Recent content by hlsmith

You model propensity scores and put those into the outcome model as weights. The outcome model is typically a simple regression, exposure and outcome. Can you provide a histogram of the outcome variable.

Yeah I thought you were likely human or a tricky bot. Good to hear you aren't metal/silicon!

If I was in your shoes, it seems like of those eligible, you could run a propensity score model to get weights to use in your outcomes model. As you mentioned, you may not have access to all the variables but this would be better than a naive or conditional model. For the propensity score model...

I have never seen this, but I wonder of internal validation could be use via having a holdout set to confirm cut-offs. I haven't reviewed many of these, but yes 2 seems to be the blatant and magical number in this one.

Please describe in more detail what these data represent. I would calculate the proportion of with the event and calculate a confidence interval around it (binomial data). But without more information I am just guessing at the context and objective. Say we were talking about males vs females...

Time series or random effects may be of interest, since observations across years are correlated. For example, my weight today is correlated with my weight last week and to a lesser extent the week prior. Ignoring this dependency structure across time can lead to biases in the interpretation of...

Hey @Dick_ mob1 - what is three minnus 2? Just checking you aren't a bot given your posting on old threads and having such a cool avatar picture.

Alright, for a sample size calculation you should pick the closes (smallest difference)comparison you can think of that you are interested in and power for that. All other tests should then be reasonably powered. You can validated the results using the data you didn't sample from. HOWEVER, if...

Yeah if you have the population use it. Run analyses on a server if at an university, if you are using a local machine run it in parallel. If you don't have multiple cores run it over night. Not using the full data is running from the real problem, your inability to truly answer your questions...

You word this as though you have access to the full population data. If so, why not use the who thing? In both scenarios, you just use random sampling without replacement. Boom you are done. Is there a particular question you are trying to power using these data or a certain level of...

What are you trying to explicitly model? Please provide an example of what your data may look like. In a basic survival model you have an exposure (binary treatment: 0,1), censoring variable (person censored: 0,1), and time (typically a continuous variable until person had event or was...

If this is an assignment, then yeah, an r = 0.8 is fairly high in most contexts.

Sometimes if cutting and pasting was used, your quotation marks may be backwards or not registered correctly. You can also try rewriting the line of code from scratch and seeing if that works.

a) looks like it is just requesting you model a least squares (simple linear regression). As for b.), I am not familiar enough to know what they are looking for, polynomials?

What does the 'B' in Benoit B. Mandelbrot stand for?