on of genetic testing
The book we will focus on two main types of evaluation-related activities: (1) the assessment of how and when genetic tests can be or are used to promote health and to diagnose and prevent human disease; and (2) the development of standards and guidelines for assuring quality genetic testing. As defined by the Task Force on Genetic Testing, genetic tests include the analysis of human DNA, RNA, chromosomes, proteins, and certain metabolites in order to detect a person's genotype for clinical purposes, including predicting risk of disease, identifying carriers, and establishing prenatal and clinical diagnosis or prognosis (37).
The Task Force on Genetic Testing recognized the need to evaluate several types of data parameters (analytic validity, clinical validity, and clinical utility as defined in Table 5) for each genetic test before transitioning the test from research to clinical practice. Since evaluation of genetic tests used in the prediction of adult-onset diseases may require years of follow up, the Task Force also outlined the need for post-market reevaluation of the same three parameters for genetic tests in the context of "real-world" use and to reevaluate policies and recommendations on the use of genetic tests. These and other parameters of the pre-analytic and post-analytic testing process need to be continuously evaluated in population-based settings.
The second main area of evaluation concerns the development of standards, regulations, and guidelines to ensure the accuracy, validity, and precision of laboratory procedures and to ensure that other quality assurance issues are addressed as well.
All clinical laboratories in the United States that provide information to referring physicians are certified under the Clinical Laboratory Improvement Act (CLIA) Amendments of 1988 (38). CLIA standards for quality control, proficiency testing, personnel, and other quality assurance practices apply to all genetic tests. CLIA regulations, which are jointly developed and administered by the Health Care Financing Administration and CDC, include additional specific requirements for cytogenetic testing. A genetics subcommittee of the CLIA Advisory Committee has considered more specific requirements for molecular genetic testing.
Another role for public health could be development of model quality assurance programs, including proficiency testing programs for genetic testing in public health programs such as the Newborn Screening Quality Assurance Program (Chapter 13). These model programs would set standards for testing, monitor the quality of testing, and recommend improvements for laboratory quality assurance.
The need for quality assurance programs in molecular genetic testing is highlighted in the results of a mail survey of 245 molecular genetic testing laboratory directors conducted by McGovern et al. (39). The researchers collected and analyzed data regarding availability of clinical molecular genetic testing, including data on personnel standards and laboratory practices.. They found a wide range of mean quality assurance (QA) scores, with 15% of the laboratories scoring lower than 70%, suggesting that both personnel qualification and laboratory practice standards are in need of improvement to ensure quality in clinical molecular genetic testing laboratories. Evaluation of genetic testing is explored in more detail in Section III (chapters 12 and 13).
III. Development, implementation, and evaluation of population interventions
The translation of advances in human genetics into actual disease prevention opportunities requires strong public health leadership in developing, implementing and evaluating disease intervention strategies. Burgeoning genetic knowledge is accompanied by high expectations that identification of genetically susceptible people will permit tailoring of prevention efforts to improve their effectiveness; yet, the clinical use of genetic information poses risks as well. Social scientists have postulated an adverse effect of genetic testing on psychological well-being and famil