Forging ahead: Linking health and behavior to improve quality of life in older people

This chapter will focus on conceptual and methodological issues related to health promotion/disability prevention for older people. The first section will begin with a discussion of why older people, as compared to younger persons, are not traditionally seen as targets of health promotion efforts. In recent years several national working groups have been established to examine how older people's health and functioning can be improved. Their objectives and recommendations for older Americans will be reviewed. The second section will address the conceptual framework underlying health and behavior research supported by the National Institute on Aging. The movement from correlational studies to studies of basic mechanisms linking health and behaviour will be discussed, with particular attention to interactions with aging processes. Examples of health and behavior research representing these processes will be presented as well as methodological issues in the measurement of health and functional outcomes for older people. Measurement of quality of life in the cognitively impaired is seen as especially difficult. The third section will review several common themes emanating from these research studies. These include attention to a life course perspective, variability in aging processes, alternative research approaches, and intervention strategies for both initiating and maintaining recommended behavioral changes. A fourth section will review current areas of investigation at the National Institute of Aging. Successful intervention strategies in both community and institutional settings will to presented. These include: (1) a comprehensive behavioral and environmental falls prevention program which has been shown to reduce falls in the community; (2) a health education program to increase older women's use of cancer-related health practices; and (3) behavioral strategies for reducing incontinence in nursing homes. A new NIA initiative on special care units for persons with dementia will also be discussed. The fifth and final section will deal with issues involved in the translation of research into policy and practice. Approaches for increasing the relevance of research to policymakers will be discussed.     

Assessing Potential Human Health Hazards and Benefits from Subtherapeutic Antibiotics in the United States: Tetracyclines as a Case Study

Many scientists, activists, regulators, and politicians have expressed urgent concern that using antibiotics in food animals selects for resistant strains of bacteria that harm human health and bring nearer a “postantibiotic era” of multidrug resistant “super‐bugs.” Proposed political solutions, such as the Preservation of Antibiotics for Medical Treatment Act (PAMTA), would ban entire classes of subtherapeutic antibiotics (STAs) now used for disease prevention and growth promotion in food animals. The proposed bans are not driven by formal quantitative risk assessment (QRA), but by a perceived need for immediate action to prevent potential catastrophe. Similar fears led to STA phase‐outs in Europe a decade ago. However, QRA and empirical data indicate that continued use of STAs in the United States has not harmed human health, and bans in Europe have not helped human health. The fears motivating PAMTA contrast with QRA estimates of vanishingly small risks. As a case study, examining specific tetracycline uses and resistance patterns suggests that there is no significant human health hazard from continued use of tetracycline in food animals. Simple hypothetical calculations suggest an unobservably small risk (between 0 and 1.75E‐11 excess lifetime risk of a tetracycline‐resistant infection), based on the long history of tetracycline use in the United States without resistance‐related treatment failures. QRAs for other STA uses in food animals also find that human health risks are vanishingly small. Whether such QRA calculations will guide risk management policy for animal antibiotics in the United States remains to be seen.     

Family factors in child care research

The purpose of this article is to review evidence concerning the joint impact of family characteristics and child care experiences in understanding children's development. Although child care experiences are related to children's development across a variety of domains, family characteristics, particularly socioeconomic status and parenting quality, are typically stronger predictors of children's outcomes. An important implication of these findings is that high-quality child care experiences are likely to have stronger effects on children who are at risk of poorer outcomes because of less optimal family environments; evidence from experimental and nonexperimental studies generally supports this conclusion. From a policy perspective, an important goal for future research is to identify subgroups of families within the heterogeneous low-income population that are in particular need of relatively more intensive services and to develop effective interventions that are tailored to their needs.     

A general causal model to guide alcohol, tobacco, and illicit drug prevention: assessing the research evidence

The problems associated with the use of alcohol, tobacco, and other drugs (ATOD) extract a significant health, social, and economic toll on American society. While the field of substance abuse prevention has made great strides during the past decade, two major challenges remain. First, the field has been disorganized and fragmented with respect to its research and prevention practices; that is, there are often separate ATOD prevention "specialists." Second, both the prevention researchers who test the efficacy of specific prevention strategies and the practitioners who implement prevention efforts often lack an overall perspective to guide strategy selection. To address these limitations, we present an ATOD causal model that seeks to identify those variables (Domains) that are theoretically salient and empirically connected across alcohol, tobacco, and illicit drugs. For the researcher, the model demonstrates important commonalities, as well as gaps, in the literature. For the practitioner, the model is a means to recognize both the complexity of the community system that produces ATOD problems and the multiple intervention points that are possible within this system. Researchers and practitioners are thus challenged to work synergistically to find effective and cost-effective approaches to change or reduce ATOD use and associated problems.     

Discrete Probability Distributions for Probabilistic Fracture Mechanics

Recently, discrete probability distributions (DPDs) have been suggested for use in risk analysis calculations to simplify the numerical computations which must be performed to determine failure probabilities. Specifically, DPDs have been developed to investigate probabilistic functions, that is, functions whose exact form is uncertain. The analysis of defect growth in materials by probabilistic fracture mechanics (PFM) models provides an example in which probabilistic functions play an important role. This paper compares and contrasts Monte Carlo simulation and DPDs as tools for calculating material failure due to fatigue crack growth. For the problem studied, the DPD method takes approximately one third the computation time of the Monte Carlo approach for comparable accuracy. It is concluded that the DPD method has considerable promise in low-failure-probability calculations of importance in risk assessment. In contrast to Monte Carlo, the computation time for the DPD approach is relatively insensitive to the magnitude of the probability being estimated.     

Children''s Exposure to Arsenic from CCA-Treated Wooden Decks and Playground Structures

CCA-treated wood is widely used in the fabrication of outdoor decks and playground equipment. Because arsenic can be removed from the surface of CCA-treated wood both by physical contact and by leaching, it is important to determine whether children who play on such structures may ingest arsenic in quantities sufficient to be of public health concern. Based on a review of existing studies, it is estimated that arsenic doses in amounts of tens of micrograms per day may be incurred by children having realistic levels of exposure to CCA-treated decks and playground structures. The most important exposure pathway appears to be oral ingestion of arsenic that is first dislodged from the wood by direct hand contact, then transferred to the mouth by children's hand-to-mouth activity. The next most important pathway appears to be dermal absorption of arsenic, while ingestion of soil that has become contaminated by leaching from CCA-treated structures appears to be of lesser importance, except possibly in the case of children with pica. Considerable uncertainty, however, is associated with quantitative estimates of children's arsenic exposure from CCA-treated wood. Priorities for refining estimates of arsenic dose include detailed studies of the hand-to-mouth transfer of arsenic, studies of the dermal and gastrointestinal absorption of dislodgeable arsenic, and studies in which doses of arsenic to children playing in contact with CCA-treated wood are directly determined by measurement of arsenic in their urine, hair, and nails.