+ Reply to Thread
Results 1 to 3 of 3

Thread: Time 2 Sample Size

  1. #1
    Points: 1,171, Level: 18
    Level completed: 72%, Points required for next Level: 29

    Posts
    2
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Time 2 Sample Size




    Hi
    I was hoping for some advice. I'm looking at the same sample at 2 timepoints.
    At the first time point I had 95 participants and at follow up I only got 18 replies back.

    Is it worth doing any analysis between the two timepoints, or is the sample at time 2, too small for any reliable results.
    Having a quick look at the data, there is a significant positive correlation between Time 1 anxiety, depression with time 2.

    Many advice would be great
    Trish

  2. #2
    TS Contributor
    Points: 12,287, Level: 72
    Level completed: 60%, Points required for next Level: 163
    rogojel's Avatar
    Location
    I work in Europe, live in Hungary
    Posts
    1,471
    Thanks
    160
    Thanked 332 Times in 312 Posts

    Re: Time 2 Sample Size

    hi,
    I think that the problem is not so much the sample size but the fact that you might have a biased second sample.It is quite possible that there is some pattern in the respondents to the aecond query - i.e, if mostly those answered who had depression while those who did not just ignored the questions, it will look as if therebwas a realtionship even though there wouldn't be any in the whole population.

    regards

  3. #3
    Omega Contributor
    Points: 38,413, Level: 100
    Level completed: 0%, Points required for next Level: 0
    hlsmith's Avatar
    Location
    Not Ames, IA
    Posts
    7,004
    Thanks
    398
    Thanked 1,186 Times in 1,147 Posts

    Re: Time 2 Sample Size


    Yeah, this is a common issue. Most likely you are out of luck. Perhaps there is a pattern in characteristics of those who responded to both. If so, you may be able to solely generalize and interpret results solely to those patients.

    Ideally lost to follow-up is random, but typically empirically it is not.
    Stop cowardice, ban guns!

+ Reply to Thread

           




Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts






Advertise on Talk Stats