Secondary Prevention 1: Cancers and Principles of Screening

Screening tests are used to differentiate between persons with and without the condition of interest in a defined population. Screening strategies, or mass screening, is applied relatively indiscriminately to a population. Cancer is the second-leading overall cause of death in the United States; however, it is the leading cause of death for those under 85. Cancer risk is associated with environmental risk factors. Racial disparities in cancer incidence and death persist in the United States; level of education also appears to affect cancer survival. The United States Preventive Services Task Force has established evidence-based guidelines for screening, counseling, and chemoprevention.

Biostatistics 1: Basic Concepts

Chapter 1 reviews basic concepts of biostatistics. Topics include descriptive data, probability and odds, estimation and sampling error, hypothesis testing, and power and sample size calculations. The discussion of descriptive data includes types of data (discrete vs continuous and nominal vs ordinal), central tendency (mean, median, and mode), skewed distributions, and measures of dispersion (range, variance, standard deviation). Probability and odds are broken down into laws of probability, odds, odds ratio, relative risk, and probability distribution. The examination of estimation and sampling error covers concepts such as random error, bias, standard error, point estimation, and interval estimation.

Aerospace Medicine

Aerospace medicine focuses on the clinical care, research, and operational support of the health, safety, and performance of crewmembers and passengers of air and space vehicles, together with the support personnel who assist operation of such vehicles. Understanding of the 5 basic gas laws aids understanding of aeromedically significant effects, specifically hypoxia, volume changes at higher altitudes, and decompression illness. Signs and symptoms of decompression illness may include pain in and around joints. More serious is the affliction of heart and lungs or neurologic problems. Physiologic stressors of commercial flight can include decreased partial pressure of oxygen, vibration, noise, humidity, expansion of trapped gases, and thermal stress. Aeromedical transportation of patients with more serious medical conditions requires appropriate equipment, staffing, and coordination of logistical issues. There are 15 specific conditions that disqualify aviators under FAA rules. The primary purpose of aircraft mishap investigations is to prevent future accidents, injuries, and fatalities. Accidents are investigated with multidisciplinary teams, including physicians, following standardized investigation guidelines.

Immunization

The use of vaccines can be traced back to China and India before 200 BC. Vaccination, now considered one of the most effective public health interventions, became common practice in the 1940s with the introduction of vaccines for diphtheria and tetanus. Since that time, many infectious diseases have been well controlled through vaccination. This chapter focuses on live and attenuated bacterial and viral vaccines and those that are composed of toxoids. Hepatitis B, pneumococcal disease, and influenza are the most common vaccine-preventable diseases in adults. Rates of childhood vaccination remain suboptimal. Ideally, vaccination begins before infants are dismissed home after birth. Targeted awareness campaigns can be used to educate providers and the public about the importance of immunization.

Epidemiology 2: Study Design

The usefulness of evidence arising from scientific research is influenced by several factors, and foremost among these factors is the design of the epidemiologic study from which the findings are drawn. In evidence-based medicine, the quality of scientific evidence is often graded on the base of the type of study design and includes appraisal of methods by which studies of exposure and outcomes are planned and implemented. Several factors must be considered when designing a scientific study, including the hypothesis being tested, study cost, time frame, subject characteristics, choice of variables or measurements, and ethical concerns. In this chapter, the different types of study designs commonly encountered in clinical research, common measures of morbidity and mortality in epidemiology, and errors (random and systematic) that may threaten conclusions derived from inferences arising from epidemiologic studies are discussed.

Public Health Practice, Leadership, and Health Care Law

Public health is focused on health at the population level. This broad focus allows public health officials to use strategies and tools that differ from those used by health care providers, who focus on individual patients. Determinants of health include access to education, safe working environments, and safe and reliable sources of nutrition. Community empowerment aims to create sustainable change through vocational training, health education, policy changes, and other actions. Quarantine, incarceration, or forced treatment can be used by public health agencies if they provide proof of danger to the community. Licensure authorizes an agency to create rules that regulate the activities of the professional or entity; medical examinations can be mandated. The ethical principles of nonmaleficence and beneficence are the same for public health and medicine. Ethics in public health also consider the needs of the population and how that may interfere with individual freedoms. Various types of cost analyses can be performed to determine where best to apply available public health funds.

Behavioral Medicine and Substance Abuse

The goal of preventive medicine is to prevent premature death and disability. The successful practitioner of preventive medicine mush be skilled at facilitating behavior change in patients because behaviors such as smoking, sedentary lifestyle, poor nutrition, alcohol misuse, and illegal drug use are the leading causes of premature death and disability in the United States. This chapter focuses on the key knowledge and skills necessary for physicians to stimulate changes in patient behavior.

Occupational Medicine

Occupational medicine is the medical specialty devoted to 1) prevention and management of occupational injury, illness, and disability, and 2) promotion of health and productivity of workers, their families, and communities. Historically, occupational medicine was termed industrial medicine when heavy industry (eg, lumbering, automobile manufacturing, mining, railroads, steel manufacturing) employed physicians to provide acute medical and surgical care for workers. However, by 1945, medical programs had spread to business organizations that predominantly were staffed with clerical and service employees (eg, banks, insurance companies, mercantile establishments). The broader designation of occupational medicine then came into common use. Occupational medicine was recognized as a specialty by the American Board of Preventive Medicine in 1955.

Injury Prevention and Control

In its most basic definition, human injury is the result of a transfer of energy of sufficient magnitude to damage tissues of the human recipient. Adoption of the infectious disease model of an agent (energy), a carrier (living or inanimate; a vector), and the affected person (host) has proved helpful in analyzing the chain of causation that leads to injury. For the inclusion of important injuries, the definition of causation is often modified to include exposures that prevent needed energy from reaching a host-for example, a lack of thermal energy (heat) that results in frostbite. For persons younger than 45, injury is the most frequent cause of death. Years of potential life lost is an important measure of the cost and health burden of injuries on society. With systematic identification of the causal factors of injury and the events leading up to and following injury, a comprehensive intervention can be carried out to reduce the occurrence of injury in various settings.

Obesity, Nutrition, and Physical Activity

The prevalence of obesity has increased markedly over the past few decades in the United States. This increase has occurred across all ethnic groups and all ages, including childhood and adolescence. After obesity has developed, long-term results from the treatment of obesity are generally poor. The importance of diet and nutrition in the prevention of the disease has been widely reported. An estimated 365,000 deaths occur each year because of suboptimal diet and activity habits. Dietary factors play a prominent role in 5 of the 10 leading causes of death for Americans: heart disease, cancer, stroke, diabetes mellitus, and cerebrovascular disease. The health benefits of physical activity and exercise are broad, strong, and well-documented. Health benefits appear to increase linearly with the total amount of physical activity.