@ All forum members , Biostatistic help needed . - bugguy19

[ArchivalUser]

*D*Randomized Clinical Trial.

RCT
-Subjects in the study are randomly allocated into "intervention'' & "control" groups to receive OR not receive an experimental preventive or therapeutic procedure or intervention.
-Generally regarded as the most scientifically rigorous studies available in epidemiology.

Here we are presented with 2 arms;
1st -> Only the conventional therapy
2nd -> Diet & exercise that add to conventional therapy

Pat are assigned to ONLY ONE of the two study arms. Due to the nature of the intervention (exercise + diet), and UNBLINDED to their study group. => "Randomized Clinical Trial".

@bug, In CASE control studies, ppl WITH & WITHOUT a specific outcome are chosen, then looking backward in time, one tries to detect possible causes or risk factors. Asks, “What happened?”

[ArchivalUser]

http://i.imgur.com/GE4Sqh7.png?1 Most likely explanation?

[ArchivalUser]

Regression towards the mean?

[ArchivalUser]

Agree with innlake , regression toward the mean

Thank you cardio , I do have problem with study designs but am working on it , thank you again for your great questions.

[ArchivalUser]

How is it regression towards mean?i dint understand help pls

[ArchivalUser]

RT.*E*
Statistical regression effect/OR RTTM

@bdrusa, I let bug or innlake help you on that from their understanding point . (if not, I will)

[ArchivalUser]

In study 200 pats are enrolled to evaluate the accuracy of new ELISA based test for influenza. 100 of the pats were Dx with influenza by the reference standard culture of respiratory secretions. 80 of the pats with influenza had a (+) ELISA based test as did five of the pat without influenza.

@bug, SHOW ME your cal for “sensitivity” of ELISA based test?

[ArchivalUser]

bdrusa, this is how I understand Regression towards the mean:
During first visit some people had extremely high blood pressure for them ( for instance , a pt`s BP is 150/90 usually, but during that particular visit it was 170/100 , and this pt was included in study since he met cut-off criteria DPB 100, for example).
Next time pt came to see Dr, his BP came back to his usual range 150/90 and he does not meet cut off criteria any longer.
In other words, BP regressed to mean value.
Cardio, please, correct me if I am wrong.

[ArchivalUser]

Cardio, could you, please, give more Q on study design and bias, please?
It is my weak area, it is just hard to understand for me. I have my day "X" just in a day... I am a little bit scared, because my NBME scores are up and down and I would like to improve what possible.
And THANK YOU SO MUCH for all your help here!!!

[ArchivalUser]

Thanks for explaining but I don't get anything I m having thought block due to anxiety pls explain in simple way