设a为m×n的矩阵,m what is the definition of epidemiology ?
what is the definition of epidemiology ?
which one is true about epidemiology ?
which one is not the characteristics of epidemiology ?
what is the fundamental difference between observational and experimental methods in epidemiological studies ?
what is the difference between epidemiology and clinical medicine ?
please describe the major function of epidemiology
the relationship between numerator and denominator in rate
the relationship between incidence and prevalence
is it correct that the mortality rate of hydrophobia is 100%
what are the two parts of da?
what is the study to compare the history of oral contraceptives between patients with cervical carcinoma and other patients hospitalized at the same time in order to explore the relationship between oral contraceptives and cervical carcinoma ?
what is the numerator of incidence in an exposed population during a certain period ?
the definition of prevalence is
a approach to comprehensively describe the distributions of time, population, and region for a disease is
which of the following characteristics do descriptive studies have?
what are the advantages of the prevalence survey study?
which is the method of yzing and researching in groups without inidual data?
which is the characteristics of the sampling survey that are not included?
which is the way to early detection and treatment of patients?
in order to ensure that the sample can reflect the overall situation, what should be considered in the ysis?
to test the cause of a hypothesis, who should be included in a cohort study?
regarding the historical cohort study, which is wrong with the statement?
from the methodological point of view, what type of research does the cohort study belong to?
which is the most common bias in cohort studies?
describe the factors influencing the sample size.
what is the nested case-control study?
the advantages and disadvantages of using prevalent case
what are the advantages and disadvantages of matching
can you distinguish the matched and unmatched case-control
what are limitations of case-control studies?
a case-control study is characterized by all of the following except:
which of the following is a case-control study?
state the main advantages and disadvantages of case-control studies
which feature cannot be found in randomized controlled trials
the difference in epidemiological experimental studies compared with prospective cohort studies is
describe the characteristics of clinical trials.
the incorrect statement about screening test is
when the consequences of misdiagnosis are serious, the test is required to have a higher
the indicator that can be used to evaluate the accuracy of the diagnostic test method is
carry one screening test, which principle should be followed?
which one is correct about necessary cause ?
one factor and a disease are both related to another factor.the resulting statistical asssociation between the disease and another factor is called