Books, E-Books Great Discounts

PREVALENCE

Sociologyindex, Sociology Books 2011, Prevalence, Incidence, epidemiology

In epidemiology, the term prevalence tells us about the number of particular events in the community. AIDS for example may be very prevalent (the total number with this syndrome) but the incidence (new cases) is going down each year. The prevalence of a disease in a statistical population is defined as the total number of cases of the disease in the population at a given time, or the total number of cases in the population, divided by the number of individuals in the population.

"Prevalence" means "extent", but in scientific English it means "proportion" which is expressed as a percentage. Prevalence is distinct from incidence.

Prevalence is a measurement of all individuals affected by the disease within a particular period of time.

Incidence is a measurement of the number of new individuals who contract a disease during a particular period of time.

Lifetime prevalence is the number of individuals in a statistical population that at some point in their life have experienced a disorder, compared to the total number of individuals. A 12-month prevalence is used in conjunction with lifetime prevalence.

Point prevalence, the prevalence of disorder at a more specific point in time. Point prevalence means the prevalence, or number of cases, a “snapshot” of cases, at a certain point in time.  The point in time could be any length, from an hour to a month. It is important to note that while point prevalence reflects the magnitude of health events; it may not be useful in finding causes for disease.

Incidence is a contrasting term to prevalence telling us the frequency of occurrence of some event during a particular time period. For instance, there were 581 criminal homicides in 1997, or the rate of crime for one year is higher or lower than for the previous year.

Incidence is the number of new cases of a condition, symptom, or death that arise during a specific period of time.. Incidence is often expressed as a percentage of a population (for example, 25% of Americans were diagnosed with the flu in 2002). Incidence shows the likelihood that a person in that population will be affected by the condition.

Incidence proportion and cumulative incidence are the number of new cases within a specified time period divided by the size of the population initially at risk. The incidence rate is the number of new cases per unit of person-time at risk.

Cumulative incidence is the incidence calculated using a period of time during which all of the individuals in the population are considered to be at risk for the outcome. It is sometimes referred to as the incidence proportion.

Examples of prevalence studies:

How common is anorexia nervosa? A prevalence study
AH Crisp, RL Palmer and RS Kalucy
The British Journal of Psychiatry 128: 549-554 (1976) © 1976 The Royal College of Psychiatrists
During 1972-74 nine populations of schoolgirls were surveyed in respect of the occurrence of anorexia nervosa. As well as the current school year, previous years (going back variously 3-6 years) were also carefully studied within seven of the schools. Anorexia nervosa was only identified as present or having been present if the diagnosis was unequivocal: for instance, seemingly evident and severe cases which could not be traced were excluded. The condition in severe form was found to be relatively common in the independent sector of education, probably implying a social class factor. In all such schools, the prevalence was one severe case in approximately every 200 girls. In those aged 16 and over it amounted to one severe case in about every 100 girls. Overall, these schools encountered one 'new' severe case in every 250 pupils aged 16 years and over. The condition is likely to be even more common than this study allows because of the stringent limits set here on inclusion of cases and the age-bands studied. It is concluded that severe anorexia nervosa is a common condition and is probably getting more common.

Misuse of "study drugs:" prevalence, consequences, and implications for policy
Steve Sussman, Mary Ann Pentz, Donna Spruijt-Metz and Toby Miller
Substance Abuse Treatment, Prevention, and Policy 2006, 1:15doi:10.1186/1747-597X-1-15
Abstract: Background: Non-medical/illegal use of prescription stimulants popularly have been referred to as "study drugs". This paper discusses the current prevalence and consequences of misuse of these drugs and implications of this information for drug policy.
Results: Study drugs are being misused annually by approximately 4% of older teens and emerging adults. Yet, there are numerous consequences of misuse of prescription stimulants including addiction, negative reactions to high dosages, and medical complications. Policy implications include continuing to limit access to study drugs, finding more safe prescription drug alternatives, interdiction, and public education.
Conclusion: Much more work is needed on prescription stimulant misuse assessment, identifying the extent of the social and economic costs of misuse, monitoring and reducing access, and developing prevention and cessation education efforts.

Does Religion Increase the Prevalence and Incidence of Obesity and Severe Obesity in Adulthood?
Clark, Krista. and Ferraro, Kenneth
Paper presented at the annual meeting of the American Sociological Association
Abstract: Previous research reveals that religion in America is related to variations in body weight, but the reasons for this association remain unclear. This paper examines the relationships between religion and both obesity and severe obesity, which have increased in prevalence in the United States over the past two decades. Using longitudinal data from a national sample of adults, this study prospectively examines whether dimensions of religious life are associated with the development of obesity during eight years of follow-up. Four dimensions of religiosity (attendance, salience, media practice, and consolation) and religious affiliation are examined. Logistic regression analyses reveal that high levels of religious media practice and affiliation with a Baptist denomination increased the risk of obesity and severe obesity. Although religious media practice was associated with greater risk of obesity, attendance at religious services did not influence the prevalence or incidence of obesity or severe obesity.

Books, E-Books Great Discounts