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  • Bonferroni after pairwise comparisons after "meologit"

    Hi everybody. I apologize if I bother you.

    I'm doing a study about which I've already gotten help from Joseph Coveney and Clyde Schechter (I thank you again).

    I have an ordinal outcome (symptom severity that increases from 0 to 5) and which is evaluated in 4 different timepoints (30, 60, 120, 180 minutes) 4 drug doses.

    meologit v i.dose##i.time || id:, or

    I am interested in making pairwise comparisons between all crossed doses at each of the 4 timepoints in order to evaluate the dose-response.

    So I'm interested in seeing the overall odds/ratio of having higher severity in one dose than the other. For example, in dose 2 versus 1, and so on.

    I used the following command:
    pwcompare i.dose##i.time, pveffects or mcompare(bonferroni) cim eff

    Is it correct? I also wonder: how does Bonferroni's correction take place in this case? Are the unadjusted p multiplied by ALL listed comparisons?

    I'm interested in multiplying by 10 (I have ten pairwise comparisons for each timepoint).

    To do this the only option is to have unadjusted p-values with
    pwcompare i.dose#i.time, pveffects or ci eff
    and multiply them by 10 manually?

    Thank you.
    I'm afraid I duplicated the content because I've already asked about this study elsewhere, but it was difficult to relate to other posts to relate to this request.

    My data are below



    Code:
    * Example generated by -dataex-. For more info, type help dataex
    clear
    input byte dose int time byte(rat v) float id
    0  30 1 4  1
    0  60 1 5  1
    0 120 1 5  1
    0 180 1 5  1
    0  30 2 5  2
    0  60 2 5  2
    0 120 2 5  2
    0 180 2 5  2
    0  30 3 5  3
    0  60 3 5  3
    0 120 3 5  3
    0 180 3 5  3
    0  30 4 4  4
    0  60 4 4  4
    0 120 4 4  4
    0 180 4 5  4
    0  30 5 4  5
    0  60 5 5  5
    0 120 5 5  5
    0 180 5 5  5
    0  30 6 3  6
    0  60 6 4  6
    0 120 6 5  6
    0 180 6 4  6
    0  30 7 4  7
    0  60 7 5  7
    0 120 7 5  7
    0 180 7 5  7
    0  30 8 5  8
    0  60 8 5  8
    0 120 8 5  8
    0 180 8 5  8
    1  30 1 4  9
    1  60 1 5  9
    1 120 1 5  9
    1 180 1 5  9
    1  30 2 3 10
    1  60 2 5 10
    1 120 2 5 10
    1 180 2 5 10
    1  30 3 5 11
    1  60 3 4 11
    1 120 3 5 11
    1 180 3 5 11
    1  30 4 4 12
    1  60 4 5 12
    1 120 4 5 12
    1 180 4 4 12
    1  30 5 4 13
    1  60 5 4 13
    1 120 5 4 13
    1 180 5 4 13
    1  30 6 4 14
    1  60 6 5 14
    1 120 6 5 14
    1 180 6 5 14
    1  30 7 4 15
    1  60 7 5 15
    1 120 7 5 15
    1 180 7 5 15
    1  30 8 5 16
    1  60 8 5 16
    1 120 8 4 16
    1 180 8 5 16
    2  30 1 2 17
    2  60 1 2 17
    2 120 1 5 17
    2 180 1 5 17
    2  30 2 2 18
    2  60 2 3 18
    2 120 2 5 18
    2 180 2 5 18
    2  30 3 2 19
    2  60 3 3 19
    2 120 3 5 19
    2 180 3 3 19
    2  30 4 3 20
    2  60 4 4 20
    2 120 4 4 20
    2 180 4 5 20
    2  30 5 2 21
    2  60 5 3 21
    2 120 5 5 21
    2 180 5 5 21
    2  30 6 2 22
    2  60 6 3 22
    2 120 6 5 22
    2 180 6 4 22
    2  30 7 1 23
    2  60 7 3 23
    2 120 7 5 23
    2 180 7 5 23
    2  30 8 2 24
    2  60 8 3 24
    2 120 8 5 24
    2 180 8 5 24
    3  30 1 0 25
    3  60 1 2 25
    3 120 1 2 25
    3 180 1 2 25
    end

  • #2
    Gianfranco:
    I would consider:
    Code:
    pwcompare i.dose##i.time, pveffects mcompare(bonferroni)
    Kind regards,
    Carlo
    (Stata 19.0)

    Comment


    • #3
      Thank you Carlo Lazzaro . But i.dose##i.time will produce tens of comparisons. Will p values will be multiplied for all these tens of comparisons?
      Thanks again.

      Comment


      • #4
        Gianfranco:
        looking at the p-values with and without the Bonferroni's correction, the answer seems to be adfirmative.
        Kind regards,
        Carlo
        (Stata 19.0)

        Comment

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