Re: Study design: Controls vs pateints groups [SEC: UNOFFICIAL]

[Gosse, Michelle]

Hi there,

How do you intend to analyse the results? What statistics method(s) do you intend to use and what variables will be in the model (e.g. do you wish to include your four age groups as groups, or as actual age)?

Cheers
Michelle




-----Original Message-----
From: SPSSX(r) Discussion [mailto:[hidden email]] On Behalf Of pran909
Sent: Tuesday, 12 July 2011 4:22 PM
To: [hidden email]
Subject: Study design: Controls vs pateints groups

Hi,
we are conducting one clinical study now. it is an observational study in which we want to compare the levels of a particular endogenous compound between healthy controls and patients. Based on a pilot study, we calculated that 200 controls and 200 patients are required for this study to detect a significant difference with 80% power. The subject recruitment started for healthy controls group recently. In case of healthy controls, we will be recruiting 50 subjects from each of the four age groups (19-29, 30-41, 42-53, 54-65) so as to ensure adequate distribution of age across all age ranges.

But we do not have any fixed criteria (like 50 from each age group) for patients group. However, the patients who will be recruited will be in the age range of 19-65.  Does this clinical study design look alright?

or is it necessary that we recruit subjects in patients group similar to control group (like equally spread across 4 age groups: 50 subjects each)?

Are there any other alternatives that we can follow?



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