Questions tagged [epidemiology]

Epidemiology is the study of the distribution and spread of disease or illness at the population level.

Epidemiology is the study of the distribution and spread of disease or illness at the population level. Epidemiologists make use of techniques and approaches from numerous fields. Statistical and mathematical models drawn from biostatistics may be used to model or predict disease rates, while social science approaches such as interviewing and survey research might be used to elucidate information on social risk factors for disease. Epidemiology is considered one of the foundational methods employed in the practice of public health.

Drawing distinctions between health services research, epidemiology, and clinical research can be challenging, as these all generally share the same biostatistical foundation and differ only in approach and subject matter. Health services research focuses on the health care system, epidemiology focuses on population-level distributions of disease, and clinical research focuses on specific aspects of clinical care. Questions regarding all three can be placed under this tag, as CrossValidated does not have an HSR or clinical research tag.

Clinical trials - specifically designed trials for new drugs or interventions with strict regulatory guidance and statistical methods - are separate from these fields, and should be put under the clinical-trials tag.

Suggested reading:

http://www.who.int/topics/epidemiology/en/

http://en.wikipedia.org/wiki/Epidemiology

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How would life expectancy impact the calculation of disease prevalence?

I want to understand how to make calculations on the prevalence of a disease in a country population and the impact that the element of average life expectancy (of those suffering with the disease at time of diagnosis) has on this calculation. Are…
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What would be a suitable way to present a prevalence rate?

Suppose we say that the prevalence rate of some disease is $1$ in $50$. Does this make sense? Or should be convert this into a $ \%$? That is, should we say that the prevalence rate is $2 \%$?
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Absolute risk and prevalence?

From Wikipedia If the absolute risk in the control group is available, conversion between the two is calculated by: $$ RR \approx \frac{OR}{1 - R_C + (R_C \times OR)}$$ where: RR = relative risk OR = odds ratio RC = absolute risk in the…
Tim
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What is the difference between period prevalence and incidence rate?

I am confused about the difference between period prevalence and incidence rate. Following are from Wikipedia: The incidence rate is the number of new cases per population in a given time period. Period prevalence is the proportion of the…
Tim
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I am getting different results odds ratio packages R and I don't know which one is correct

I am having an issue with calculating the odds ratio for my variables, when I used epitab from epitools I get a different result than using oddsratio() I have tried changing the level of reference. This is the data: Disease Feeding 1 0 zero-pasture…
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What is the relevance of comparing the number of positive Covid cases at the same date in 2020 and 2021?

I am following the news in a country (which I will leave unnamed) where I am currently on holiday. Same as in a related question I asked last year, I find myself completely baffled and dumbfounded by the way Covid data are reported. Every single…
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Ways to Estimate Date of Conception

Why don't epidemiologists ask people when they had sex? Why do they estimate time of conception from the birth date? This seems to introduce unnecessary error. Wouldn't it be better to record the time you had sex in some sort of database (assuming…
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What should this poor guy be told?

Possible Duplicate: What are the chances my wife has lupus? A day or two ago a man posted a question on math.stackexchenge about whether his wife likely has lupus, given the diagnosis. First, …
Will Jagy
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Convenience sample equivalent of "prevalence"

EDIT: To clarify, my original (sleep-deprived) post: We used the term 'prevalence' to describe the proportion of patients with a certain characteric in a cross-sectional convenience sample. A collaborator expressed concern regarding the use of the…
graggsd
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Can someone tell me is this research on light exposure at night linked to breast cancer is garbage?

I saw the report on the study that claims the following: The study found a direct relationship between a woman’s neighborhood nighttime light level before diagnosis and her later risk of developing breast cancer: The higher the light level, the…
Aksakal
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What type of study is this?

Suppose someone is trying to estimate the diagnostic prevalence of ADHD in a cohort of individuals born in 1985. What type of study is this? This is not a prospective cohort study because we are not comparing two groups (i.e an exposed and unexposed…
ross
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Incidence density

Suppose there are $6$ people in a population. During $2$ weeks $3$ people get the flu. Cases of the flu last $2$ days. Also people will get the flu only once during this period. What is the incidence density of the flu? Would it be $\frac{3}{84…
larry
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How to calculate the doubling rate for infections?

I'm playing with the JHU nCOV data and looking to calculate the doubling rate in my region (Western Australia) - I can get it down to an integer value via a kind of brute force (halve the current case value, use excel maxifs to look at the most…
baradhili
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T test and P value

Possible Duplicate: What is the meaning of p values and t values in statistical tests? I currently start epidemiology class, I am very confuse of p value and t test, what do they mean? how to use them ? can anyone explain the differences between…
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How is the prevalence of a rare disease estimated?

I am working in biostatistics and often have the following conversation with medics: we are talking about some very interesting, but also very rare, disease/disorder (or side effect of a drug) until the point comes, where somebody says "the…
LuckyPal
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