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Pearl Index
The Pearl Index, also called the Pearl rate, is the most common technique used in clinical trials for reporting the effectiveness of a birth control method. It is a very approximate measure of the number of unintended pregnancies in 100 woman-years of exposure that is simple to calculate, but has a number of methodological deficiencies. The index was introduced by Raymond Pearl in 1934. It has remained popular for over eighty years, in large part because of the simplicity of the calculation. Calculation Several kinds of information are needed to calculate a Pearl Index for a particular study: * the total number months or cycles of exposure by women in the study * the number of pregnancies * the reason for leaving the study (pregnancy or other reason) * the number of children in a single pregnancy (twins or triplets can affect the final number) There are two calculation methods for determining the Pearl Index: * in the first method, the relative number of pregnancies in the study ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clinical Trials
Clinical trials are prospective biomedical or behavioral research studies on human participants designed to answer specific questions about biomedical or behavioral interventions, including new treatments (such as novel vaccines, drugs, dietary choices, dietary supplements, and medical devices) and known interventions that warrant further study and comparison. Clinical trials generate data on dosage, safety and efficacy. They are conducted only after they have received health authority/ethics committee approval in the country where approval of the therapy is sought. These authorities are responsible for vetting the risk/benefit ratio of the trial—their approval does not mean the therapy is 'safe' or effective, only that the trial may be conducted. Depending on product type and development stage, investigators initially enroll volunteers or patients into small pilot studies, and subsequently conduct progressively larger scale comparative studies. Clinical trials can vary i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Birth Control
Birth control, also known as contraception, anticonception, and fertility control, is the use of methods or devices to prevent unwanted pregnancy. Birth control has been used since ancient times, but effective and safe methods of birth control only became available in the 20th century. Planning, making available, and using birth control is called family planning. Some cultures limit or discourage access to birth control because they consider it to be morally, religiously, or politically undesirable. The World Health Organization and Centers for Disease Control and Prevention, United States Centers for Disease Control and Prevention provide guidance on the safety of birth control methods among women with specific medical conditions. The most effective methods of birth control are Sterilization (medicine), sterilization by means of vasectomy in males and tubal ligation in females, intrauterine devices (IUDs), and contraceptive implant, implantable birth control. This is follo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Raymond Pearl
Raymond Pearl (June 3, 1879 – November 17, 1940) was an American biologist, regarded as one of the founders of biogerontology. He spent most of his career at Johns Hopkins University in Baltimore. Pearl was a prolific writer of academic books, papers and articles, as well as a committed populariser and communicator of science. At his death, 841 publications were listed against his name. Early life Pearl was born into an upper-middle class family on June 3, 1879, in Farmington, New Hampshire, the son of Ida May (McDuffee) and Frank Pearl. At an early age, Pearl was exposed to the classics. His parents and grandparents wanted him to study Greek and Latin. However, when he attended Dartmouth College at 16 years old, he became fascinated by biology and graduated with a B.A. as the youngest in his class. At Dartmouth, he was known to be an exceptional student as well as a skilled musician. He was capable of playing almost every wind instrument, and he planned amateur music perfo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Menstrual Cycle
The menstrual cycle is a series of natural changes in hormone production and the structures of the uterus and ovaries of the female reproductive system that make pregnancy possible. The ovarian cycle controls the production and release of eggs and the cyclic release of estrogen and progesterone. The uterine cycle governs the preparation and maintenance of the lining of the uterus (womb) to receive an embryo. These cycles are concurrent and coordinated, normally last between 21 and 35 days, with a median length of 28 days, and continue for about 30–45 years. Naturally occurring hormones drive the cycles; the cyclical rise and fall of the follicle stimulating hormone prompts the production and growth of oocytes (immature egg cells). The hormone estrogen stimulates the uterus lining ( endometrium) to thicken to accommodate an embryo should fertilization occur. The blood supply of the thickened lining provides nutrients to a successfully implanted embryo. If implantation does n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unintended Pregnancy
Unintended pregnancies are pregnancies that are mistimed, unplanned or unwanted at the time of conception. Sexual activity without the use of effective contraception through choice or coercion is the predominant cause of unintended pregnancy. Worldwide, the unintended pregnancy rate is approximately 45% of all pregnancies, but rates of unintended pregnancy vary in different geographic areas and among different sociodemographic groups. Unintended pregnancies may be unwanted pregnancies or mistimed pregnancies. While unintended pregnancies are the main reason for induced abortions, unintended pregnancies may also result in other outcomes, such as live births or miscarriages. Unintended pregnancy has been linked to numerous poor maternal and child health outcomes, regardless of the outcome of the pregnancy. Efforts to decrease rates of unintended pregnancy have focused on improving access to effective contraception through improved counseling and removing barriers to contraception a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Comparison Of Birth Control Methods
There are many methods of birth control (or contraception) that vary in requirements, side effects, and effectiveness. As technology, education, and awareness about contraception has evolved, new contraception methods have been theorized and put in application. Although no method of birth control is ideal for every user, some methods remain more effective, affordable or intrusive than others. Outlined here are the different types of barrier methods, hormonal methods, various methods including spermicides, emergency contraceptives, and surgical methods and a comparison between them. It is worth noting that while many methods may prevent contraception, only male and female condoms are effective in order to prevent sexually transmitted infections. Methods Hormonal methods The IUD (intrauterine device) is a 'T' shaped device that is inserted into the uterus by a trained medical professional. There are two different types of IUDs, a copper or a hormonal IUD. The copper IUD ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Decrement Table
Decrement tables, also called life table methods, are used to calculate the probability of certain events. Birth control Life table methods are often used to study birth control effectiveness. In this role, they are an alternative to the Pearl Index. As used in birth control studies, a decrement table calculates a separate effectiveness rate for each month of the study, as well as for a standard period of time (usually 12 months). Use of life table methods eliminates time-related biases (i.e. the most fertile couples getting pregnant and dropping out of the study early, and couples becoming more skilled at using the method as time goes on), and in this way is superior to the Pearl Index. Two kinds of decrement tables are used to evaluate birth control methods. Multiple-decrement (or competing) tables report net effectiveness rates. These are useful for comparing competing reasons for couples dropping out of a study. Single-decrement (or noncompeting) tables report gross effective ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Life Table
In actuarial science and demography, a life table (also called a mortality table or actuarial table) is a table which shows, for each age, what the probability is that a person of that age will die before their next birthday ("probability of death"). In other words, it represents the survivorship of people from a certain population. They can also be explained as a long-term mathematical way to measure a population's longevity. Tables have been created by demographers including Graunt, Reed and Merrell, Keyfitz, and Greville. There are two types of life tables used in actuarial science. The period life table represents mortality rates during a specific time period of a certain population. A cohort life table, often referred to as a generation life table, is used to represent the overall mortality rates of a certain population's entire lifetime. They must have had to be born during the same specific time interval. A cohort life table is more frequently used because it is able to ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Birth Control
Birth control, also known as contraception, anticonception, and fertility control, is the use of methods or devices to prevent unwanted pregnancy. Birth control has been used since ancient times, but effective and safe methods of birth control only became available in the 20th century. Planning, making available, and using birth control is called family planning. Some cultures limit or discourage access to birth control because they consider it to be morally, religiously, or politically undesirable. The World Health Organization and Centers for Disease Control and Prevention, United States Centers for Disease Control and Prevention provide guidance on the safety of birth control methods among women with specific medical conditions. The most effective methods of birth control are Sterilization (medicine), sterilization by means of vasectomy in males and tubal ligation in females, intrauterine devices (IUDs), and contraceptive implant, implantable birth control. This is follo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methods Of Birth Control
Method ( grc, μέθοδος, methodos) literally means a pursuit of knowledge, investigation, mode of prosecuting such inquiry, or system. In recent centuries it more often means a prescribed process for completing a task. It may refer to: *Scientific method, a series of steps, or collection of methods, taken to acquire knowledge *Method (computer programming), a piece of code associated with a class or object to perform a task *Method (patent), under patent law, a protected series of steps or acts *Methodology, comparison or study and critique of individual methods that are used in a given discipline or field of inquiry *''Discourse on the Method'', a philosophical and mathematical treatise by René Descartes * ''Methods'' (journal), a scientific journal covering research on techniques in the experimental biological and medical sciences Arts *Method (music), a kind of textbook to help students learning to play a musical instrument * ''Method'' (2004 film), a 2004 film directed by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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