Statistics &
Its Scopes

Statistics:Statistic means a measured or counted fact or piece of information stated as a figure such as height of one person,newborn mortality rate etc.
Its actually a body of methods for making reasonable and wise decisons in the face of uncertainty . These are used in the analysis of numerical data of various aspects including interpretation of data on the basis of certain statistical principles.

**Statistics is a field of study concerned with techniques or methods of collection of data classification ,summarizing, interpretation, drawing, inferences, testing of hypothesis, making recommendations etc only when a part of data is used.

Statistics thus contains:
•	Mathematics
•	Logic
•	Coommon Sense

Biostatistics/Biometry:Biostatistics is the term used when tools of statistics are applied to the data that is derived from biological sciences. In other words when the principles of statistics are applied to study of organisms or living system, the study is called biostatistics or biometry.

Scopes of Statistics:

1.In Physiology and Anatomy:

a)To define what is normal or healthy in a population and to find limits of normality in variables such as weight & pulse rate.

b)To find the difference between means and proportions of normal at two places or in different periods. The maen height of Bangladeshi boys is less than the mean height of American boys . Whether this difference is due to chance or a natural variation or because of some other factors such as better nutrition playing a part, has to be decided.

c)To find the correlation between two variables X and Y such as height & weight whether weight increases or decreases proportionately with height & if so by how much has to be found.

2.In Pharmacology:

a)To find the action of drug. For examples,a drug given to animals or humans to see whether the changes produced are due to drug or by chance

b)To compare the action of two different drugs or two successive dosages of the same drug.

c)To find the relative potency of a new drug with respect to a standard drug.

3.In Medicine:

a)To compare the efficacy of a particular drug, operation or line of treatment . For example, the percentage cured,relieved or died in the experiment & control groups is compared & difference due to chance or otherwise is found by applying statistical technique.

b)To find an association between two attributes such as cancer & smoking -an appropriate test is applied for this purpose.

c)To identify sign & symptoms of a disease or syndrome . Cough in typhoid is found by chance and fever is found in almost every case . The proportional incidence of one symptom or another indicates whether it is a characteristic feature of the disease or not.

4.In Community Medicine & Public Health:

a)To test usefulness of vaccines in the field - percentage of attacks or deaths among the vaccinated subjects is compared with that among the unvaccinated ones to find whether the difference observed as statistically significant .

b)In epidemilogical studies - the role of causative factors is statistically tested . Deficiency of iodine as an important cause of goitre in a community is confirmed  only after comparing the incidence of goitre cases before and after giving iodised salt .

Reference:
1.Mahajan BK 2002 (Methods in Biostatistics)(6th edition)
2.Zaman SM,HK Rahim and M Howlader 1982.(Simple Lessons from Biometry),BRRI
3.Class Note