Muin J Khoury, Director, Office of Public Health Genomics, Centers for Disease Control and Prevention
A new podcast from the CDC Expert Commentary Series on Medscape—Family Health History: Use It to Inform Preventive Services for Your Patients— describes how family health history can inform the delivery of preventive health services. The podcast presents three case studies based on recommendations of the US Preventive Services Task Force (USPSTF): screening for lipid disorders in adults, colorectal cancer screening, and BRCA genetic counseling and evaluation. Each case study demonstrates how family health history can be used to define a population subgroup whose increased risk could warrant more intensive preventive intervention. Family health history—which reflects the effects of genetic and environmental risk factors shared within families—has been called the “first genetic test.”
CDC’s Office of Public Health Genomics recently announced a list of health-related genomic tests and applications, stratified into three tiers according to the availability of scientific evidence and evidence-based recommendations . Tier 1 applications have evidence establishing validity and utility, and their use is supported by evidence-based recommendations; tier 2 applications have evidence establishing validity and promising utility, and may be useful for informed decision making, but lack evidence-based recommendations for their use; and tier 3 applications have inadequate evidence of validity and/or utility, or have evidence-based recommendations against their use. This list was recently expanded to incorporate a broader array of recommendations on cancer genomic tests.
Now we update the list to include 17 USPSTF recommendations that take family health history into account in guiding the delivery of preventive services. To tier 1, we have added three USPSTF A and B recommendations that are explicitly based on family health history: screening for lipid disorders in adults, screening for osteoporosis, and chemoprevention of breast cancer. We have also added to tier 1 two recommendations for genetic services when there is a known genetic mutation in the family: screening for hemochromatosis and BRCA genetic counseling and evaluation.
We have added to tier 2 four USPSTF A and B recommendations and nine USPSTF I (insufficient evidence) recommendations that explicitly include family health history as a “clinical consideration” when offering the service. Tier 3 now includes two USPSTF D recommendations that explicitly recommend against routine genetic services in the general population: screening for hemochromatosis and BRCA genetic counseling and evaluation. Multiple entries on the list for a single genetic testing application, such as BRCA genetic counseling and evaluation, are not surprising since each application can be considered for multiple indications and in different target populations.
So far, we have considered only recommendations or guidelines from USPSTF. Increased risk family health history criteria vary considerably among guidelines, making efforts to compare and harmonize them very challenging.
The vast majority of the USPSTF recommendations that take family history into account map to tier 2, indicating that there are important gaps in the data needed to support use of family health history to guide preventive services. Indeed, a 2009 NIH state-of-the-science conference on family history and improving health found the evidence supporting the systematic collection of family health history in primary care to be very limited. The recent addition of family health history to the national standards for “meaningful use” of electronic health records is an important first step which could help to address these gaps by allowing improved monitoring of the use and impact of family health history in practice.
The growing list of tier 1 applications underscores the role of public health to support effective implementation of evidence-based genomic testing and family history recommendations to realize population health impact. Common approaches, such as promoting the collection of structured family health history information through educational interventions, facilitating the identification of at-risk family members through policy approaches, and monitoring awareness and use of evidence-based recommendations through surveillance and surveys, could apply across multiple recommendations to maximize resources.