case control

  1. R

    Comparing quantitative parameter between two groups with only one of these having repeated measures

    My question regards the best way of comparing two groups for differences in the levels of several quantitative parameters. Here, for only one of the groups there are 4 repeated measurements at different intervals. The data -We have two groups we want to compare: one consists of ~200 patients at...
  2. C

    Study Design for assessing efficacy of New Clinical Sign

    Hi! I am looking for some guidance as to what statistical tests I would need to do to know the significance of a study. The situation is this: Disease in Question is Sinusitis Gold Standard for Diagnosis is CT, but is seldom done as not all cases require confirmation. Cost-effectiveness...
  3. M

    Measurement error in binary outcome variable for a case-control study

    I am currently working on a case-control study on a rare disease using a large patient database. Using conditional logistic regression I will calculate odds ratios for different exposures in cases and controls. The validity of the records for the disease of interest (outcome) is unknown. I...
  4. R

    Disproportional Sampling for Uneven Case Controls

    Hello, I am looking to do a random sampling analysis of a case/control dataset containing 6X as many controls as cases. Therefore, I need to correct for this overabundance of controls (without simply removing the controls) using disproportional sampling. Is switching the # cases and...
  5. M

    frequency of heterozygous allele between two groups

    I am sorry I am not statistician but I have a very simple (maybe stupid:)) question. I have case group of 4460 and controls of 5085, P value is 0.0172. 232 of cases are heterozygous for the allele understudy and 245 controls are heterozygous for the same allele P value is 0.0232. I would...
  6. C

    Case control, lot of parameters, N and n-Normal dist. Which test and data expression?

    Firstly, my english are not so good, sorry. I will be very happy if someone help me. I am doing a case-control study, people with and without schistosomiasis. How may I perform the Kolmogorov-Smirnov test, my groups must be together or not? I think that they must stay together. Then, I...
  7. victorxstc

    Is my study case-control or retrospective cohort?

    Hi AFAIK if we split the sample by the exposure, it is retrospective cohort; and if we split it by the disease, it is case control. I am studying the association between malocclusion and the efficacy of mastication. I have divided the sample into two groups: people with and without...