الصفحة الرئيسية
س .و .ج
من طرف السلام عليكم
هدا المخلص شاركوا في اعداده
زينب علي
وزهرة علي
ومشكورين على هالمجهود الطيب
اترككم مع الملخص
هدا المخلص شاركوا في اعداده
زينب علي
وزهرة علي
ومشكورين على هالمجهود الطيب
اترككم مع الملخص
Epidemiology:
Is the study of frequency, distribution & determinants of health & health related events occurring in community and application of this knowledge to prevent diseases, promot health & prolong life.
Measurement of mortality:
Case fatality rates = Total no of deaths(disease) / Total no of cases(same disease)
Measurement of morbidity:
Attack rate: Is an incidence rate when population is exposed to risk for a limited period of time( during an epidemic)
Secondary attack rate:
Number of exposed persons developing disease within the range of the incubation period following exposure to a primary case.
Measurement of fertility (Natality):
a. Crude birth rate (CBR) = (no. of live birth in yr / mid yr population) X 1000.
b. General fertility rate (GFR) = (no. of live birth in yr / no. of women in age (15-49yr) ) X 1000.
c. Total fertility rate (TFR) = average no of children a women would have during her reproductive yrs.
d. Net reproduction rate (NRR) = no of daughters born to women.
Cross-sectional / prevalence study:
simplest, observational, based on single observation / examination of cross-section of population, at one point of time, more useful for chronic diseases.
Longitudinal studies / Incidence:
observation are repeated in same population over a prolonged period of time by follow-up examinations.
Secular trends:
The long-term-time trend of disease occurrence. There are changes in the incidence or prevalence of a disease that occur over long periods of time.
Epidemics:
are increase in incidence above the expected in a defined geographic area within a defined time period. Used in respect of infectious diseases. / تعريف شرشور Sudden increase of causes of a particular disease (high expectation).
Personal characteristics:
Host factors(age, gender, sex, lifestyle, marital status).
Differences in personal characteristics may contribute to disease occurrence in the following ways:
1. Determining degree of exposure
2. differences in susceptibility
3. likelihood of specific immunity.
Features of case control method:
a. Exposure and outcome occurred before the start of the study.
b. Study proceeds backwards from effect to cause.
c. Uses a control to support the result.
Basic steps of case control study:
1. Selection of cases and controls.
2. Matching.
3. Measurement of exposure.
4. Analysis.
5. Interpretation of results.
Matching:
The process by which we select controls in such a way that they are similar to cases with regard to certain pertinent selected variables which influence the outcome of disease, if not adequately matched for comparability could distort the results.
Confounding factor:
Defined as one which is associated both with exposure and disease and distributed equally in study and control groups. E.g. smoking, drinking alcohol.
