Recent content by Mamaho

  1. M

    Logistic regression with partly aggregated data

    Thank you very much. I will give the article a look.
  2. M

    Logistic regression with partly aggregated data

    Thank you. I agree simulating would make sense. There is no known predictors for assay concentration. I have attached my histogram, without a few high values. Due to units, my data shows 1/10 of the above numbers, i.e 100=10. The concentration distribution is known to start at 0 then rise to a...
  3. M

    Logistic regression with partly aggregated data

    The bioassay can´t estimate values below 100 (LDV). We are looking at a total of 463 observations with 147 below 100 (LDV) and 316 with an exact value. I just tried to assign the 147 measurements a range of values from 0-100 and running logistic regressions. It did not change a lot on the model...
  4. M

    Logistic regression with partly aggregated data

    Thank you for your reply and sorry for my very late reply. I got put on another project and just came back from vacation. I am not completely sure what result i would get running this regression and how it will help me identify problematic data. Kind regards
  5. M

    Logistic regression with partly aggregated data

    Thank you for your reply and sorry my very late reply. I got put on another project and just came back from vacation. I will look into your proposal of running a GAM excluding the LDVs.
  6. M

    Logistic regression with partly aggregated data

    There is population based contration distributions of the x variable. But i can not discriminate between the observations hence i do not see how i can assign them different x-values. Would it be a statistical problem assigning them all with the same value (the lowest detectable limit) when using...
  7. M

    Logistic regression with partly aggregated data

    Hi, I want to use logistic regression on a data set. The y-variable is a binary outcome (yes or no to adverse effects) and the x value is blood concentration of a protein (continous variable). I want to test if higher concentration is related to more frequent adverse effects. I have 450...