No announcement yet.
  • Filter
  • Time
  • Show
Clear All
new posts

  • paired data problem

    I have data for the lipid profile before treatment, 4 weeks, 12 weeks after treatment.

    Paired data analyses showed that LDL significantly increased 4 weeks after treatment, and no difference was noted between 4wk and 12 wk.

    Could I conclude that the increase will mostly occur in 4 weeks after the treatment starts, and it isn't significant thereafter?

    What is a better analysis for the conclusion I want?

    Thank you.

  • #2
    Below are the results by paired t test. Thank you for your help.
    SVR is 12 week after treatment
    LDL is before treatment
    4wk is 4 wk after treatment
    Click image for larger version

Name:	4 week and 12 week.jpg
Views:	1
Size:	50.8 KB
ID:	1483193

    Click image for larger version

Name:	before treatment and 4 week.jpg
Views:	1
Size:	43.9 KB
ID:	1483194


    • #3
      looking at your outcome tables, what strikes me is the different number of observations between tests perfomed at 4 and 12 week after the treatment start.
      I find difficult to get what's your original sample size and why it increased from the the first to the second measurement.
      That said, you may want to consider a panel data regression (provided that the mesurements were taken on the same sample od patients):
      xtreg LDL i.week
      As per -hausman- test you can investigate whether -fe- or -re- specification fits you data better.
      Kind regards,
      (Stata 15.1 SE)