Montana Clinical Communication Surveillance Report

Issue: April-June 2006


Montana Cardiovascular Health and Diabetes Programs

Montana Department of Public Health and Human Services,
Chronic Disease Prevention and Health Promotion Program
Room C314, Cogswell Building
PO Box 202951
Helena, Montana 59620-2951

Cardiovascular Disease (CVD) And CVD Risk Factors Among Montana American Indians With And Without Disability

Background: Diabetes and cardiovascular disease (CVD), including stroke and myocardial infarction, are among the leading causes of death for American Indians in Montana and cause significant disability in the community.1 In the first national survey of disability among American Indians and Alaska Natives conducted in association with the 2000 Census, functional limitations that “substantially limited one or more basic physical activities” were reported by 28% of those 45 years of age and older.2 The high disability rates in the national sample ranged by age from 19% of those 45-49 years old to 67% of those aged 85 and older. Compared to non-disabled American Indians and Alaska Natives, those reporting disability to the United States Census were more likely to be poor, unemployed, and have less education, but no data were available on the actual causes of disability or the presence of chronic disease or cardiovascular risk factors in the disabled.

In Montana in 2003, a telephone survey of American Indians living on or near the reservations in Montana included questions which assessed both disability and CVD and risk factors for CVD. 3 The survey was adapted from the Behavioral Risk Factor Surveillance System Survey (BRFSS) and included a large sample of adult Indians. This report examines the associations between self-reported cardiovascular disease and risk factors and disability assessed by self-reported limitations due to physical, mental or emotional problems.

Methods: The Montana Department of Public Health and Human Services in collaboration with the Billings Area Indian Health Service conducted a random digit dialing telephone survey among 1,000 adult Indians in Montana in 2003.3 Trained interviewers made telephone calls to a random sample of households with three-digit telephone prefixes located on or near the seven reservations. The number of completed calls was proportional to the number of Indian households on each reservation. Based on the total number of Indian adults aged >18 years living in the household, one adult from the household was selected to participate.

Respondents were asked questions regarding their history of CVD and CVD risk factors including myocardial infarction, angina, stroke, diabetes, hypertension, high cholesterol, smoking, and overweight. Respondents who smoked cigarettes every day or some days were categorized as current smokers. Self-reported height and weight were used to determine each respondent’s body mass index (BMI, kg/m2); those with BMI >30.0 kg/m2 were categorized as obese. Respondents were also asked two questions regarding their disability status. These included “Are you limited in any way in any activity because of physical, mental, or emotional problems?” and “Do you now have any health problem that requires you to use special equipment, such as a cane, a wheelchair, a special bed, or a special telephone?” Response rates ranged from 97 – 100 percent across the items. Four persons who refused to provide their age were assigned the median age. Eight respondents did not know their height and one refused to provide that, so each was assigned a gender-specific median height. Four of these eight persons, along with 18 others did not know their weight, while 17 others refused to provide their weight; so each non-responder was assigned a gender- and height-specific median weight, so that BMI (kg/m2) could be calculated for all 1,000 cases. For all the dichotomous items, “Yes” responses were coded as 1, while “no” responses and the few “don’t knows” or “refusals” were coded as 0. The analyses were conducted for men and women and younger (18-44 years) and older (>45 years) respondents, as well as another critical CVD risk factor, the respondent’s disability status. Mantel-Haenszel tests and common odds ratios (SPSS V14.0 SPSS Inc., Chicago, IL) were used to compare data from 219 and 781 American Indian adults with and without disability residing on or near Montana’s seven reservations.

Results: Overall, one-fifth (22%) of respondents reported being disabled. Twenty-one percent reported limitations in activities due to physical, mental or emotional problems, and 8% reported health problems that required the use of special equipment. Cardiovascular disease and CVD risk factors were prevalent among respondents: 11% reported a history of CVD, 16% diabetes, 34% high blood pressure, 22% high cholesterol, 36% were current smokers, and 38% were obese.

Respondents who reported a disability had a significantly greater prevalence of CVD (25% vs. 7%), diabetes (28% vs. 12%), high blood pressure (53% vs. 28%), high cholesterol (30% vs. 20%), and obesity (47% vs. 36%) compared to respondents who did not report a disability (Figure 1). There were no significant differences in the prevalence of current smoking among respondents with and without a disability (37% vs. 36%).

Description of Figure 1. Prevalence of CVD and CVD-related risk factors among American Indian Adults with and without a disability, Montana 2003. 25% of American Indian adults with a disability reported having cardiovascular disease, including heart attack, angina/coronary heart disease or stroke. 7% of American Indian adults without disability reported having cardiovascular disease, including heart attack, angina/coronary heart disease or stroke. This was a significant disability effect, P 0,05. 28% of American Indian adults with a disability reported having diabetes. 12% of American Indian adults without disability reported having diabetes. This was a significant disability effect, P 0,05. 53% of American Indian adults with a disability reported having high blood pressure. 28% of American Indian adults without disability reported having high blood pressure. This was a significant disability effect, P 0,05. 37% of American Indian adults with a disability reported being current smokers. 36% of American Indian adults without disability reported being current smokers. 30%of American Indian adults with a disability reported having high cholesterol. 20% of American Indian adults without disability reported having high cholesterol. This was a significant disability effect, P 0,05. 47% of American Indian adults with a disability reported being obese. 36% of American Indian adults without disability reported being obese. Obesity is defined as a Body Mass Index equal to or greater than 30.0 kg/m2. This was a significant disability effect, P 0,05. End of description.

Among women, the prevalence of CVD, diabetes, high blood pressure, high cholesterol, and obesity was significantly higher in respondents who reported a disability compared to respondents who did not report a disability (Table 1). Among men, the prevalence of CVD, diabetes, and high blood pressure, was significantly higher in respondents who reported a disability compared to respondents who did not report a disability.

Description of Table 1. Prevalence of CVD & CVD-related risk factors among Montana American Indian adults with & without disability by gender and by age, 2003. The total number of people without disability was 781. The total number of people with a disability was 219. By gender: There were 589 females and 411 males. Of the 589 females, 452 did not have a disability and 137 did have a disability. Of the 411 males, 329 did not have a disability and 82 did have a disability. 25 females without disability had cardiovascular disease (6%). 25 females with disability had cardiovascular disease (18%). 30 males without disability had cardiovascular disease (9%). 30 males with disability had cardiovascular disease (37%). For both sexes, this was a significant disability effect, P 0,05.

52 females without disability had diabetes (12%). 41 females with disability had diabetes (30%). 44 males without disability had diabetes (13%). 21 males with disability had diabetes (26%). For both sexes, this was a significant disability effect, P 0,05.

110 females without disability had high blood pressure (24%). 70 females with disability had high blood pressure (51%). 110 males without disability had high blood pressure (33%). 55 males with disability had high blood pressure (45%). For both sexes, this was a significant disability effect, P 0,05.

168 females without disability were current smokers (37%). 48 females with disability were current smokers (35%). 113 males without disability were current smokers (34%). 32 males with disability were current smokers (39%).

86 females without disability had high cholesterol (19%). 45 females with disability had high cholesterol (33%). This was a significant disability effect, P 0,05. 68 males without disability had high cholesterol (21%). 21 males with disability had high cholesterol (26%).

164 females without disability were obese (36%). 67 females with disability were obese (49%). This was a significant disability effect, P 0,05. 118 males without disability were obese (36%). 35 males with disability were obese (43%).

By age: There were 480 participants between the ages of 18 and 44. There were 520 participants ages 45 and older. 419 participants without disability were between the ages of 18 and 44. 61 participants with disability were between the ages of 18 and 44. 362 participants ages 45 and older did not have a disability and 158 did have a disability.

8 participants between the ages of 18 and 44 without disability had cardiovascular disease (2%). 4 participants between the ages of 18 and 44 with disability had cardiovascular disease (7%). 47 participants ages 45 and older without disability had cardiovascular disease (13%). 51 participants ages 45 and older with disability had cardiovascular disease (32%). For all ages, this was a significant disability effect, P 0,05.

20 participants between the ages of 18 and 44 without disability had diabetes (5%). 81 participants between the ages of 18 and 44 with disability had diabetes (13%). 76 participants ages 45 and older without disability had diabetes (21%). 54 participants ages 45 and older with disability had diabetes (34%). For all ages, this was a significant disability effect, P 0,05.

74 participants between the ages of 18 and 44 without disability had high blood pressure (18%). 20 participants between the ages of 18 and 44 with disability had high blood pressure (33%). 146 participants ages 45 and older without disability had high blood pressure (40%). 95 participants ages 45 and older with disability had high blood pressure (60%). For all ages, this was a significant disability effect, P 0,05.

168 participants between the ages of 18 and 44 without disability were current smokers (40%). 33 participants between the ages of 18 and 44 with disability were current smokers (54%). This was a significant disability effect, P 0,05. 113 participants ages 45 and older without disability were current smokers (31%). 47 participants ages 45 and older with disability were current smokers (30%).

40 participants between the ages of 18 and 44 without disability had high cholesterol (10%). 11 participants between the ages of 18 and 44 with disability had high cholesterol (18%). This was a significant disability effect, P 0,05. 114 participants ages 45 and older without disability had high cholesterol (31%). 55 participants ages 45 and older with disability had high cholesterol (35%).

143 participants between the ages of 18 and 44 without disability were obese (34%). 28 participants between the ages of 18 and 44 with disability were obese (46%). 139 participants ages 45 and older without disability were obese (38%). 74 participants ages 45 and older with disability were obese (47%). End of description.

Among respondents aged 18 to 44 years, the prevalence of CVD, diabetes, high blood pressure, current smoking, and high cholesterol, was significantly higher in respondents who reported a disability compared to respondents who did not report a disability (Table 1). Among respondents 45 years of age and older, the prevalence of CVD, diabetes, and high blood pressure, was significantly higher in respondents who reported a disability compared to respondents who did not report a disability.

After adjusting for age and gender, respondents with disabilities were more likely to have CVD (odds ratio = 3.4), diabetes (2.1), and high blood pressure (2.3), and obesity (1.5) compared to respondents without disabilities (Table 2). Respondents with disabilities were also more likely than their non-disabled peers to have high cholesterol (1.2) and be current smokers (1.2), but these factor differences were not significant once gender and age were statistically controlled.

Description of Table 2. Gender & age-adjusted risk (odds ratio) of disability on CVD & CVD-related risk factors of Montana American Indian adults, 2003. Note: N = 1,000, two-sided test; the Mantel-Haenszel common odds ratio estimate is asymptotically normally distributed under the common odds ratio of 1,000 assumption; so is the natural log of the estimate (beta estimate). For CVD, the beta estimate is 1.23 (standard error of 0.22), for a significance of 0.000 and an odds ratio estimate of 3.40 (95% confidence interval of 2.21-5.25). For diagnosed diabetes, the beta estimate is 0.74 (standard error of 0.19), for a significance of 0.000 and an odds ratio estimate of 2.10 (95% confidence interval of 1.44-3.06). For high blood pressure, the beta estimate is 0.83 (standard error of 0.17), for a significance of 0.000 and an odds ratio estimate of 2.30 (95% confidence interval of 1.66-3.18). For current smoking, the beta estimate is 0.16 (standard error of 0.16), for a significance of 0.341 and an odds ratio estimate of 1.17 (95% confidence interval of 0.85-1.61). For high cholesterol, the beta estimate is 0.27 (standard error of 0.18), for a significance of 0.133 and an odds ratio estimate of 1.31 (95% confidence interval of 0.92-1.86). For obesity, the beta estimate is 0.39 (standard error of 0.16), for a significance of 0.016 and an odds ratio estimate of 1.48 (95% confidence interval of 1.09-2.02). End of description.

Discussion: Our findings suggest that the prevalence of CVD and many CVD-related risk factors are higher in American Indian adults with disability compared to those without disability, overall, in men and women, and in younger and older adults. The prevalence of disability among American Indian adults is similar to what has been reported among Montana adults overall (20% in 2003). 4 Overall, Montanans who reported a disability had higher prevalence rates of obesity (28% vs. 16%), current smoking (24% vs. 16%), CVD (18% vs. 6%), high blood pressure (37% vs. 17%), high cholesterol (39% vs. 27%), and diabetes (11% vs. 4%) compared to persons reporting no disability. 4

There are a number of limitations to these analyses. First, the surveys did not include Montana households without telephones, or American Indian households outside the seven reservations. Second, the information regarding CVD, CVD-related risk factors, and disability are self-reported and may be subject to recall bias.

The higher prevalence of disability among persons with CVD and CVD-related risk factors, unfortunately is not surprising, given the high prevalence of complications and functional limitations associated with diabetes (e.g., retinopathy, neuropathy, lower extremity amputations), stroke, and myocardial infarction. The association between self-reported disability and a history of CVD is of particular concern because feelings of disability have been found to be a predictor of mortality among cardiac patients up to 8 years after a myocardial infarction.5 Continued public health and clinical efforts will be needed to reduce modifiable CVD risk factors (e.g., regular physical activity, healthy diet, smoking cessation) among those with and without disability. Special effort will be needed to reach those with disabilities.

References:

1. Harwell, T.S., Oser, C.S., Okon, N.J., Fogle, C.C., Helgerson, S.D., & Gohdes, D. Defining disparities in cardiovascular disease for American Indians: Trends in heart disease and stroke mortality among American Indians and whites in Montana, 1991 to 2000. Circulation 112(15):2263-7, 2005.

2. Fuller-Thomson, E., Minkler, M. Functional limitations among older American Indians and Alaska Natives: Findings from the Census 2000 supplementary survey. American Journal of Public Health 95:1945-1948, 2005.

3. Oser, C.S., Harwell, T.S., Strasheim, C., Fogle, C., Blades, L.L., Dennis, T.D., Johnson, E.A., Gohdes, D., & Helgerson, S.D. Increasing prevalence of cardiovascular risk factors among American Indians in Montana. American Journal of Preventive Medicine 28(3):295-7, 2005.

4. Montana Department of Public Health and Human Services. Assessing disability and secondary health conditions of Montana adults. 2005.

5. Van der Vlugt, M.J., van Domburg, R.T., Pedersen, S.S., Veerhoek, R.J., Leenders, I.M., Pop, G.A.M., ter Keurs, D., Deckers. J.W., Simoons. M.L., Erdman, R.A.M. Feelings of being disabled as a risk factor for mortality up to 8 years after acute myocardial infarction. Journal of Psychosomatic Research 59:247-253, 2005.

Reported by R. Brod and M.A. Traci – Montana Disability and Health Program.

Acknowledgment: Special thanks to both the Montana Diabetes Project and Cardiovascular Health Program for their technical assistance for preparation of this report.

What are the Montana Diabetes Prevention and Cardiovascular Health Programs and how can we be contacted?

The Montana Diabetes Control and Cardiovascular Health Programs are funded through cooperative agreements with the Centers for Disease Control and Prevention, Division of Diabetes Translation, the Division of Adult and Community Health and through the Montana Department of Public Health and Human Services. The mission of the Diabetes Control and Cardiovascular Health Programs is to reduce the burden of diabetes and cardiovascular disease among Montanans. Our web pages can be accessed at http://ahec.msu.montana.edu/diabetes/default.htm  and http://montanacardiovascular.state.mt.us .

For further information please contact us at:

Cardiovascular Health & Diabetes Prevention Section Supervisor: Bonnie Barnard, MPH, CIC bbarnard@mt.gov

Diabetes Quality Improvement Coordinator: Linda Stewart, BSN, RN, lstewart@mt.gov

Diabetes Education Coordinator: Marcene Butcher, RD, CDE, marcibutcher@msn.com

Epidemiologist: Carrie Oser, MPH, coser@mt.gov

Diabetes Program Manager: Elizabeth “Liz” Johnson, RN, CNP, lizj@mt.gov

CVH Secondary Prevention Specialist, Michael McNamara, MS, mmcnamara@mt.gov

CVH Health Education Specialist: Crystelle Fogle, MS, MBA, RD, cfogle@mt.gov

CVH Health Education Specialist: Chelsea A. Fagen, BA, cfagen@mt.gov

Or you may call: Susan Day, Accountant
Phone 406/444-6677; sday@mt.gov

Ann Bay, Administrative Assistant
Phone 406/444-5508; abay@mt.gov

The Montana Department of Public Health and Human Services attempts to provide reasonable accommodations for any known disability that may interfere with a person participating in any service, program or activity of the department. Alternative accessible formats of this document will be provided upon request. For more information, call (406) 444-6677 or TDD: 1 (800) 253-4091. 3,950 copies of this public document were published at an estimated cost of $.27 per copy for a total cost of $1,050 which includes $1,050 for printing and $.00 for distribution.

Return to the top

Montana Disability and Health Program
  • Public Awareness Calendar
  • February
  • March
  • April
  • May
  • June
  • July
  • August
  • September
  • October
  • November
  • December