Epidemiology is the study and analysis of the distribution, patterns and determinants of health and disease conditions in a defined population.
Mortality rate, or death rate, is a measure of the number of deaths in a particular population, scaled to the size of that population, per unit of time. Mortality rate is typically expressed in units of deaths per 1,000 individuals per year; thus, a mortality rate of 9.5 in a population of 1,000 would mean 9.5 deaths per year in that entire population, or 0.95% out of the total. It is distinct from "morbidity", which is either the prevalence or incidence of a disease, and also from the incidence rate.
The 1918–1920 flu pandemic, also known as the Great Influenza epidemic or by the common misnomer Spanish flu, was an exceptionally deadly global influenza pandemic caused by the H1N1 influenza A virus. The earliest documented case was March 1918 in the state of Kansas in the United States, with further cases recorded in France, Germany and the United Kingdom in April. Two years later, nearly a third of the global population, or an estimated 500 million people, had been infected in four successive waves. Estimates of deaths range from 17 million to 50 million, and possibly as high as 100 million, making it one of the deadliest pandemics in history.
Estimates of the casualties from the Iraq War have come in several forms, and those estimates of different types of Iraq War casualties vary greatly.
A case–control study is a type of observational study in which two existing groups differing in outcome are identified and compared on the basis of some supposed causal attribute. Case–control studies are often used to identify factors that may contribute to a medical condition by comparing subjects who have the condition with patients who do not have the condition but are otherwise similar. They require fewer resources but provide less evidence for causal inference than a randomized controlled trial. A case–control study is often used to produce an odds ratio. Some statistical methods make it possible to use a case–control study to also estimate relative risk, risk differences, and other quantities.
The Lancet, one of the oldest scientific medical journals in the world, published two peer-reviewed studies on the effect of the 2003 invasion of Iraq and subsequent occupation on the Iraqi mortality rate. The first was published in 2004; the second in 2006. The studies estimate the number of excess deaths caused by the occupation, both direct and indirect.
Sedentary lifestyle is a lifestyle type, in which one is physically inactive and does little or no physical movement and/or exercise. A person living a sedentary lifestyle is often sitting or lying down while engaged in an activity like socializing, watching TV, playing video games, reading or using a mobile phone or computer for much of the day. A sedentary lifestyle contributes to poor health quality, diseases as well as many preventable causes of death.
Global health is the health of the populations in the worldwide context; it has been defined as "the area of study, research, and practice that places a priority on improving health and achieving equity in health for all people worldwide". Problems that transcend national borders or have a global political and economic impact are often emphasized. Thus, global health is about worldwide health improvement, reduction of disparities, and protection against global threats that disregard national borders, including the most common causes of human death and years of life lost from a global perspective.
In epidemiology, case fatality rate (CFR) – or sometimes more accurately case-fatality risk – is the proportion of people who have been diagnosed with a certain disease and end up dying of it. Unlike a disease's mortality rate, the CFR does not take into account the time period between disease onset and death. A CFR is generally expressed as a percentage. It is a measure of disease lethality, and thus may change with different treatments. CFRs are most often used for with discrete, limited-time courses, such as acute infections.
Multimorbidity, also known as multiple long-term conditions (MLTC), means living with two or more chronic illnesses. For example, a person could have diabetes, heart disease and depression at the same time. Multimorbidity can have a significant impact on people's health and wellbeing. It also poses a complex challenge to healthcare systems which are traditionally focused on individual diseases. Multiple long-term conditions can affect people of any age, but they are more common in older age, affecting more than half of people over 65 years old.
Maternal health is the health of women during pregnancy, childbirth, and the postpartum period. In most cases, maternal health encompasses the health care dimensions of family planning, preconception, prenatal, and postnatal care in order to ensure a positive and fulfilling experience. In other cases, maternal health can reduce maternal morbidity and mortality. Maternal health revolves around the health and wellness of pregnant women, particularly when they are pregnant, at the time they give birth, and during child-raising. WHO has indicated that even though motherhood has been considered as a fulfilling natural experience that is emotional to the mother, a high percentage of women develop health problems and sometimes even die. Because of this, there is a need to invest in the health of women. The investment can be achieved in different ways, among the main ones being subsidizing the healthcare cost, education on maternal health, encouraging effective family planning, and ensuring progressive check up on the health of women with children. Maternal morbidity and mortality particularly affects women of color and women living in low and lower-middle income countries.
Tropical diseases, especially malaria and tuberculosis, have long been a public health problem in Kenya. In recent years, infection with the human immunodeficiency virus (HIV), which causes acquired immune deficiency syndrome (AIDS), also has become a severe problem. Estimates of the incidence of infection differ widely.
Economic epidemiology is a field at the intersection of epidemiology and economics. Its premise is to incorporate incentives for healthy behavior and their attendant behavioral responses into an epidemiological context to better understand how diseases are transmitted. This framework should help improve policy responses to epidemic diseases by giving policymakers and health-care providers clear tools for thinking about how certain actions can influence the spread of disease transmission.
The obesity paradox is the finding in some studies of a lower mortality rate for overweight or obese people within certain subpopulations. The paradox has been observed in people with cardiovascular disease and cancer. Explanations for the paradox range from excess weight being protective to the statistical association being caused by methodological flaws such as confounding, detection bias, reverse causality, or selection bias.
The Bradford Hill criteria, otherwise known as Hill's criteria for causation, are a group of nine principles that can be useful in establishing epidemiologic evidence of a causal relationship between a presumed cause and an observed effect and have been widely used in public health research. They were established in 1965 by the English epidemiologist Sir Austin Bradford Hill.
The epidemiology of depression has been studied across the world. Depression is a major cause of morbidity and mortality worldwide, as the epidemiology has shown. Lifetime prevalence estimates vary widely, from 3% in Japan to 17% in India. Epidemiological data shows higher rates of depression in the Middle East, North Africa, South Asia and the United States than in other regions and countries. For most countries among the 10 studied, the number of people who experience depression during their lifetimes falls within an 8–12% range.
Globally, an estimated 537 million adults are living with diabetes, according to 2019 data from the International Diabetes Federation. Diabetes was the 9th-leading cause of mortality globally in 2020, attributing to over 2 million deaths annually due to diabetes directly, and to kidney disease due to diabetes. The primary causes of type 2 diabetes is diet and physical activity, which can contribute to increased BMI, poor nutrition, hypertension, alcohol use and smoking, while genetics is also a factor. Diabetes prevalence is increasing rapidly; previous 2019 estimates put the number at 463 million people living with diabetes, with the distributions being equal between both sexes icidence peaking around age 55 years old. The number is projected to 643 million by 2030, or 7079 individuals per 100,000, with all regions around the world continue to rise. Type 2 diabetes makes up about 85-90% of all cases. Increases in the overall diabetes prevalence rates largely reflect an increase in risk factors for type 2, notably greater longevity and being overweight or obese. The prevalence of African Americans with diabetes is estimated to triple by 2050, while the prevalence of whites is estimated to double. The overall prevalence increases with age, with the largest increase in people over 65 years of age. The prevalence of diabetes in America is estimated to increase to 48.3 million by 2050.
The COVID-19 pandemic has impacted healthcare workers physically and psychologically. Healthcare workers are more vulnerable to COVID-19 infection than the general population due to frequent contact with infected individuals. Healthcare workers have been required to work under stressful conditions without proper protective equipment, and make difficult decisions involving ethical implications. Health and social systems across the globe are struggling to cope. The situation is especially challenging in humanitarian, fragile and low-income country contexts, where health and social systems are already weak. Services to provide sexual and reproductive health care risk being sidelined, which will lead to higher maternal mortality and morbidity.
Health Care In Danger is a campaign organized by the International Committee of the Red Cross that highlights violent attacks on patients, healthcare workers, and healthcare facilities in conflict zones.
