Repeated topical treatment, in contrast to single oral doses, with Vitamin A-containing preparations does not affect plasma concentrations of retinol, retinyl esters or retinoic acids in female subjects of child-bearing age.

BACKGROUND: Vitamin A is widely used in cosmetic preparations. Given that oral Vitamin A and its metabolites present a potential reproductive risk, the present study investigated the effect of topical Vitamin A on human endogenous plasma levels of Vitamin A and its metabolites. METHODS: Two groups of 14 female volunteers of child-bearing age were kept on a Vitamin A-poor diet and treated topically for 21 days with creams containing 0.30% retinol or 0.55% retinyl palmitate on approximately 3000 cm2 of their body surface area, amounting to a total of approximately 30,000 IU Vitamin A/subject/day. After a 12-day wash-out period, the study groups received single oral doses of 10,000 IU or 30,000 IU retinyl palmitate (RP), corresponding to the maximal EU allowance during pregnancy or three-times higher, respectively. Blood samples were collected over 24h on study days -3 (pre-study), 1, 21 (first and last days of topical treatment) and 34 (oral administration) at 0, 1, 2, 4, 6, 8, 12, 14-16 h and 24 h after treatment for determination of plasma concentrations of retinol (REL), retinyl palmitate (RP), oleate (RO) and stearate (RS), 9-cis-, 13-cis-, all-trans- (AT), 13-cis-4-oxo- or AT-4-oxo-retinoic acids (RAs). RESULTS: With the exception of transient mild (RP-group) to moderate (REL-group) local irritation on the treatment sites, no adverse local or systemic effects were noted. On days 1 or 21 of topical treatment, no changes were measured in individual or group mean plasma Cmax, AUC0-24 h or other pharmacokinetic parameters of REL, retinyl esters or RAs relative to pre-study data. In contrast, single oral doses of RP at 10,000 IU or 30,000 IU produced dose-related and sustained increases in Cmax and AUC0-24 h values of plasma RP, RO, RS, 13-cis- and 13-cis-4-oxo-RAs, as well as a transient increase in AT-RA. In conclusion, our results provide evidence that human topical exposure to retinol- or retinyl ester-containing cosmetic creams at 30,000 IU/day and maximal use concentrations do not affect plasma levels of retinol, retinyl esters or RAs, whereas single oral doses at 10,000 IU or 30,000 IU produce significant increases in plasma retinyl esters and RAs.

An assessment of the phototoxic hazard of a personal product ingredient using in vitro assays.

Where substances are intended for use in personal products applied to the skin an assessment of potential phototoxic hazard is required. This report describes a tiered testing strategy involving in vitro assays used for the phototoxic hazard assessment of a personal product ingredient (Ingredient X). The initial assay was measurement of a UV/visible absorption spectrum to identify absorption at relevant wavelengths. This was followed by in vitro assays for phototoxicity (3T3 cell neutral red uptake phototoxicity test) and photoallergy (photobinding to human serum albumin). These in vitro screens gave equivocal results for Ingredient X which appeared to suggest a weak phototoxic reaction. To further evaluate the phototoxic hazard of Ingredient X to human skin, a phototoxicity assay using a 3-D human skin model was conducted. Ingredient X did not cause phototoxicity in this assay. Overall conclusions from these studies were that although Ingredient X showed slight intrinsic potential for photoactivation, it was unlikely to present a hazard to human skin. This report illustrates the value in a step-wise strategy of the use of human skin models to help interpret the results of other in vitro phototoxicity assays.

An evidence-based review of patient-centered behavioral interventions for hypertension.

INTRODUCTION: While behavioral interventions may be viewed as important strategies to improve blood pressure (BP), an evidence-based review of studies evaluating these interventions may help to guide clinical practice. METHODS: We employed systematic review and meta-analysis of the literature (1970-1999) to assess the independent and additive effects of three behavioral interventions on BP control (counseling, self-monitoring of BP, and structured training courses). RESULTS: Of 232 articles assessing behavioral interventions, 15 (4072 subjects) evaluated the effectiveness of patient-centered counseling, patient self-monitoring of BP, and structured training courses. Pooled results revealed that counseling was favored over usual care (3.2 mmHg [95% CI, 1.2-5.3] improvement in diastolic blood pressure [DBP] and 11.1 mmHg [95% CI, 4.1-18.1] improvement in systolic blood pressure [SBP]) and training courses (10 mmHg improvement in DBP [95% CI, 4.8-15.6]). Counseling plus training was favored over counseling (4.7 mmHg improvement in SBP [95% CI, 1.2-8.2]) and afforded more subjects hypertension control (95% [95% CI, 87-99]) than those receiving counseling (51% [95% CI, 34-66]) or training alone (64% [95% CI, 48-77]). CONCLUSIONS: Evidence suggests that counseling offers BP improvement over usual care, and that adding structured training courses to counseling may further improve BP. However, there is not enough evidence to conclude whether self-monitoring of BP or training courses alone offer consistent improvement in BP over counseling or usual care. The magnitude of BP reduction offered by counseling indicates this may be an important adjunct to pharmacologic therapy.

A computerized tool for evaluating the effectiveness of preventive interventions.

In identifying appropriate strategies for effective use of preventive services for particular settings or populations, public health practitioners employ a systematic approach to evaluating the literature. Behavioral intervention studies that focus on prevention, however, pose special challenges for these traditional methods. Tools for synthesizing evidence on preventive interventions can improve public health practice. The authors developed a literature abstraction tool and a classification for preventive interventions. They incorporated the tool into a PC-based relational database and user-friendly evidence reporting system, then tested the system by reviewing behavioral interventions for hypertension management. They performed a structured literature search and reviewed 100 studies on behavioral interventions for hypertension management. They abstracted information using the abstraction tool and classified important elements of interventions for comparison across studies. The authors found that many studies in their pilot project did not report sufficient information to allow for complete evaluation, comparison across studies, or replication of the intervention. They propose that studies reporting on preventive interventions should (a) categorize interventions into discrete components; (b) report sufficient participant information; and (c) report characteristics such as intervention leaders, timing, and setting so that public health professionals can compare and select the most appropriate interventions.

Developing the Guide to Community Preventive Services--overview and rationale. The Task Force on Community Preventive Services.

When the GUIDE TO COMMUNITY PREVENTIVE SERVICES: Systematic Reviews and Evidence-Based Recommendations (the Guide) is published in 2001, it will represent a significant national effort in encouraging evidence-based public health practice in defined populations (e.g., communities or members of specific managed care plans). The Guide will make recommendations regarding public health interventions to reduce illness, disability, premature death, and environmental hazards that impair community health and quality of life. The Guide is being developed under the guidance of the Task Force on Community Preventive Services (the Task Force)-a 15-member, nonfederal, independent panel of experts. Subject matter experts, methodologists, and scientific staff are supporting the Task Force in using explicit rules to conduct systematic literature reviews of evidence of effectiveness, economic efficiency, and feasibility on which to base recommendations for community action. Contributors to the Guide are building on the experience of others to confront methodologic challenges unique to the assessment of complex multicomponent intervention studies with nonexperimental or nonrandomized designs and diverse measures of outcome and effectiveness. Persons who plan, fund, and implement population-based services and policies to improve health at the state and local levels are invited to scrutinize the work in progress and to communicate with contributors. When the Guide is complete, readers are encouraged to consider critically the value and relevance of its contents, the implementation of interventions the Task Force recommends, the abandonment of interventions the Task Force does not recommend, and the need for rigorous evaluation of the benefits and harms of promising interventions of unknown effectiveness.

Scope and organization of the Guide to Community Preventive Services. The Task Force on Community Preventive Services.

BACKGROUND: The diverse nature of the target audience (i.e., public health decision-makers) for the Guide to Community Preventive Services: Systematic Reviews and Evidence-Based Recommendations (the Guide) dictates that it must be broad in scope. In addition, for the Guide to be most useful for its target audience, its organization and format must be carefully considered. DETERMINING THE SCOPE OF THE GUIDE: Healthy People objectives and actual causes of death were used to determine the contents of the Guide. A priority setting exercise resulted in the selection of 15 topics for systematic reviews using the following criteria: burden of the problem, preventability, relationship to other public health initiatives, usefulness of the package of topics selected and level of current research and intervention activity in public and private sectors. Interventions within each topic target state and local levels and include population-based strategies, individual strategies in other than clinical settings and group strategies. ORGANIZATION OF THE GUIDE: The Guide is organized into: Introduction, Reviews and Recommendations (three sections: Changing Risk Behaviors, Reducing Diseases, Injuries, or Impairments, and Addressing Environmental and Ecosystem Challenges), Appendixes, and Indexes. DISCUSSION: The scope and organization of the Guide were determined using relevant public health criteria and expert opinion to provide a useful and accessible document to a broad target audience. While the final contents of the Guide may change during development, the working table of contents described in this paper provides a framework for development of the Guide and conveys its scope and intention.

Poverty and ill health: physicians can, and should, make a difference.

A growing body of research confirms the existence of a powerful connection between socioeconomic status and health. This research has implications for both clinical practice and public policy and deserves to be more widely understood by physicians. Absolute poverty, which implies a lack of resources deemed necessary for survival, is self-evidently associated with poor health, particularly in less developed countries. Over the past two decades, economic decline or stagnation has reduced the incomes of 1.6 billion people. Strong evidence now indicates that relative poverty, which is defined in relation to the average resources available in a society, is also a major determinant of health in industrialized countries. For example, persons in U.S. states with income distributions that are more equitable have longer life expectancies than persons in less egalitarian states. There are numerous possible approaches to improving the health of poor populations. The most essential task is to ensure the satisfaction of basic human needs: shelter, clean air, safe drinking water, and adequate nutrition. Other approaches include reducing barriers to the adoption of healthier modes of living and improving access to appropriate and effective health and social services. Physicians as clinicians, educators, research scientists, and advocates for policy change can contribute to all of these approaches. Physicians and other health professionals should understand poverty and its effects on health and should endeavor to influence policymakers nationally and internationally to reduce the burden of ill health that is a consequence of poverty.

The physician's perception of health care.

A general malaise appears to have settled on the American medical scene; most Americans continue to trust their own physicians but do not trust the medical profession or the health system as a whole, while many physicians feel harassed by the regulatory, bureaucratic, or litigious intrusions upon the patient-doctor relationship. The strains on mutual trust among physicians, their patients, and the public are being played out against a background of contradictions. The advances of biomedicine are offset by the neglect of social and behavioural aspects of medical care. Preoccupation with specialized, hospital-based treatment is accompanied by isolation of public health and preventive interests from medical education and practice. Society remains uncertain whether health care is a right or a privilege while accepting public responsibility for financing the health care of certain groups such as the indigent sick (Medicaid), the elderly (Medicare), Native Americans, or members of the armed forces and veterans. Rising expectations about better outcomes through advances in technology are accompanied by rising anxieties about cost, appropriateness of care, access, and quality. Physicians must alter their perception of health care by adopting a population-based approach to need, a commitment to restoring equity in staffing patterns and compensation between primary care and specialty care, and adoption of a social contract that provides for full access by all Americans to basic cost-effective preventive and clinical services before spending on less cost-effective services.

Diffusion of the U.S. Preventive Services Task Force recommendations into practice.

The U.S. Preventive Services Task Force's "Guide to Clinical Preventive Services" summarizes the results of a critical review of the literature pertaining to the effectiveness of 169 interventions in modifying 60 risk factors or conditions. The ultimate impact of the guide depends on the diffusion into clinical practice of its recommendations. This report reviews the factors influencing the diffusion process. Three categories of behavioral influence--predisposing, enabling, and reinforcing factors--apply to this diffusion process. Predisposing factors include knowledge and attitudes, personal health behaviors, confidence, and beliefs about patients' interests in health-promotion advice. Enabling factors include competence to perform preventive services, reimbursement for preventive services, organization of the practice setting, time to provide preventive services, a reminder system, and a coherent set of guidelines that are perceived as scientific and unambiguous. Reinforcing factors include peer support, feedback, evidence of results, and an enhanced sense of self-efficacy in fulfilling one's role as a healer. Recommendations are given for using these factors to increase the diffusion of preventive services into clinical practice.

Effectiveness of methods used to teach breast self-examination.

The efficacy of breast self-examination (BSE) is limited by the extent to which women can be taught to perform a frequent and proficient examination. We randomized 783 women from a health maintenance organization into group instruction, individual instruction, individual instruction with a reminder system, or minimal intervention designed to simulate an office encounter where BSE was encouraged but not taught. The percentage of lumps 1 cm and smaller detected in silicone breast models, the number of false-positive detections, the search technique, and the self-reported BSE frequency were measured before and four months after intervention. Multiple tests for comparisons of interventions showed that the interventions containing BSE instruction were comparable in increasing true- and false-positive detection of lumps and in improving search technique, but the minimal intervention resulted in lower scores for all three outcomes (P less than .0001). Women in all four intervention groups increased their BSE frequency over the four-month follow-up period, but the greatest improvement in frequency was reported among women receiving reminders.

Inventory of knowledge and skills relating to disease prevention and health promotion.

An inventory of the knowledge and skills appropriate for the instruction of medical students in the disciplines of disease prevention and health promotion was developed by a steering committee of medical practitioners and teachers, with the input of over 70 colleagues. The inventory, which is intended as a guide for curriculum planners, defines the fundamentals of subject areas appropriate for the general education of all physicians, including the skills and knowledge related to delivery of personal disease prevention/health promotion services, quantitative methods, health services organization and delivery, and community dimensions of medical practice, as well as attitudes and philosophy.