survey

SURVEY

WHAT IS SURVEY ?

Is an investigation in which information is
systematically collected ,but in which experimental method is not used.

It is most easily defined negatively as anon-experimental investigation

BASIC ORAL HEALTH SURVEYS:-


Are defined as survey to collect the basic information
about oral disease status & treatment needs that is
needed for planning or monitoring oral health care
programmes.
•Surveys are not designed to collect information about clinical effectiveness of different preventive or care procedures or etiological factors affecting disease distribution or severity.
•However the information obtained can be used for monitoring the effectiveness of oral care services.

SURVEY PROCEDURES

1. ESTABLISHING THE OBJECTIVES

2. DESIGNING THE INVESTIGATION

3. SELECTING THE SAMPLE

4. CONDUCTING THE EXAMINATION

5. ANALYSING THE DATA

6. DRAWING THE CONCLUSIONS

7. PUBLISHING THE RESULT


OBJECTIVES OF ORAL HEALTH SURVEYS:-
1. Initially to provide a full picture of the oral
health status & needs of a population.

2. Subsequently to monitor changes in disease

levels or patterns.

B. DESIGNING THE INVESTIGATION

Types of study –
a. Descriptive
b. Analytical
There are two main subdivisions of both:-

Prevalence Study / Cross sectional-

Where the occurrence of a disease or condition in a population is
expressed at a given point in time.
Used for making comparisons b/w two or more population or b/w the same population of different time.

Incidence (Longitudinal) Study-

Where the amount of new disease in a population is measured over a period of time.
Usually expressed as the proportion of the population which become affected per unit of time.
It is concerned with events which happen during the investigations.
By this study we can measure the extent of the new disease , often refer to as the increment
Prevalence- condition existing at a particular point in time.
Incidence – change in a condition over a period in time.
Controls:- A parallel group not exposed must also be studied in the same way called group.
Importance- in order to avoid argument & implies a cause & effect relationship without further substantiation.


Designing the Investigation

Pathfinder surveys

•A practical, economic survey sampling methodology

•Uses stratified cluster sampling technique.

•Includes most imp sub groups

•Index age groups

•Minimum expense

PATHFINDER SURVEYS CAN BE EITHER

1. PILOT SURVEY
2. NATIONAL PATHFINDER SURVEY

PILOT SURVEY:-

Is one that includes only the most important subgroups in the population &only
1 or 2 index ages usually 12 yrs or one another age gr.
This survey provide minimum amount of data needed to commence planning .
Additional data has to be collected in order to provide a baseline for the
implementation & monitoring of services.

NATIONAL PATHFINDER SURVEY:-

Incorporates sufficient examination sets to cover all important subgroups of the
population that may have differing disease levels or treatment needs & at least 3
of the age groups or index ages.
This type of survey is suitable for the collection of data for the planning &
monitoring of services.

Types of pathfinder survey

1 •Pilot –includes 1‐2 index age
‐provides minimum amount data to commence planning

2. National‐covers all imp sub groups

‐min three index age
‐nation wide planning

Index age groups

•5 years‐primary teeth
•12 years‐all permanent teeth erupted
‐global monitoring age of caries
15 years‐permanent teeth exposed to oral environment for 3‐9 years
35‐44 years‐standard monitoring group for health conditions of adults
65‐74 years‐aging





C.SELECTING THE SAMPLE
It is impossible to examine every individual in the
population.(manpower ,money, time ,are considered)

TYPES:-

• 1. RANDOM SAMPLE
• 2. CLUSTER SAMPLE
• 3. STRATIFIED RANDOM SAMPLE
• 4. SAMPLING BY STAGES

SELECTED SAMPLE

A criteria is set if a person fulfills the criteria he is selected for the sample Selection may be done either by
1. Self selected- which is haphazard or
2. systematic Research workers

1. RANDOM SAMPLE

Where each individual have an equal chance of being included in the sample.

Population

Sample

Convenience Sampling

Researcher

1.Simple Random Sampling

2,6,7,12, 18

Each member of the population is listed in fashion (e.g., numerically)
and then a sample is drawn by randomly selecting members of the population

2. CLUSTER SAMPLE

Done for administrative & economic reasons
Clusters may be villages , buildings ,classes of schoolchildren or
family.

3.Systematic/Sequential Random Sampling

A random start in the sequence is selected, and sample is selected by selecting cases sequentially in the list to produce the desired sample size
Desired sample size;5
Random strat;20
Increment; 20/5=4

4. SAMPLING BY STAGES

Ex:- in the two stage sampling the population is divided into a set of 1 st
stage sampling units(Primary Sampling Units) & a sample of these units is
selected by simple ,random, stratified or systematic sampling.
Individuals are then chosen from each of these primary units any method
of samplings.
Size of sample is dependent on the statistical characteristics of the data to
be collected.
Larger the sample less the sampling variation i.e. less chance of misleading
result.

Conducting the Examination

Obtaining approval form the authorities
Permission to examine population groups must be obtained from a local,regional/national authority.
Budgeting
Abudget for the survey should be prepared which should include all there sources required ,including personnel to carry out the survey.

Scheduling

One of the most important aspects of survey planning is the preparation of schedule for data collection other wise there is a waste of time waiting for subjects to arrive or unnecessary delay.
Emergency care and referral
A list a referral facilities and addresses should be prepared before the survey so that the emergency conditions detected during the examination can be referred to appropriate care.

Training and calibrating examiners