Confounding & Effect Modification - USMLE Forums
USMLE Forums Logo
USMLE Forums         Your Reliable USMLE Online Community     Members     Posts
Home
USMLE Articles
USMLE News
USMLE Polls
USMLE Books
USMLE Apps
Go Back   USMLE Forums > USMLE Step 1 Forum

USMLE Step 1 Forum USMLE Step 1 Discussion Forum: Let's talk about anything related to USMLE Step 1 exam


Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 06-24-2014
USMLE Forums Addict
 
Steps History: 1+CK+CS
Posts: 148
Threads: 37
Thanked 73 Times in 57 Posts
Reputation: 83
Default Confounding & Effect Modification

Can some one explain the difference between these two??I am confused
Reply With Quote Quick reply to this message



  #2  
Old 06-24-2014
USMLE Forums Addict
 
Steps History: 1+CK+CS
Posts: 148
Threads: 37
Thanked 73 Times in 57 Posts
Reputation: 83
Default

Got the explanation myself by searching here in this forum....so i am sharing it here...


The difference between confounding , effect modification in bio statistics :

1- Confounding bias :

Alcohol ( exposure ) Oral cancer ( outcome )

Smoking is a confounding bias here. Why ?

Because smoking is related to BOTH the exposure and the outcome. People who smoke will more often than not, also drink, and people who have oral cancer, were probably smokers ( smoking is a known risk factor for oral cancer).

2- Effect modification :

OCPs ( exposure ) Breast cancer (outcome )

Family history of breast cancer is an effect modification here.
Can you guess why ?

Asbestos ( exposure ) Lung cancer(outcome)

Smoking is an effect modification

Estrogens ( exposure ) DVT (outcome )

Smoking is an effect modification

So do you notice the difference ?? The effect modification is ONLY related to the outcome, but NOT to the exposure. Think with me here : smoking does not effect neither asbestos exposure nor estrogen levels or intake,BUT definitely is a risk for lung cancer and DVT !!

Family history of breast cancer has nothing to do with choosing to use OCPs , but definitely has a factor in increasing risk of breast cancer !!
Reply With Quote Quick reply to this message



Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the USMLE Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:
Medical School
Choose "---" if you don't want to tell. AMG for US & Canadian medical schools. IMG for all other medical schools.
USMLE Steps History
What steps finished! Example: 1+CK+CS+3 = Passed Step 1, Step 2 CK, Step 2 CS, and Step 3.

Choose "---" if you don't want to tell.

Favorite USMLE Books
What USMLE books you really think are useful. Leave blank if you don't want to tell.
Location
Where you live. Leave blank if you don't want to tell.

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes


Similar Threads
Thread Thread Starter Forum Replies Last Post
Confounding vs Effect Modification Lara USMLE Step 1 Forum 1 11-18-2012 06:37 AM
Effect modification vs confounding? anomali USMLE Step 1 Forum 2 10-10-2012 05:57 AM
Confounding and Effect Modification numbndumb USMLE Step 1 Forum 1 06-11-2012 08:41 PM
Effect Modification vs Confounding Pelz USMLE Step 1 Forum 6 05-31-2012 01:19 PM
Differenece between Confounding & Effect Modification dr-ahmed USMLE Step 2 CK Forum 4 12-24-2011 02:24 PM

RSS Feed
Find Us on Facebook
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.

USMLE® & other trade marks belong to their respective owners, read full disclaimer
USMLE Forums created under Creative Commons 3.0 License. (2009-2014)