health C O L O R A DO DEP ART MENT OF PUBL I C HE AL TH AND E NVIR O N ME N T
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N IO UN
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February 2013
CO
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No. 88
Obesity and Physical Inactivity in Colorado: Demographic Characteristics and Regional Distribution Claire Zelie, Devon Williford, MPH, Health Statistics Section, Colorado Department of Public Health and Environment
Introduction Health Statistics Section
Alyson Shupe, Ph.D., Section Chief
Monica Clancy
Maternal and Child Health Surveillance Unit Rickey Tolliver, M.P.H., Director
Janelle Smith
Claire Zelie
Public Health Informatics Unit
Paul Turtle, Director
Steven Bromby
Doug Duncan
Gloria Mora
Jeff Scott
Bruce Straw
Survey Research Unit Becky Rosenblatt, M.A., Director
Mark King
Michael Poisson
Ava Williams
Vital Statistics Unit
Mary Chase, Director
Kirk Bol, M.S.P.H.
Alison Grace Bui, M.P.H.
Juanita Galvan
Karl Herndon
Marybeth Maligie, M.P.H.
4300 Cherry Creek Drive South Denver, Colorado 80246-1530 (303)692-2160 (800)886‑7689
[email protected] www.colorado.gov/cdphe/hs
Obesity continues to be a major concern for the health of Americans. While Colorado ranks as the leanest state in the United States, the percentage of obese adults has more than doubled in the last 16 years (10.3% in 1996 to 20.7% in 2011).1 As of 2011, more than 1 million Coloradans were considered obese. Obesity can be caused by several factors including genetics, metabolism, personal behaviors, culture, and socioeconomic status. Recent studies have shown that obesity rates in rural areas are often higher than urban areas in the U.S.2-4 In Colorado, over 700,000 people live in rural areas of the state, which encompass over 75 percent of the total area of Colorado.5 Rural areas in Colorado have been associated with a number of disparities in health and access to health services, including higher rates of motor vehicle deaths, tobacco use, suicide rates, and higher rates of uninsured populations.5 This differentiation between urban and rural status is important for public health and health interventions due to the differential access to amenities between the two regions that may influence health. Addressing what has become a national epidemic starts with a closer look at the communities that are most acutely affected. This report will address obesity prevalence as well as physical inactivity by various health indicators and regions in Colorado.
Methods Data source
The Colorado Behavioral Risk Factor Surveillance System (BRFSS) is a telephone survey of adults ages 18 and older developed by the Centers for Disease Control and Prevention (CDC), and conducted by individual states and U.S. territories on a yearly basis. In 2011, 13,612 respondents representing all 64 counties in Colorado were interviewed. Data were collected using random-digit dialing among households with a telephone or a cellular phone. Findings have been weighted using a raking method (first introduced in 2011) to reflect the characteristics of the general population. Regions
Obesity and physical inactivity prevalence were analyzed by state, county and Health Statistics Region (HSR). The 64 counties were grouped as either rural or urban counties (as defined by the Colorado Rural Health Center, see Table 1).5 Health Statistics Regions were
Table 1. Definitions Term Definition
Source
Urban
A county with ≥ 50,000 people
Colorado Rural Health Center
Rural
A county with < 50,000 people
Colorado Rural Health Center
Health Statistics Region
The boundary for a region for public health planning purposes
Colorado Department of Public Health
determined by the size of the population in each county and key
and Environment, Health Statistics Section
demographic factors for each county.
Body Mass Index (BMI)
weight (kg) / [height (m)]2
CDC
Obesity
Body Mass Index (BMI) of 30 or higher
CDC
Source: Colorado Rural Health Center; Health Statistics Section, Colorado Department of Public Health and Environment; CDC
constructed by the Health Statistics Section at the Colorado Department of Public Health and Environment to be used for regional analysis, particularly when county-level data do not have sufficient sample size for reliable interpretation (fewer than 50 respondents to a question). Statistical analyses
Descriptive statistics were calculated to determine the mean prevalence and confidence intervals for each variable of interest. Multiple logistic regression was used to calculate the odds ratios for obesity between regions, adjusting for race and ethnicity, age, income, and education. Obesity prevalence estimates presented for the United States were retrieved from the CDC BRFSS. Body mass index (BMI) (kg/m2), is a widely used tool among medical professionals and major health organizations as an approximate measurement of body fat.6 Body mass index was categorized into four levels: underweight, normal, overweight, and obese. Individuals with a BMI measurement of 30.0 or higher were categorized as obese. Respondents were categorized as physically inactive if they reported not having exercised at all in the past month outside of their job. Race and ethnicity were categorized as non-Hispanic White, White Hispanic, Black, and non-Hispanic Other Race. Results are presented with 95 percent confidence intervals or p-value. Differences are considered significant if their confidence intervals do not overlap, or the p-value of the comparison test is less than 0.05. Data were analyzed using SAS 9.3 (SAS Institute Inc., Cary, North Carolina).
2 Colorado Department of Public Health and Environment
Results Obesity and physical inactivity by region
In 2011, the statewide obesity rate was 20.7 percent (95% CI: 19.7-21.8%) and the prevalence of physical inactivity was 16.5 percent (95% CI: 15.5-17.4%). Interestingly, there was not a significant difference in obesity rates between rural and urban areas of Colorado (19.0% versus 20.7% respectively, p=0.18). However, the rate of physical inactivity was significantly higher in rural areas than in urban areas (18.7% versus 15.9% respectively, p=0.02). Health Statistics Regions with higher obesity rates also had higher rates of physical inactivity. For example, HSRs on the eastern plains such as HSR 1, 5, 6 and 7 had some of the highest obesity rates and rates of physical inactivity in Colorado. In contrast, HSRs in northwestern Colorado had some of the lowest obesity rates and rates of physical inactivity (Figures 1 and 2). With the exception of Mesa County (with an obesity rate of 23.3%), regions in southwestern Colorado had slightly lower obesity rates than the state average.
Figure 1. Prevalence (%) of obesity by Health Statistics Region, Colorado BRFSS, 2011.
REGION 2
JACKSON
MOFFAT
REGION 11
BOULDER GRAND
REGION 16
RIO BLANCO
GARFIELD
LOGAN
MORGAN
SUMMIT
REGION 14 REGION 15
REGION 21
ARAPAHOE
JEFFERSON DOUGLAS
PITKIN
REGION 19
LAKE
REGION 17
REGION 5
TELLER
CHAFFEE
KIOWA
FREMONT
REGION 7
OURAY SAN MIGUEL
HINSDALE
CUSTER
SAGUACHE
CROWLEY
PUEBLO OTERO
REGION 8
DOLORES SAN JUAN
CHEYENNE
EL PASO
REGION 13
REGION 10
MONTROSE
LINCOLN
REGION 4
DELTA GUNNISON
MINERAL
PROWERS
BENT
REGION 6
HUERFANO RIO GRANDE ALAMOSA
REGION 9 MONTEZUMA
KIT CARSON
ELBERT
REGION 3
PARK
MESA
YUMA
WASHINGTON
ADAMS
CLEAR CREEK
EAGLE
REGION 1
REGION 20
BROOMFIELD DENVER GILPIN
REGION 12
PHILLIPS
WELD
LARIMER
ROUTT
SEDGWICK
REGION 18
LA PLATA ARCHULETA
CONEJOS
COSTILLA
LAS ANIMAS
BACA
Percent Prevalence by Health Statistics Region Lowest quartile (10.1 - 16.2) Second quartile (16.3 - 20.2) Third quartile (20.3 - 23.3) Highest quartile (23.4 - 31.6) State average 20.7 (95% C.I.: 19.7 - 21.8) Statistically lower than average
Source: Colorado BRFSS, 2011
Statistically higher than average
3 Health Statistics Section
Figure 2. Prevalence (%) of physical inactivity by Health Statistics Region, Colorado BRFSS, 2011.
JACK SON
MOFFAT
REGION 11
REGION 16
GRAND RIO BLANCO
EAGLE
REGION 12
REGION 14 REGION 15
21
ARAPAHOE
DOUGLA S
MESA
LAKE
REGION 17
REGION 3
REGION 5
TELLE R
CHAFFEE
KIOWA
FREMONT
REGION 7
OURAY HINSDAL E
CUSTER
SAGUACHE
OTERO
MINERAL AL AMOSA
LA PLATA ARCHULETA
PROWERS
BENT
REGION 6
HUERFANO RIO GRANDE
REGION 9
CROWLEY
PUEBLO
REGION 8
DOLORES SAN JUAN
CHEYENNE
EL PASO
REGION 13
REGION 10
SAN MIGUEL
LINCOLN
REGION 4
DELTA GUNNISON
MONTEZUMA
KIT CARSON
ELBERT
PARK
MONTROSE
YUMA
WASHINGTON
ADAMS
JEFFERSON
PITKIN
REGION 19
REGION 1
REGION 20
BROOMFIELD DENVER GILPIN CLEAR CREEK SUMMIT REGION
PHILLIPS
MORGAN
BOULDER
GARFIELD
LOGAN WELD
LARIME R
ROUTT
SEDGWICK
REGION 18
REGION 2
CONEJOS
COSTILLA
LAS ANIMAS
BACA
Percent Prevalence by Health Statistics Region Lowest quartile (10.4 - 14.1) Second quartile (14.2 - 16.1) Third quartile (16.2 - 21.0) Highest quartile (21.1 - 30.6) State average 16.5 (95% C.I.: 15.5 - 17.4) Statistically lower than average
Source: Colorado BRFSS, 2011
4 Colorado Department of Public Health and Environment
Statistically higher than average
Among all 21 Health Statistics Regions, HSR 7 (Pueblo County) had the highest obesity rate at 31.6 percent (95% CI: 24.9-38.3%) and HSR 12 (Eagle, Garfield, Grand, Summit and Pitkin Counties) had the lowest obesity rate at 10.1 percent (95% CI: 5.7-14.5%). In comparison, the estimated median rate of obesity for the U.S. in 2011 was 27.8 percent. The odds ratio for obesity in HSR 7 compared to HSR 12 was 3.2, after adjusting for race and ethnicity, age, income, and education. HSR 8 (Alamosa, Costilla, Conejos, Mineral, Rio Grande and Saguache counties) had the highest rate of physical inactivity at 30.6 percent (95% CI: 20.5, 40.6%) and HSR 12 had the lowest rate of physical inactivity at 10.4 percent (95% CI: 5.914.9%). Nationally, the estimated median rate of physical inactivity was 26.2 percent. The adjusted odds ratio for reported physical inactivity in HSR 8 compared to HSR 12 was 2.1.
Figure 3. Prevalence (%) of obesity and physical inactivity by Health Statistics Region, Colorado BRFSS, 2011. 35.0 30.6 30.0
27.6
Percent
25.0
23.1
26.2
21.0
20.8
19.1
20.0 15.9 15.0
14.9 12.6
10.1
11.9
13.8
15.6
14.1
10.9
10.5
10.4
17.3
17.1
16.1
16.0
12.4
10.0
5.0
26.7
15.6
16.0
16.2
3
16
2
19.4
19.5
20.0
10
13
21
20.0
20.2
20.9
21.1
21.7
9
4
8
20
18
23.1
23.3
23.8
24.8
15
19
5
14
28.6
28.9
1
6
31.6
0.0 12
17
11
Health Statistics Region
Source: Colorado BRFSS, 2011
7
Prevalence of obesity Prevalence of inactivity
5 Health Statistics Section
Obesity and physical inactivity by demographic
or more a year). Nationally, obesity rates followed similar patterns by education and income group.
characteristics
Obesity rates and rates of physical inactivity in Colorado differed by demographic characteristics, which reflected similar trends to the U.S. For example, White Hispanic and Black populations had higher rates of obesity than non-Hispanic White or Other non-Hispanic Race populations both in Colorado and the U.S. (Figure 4). Stratified by education, adults in Colorado with less than a high school education had the highest obesity rates among all education groups (25.7%), while obesity prevalence declined to 15.6 percent in the highest education group (college graduates or higher). Similarly, the lowest income group had the highest obesity rates among all income groups (25.9%), and this rate declined to 18.7 percent for the highest income group (household income of $50,000
By age group, obesity prevalence was the lowest among 18 to 24 year-olds (10.2%), and then increased to 24.2 percent for 45 to 64 year-olds before declining moderately. While there was only a slight difference in obesity rates between males and females (21.1% versus 20.3% respectively), there was a difference in obesity prevalence between sexes within the Black population (27.4% for males versus 41.5% for females). There was no demonstrable difference in obesity or physical inactivity by sex for other race and ethnic groups. For a comparison between Colorado and the U.S. by these demographic characteristics, see Figure 4.
Figure 4. Prevalence (%) of obesity by demographic characteristic for Colorado and the U.S., Colorado and National BRFSS, 2011. Percent
Sex
0.0
5.0
10.0
15.0
20.0
Male
26.5 26.5
34.2
Non -Hispanic Other Race
10.2
15.6 19.3
25.9 22.7
30.5
24.2
45 -54
20.2
25.7
Education
23.5
High school graduate
15.6
29.0
21.5 25.9
Less than $15,000
23.7
$25,000 to < $35,000
18.7
30.7 29.5
21.3
$35,000 to < $50,000
Colorado Department of Public Health and Environment
32.2
24.2
$15,000 to < $25,000
Source: Colorado BRFSS, 2011 and CDC BRFSS, 2011
31.4 30.3
22.3
Some college
$50,000 or more
32.9
25.4
Less than high school
College graduate or higher
32.7
24.2
55 -64 65+
36.7
Colorado U.S.
20.8
35 -44
Household income
28.9
African American 18.0
40.0
28.3
18.9
25 -34
6
35.0
27.4
White Hispanic
18 -24
Age
30.0
20.3
Female
Non - Hispanic White Race/ethnicity
25.0 21.1
28.5 25.8
Similar trends were found in the prevalence of physical inactivity by various demographic characteristics. By race and ethnicity, the White Hispanic population had the highest rate of physical inactivity at 23.5 percent, followed by the Black population at 20.2 percent. Respondents in the lowest education level and in the second lowest income group had the highest rates of physical inactivity among their respective groups (27.7% and 25.4%, respectively). See Figure 5 for more information on the prevalence physical inactivity by each characteristic for Colorado and the U.S. Figure 5. Prevalence (%) of physical inactivity by demographic characteristic for Colorado and the U.S., Colorado and National BRFSS, 2011. Percent
Sex
0.0
5.0
10.0
15.0
Race/ethnicity
25.0
15.9
Male
30.0
24.2 23.5
White Hispanic
31.5
20.2
African American
29.5
15.6
11.4
18 -24
26.6
16.4 14.2
25 -34
22.0
15.0
35 -44
23.9 17.7
45 -54
26.3
18.0
55 -64
28.4 22.4
65+
34.1 27.7
Household income
Education
Less than high school 15.8
Some college 8.8
31.5
23.3
15.3 25.0
Less than $15,000
34.6
25.4
$15,000 to < $25,000 20.2
$25,000 to < $35,000 14.9
$35,000 to < $50,000 $50,000 or more
39.6
22.6
High school graduate
College graduate or higher
40.0
26.5
14.5
Non -Hispanic Other Race
35.0
24.2
17.1
Female
Non -Hispanic White
Age
20.0
10.9
33.2 29.8
26.1 18.5 Colorado
Source: Colorado BRFSS, 2011 and CDC BRFSS, 2011
U.S.
7 Health Statistics Section
Discussion Findings from this study demonstrate variability in risk factors and regional differences in obesity for Coloradans. Similar to patterns experienced in the U.S. as a whole, respondents with lower income, lower education, and who were non-white or white Hispanic experienced higher obesity rates and higher rates of physical inactivity. In contrast, non-Hispanic white respondents, younger adults, college graduates, and respondents with higher incomes experienced lower obesity rates and lower rates of physical inactivity. While there was not a significant difference in obesity in urban versus rural areas of the state, there were clusters of Health Statistics Regions that had demonstrably higher and lower rates in obesity and physical inactivity (southeast Colorado and northwest Colorado respectively). This may be due to differences in the demographic and geographic characteristics of counties that are considered rural in Colorado. For instance, rural counties in the mountains tend to have populations that engage in more physical activity (skiing, hiking, biking, etc.) compared to rural counties on the eastern plains that do not have high levels of recreational physical activity. In-depth interpretation of this information may provide insight into what factors may contribute to more or less physical activity outside of one’s work and what other components of rural areas may be considered risk factors for obesity. While Colorado is known as an active and healthy state, these results demonstrate that obesity and sedentary lifestyles remain persistent even among ostensibly healthy populations.
Limitations In this report, occupational physical activity was excluded from the analysis. Due to higher rates of manual labor in some rural areas versus urban areas, estimates of recreational activity in rural areas may underestimate the true amount of physical activity among these populations. In addition, the BRFSS relies on the judgment and honesty of the respondent. Social desirability bias may occur as a result (i.e., respondents answering questions about their weight or physical activity in a manner that is viewed as favorable or socially acceptable by others), which may cause the estimates in this project to be lower than the true value. This is a general limitation of survey data analysis, which must always be considered when interpreting findings.
References 1. Colorado Department of Public Health and Environment. Colorado’s 10 Winnable Battles: Obesity. Available at: http://www. colorado.gov/cs/Satellite/CDPHE-Main/CBON/1251628821910. Accessed 21 August 2012. 2. Jackson, J. E., Doescher, M. P., Jerant, A. F. and Hart, L. G. (2005), A National Study of Obesity Prevalence and Trends by Type of Rural County. The Journal of Rural Health, 21: 140–148. doi: 10.1111/j.1748-0361.2005.tb00074. 3. Befort, C. A., Nazir, N. and Perri, M. G. (2012), Prevalence of Obesity Among Adults From Rural and Urban Areas of the United States: Findings From NHANES (2005-2008). The Journal of Rural Health, 28: 392–397. doi: 10.1111/j.17480361.2012.00411. 4. Edelman, M. A. and Menz, B. L. (1996), Selected Comparisons and Implications of a National Rural and Urban Survey on Health Care Access, Demographics, and Policy Issues. The Journal of Rural Health, 12: 197–205. doi: 10.1111/j.17480361.1996.tb00794. 5. A Snapshot of Rural Health in Colorado. (2011) Colorado Rural Health Center. State Office of Rural Health. Accessed 13 December 2012. Available at: http://www.coruralhealth.org/resources/documents/2011snapshot.pdf. 6. “Body Mass Index.” (2011). The Centers for Disease Control and Prevention website. Accessed 13 December 2012. Available at: http://www.cdc.gov/healthyweight/assessing/bmi/.