Half-life: From 2 Different Sources
The time taken for the activity of a substance to reduce to half its original level. The term is usually used to refer to the time taken for the level of radiation emitted by a radioactive substance to decay to half its original level. The concept is useful in radiotherapy for assessing how long material will stay radioactive in the body. Half-life is also used to refer to the length of time taken by the body to eliminate half the quantity of a drug.
The time taken for the PLASMA concentration of an administered drug to decline by half as a result of redistribution, METABOLISM and EXCRETION.
The average number of years of life remaining to a person at a particular age based on a given set of age-specific death rates, generally the mortality conditions existing in the period mentioned.... life expectancy
Emergency mouth-to-mouth resuscitation of an unconscious person (see APPENDIX 1: BASIC FIRST AID).... kiss of life
Care of older persons who are dying.... end-of-life care
1 The entire course of a person’s life – from infancy to old age. 2 The genetically prescribed course followed by all living organisms, including humans.... life cycle
A colloquial description of the feelings of anxiety and distress experienced by some individuals in early middle age. They realise that by 45 years of age they are no longer young, and men in particular try to turn the clock back by changing jobs, dressing trendily, taking up energetic or unusual sports or engaging in extramarital liaisons. Sometimes those in mid-life crises develop mild or even serious DEPRESSION. The feelings of anxiety and insecurity usually disappear with time but some people may bene?t from counselling.... mid-life crisis
The product of the interplay between social, health, economic and environmental conditions which affect human and social development. It is a broad-ranging concept, incorporating a person’s physical health, psychological state, level of independence, social relationships, personal beliefs and relationship to salient features in the environment. As people age, their quality of life is largely determined by their ability to access needed resources and maintain autonomy and independence.... quality of life
See ALTE.... acute life-threatening event (alte)
See CLIMACTERIC; MENOPAUSE.... change of life
A modification of conventional life expectancy to account for time lived with disability. It is the number of healthy years of life that can be expected on average in a given population. It is generally calculated at birth, but estimates can also be prepared at other ages. It adjusts the expectation of years of life for the loss on account of disability, using explicit weights for different health states.... disability-adjusted life expectancy
The number of healthy years of life lost due to premature death and disability.... disability-adjusted life years (dalys)
The average number of years an individual of a given age is expected to live if current mortality rates continue to apply. See “life expectancy”.... expectation of life
Individual outcome measure that extends beyond traditional measures of mortality and morbidity to include such dimensions as physiology, function, social activity, cognition, emotion, sleep and rest, energy and vitality, health perception and general life satisfaction (some of these are also known as health status, functional status or quality-of-life measures).... health-related quality-of-life (hrql) measure
See “disability-adjusted life expectancy”.... healthy life expectancy
See “life cycle”.... life course
Longevity, Health, Healing... life everlasting
Insurance providing for payment of a stipulated sum to a designated beneficiary upon death of the insured.... life insurance
See “well-being”.... life satisfaction
The longest period over which the life of any plant or animal organism or species may extend, according to the available biological knowledge concerning it.... life span
Drugs, medical devices, or procedures that can keep alive a person who would otherwise die within a foreseeable, though usually uncertain, time. Examples include cardiopulmonary resuscitation, mechanical ventilation, renal dialysis, nutritional support (i.e. tube or intravenous feeding) and provision of antibiotics to fight life-threatening infections.... life-sustaining treatment
The set of habits and customs that is influenced, modified, encouraged or constrained by the lifelong process of socialization. These habits and customs include the use of substances, such as alcohol, tobacco, tea or coffee; dietary habits; and exercise. They have important implications for health and are often the subject of epidemiological investigation.... lifestyle
Drugs used for non-health problems or for disorders that are in the grey area between a genuine health need and a desire to change a ‘lifestyle failing’ by the use of medication. Examples are: SILDENAFIL CITRATE, which is prescribed for men unable to achieve penile erection (erectile dysfunction); and ORLISTAT, a drug used to combat OBESITY.... lifestyle medicines
Housing built to be adaptable to people’s changing needs, thus avoiding the need for expensive and disruptive adaptations.... lifetime home
Years of life saved by a medical technology or service, adjusted according to the quality of those years (as determined by some evaluative measure). QALYs are the most commonly used unit to express the results in some types of cost-effectiveness analysis.... quality-adjusted life years (qalys)
(ALS) a structured and algorithm-driven method of life support for use in the severest of medical emergencies, especially cardiac arrest. Doctors, nurses, and paramedic personnel involved in ALS receive special training in the use of equipment (e.g. defibrillators and appropriate drugs). Paediatric advanced life support (PALS) is ALS for use in severe medical emergencies in children, while advanced trauma life support(ATLS) is specifically for patients who have been subjected to major trauma, such as a serious road accident. Compare basic life support.... advanced life support
the provision of treatment designed to maintain adequate circulation and ventilation to a patient in *cardiac arrest, without the use of drugs or specialist equipment. Compare advanced life support.... basic life support
(DLQI) a validated questionnaire designed by Finlay in 1994 to assess the impact of skin diseases on psychological and social wellbeing. It is the most common *quality of life tool used as an endpoint in dermatology clinical trials. DLQI scores of more than 10 (indicating a severe impact on life) are required before biological treatments for psoriasis may be administered in the UK.... dermatology life quality index
(DALY) a common research measure of disease burden that accounts for both morbidity and mortality. One year lived in full health is equivalent to one DALY. Disabilities and disease states are assigned a weighting that reduces this figure, such that a year lived with disability is equivalent to less than one DALY. Some studies also use social weighting, in which years lived as a young adult receive a greater DALY weight than those lived as a young child or older adult. See also health-adjusted life expectancy; quality of life.... disability-adjusted life year
a measure developed by the World Health Organization to capture life expectancy in terms of both morbidity and mortality. The number of years lived with ill-health, weighted according to severity, are subtracted from the overall life expectancy. Previously known as disability-adjusted life expectancy, it is sometimes referred to as healthy life expectancy. See also disability-adjusted life year.... health-adjusted life expectancy
an actuarial presentation of the ages at which a group of males and/or females are expected to die and from which mean life expectancy at any age can be estimated, based on the assumption that mortality patterns current at the time of preparation of the table will continue to apply.... life table
the religious or moral belief that all life – and especially all human life – is intrinsically valuable and so should never be deliberately harmed or destroyed. Many of those who hold such a view will have ethical objections to *euthanasia, *abortion, and *embryo research. The phrase may also be used to denote that the value of life should always be respected, whatever the perceived quality of that life. See also humanity; personhood.... sanctity of life
(YLL, years of potential life lost, YPLL, potential years of life lost, PYLL) a measure of premature mortality that calculates the number of additional years a person could have expected to live, on average, had they not died prematurely. A reference age intended to represent the total number of years a person can expect to live, on average, is required for the calculation: this is often given in square brackets after YLL. Negative values for YLL are not used: if somebody survives longer than the reference age, their YLL is calculated as 0. YLLs for different diseases can be compared across populations to give an indication of which diseases carry the greatest burden of premature mortality.... years of life lost
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