20 minutes of vigorous-intensity physical activity on 3 or more days per week). (See Appendix A for a more detailed description of how the physical activity classifications were derived from the BRFSS.)

Respondents were defined as having doctor-diagnosed arthritis if they answered “yes” to the question: “Have you ever been told by a doctor that you have arthritis?” This definition of arthritis differs from that of the Centers for Disease Control and Prevention, in that we excluded those respondents who had chronic joint symptoms but who had never been told by a doctor that they have arthritis (9). We applied this definition of arthritis to make the study findings more relevant to the medical community.

Statistical analysis.

We performed the statistical analyses using SAS statistical software (version 8.01; SAS Institute, Cary, NC). For each survey, we calculated sample weights that took account of the unequal selection probabilities resulting from both the cluster design and the planned oversampling of certain subgroups. All analyses reported incorporated sampling weights.

RESULTS

  1. Top of page
  2. Abstract
  3. SUBJECTS AND METHODS
  4. RESULTS
  5. DISCUSSION
  6. REFERENCES
  7. APPENDIX A

Table 1 presents prevalence estimates of physical activity in adults with and without arthritis from the 2001 BRFSS. These data were broken down by a variety of demographic characteristics. Overall, 16.0 ± 0.8% of US adults (mean ± SEM) were estimated to be physically inactive, 38.7 ± 0.01% reported having insufficient levels of physical activity, and 45.3 ± 0.01% reported engaging in recommended levels of physical activity.

Table 1. Prevalence of physical activity (PA) in adults with or without arthritis from the 2001 Behavioral Risk Factor Surveillance Survey*
DemographicsPA level prevalence, %
InactiveInsufficientMeet recommendations
TotalWith arthritisWithout arthritisTotalWith arthritisWithout arthritisTotalWith arthritisWithout arthritis
  • *

    Inactive defined as engaging in no leisure time PA. Insufficient PA defined as engaging in some moderate and/or vigorous-intensity PA, but not of the recommended frequency or duration. Meet recommendations defined as meeting public health recommendation of at least 30 minutes of moderate-intensity PA on 5 or more days per week or at least 20 minutes of vigorous-intensity PA on 3 or more days per week. BMI = body mass index.

  • The largest standard error of the listed percentages is 1.1%.

Sex         
 Male14.821.713.237.135.837.448.242.549.4
 Female17.125.014.240.239.440.542.735.645.3
Age group, years         
 18–2410.89.610.933.735.633.655.554.855.6
 25–3411.414.911.239.036.339.249.649.449.6
 35–4412.116.911.441.138.741.446.944.447.3
 45–5415.819.714.541.840.242.342.440.243.2
 55–6418.321.916.140.441.239.941.236.944.0
 65+28.231.125.034.835.334.337.033.740.7
Race/ethnicity         
 White13.621.511.038.838.139.047.740.350.0
 African American24.135.420.839.839.839.836.224.939.4
 Hispanic22.430.421.037.234.937.640.434.741.4
 Other16.823.515.641.238.941.742.037.642.8
BMI         
 Normal13.320.311.936.235.436.450.544.351.8
 Overweight14.721.312.638.837.839.146.540.948.2
 Obese20.928.717.343.541.544.535.629.938.2
Education, years         
 ≤840.347.636.532.928.035.426.824.428.1
 9–1127.635.524.534.134.134.038.330.441.5
 12 or equivalent18.725.216.638.338.938.143.035.945.3
 13–1512.819.511.039.439.939.247.840.649.8
 >158.813.37.940.739.640.950.547.251.2
Smoking         
 Never15.423.913.439.439.639.445.136.447.2
 Former16.322.813.338.537.039.145.340.247.6
 Current16.924.914.737.236.137.546.039.147.8
Total16.023.813.738.738.038.945.338.347.4

Nearly one-quarter (23%) of the surveyed US adults reported having doctor-diagnosed arthritis. Among those persons reporting arthritis, 23.8 ± 0.2% were physically inactive, 38.0 ± 0.2% were insufficiently active, and 38.3 ± 0.2% met the public health recommendations for physical activity.

As shown in Table 1, by level of education, the prevalence of physical inactivity among adults with arthritis was highest among those subjects with 8 or fewer years of education (47.6%), followed by those with 9–11 years of education (35.5%). Subjects with arthritis in the oldest age category (age 65 years or older) had the highest prevalence of inactivity (31.1%). When classified according to race, African American and Hispanic subjects with arthritis had the highest prevalences of physical inactivity (35.4% and 30.4%, respectively).

DISCUSSION

  1. Top of page
  2. Abstract
  3. SUBJECTS AND METHODS
  4. RESULTS
  5. DISCUSSION
  6. REFERENCES
  7. APPENDIX A

These cross-sectional population-based survey data indicate that fewer than 4 of 10 US adults with self-reported, doctor-diagnosed arthritis reported meeting the public health recommendations for physical activity, and thus failed to accumulate at least 30 minutes of moderate-intensity physical activity on 5 or more days per week or 20 minutes of vigorous-intensity physical activity on 3 or more days per week. This observed prevalence rate falls well below the nearly 50% of US adults without arthritis who reported meeting the physical activity recommendations. Moreover, about one-quarter of the adults with arthritis reported being physically inactive, compared with 14% of adults without arthritis, whereas a similar rate of adults with or without arthritis were classified as insufficiently active (∼38%). We also found that the highest rates of physical inactivity were among persons with less formal education, African Americans, persons age 65 years or older, and Hispanics.

Our estimated prevalence rates of physical activity in adults with arthritis differed by ∼3–20% from those reported by Hootman and colleagues (10) from the 2000 BFRSS. For example, we observed a prevalence rate of physical inactivity of 21.7% among men with arthritis, whereas they reported a prevalence of 27.6% among men. It is important to note, however, that in 2001, the BRFSS Physical Activity Module was modified to improve the assessment of moderate-intensity physical activity. Moreover, Hootman et al defined arthritis as either doctor-diagnosed arthritis or the presence of chronic joint symptoms, whereas we restricted our arthritis group to only those persons who reported doctor-diagnosed arthritis. Thus, comparing estimates between the 2 studies may not be worthwhile.

Nonetheless, both sets of findings suggest that the majority of persons with arthritis do not meet the public health recommendations for physical activity. This is troubling, since physical activity has not only been shown to reduce pain and improve functioning and overall health in persons with arthritis (1, 2, 11), but also reduces medical costs (12). The reasons why the majority of persons with arthritis are not meeting physical activity recommendations are unclear, but may be related to arthritis-specific barriers to physical activity such as fear of making their arthritis worse, the lack of a physical activity recommendation from their physician/rheumatologist (13), and fatigue, as well as general barriers to physical activity such as lack of time, inclement weather, lack of self-motivation, and similar factors (14). It is also unknown why certain subgroups with self-reported arthritis (e.g., older adults, minorities) have a higher prevalence of inactivity, but this may be related to specific barriers unique to these groups that have yet to be identified.

From a public health perspective, the ∼25% of adults with arthritis who are currently inactive should be the priority of any efforts designed to promote physical activity in adults with arthritis. Our findings also suggest that a considerable proportion of adults with arthritis (∼38%) are physically active but not active enough to meet the recommendations. Finding ways to promote increased activity among this group may not be as challenging as promoting physical activity in subjects who are inactive, since these persons are already somewhat active, and promoting a modest increase in the duration and frequency of their current level of physical activity would allow them to meet the recommendations. Fortunately, there are many forms of moderate-intensity physical activity (e.g., swimming, bicycling, walking) that are gentle to the joints and can be performed regularly, both to improve functional status and to promote health in adults with arthritis.

Our findings are subject to limitations. First, the BRFSS is a self-report telephone survey and, therefore, prone to measurement error. Second, the self-reported arthritis was not confirmed by a physician, nor were the different types of arthritis/rheumatic diseases distinguished within the survey. Thus, interpreting and/or generalizing these findings to patients with specific arthritic or rheumatic diseases should be done with caution. Third, physical activity levels were also self-reported and not verified independently. Moreover, the way the BRFSS classifies the 3 levels of physical activity has shortcomings. For example, the classification scheme makes it possible for someone who accumulates 30 minutes of moderate-intensity physical activity in short bouts (i.e., 6 five-minute bouts) to be classified as insufficiently active, even though he or she is actually meeting the physical activity recommendations. Thus, it is possible that some proportion of those in the insufficiently active category were misclassified. Fourth, the BRFSS does not include the estimated 3–5% of the population that does not have telephones (7).

In conclusion, the majority of adults with arthritis do not meet the public health recommendations for physical activity. Thus, efforts should be made to ensure that persons with arthritis not only are made aware of the benefits of physical activity, but also are prescribed interventions to assist them in becoming more physically active. In particular, interventions should be developed that target those subgroups with the highest prevalences of inactivity (those with lower levels of formal education, minorities, and those age 65 years or older) to ensure that they can enjoy both the general health and arthritis-specific benefits that come from being physically active. Indeed, conducting market research to identify the preferences of subgroups of adults with arthritis, which would inform the development and promotion of tailored physical activity interventions, has recently been identified by the ACR exercise/physical activity work group as a research priority (15). Our findings support the importance of this research recommendation.

REFERENCES

  1. Top of page
  2. Abstract
  3. SUBJECTS AND METHODS
  4. RESULTS
  5. DISCUSSION
  6. REFERENCES
  7. APPENDIX A
  • 1
    American College of Rheumatology Subcommittee on Osteoarthritis Guidelines. Recommendations for the medical management of osteoarthritis of the hip and knee: 2000 update. Arthritis Rheum 2000; 43: 190515.
  • 2
    Van den Ende CHM, Vliet Vlieland TPM, Munneke M, Hazes JMW. Dynamic exercise therapy for rheumatoid arthritis (Cochrane review). In: The Cochrane Library, 4. Oxford: Update Software; 2001.
  • 3
    Chang R, Roubenoff R, Mayer J, Brandt KD, Schanberg LE. Work group recommendations: 2002 exercise and physical activity conference, St. Louis, Missouri. Session IV: exercise in the presence of rheumatic diseases. Arthritis Care Res 2003; 49: 280.
  • 4
    US Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Center for Chronic Disease Prevention and Health Promotion. Physical activity and health: a report of the Surgeon General. Atlanta,GA; 1996.
  • 5
    US Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Center for Chronic Disease Prevention and Health Promotion, Division of Nutrition and Physical Activity. Promoting physical activity: a guide for community action. Champaign, IL: Human Kinetics; 1998.
  • 6
    Centers for Disease Control and Prevention. Health risks in America: gaining insight from the Behavioral Risk Factor Surveillance Survey System. Atlanta, GA: US Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention; 1997.
  • 7
    Centers for Disease Control and Prevention. 2001 Behavioral Risk Factor Surveillance Survey users manual. Atlanta, GA: US Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention; 2002.
  • 8
    Gentry EM, Kalsbeek WD, Hogelin GC, Jones JT, Gaines KL, Forman MR, et al. The behavioral risk factor surveys. II. Design, methods, and estimates from combined state data. Am J Prev Med 1985; 1: 914.
  • 9
    Centers for Disease Control and Prevention. Prevalence of self-reported arthritis or chronic joint symptoms among adults, United States, 2001. MMWR 2002; 51: 94650.
  • 10
    Hootman JM, Macera CA, Ham SA, Helmick CG, Sniezek JE. Physical activity levels among the general US population and in adults with and without arthritis. Arthritis Care Res 2003; 49: 12935.
  • 11
    Stenstrom CH, Minor MA. Evidence for the benefit of aerobic and strengthening exercise in rheumatoid arthritis. Arthritis Care Res 2003; 49: 42834.
  • 12
    Wang G, Helmick CG, Macera C, Zhang P, Pratt M. Inactivity-associated medical costs among US adults with arthritis. Arthritis Rheum 2001; 45: 43945.
  • 13
    Iversen MD, Fossel AH, Daltroy LH. Rheumatologist–patient communications about exercise and physical therapy in the management of rheumatoid arthritis. Arthritis Care Res 1999; 12: 18092.
  • 14
    Sallis JF, Hovell MF, Hofstetter CR. Predictors of adoption and maintenance of vigorous physical activity in men and women. Prev Med 1992; 21: 23751.
  • 15
    Meenan R, Sharpe P, Boutaugh M, Brady T. Work group recommendations: 2002 exercise and physical activity conference, St. Louis, Missouri. Session VI: population approaches to health promotion and disability prevention through physical activity. Arthritis Care Res 2003; 49: 447.

APPENDIX A

  1. Top of page
  2. Abstract
  3. SUBJECTS AND METHODS
  4. RESULTS
  5. DISCUSSION
  6. REFERENCES
  7. APPENDIX A

DESCRIPTION OF THE CALCULATION OF 3 LEVELS OF PHYSICAL ACTIVITY IN THE BEHAVIORAL RISK FACTOR SURVEILLANCE SURVEY (BRFSS)

Seven Variables in the BRFSS Physical Activity Module
  • 1
    Physical Activity at Work (“JOBACTIV”): “When you are at work, which of the following best describes what you do?” Options include: mostly sitting or standing, mostly walking, mostly heavy labor or physically demanding work. (This variable is not used in the calculation of the Physical Activity Recommendation Risk Factor.)
  • 2
    Moderate Physical Activity (“MODPACT”): “… do you do moderate activities for at least 10 minutes at a time, such as brisk walking, bicycling, vacuuming, gardening, or anything else that caused small increases in breathing or heart rate?”
  • 3
    Moderate Physical Activity Days (“MODPADAY”): “How many days per week do you do these moderate activities for at least 10 minutes at a time?”
  • 4
    Moderate Physical Activity Time (“MODPATIM”): “On days when you do moderate activities for at least 10 minutes at a time, how much total time per day do you spend doing these activities?”
  • 5
    Vigorous Physical Activity (“VIGPACT”): “Do you do vigorous activities for at least 10 minutes at a time, such as running, aerobics, heavy yard work, or anything else that causes large increases in breathing or heart rate?”
  • 6
    Vigorous Physical Activity Days (“VIGPADAY”): “How many days per week do you do these vigorous activities for at least 10 minutes at a time?”
  • 7
    Vigorous Physical Activity Time (“VIGPATIM”): “On days when you do vigorous activities for at least 10 minutes at a time, how much total time per day do you spend doing these activities?”
Calculated Variables

_MODPAMN: The “hours” portion of MODPATIM is multiplied by 60 and added to the “minutes” portion of MODPATIM.

_VIGPAMN: The “hours” portion of VIGPATIM is multiplied by 60 and added to the “minutes” portion of VIGPATIM.

Physical Activity Recommendation Risk Factor (“_RFPAREC”)

Meets Physical Activity Recommendations = (MODPACT=yes and MODPADAY=5, 6, 7 days per week and 30<=_MODPAMN<=599) or (VIGPACT=yes and VIGPADAY=3, 4, 5, 6, 7 days per week and 20<=_VIGPAMN<=599)

Insufficiently Active = (MODPACT=yes and MODPADAY<5 days per week or _MODPAMN<30) or (VIGPACT=yes and VIGPADAY<3 days per week or _VIGPAMN<20)

Physically Inactive = (MODPACT=no or MODPADAY=do less than 10 minutes activity weekly) or (VIGPACT=no or VIGPADAY=do less than 10 minutes activity weekly)