INTRODUCTION TO

BIOSTATISTICSPRESENTED BY :-DR SAKSHI KAUR CHHABRA2ND YEAR POST GRADUATEDEPARTMENT OF PUBLIC HEALTH DENTISTRY

STATISTICS

STATIC or DATUM means a measured or counted fact or piece of information stated as a figure such as height of one person, birth of a baby, etc.

They are collected from records, experiments and surveys, in all walks of life such as economics, politics, education, industry, business, administration etc. Medicine too, including preventive medicine and public health, in such field.

STATISTICS

A simple but concise definition by Croxton and Cowden :-

‘Statistics is defined as the

1. Collection2. Organization3. Presentation4. Analysis 5. Interpretation of numerical data.’

biostatistics

It is the branch of statistics concerned with mathematical facts and data related to biological events.

It is the science that helps in managing medical uncertainties.

biostatistics

Biostatistics covers applications and contributions not only from health, medicines

and, nutrition but also from fields such as genetics, biology, epidemiology, and many

others.

It is mainly consists of various steps like generation of hypothesis, collection of data,

and application of statistical analysis.

APPLICATION OF BIOSTATISTICS

[1] AS A SCIENCE

[2] AS A FIGURES

[1] AS A SCIENCE

A. IN COMMUNITY MEDICINE AND PUBLIC HEALTH

B. IN PHYSIOLOGY AND ANATOMY

C. IN PHARMACOLOGY

D. IN MEDICINE

E. IN CLINICAL MEDICINE

F. IN PREVENTIVE MEDICINE

[A] IN PUBLIC HEALTH

1) To evaluate the efficacy of sera and vaccines in the field.

2) In epidemiological studies - the role of causative factors is statistically tested.

3) To test whether the difference between two populations is real or a chance

occurrence.

4) To study the correlation between attributes in the same population.

5) To measure the morbidity and mortality.

6) To evaluate achievements of public health programs.

7) To fix priorities in public health programs.

8) To help promote health legislation and create administrative standards for oral health.

9) It helps in compilation of data, drawing conclusions and making recommendations.

10) For students of medicine/dentistry

[B] IN PHYSIOLOGY AND ANATOMY

1) To define what is normal or healthy in a population.

2) To find the limits of normality in variables such as weight and pulse rate etc. in a

population.

3) To find the difference between means and proportions of normal at two places or

in different periods.

[C] IN PHARMACOLOGY

1) To find out the action of drug.

2) To compare the action of two different drugs or two successive dosages of the same

drug.

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

[C] IN PHARMACOLOGY

1) To find out the action of drug.

2) To compare the action of two different drugs or two successive dosages of the same

drug.

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

[D] IN MEDICINE

1) To compare the efficacy of a particular drug, operation or line of treatment.

2) To find an association between two attributes such as cancer and smoking or

filariasis and social class.

3) To identify signs and symptoms of a disease or syndrome.

4) In epidemiological studies – the role of causative factors is statistically tested.

[E] IN CLINICAL MEDICINE

1) Documentation of medical history of diseases.

2) Planning and conduct of clinical studies.

3) Evaluating the merits of different procedures.

4) In providing methods for definition of ‘normal’ and ‘abnormal’.

[F] IN PREVENTIVE MEDICINE

1) To provide the magnitude of any health problem in the community.

2) To find out the basic factors underlying the ill-health.

3) To evaluate the health programs which was introduced in the community(success/failure).

4) To introduce and promote health legislation.

[2] AS A FIGURES

Health and vital statistics are essential tools in demography, public health, medical

practice and community services.

Recording of vital events in birth and death registers and diseases in hospitals is like

book keeping of the community, describing the incidence or prevalence of diseases,

defects or deaths in a defined population.

Such events properly recorded form the eyes and ears of a public health or medical

administrator.

1) What are the leading causes of death?

2) What are the important cause of sickness?

3) Whether a particular disease is rising or falling in severity and prevalence? etc.

USES OF STATISTICS IN DENTAL SCIENCE

1. To find the statistical difference between means of two groups. Ex: Mean plaque scores of two groups.

2. To assess the state of oral health in the community and to determine the availability and utilization of dental care facilities.

3. To indicate the basic factors underlying the state of oral health by diagnosing the community and find solutions to such problems.

4. To determine success or failure of specific oral health care programs or to evaluate the program action.

5. To promote oral health legislation and in creating administrative standards for oral health care delivery.

data

A collective recording of observations either numerical or otherwise.

A collection of facts from which conclusions may be drawn.

COLLECTION OF DATA

Demographic data comprise details of population size, geographic distribution, ethnic groups, socio-economic factors etc.

Such data are obtained from :-

1. Census2. Experiments3. Surveys4. Hospital records5. Other public health reports6. Oral health care programmes

Classification of data

Depending on the nature of the variable, data is classified into 2 broad categories :-

A. QUALITATIVE DATA

B. QUANTITATIVE DATA

Classification of data[A] QUALITATIVE DATA

When the data is collected on the basis of qualities like sex, malocclusions, cavity etc.

[B] QUANTITATIVE DATA

When the data is collected through measurement using calipers like arch length, arch width, fluoride concentration in water supply etc.

Classification of data

QUALITATIVE DATA

DISCRETE DATA :- When the variable under observation takes only fixed values like whole numbers, the data is discrete. DMFT, no. of children ( counted items ).

CONTINOUS DATA :- If the variable can take any value in a given range, decimal or fractional, it is called as continuous data like arch length, mesiodistal width of the erupted teeth. ( measured characteristics )

QUantiTATIVE DATA

NOMINAL DATA :- Consists of named categories, with no implied order among the categories.

ORDINAL DATA :- Consists of ordered categories, where differences between categories cannot be considered to be equal. Ex- Likert’s scale.

DATA CAN BE COLLECTED THROUGH

[A] PRIMARY SOURCE :- Here the data is obtained by the investigator himself. This is first hand information.

[B] SECONDARY SOURCE :- The data is already recorded is utilized to serve the purpose of the objective of the study. EXAMPLE – records of the OPD of dental clinics.

COLLECTION OF PRIMARY DATA

1) DIRECT PERSONAL INTERVIEWS

2) ORAL HEALTH EXAMINATION

3) QUESTIONNAIRE BASED

[1] DIRECT PERSONAL INTERVIEWS

[2] ORAL HEALTH EXAMINATION

It is conducted by dentist and dental auxiliary personnel

[3] QUESTIONNAIRE METHOD

In this method, a list of questions pertaining to the survey, known as questionnaire, is prepared and the various informants are requested to supple the information either personally or via post.

This method is easy to adopt when a wide geographic area is covered.

CONCLUSION

Bio-statistical techniques can assure that the results found in such a study are not

merely because of chance.

In every case of our life, Statistics plays a major role for better gaining and accurate

results.

A well-designed and properly conducted study is a basic prerequisite to arrive at

valid conclusions.

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