Can identifying families that have aggregations of chronic diseases be used to improve the health of at-risk family members and also of the population as a whole? Some data suggest that using family history in this way can be useful. Perhaps the best documented example of family history as a public health tool is the Health Family Tree Program, which was developed and used in Texas and Utah as well in the NHLBI Family Heart Study in Minnesota, Massachusetts and North Carolina in the 1980's and 1990's. This program educated young people about chronic disease and healthy lifestyles and behaviors, systematically screened families for an increased incidence of chronic diseases and risky behaviors, suggested public health interventions to lower risk, and provided data for epidemiological research and evaluation.
The Health Family Tree Program was a collaborative project between The Cardiovascular Genetics Research Clinic at the University of Utah School of Medicine, the Utah Department of Health, local public health agencies and public school partners that was implemented from 1983 through 1996 in Utah. The public schools taught a module on chronic disease in required high school health classes that included the role of family history in several chronic diseases. After informed consent, the students collected health and health behavior information on their relatives in a family tree format. The data were analyzed and a family history score was calculated. Each family was provided with a report from the Cardiovascular Genetics Research Clinic that stratified their family into average or high-risk categories for several conditions and health behaviors, including smoking, exercise habits, and alcohol use. Information about possible interventions to lower risk for chronic diseases was also included. Families who were identified to be high-risk were offered a public health intervention via the state and local public health agencies. Long-term follow up from 1983 through 1988 was conducted on a cohort of families to follow the effectiveness of interventions aimed at behavior change or entry into medical care. Significant improvement in behaviors associated with good health was documented in families with a positive family history for chronic diseases as compared to control families.
Partnership between Families, Schools, Public Health Agencies, and the University. The Health Family Tree was taught as a module in high school health classes. It included elements of health education and health promotion and identified families with a higher than average risk for chronic disease (7). The program aimed to educate students and their families about chronic diseases, and familial tendencies for chronic diseases, and provided strategies for lowering risk and maximizing the chances that relatives who were currently healthy would stay that way. This information was especially useful to families with a greater-than-average risk for specific chronic diseases because appropriate risk-reduction or medical interventions could be offered in an effort to prevent or delay these conditions. For families without a family history of chronic disease, the exercise of evaluating family health information was used to identify and emphasize protective factors that might contribute to the health of their members and reinforce health-promoting behaviors and lifestyles.
Informed consent. Parents were given written information about the module and informed consent was obtained prior to students participating in the program. There were three options for participation in the program (8). Full participation meant that a parent or guardian agreed to allow the student to collect family history about his/her relatives' health, submit this information with identifiers for evaluation to the Cardiovascular Genetics Research Clinic at the University of Utah School of Medicine, receive a report that outlined specific risk factors and potential interventions to lessen the risk for chronic diseases and, if greater-than-average familial tendencies for chronic diseases were found, agreed to a referral to a local public health agency for possible intervention. The limited participation option meant that a parent or guardian allowed the student to participate in the assignment in class, but did not agree to provide any identifying information to the academic center for analysis. In this instance, there was no individualized follow up or public health intervention. The third option was nonparticipation, which meant that the student received an alternate assignment. The program was well accepted and most families chose to participate in either the full or limited option.
Learning goals and objectives. The primary learning goal was for students to understand that familial tendencies can contribute to chronic diseases and that family members can employ preventive measures to lower their chances of developing these conditions. Students were introduced to different types of chronic disease and the ways they are diagnosed. They also learned about the basic principles of heredity and learned to distinguish between a medical pedigree and other types of family history. Students learned to understand the concept of "familial tendency" (7) as it relates to chronic diseases and learned why it is important for their own health and the health of their family members. They participated in collecting their own family health history information by completing their family tree and, with help from their parents, collected medical information about their family members. They were encouraged to informally review their family tree and estimate if they might have a familial tendency for a chronic disease. They learned that a familial tendency is not necessarily health destiny by learning about strategies that may temper a familial risk, such as seeking help from their family medical provider and by engaging in lifestyle and behavioral factors that are associated with good health. In addition to family history, they learned about other risk factors that influence health outcomes and habits that promote health, including a balanced diet, regular exercise and periodic medical checkups.
The Family Health Tree Tool. The Health Family Tree Tool collects health information about first degree relatives (parents and siblings) and second degree relatives (grandparents, aunts and uncles) of the index person, who usually is the student filling out the family tree. Specifically, information is gathered about health conditions, health habits, and environmental factors that influence health (1,3). The tool collects family history of chronic conditions, including cardiovascular disease, stroke and hypertension, breast cancer, colon cancer, osteoporosis, asthma, overweight and obesity, and diabetes. Family history of behaviors and habits that affect the risk for chronic diseases (smoking, alcohol use, overweight, sedentary lifestyle) is also collected on each family member (1).
This information is used to 1) teach the students to identify chronic diseases or conditions that may run in their families in order to make a connection between
behavioral and environmental risk factors
and disease risk in their relatives and 2)
teach and reinforce healthy behaviors and other interventions that they and their families can employ to reduce their own risk of developing similar conditions.
The information that is collected about each relative is placed into a family tree format on a large poster. This format allows collection of a large amount of medical and family history data in a relatively compact form, considering the quantity of medical information that is recorded. |
An example of one person in the Health Family Tree. Information about family members is used to identify familial factors for chronic diseases and behavioral factors that influence risk (1). |
Patterns of transmission within the family often become clear when the family history information is viewed in the context of the family relationships.
(Personal Communication: LaDene Larsen, Utah Department of Health)
The family history score-How is it calculated? What does it mean? The students transferred the information from the Health Family Tree onto a form for computerized data analysis at the University of Utah School of Medicine. The data were used to compare the observed number of family members with a specific disease with the number that would be expected based on population data. The equation to calculate this ratio is:
FHS = ( | O - E | - ½ ) | O - E |
E O - E
Public health intervention: the role of state and local public health agencies. Families identified having a positive or high risk family history were referred to local public health agencies via the Family High Risk Program in the Utah Department of Health. The goals of the Family High Risk Program were to prevent or delay the onset of selected chronic diseases through early detection by identifying families with strong familial tendencies for these conditions, by helping identified families reduce their risk for developing chronic disease and by providing regular follow-up to monitor health status and reinforce healthy behavior changes (2).
To accomplish these goals, community health nurses contacted the families identified to have an increased risk for specific conditions and provided counseling on healthy lifestyles, strategies for reducing risk, and referral to medical care, as needed. For example, if a familial tendency for breast cancer was identified, then appropriate referral for medical care, including possible cancer risk evaluation and genetic testing, was made. Health information to help families reduce their risk factors for breast cancer, recommendations for screening and early diagnosis with mammography and breast self-examination were also included (3).
Family history as a population-based screening tool. In January 2001, the Cardiovascular Genetics Research Clinic at the University of Utah School of Medicine published their cumulative experience of using the Health Family Tree to identify families at risk for cardiovascular disease and stroke. Their experience included screening 122,155 Utah families; 6,578 Texas families; and 1,442 families enrolled in the National Heart and Lung and Blood Institute (NHLBI) Family Heart Study in Massachusetts, Minnesota, North Carolina, and Utah (3). Analysis of the family history of cardiovascular disease in the Utah families, showed that 14% of these families accounted for 72% of early cardiovascular disease (onset at <55 years of age for men and < 65 years of age for women) and accounted for 48% of all cardiovascular disease at any age in the Utah families (Table 1). For stroke, 10.7% of the Utah families had a positive family history, accounting for 86% of early strokes (stroke at <75 years of age) and 68% of strokes at any age (Table 2) (3).
Table 1. Concentration of Coronary Heart Disease in Families With a Positive Coronary Family Risk Score (CHD FHS) from the Utah Health Family Tree Study, 1983-1996 (3)
CHD
FHS |
Families |
Relatives with CHD at an early age** |
Relatives with CHD at any age |
Concentration factor *** |
Type of Family history
|
No. |
% |
No. |
%
|
No. |
% |
Early |
Any Age |
> 2.0 |
1,227 |
1.0 |
2,797 |
16.8 |
3,418 |
6.3 |
16.8 |
6.3 |
Very strong
positive |
> 1.0 |
3,917 |
3.2 |
5,756 |
34.7 |
9,556 |
17.6 |
10.8 |
5.5 |
Strong positive |
> 0.5 |
17,064 |
14.0 |
11,968 |
72.1 |
26,222 |
48.4 |
5.2 |
3.5 |
Positive |
> 0.5 |
105,091 |
86.0* |
4,634 |
27.9 |
27,960 |
51.6 |
0.3 |
0.6 |
Average |
Total |
122,155 |
. |
16,602 |
. |
54,182 |
. |
1.0 |
1.0 |
. |
|
*Percentages do not add to 100% because the first 3 categories of FRS overlap.
** < 55 years of age for males at age of onset; < 65 years of age for females at age of onset.
**Concentration factor = percentage of disease divided by percentage of families.
Table 2. Concentration of Strokes in Families With a Positive Stroke Family History Score (Stroke FHS) from the Utah Health Family Tree Study 1983-1996 (3)
CHD
FHS |
Families |
Relatives with CHD at an early age** |
Relatives with CHD at any age |
Concentration factor *** |
Type of Family history
|
No. |
% |
No. |
%
|
No. |
% |
Early |
Any Age |
> 2.0 |
1,246 |
1.0 |
860 |
18.7 |
2,661 |
11.9 |
18.7 |
11.9 |
Very strong
positive |
> 1.0 |
3,727 |
1.4 |
1,004 |
21.8 |
3,645 |
16.2 |
15.6 |
11.1 |
Strong positive |
> 0.5 |
13,106 |
10.7 |
3,937 |
85.6 |
15,1712 |
67.7 |
8.0 |
6.3 |
Positive |
> 0.5 |
109,049 |
89.3* |
663 |
14.4 |
7,254 |
32.2 |
0.2 |
0.4 |
Average |
Total |
122,155 |
. |
4,600 |
. |
22,425 |
. |
1.0 |
1.0 |
. |
|
*Percentages do not add to 100% because the first 3 categories of FRS overlap.
**Age of onset < 75 years.
**Concentration factor = percentage of disease divided by percentage of families.
Depending on how many family members were affected, the sex and the age of onset of disease as compared to population norms (see above), family history was scored as very strong positive (FHS > 2.0), strong positive (FHS > 1.0), positive (FHS > 0.5) or average (FHS < 0.5). These designations defined the screening cutoffs for determining appropriate follow-up. This may be a consideration when resource prioritizations are necessary. For example, only 1% of families had an FHS of > 2 (very strong positive) for cardiovascular disease. If FHS > 2.0 is used as a cutoff for intervention eligibility, then families that contribute 17% of all cardiovascular events to the population could be identified and targeted to receive intensive interventions to lower their risks, both through lifestyle modifications and medical interventions (see Table 1). Depending on public health priorities and available resources, a different FHS might be chosen as the screening cut-off for intervention. By focusing intensive interventions on those at greatest risk, the rate of cardiovascular disease in the whole population could be lowered and public health resources used efficiently (3).
Long-Term Follow Up. The families identified to be at high risk for chronic diseases were followed periodically to reinforce healthy behaviors and continuation of medical care (5). This follow up was accomplished with a questionnaire that collected information on medical conditions and health behaviors in the families (6). A study from 1983 to1988 compared the health lifestyle indicators between 400 families with high familial risk for chronic disease and 400 families with average familial risk for chronic disease. The follow-up consisted of one visit by a community health nurse for health counseling and referral to additional services for the high-risk families. Both average-risk and high-risk families were followed annually with a questionnaire to track their health-related activities and to reinforce healthy behaviors. Health behaviors that were documented included 1) having an annual medical examination; 2) having at least an annual blood pressure check-up; 3) health behaviors such as smoking cessation, eating a healthy diet high in fruit, vegetables and grains and low in fat, exercise habits and maintaining a healthy weight. The data were collected between 1983 and 1988. The results are shown in Table 3 . When follow-up began, the high-risk families did not have as many healthy behaviors as the average-risk families (5). After six years of follow-up, both the high-risk and average-risk groups had shown increases in behaviors and habits associated with better health outcomes, although the improvement was the most dramatic in the high-risk families.
Table 3. Effect of annual follow up over 6 years (1983-1988) on indicators related to health in 400 Utah families at increased risk for chronic diseases and 400 Utah families with average-disease risk.
Healthy lifestyle indicator |
Baseline |
After 6 years of follow-up |
High-Risk
(%) |
Average-Risk (%) |
High-Risk (%) |
Average-Risk (%)
|
Medical examination annually |
35 |
75 |
87 |
88 |
Blood pressure checked annually |
40 |
80 |
96 |
94 |
Smoking cessation |
5 |
8 |
9 |
5 |
Weight decreased |
40 |
49 |
66 |
58 |
Routinely exercised |
40 |
53 |
57 |
49 |
| Fat in diet reduced |
46 |
44 |
68 |
59 |
Fruits, vegetables and grain in diet increased |
47 |
48 |
76 |
67 |
|
Conclusions:
-
Family history can be used to teach high school students and their families about chronic diseases, familial factors that contribute to the risk of developing chronic diseases and strategies for reducing this risk.
-
The family history tool and calculated FHS were effective tools for identifying families at increased risk for developing chronic diseases for targeted public health interventions.
- After six years of follow-up, lifestyle factors associated with good health improved after the public health intervention and annual questionnaire follow-up.
References
-
Williams RR, Hunt SC, Barlow GK, et al. Health Family Trees: a tool for finding and helping young family members of coronary and cancer prone pedigrees in Texas and Utah. 1988. American Journal of Public Health 78(10):1283-1286
-
Breckenridge-Potterf S, Ware J, Giles, R, Asay, A. The Family High Risk Program: Community health nurses in targeted intervention. 1988 Health Action Papers 2:15-23
-
Williams RR, Hunt SC, Heiss, G, et al. Usefulness of cardiovascular family history data for population-based preventive medicine and medical research (The Health Family Tree Study and the NHLBI Family Heart Study). 2001. Am J Cardiol. 87:129-135
-
Computerized Family History Analysis. Cardiovascular Genetics, University of Utah. No date. Personal communication from LaDene Larsen.
-
Unpublished data. Personal communication from LaDene Larsen
-
Family High Risk Program Health Survey Follow-up. Utah Department of Health, Division of Community Health Services, Bureau of Chronic Disease Control, Salt Lake City, UT. No date.
-
Health Family Tree Teaching Supplement for High School Health Education Programs. Utah Department of Health, Chronic Disease Prevention and Control, Family High Risk Program. Salt Lake City, Utah. No date.
-
Parent's Consent Form. Utah Department of Health, Chronic Disease Prevention and Control, Family High Risk Program. Salt Lake City, Utah. No date.
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