Appendix C: Worksheets

 


image of tree with people, family records, and a dna strand

A Report for the
Office of Genomics and Disease Prevention
National Center for Environmental Health
Centers for Disease Control and Prevention
Prepared by Susan Baker Toal, MPH
August 19, 2002



Assessment of Analytic Validity of a Family History Tool

Analytic validity addresses how accurately and reliably the tool identifies disease among a person’s relatives. The key elements of analytic validity are sensitivity, a measure of how well the family history tool identifies relatives with disease, and specificity, a measure of how well the tool identifies the relatives who do not have disease.

I. What factors will affect the analytic validity of a tool?

  • Setting – What settings are likely to yield more valid information? (e.g., take home questionnaires, telephone interviews, one time or continuous)
  • Format – What formats are likely to yield more valid information? (e.g., Web-based data collection, self administered surveys)
  • Disease – What diseases are likely to yield more valid information? What criteria should be used for including specific disease?
  • Risk factors – Should information about risk factors (e.g., diet, exercise, smoking) be included in the tool?
  • Other –

2. How can the sensitivity and specificity of a tool be assessed?

3. What studies have already assessed analytic validity?

4. What studies need to assess analytic validity?

5. Do data sources exist that could address analytic validity?

6. What additional studies are needed?


Assessment of Clinical Validity of a Family History Tool

Clinical validity addresses how well family history of disease can be used to stratify disease risk and predict future disease in a person. The specific elements of clinical validity include sensitivity, specificity, and negative and positive predictive value

1. What factors will affect the clinical validity of the tool?

  • Relatives – Should more than first-degree relatives be included in the tool? (e.g., second-degree, Grandparents) –
  • Disease – what diseases are likely to yield more valid information? (issues – disease prevalence, penetrance, comorbidities, other risk factors)
  • Risk stratification – what types of classification systems or family history scores are useful for stratifying risk?
  • Other –

2. How can the sensitivity, specificity, and predictive value be assessed?

3. How can the attributable risk due to family history be determined?

4. What studies have already assessed clinical validity?

5. What studies need to assess clinical validity?

6. Do data sources exist that could address clinical validity?


Assessment of Clinical Utility of a Family History Tool

Clinical utility is an assessment of the impact and usefulness of the family history tool for individuals, families, and society. Given a tool that has reasonable analytic and clinical validity, would the classification of individuals into risk groups improve the effectiveness of available early detection methods and interventions?

1. Are public health interventions more effective if they are targeted to high-risk groups?

2. Are individuals more motivated to improve their health if they know they may be at higher risk than the average population? Are they more likely to adhere to screening recommendations?

3. Would individuals in the average risk groups become complacent and less likely to engage in healthy behaviors? Does the public’s perception of genetic determinism influence behavior?

4. Is the use of family history to stratify risk and target interventions a cost-effective approach?

5. What studies have already assessed clinical utility?

6. What studies need to assess clinical utility?

7. Do data sources exist that could address clinical utility?


Ethical, Legal, and Social Implications

Labeling a person as high- or moderate-risk for disease may have important psychological, social, and economic costs.

1. Is stigma associated with being at above average risk for disease?

2. What is the psychological impact to the individual on being at above average risk?

3. Does potential exist for discrimination or adverse effects on personal and family life?

4. What would the informed consent requirements be for collecting medical information about individuals and their family members?

5. Are there effective safeguards that should be in place to protect privacy and confidentiality?

6. What studies have already assessed the ELSI associated with the use of family history?

7. What studies need to assess the ELSI associated with the use of family history?

8. Do data sources exist that could address these issues?