How to calculate sample size for retrospective cohort study design ?

More Sora Asfaw Desisa's questions See All

Cell Count Imaging of Hydrogel Inside Inserts?

I want to see if there are any technology out there that will allow me to do a cell count inside of a hydrogel (the hydrogel is inside an insert). We currently have hydrogel inside an insert and...

12 June 2024 6,390 1 View

My thesis has been posted as a preprint on Research Square, but I am not interested to post before acceptance. How I can remove the article ?

13 November 2023 8,915 1 View

260/230 ratio improvement on DNA samples?

Hello everyone, I'm currently having issues in trying to obtain an extracted DNA sample with 260/230 ratio values ranging from 2.0 to 2.2 for Nanopore downstream analysis. Right now after...

01 November 2023 5,609 0 View

I have a group of women with active TB and wanted to identify if the pregnant ones are at higher or lower risk to develop active TB ?

I have a group of women with active TB and wanted to identify if the pregnant ones are at higher or lower risk to develop active TB. Most of the women (84 %) were not pregnant or not in postpartum...

25 June 2022 8,253 12 View

Methodology for this research?

A researcher wanted to determine the effects of nutritional status on tuberculosis treatment outcomes. There are BMI values and treatment outcome status on the TB register of previous 2 years. 1...

16 March 2020 1,444 2 View

Enhancing Critical Thinking Skills for Slow Learners: A Review of Empirical Studies?

to identify themes in question with APA style references

07 August 2024 2,239 5 View

Research Methodology - Impact of Corporate Reputation on Stakeholders Behaviors?

Please can anyone support with the survey questions based on RQ measures and propose how to do it in FMCG industry and include as well the role of brand equity Thanks

06 August 2024 949 0 View

Anyone having idea about VN primer for miRNA primer design ?

How to design VN primer to attach with universal reverse primer

05 August 2024 2,116 3 View

Which distribution type should I use when calculating the average particle size from TEM image? and how to calculate the error ?

average particle size calculation from TEM

04 August 2024 2,921 1 View

How to calculate effect size of AMCE (Average Marginal Component Effect) in Randomized Conjoint Experiment?

I am following Hainmueller, Hopkins, and Yamamoto's (2014) paper for my randomized conjoint experimental data analysis. The link to the paper is provided below. I received a comment from the...

02 August 2024 4,406 0 View

Should I remove an item from a scale to raise Cronbach's alpha and McDonald's omega or is it better to leave it if they are both over .7 already?

Hello! I have this scale which had 10 items initially. I had to remove items 8 and 10 because they correlated negatively with the scale, and then I removed item 9 because Cronbach's alpha and...

01 August 2024 4,606 7 View

How to Input and Analyze Results for an Asymmetrical Factorial Design in STATISTICA 13.3?

In STATISTICA 13.3, I used the Experimental Design Builder under the Design of Experiments tab to generate a design matrix for an asymmetrical factorial design (1443) with 12 experiments. However,...

29 July 2024 4,155 2 View

Pragmatic inquiry research design?

Employing a pragmatic inquiry research design, looking for published research using this method, employing qualitative research data collection methods of semi-structured interview and focus...

28 July 2024 540 2 View

How to conduct a sensitivity power analysis for Kendall's Tau?

Is there a straightforward way to conduct a sensitivity power analysis for a Kendall's Tau correlation? I was considering using the sensitivity setting and "Correlation: point biserial model" test...

28 July 2024 6,133 8 View

How to estimate sample size for GWAS of continuous and discrete traits? What are the pre-requisites?

Genome-wide association study (GWAS) Continuous traits: eg. Height Discrete traits: eg. Eye color

28 July 2024 286 0 View

David Eugene Booth

The best thing to do is take all 400 individuals. That gives you complete information on all available individuals which is better than a sample from 400 individuals. Best, David Booth

Sora Asfaw Desisa

Thanks David Booth.

Shakil Ahmed

Agreed with Dr. David Eugene Booth

No need to calculate any sample size. As you have access to the whole study population just take all the patients.

Best of luck