Statistical Analysis Stack Exchange
Statistical Analysis Stack Exchange

Questions tagged [biostatistics]

The science of statistics applied to the analysis of biological or medical data.

Biostatistics (sometimes referred to as biometry or biometrics) is the application of statistics to a wide range of topics in biology. The science of biostatistics encompasses the design of biological experiments, especially in medicine, agriculture and fishery; the collection, summarization, and analysis of data from those experiments; and the interpretation of, and inference from, the results. A major branch of this is medical biostatistics, which is exclusively concerned with medicine and health.

Reference: Wikipedia

Excerpt reference: thefreedictionary.com

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Correlations between continuous and categorical (nominal) variables

I would like to find the correlation between a continuous (dependent variable) and a categorical (nominal: gender, independent variable) variable. Continuous data is not normally distributed. Before, I had computed it using the Spearman's $\rho$.…
Md. Ferdous Wahid
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Statistical methods for data where only a minimum/maximum value is known

Is there a branch of statistics that deals with data for which exact values are not known, but for each individual, we know either a maximum or minimum bound to the value? I suspect that my problem stems largely from the fact that I am struggling to…
user2390246
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How does a Poisson distribution work when modeling continuous data and does it result in information loss?

A co-worker is analyzing some biological data for her dissertation with some nasty Heteroscedasticity (figure below). She's analyzing it with a mixed model but is still having trouble with the residuals. Log-transforming the response variables…
N Brouwer
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What is the difference between statistics and biostatistics?

It occurred to me that, while I've pieced together some ideas over the years about the differences between statistics and biostatistics, I've never heard a formal explanation. What is the distinction between these two disciplines (currently)? And…
Matt Parker
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Gamma hurdle model for continuous response?

I am modelling invertebrate.biomass ~ habitat.type * calendar.day + habitat.type * calendar.day ^ 2, with a random intercept of transect.id (50 transects were repeated 5 times) My response is zero-heavy - about 25% are 0s - and the non-zeroes are…
Tom Finch
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Calculating the probability of gene list overlap between an RNA seq and a ChIP-chip data set

Hopefully someone on these forums can help me out with this basic problem in gene expression studies. I did deep sequencing of an experimental and a control tissue. I then obtained fold enrichment values of genes in the experimental sample over…
stlandroidfan
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What are the case studies in public health policy research where unreliable/confounded/invalid studies or models were misused?

I am drafting a literature review on a current public health issue where data are confounded: What are common historical case-studies that are used in public health/epidemiology education where invalid or confounded relationships or inferences were…
cerd
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The $z$-test vs the $\chi^2$-test for comparing the odds of catching a cold in 2 groups

I just read in a rather well-respected (popular) science magazine (the German PM, 02/2013, p.36) about an interesting experiment (without a source, unfortunately). It caught my attention because intuitively I doubted the significance of the result,…
tomka
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Which statistical test should be used to test for enrichment of gene lists?

I have performed an experiment to test the cellular sensitivity to a certain DNA damage agent. We have found 270 genes that were specifically sensitive to the drug and the total number of genes analyzed was 3668. 38 out of the 270 sensitive genes…
Laura
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Null hypothesis of equivalence

Suppose $X_1, X_2, \, ... \, , X_n$ are a simple random sample from a Normal$(\mu,\sigma^2)$ distribution. I'm interested in doing the following hypothesis test: $$ H_0: | \mu| \le c \\ H_1: |\mu| > c, $$ for a given constant $c > 0$. I was thinking…
Vic101
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What are the statistical reasons behind defining BMI index as weight/height$^2$?

Maybe this question has answer in medicine, but are there any statistical reasons why BMI index is calculated as $\text{weight}/\text{height}^2$? Why not for example just $\text{weight}/\text{height}$? My first idea is that it has something to do…
sitems
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Good examples of statistics sections in applied academic journal articles

I am a biostatistician working in an applied field and I am responsible for writing the statistics methods section for the papers I collaborate on. In reading a lot of academic papers I've come across plenty of examples of badly written stats…
ccl
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Recommendations for first time teacher (Intro to Biostatistics)

I'm teaching my first class this fall (Intro to Biostatistics). Anyone have any suggestions for teaching statistics better? Perhaps some example you wish your first teacher had used? I'm using Principles of Biostatistics by Pagano and Gauvreau.…
bdeonovic
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Sample size and cross-validation methods for Cox regression predictive models

I have a question I would like to pose to the community. I have recently been asked to provide statistical analysis for a tumor marker prognostic study. I have primarily used these two references to guide my analysis: McShane LM, et al. Reporting…
Alexander
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Standard Deviation After Subtracting One Mean From Another

I've got two sets of data from some fluorescent cells. The first set is when the cells don't have their fluorescence switched on, but they are still faintly glowing. The second set is when they do have their fluorescence switched on. I ran each of…
Charon
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