Biostatistics Notes

Biostatistics

, SAMPLE

·
BIOSTATISTICS USE SAMPLES TO STUDY THE
POPULATION FROM WHICH THESAMPLE WAS DERIVED

3 THE SAMPLE MUST TRULY REPRESENT THE
POPULATION (REPRESENTATIVES

↳ ACCURATE MEASUREMENT OF THE CHARACTERISTICS
OF INTEREST



·
SAMPLE CHARACTERISTICS ARE KNOWN AND CAN BE
MOAPURED (MEAN ,
STANDARD ERROR , -- - )
·
POPULATION CHARACTERISTICS ARE G
Not known
BUT CAN BE INFERRED FROM THE SAMPLE

W
If NOT : AS OCCURS
-




RANDOM ERROR WHEN THE RESULTS ARE DUE
:



By MANC

, EXAMPLE I

·
Is THE NEW PRUG EFFECTIVE In TUMOR sizt
REDUCTION IN LUNG CANCER PATIENTS ?

·
EXPERIMENT : RANDOMIZE PEOPLE SO THAT
SOME Of THEM TAKE THE PRUG AND
-



SOME RECEIVE HE CURRENT TREATMENT
AND COMPARE RESULTS

G THE PATIENTS RANDOMIZED ARE A SAMPLf
OF THE POPULATION Of LUNG CANCER




·
PATIENTS


·
A DIFFERENCE In THE Two GROUPS :

DRUG IS EFFECTIVE


↳
-




-
DRUG IS NOT EFFECTIVE AND THE P
DIFFERENCE WAS OBSERVED BY CHANCE M



TO MAICE THE DISTINCTION :
r
SIZE of SAMPLE
-




-
SIZE OF DIFFERENCE



( (
↓ DIFFERENCE = SAMPLE

↑ DIFFERENCE => ↓ SAMPLE

, STEPS of CLINICAL RESEARCH

1.STUDY DESIGN Types Of ARABLES
. DATA COLLECTION
2

. DATA PROCESSING
3 DATA QUALTY CHECKS
4) DATA ANALYSIS
. OUTPUT RESULTS
5 TABLES AND FIGURES


R STATISTICAL
ENVIRONM fort


·
A RESEARCH STUDY SHOULD BE REPRODUCIBLE


W


CAREFUL ATTENTION AND STICKING TO
THE CODE THROUGHOUT THE RESEARCH
PROCESS SO SCIENTISTS ARE SURE THAT
THE CAN REPEAT THE SAME ANALYSIS
MULTIPLE TIMES WITH THE SAME
RESULTS