treatment

  1. L

    plotting the effect of treatment on plants

    Hello, I have some plant data, which contains several plant groups. Within the plant groups there are different plant sizes (devided in groups). For each plant I noted whether it was infected before and after the treatment: data = data.plant > str(data.plant) $ Group.nr: Factor w/15...
  2. C

    Multi-level Meta-regression using random effect for treatment? [R pkg metafor]

    I am a biostatistician consulting on a meta-analysis of 16 studies each w/ 2 treatment arms. The main interest is in the effect of the variable plateau pressure (PP from now on), on mortality rate. As there is a strongly significant difference in PP between the two arms, I do not believe both...
  3. M

    How to analyse data when subjects received both control and experimental condition?

    Dear all, I hope to get some suggestions on how to analyse the data from an experiment I recently ran. My question is whether a new treatment has a positive effect on some or all of 4 dependent variables. 80 subjects participated in one of two versions of our experiment: pre-test > experimental...
  4. H

    Multiple Drug Treatment Effects

    Suppose I have five vitamins VA VB VC VD VE, and wish to study the effects of each drug on the weight of patients with data measured at daily frequency. The typical data look like this Patient 1 take 1000mg of VA at day 15 ; take 1000mg of VD at day 19. Patient 2 take 1000mg of VE at day 35 ...
  5. O

    Probability of Unconventional Food Item Alleviating Medical Problem Multiple Times

    For about 2 years, a medical problem has more or less repeated, as follows: The problem normally lasts approximately 3 weeks and then goes away for 3 or 4 days and then repeats. When eating a non-conventional food item, the problem goes away in approximately 2 days instead of 3 weeks...
  6. P

    sample size for control and treatment groups

    hello everyone, I am in the process of designing an agricultural experiment in which I want to compare a series of variables between a group of manufacturers who use a mobile telephone app (n=15,000) is my treatment group and another group that does not (n=100,000) which is my control group...
  7. D

    Definition of replications vs treatments (factorial design question)

    I see on wikipedia replication is "the repetition of the set of all the treatment combinations to be compared in an experiment. Each of the repetitions is called a replicate" but I think of each combination of factor levels as different treatments, how are these different? If there is a 2^2...
  8. S

    Longitudinal multilevel moderation analysis - stats geniuses, please help me!!

    Hi all, I am working on a very complicated analysis and am quite lost! :confused: I am analysing data from a randomised controlled trial. I have 3 groups (treatment 1, treatment 2, waitlist), and 3 repeated measures (baseline, time 1, time 2). In addition, I have 7 possible continuous...