Biostatistics Introduction Lecture 01.pptx

Introduction to Biostatistics

1. I N TRODUCTION TO BIOSTATISTICS Lecture 01

2. This Lecture covers: Origin and development of Biostatistics Definition of Statistics and Biostatistics Reasons to know about Biostatistics

3. “ Statistics is the science which deals with collection, classification and tabulation of numerical facts as the basis for explanation, description and comparison of phenomenon”. ------ Lovitt

4. Origin and development of statistics in Medical Research In 1929 a huge paper on application of statistics was published in Physiology Journal by Dunn. In 1937, 15 articles on statistical methods by Austin Bradford Hill, were published in book form. In 1948, a RCT of Streptomycin for pulmonary tb., was published in which Bradford Hill has a key influence. Then the growth of Statistics in Medicine from 1952 was a 8-fold increase by 1982.

5. Douglas Altman Ronald Fisher Karl Pearson C.R. Rao Carl Friedrich Gauss

6. “BIOSTATISICS ” Statistics arising out of biological sciences, particularly from the fields of Medicine and public health. The methods used in dealing with statistics in the fields of medicine, biology and public health for planning, conducting and analyzing data which arise in investigations of these branches.

7. Reasons to know about biostatistics: Medicine is becoming increasingly quantitative. The planning, conduct and interpretation of much of medical research are becoming increasingly reliant on the statistical methodology. Statistics pervades the medical literature.

8. Example: Evaluation of treatment A vs treatment B for treating bacterial pneumonia in children< 2 yrs. What is the sample size needed to demonstrate the significance of one group against other ? Is treatment A is better than treatment B or vice versa ? If so, how much better ? What is the normal variation in clinical measurement ? (mild, moderate & severe) ? How reliable and valid is the measurement ? (clinical & radiological) ? What is the magnitude and effect of laboratory and technical error ? How does one interpret abnormal values ?

9. CLINICAL MEDICINE Documentation of medical history of diseases. Planning and conduct of clinical studies. Evaluating the merits of different procedures. In providing methods for definition of “normal” and “abnormal”.

10. PREVENTIVE MEDICINE To provide the magnitude of any health problem in the community. To find out the basic factors underlying the ill-health. To evaluate the health programs which was introduced in the community (success/failure). To introduce and promote health legislation.

11. WHAT DOES STAISTICS COVER ? Planning Design Execution (Data collection) Data Processing Data analysis Presentation Interpretation Publication

12. HOW A “BIOSTATISTICIAN” CAN HELP ? Design of study Sample size & power calculations Selection of sample and controls Designing a questionnaire Data Management Choice of descriptive statistics & graphs Application of univariate and multivariate Statistical analysis techniques

13. INVESTIGATION Data Collection Data Presentation Tabulation Diagrams Graphs Descriptive Statistics Measures of Location Measures of Dispersion Measures of Skewness & Kurtosis Inferential Statistics Estimation Point estimate Interval estimate Hypothesis Testing Univariate analysis Multivariate analysis