survey lecture

8/3/2019 Survey Lecture

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Survey in dentistry


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INTRODUCTION

The first step in modern public health procedure

parallels that used by the dental clinician, only here

it is th

e community th

at must be examined. It iscalled a survey instead of an examination.

Whatever the specific problem, the initial approach

to its solution should involve an examination to

determine its dimensions and particularcharacteristics.


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Survey

Definition: "Survey is defined as "The method of

collection of facts or information about the status-

quo of large number of cases in the community".

Dental survey means "Collection of facts and

analyzing and evaluating them and comparing that

data to previous data collected with that of

different place".

or

Basic oral health surveys are defined as "Surveys to

collect the basic information about oral disease

status and treatment needs that is needed for

planning or monitoring oral health care

Programmes".


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SURVEY:

A survey is an investigation in which information

is systematically collected, but in which

experimental method is not used. There is no

active intervention. Surveys are methods for

collection of data, analyzing and evaluating them

.in order to determine the amount of disease

problems in a community and also to identify

cases that have not been identified.


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Aims of the Survey

1. To provide systematic approach to the

collection and reporting of data on oral

diseases and conditions.

2. To ensure that data collected in a wide rangeof environments are comparable.

3. To encourage oral health administrators in all

countries to make standard measurements of

oral diseases and conditions as a basis forplanning and evaluation oral health

programmes.


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Uses of Survey

1. Community diagnosis of problems of health

and disease.

2. Collection of data to describe in normalbiological factor.

3. Understanding the natural history of the

disease.

4. Testing of hypothesis for the prevention ofdiseases (dental).

5. Planning and evaluating health care services.


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Advantages:

1. Provide information on some aspects of oralhealth about which information may not be

available from any source,

2. Rates and indices can be calculated.

3. Associations and correlations can be identifiedand studied.

4. Reasons' for utilization as well as non-utilization

of oral health services can be studied.

5. Information from a well-planned6. complete and accurate compared to information

collected routinely.


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Types of Surveys

Descriptive: It sets out to describe a situation

Cross-sectional

Longitudinal

Analytic (explanatory): Tries to explain the

situation, that is to study the determinative

process

Cross-sectional

Longitudinal


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Pathfinder SurveyIt is a practical, economic survey sampling

methodology. The method used is a stratified

cluster sampling technique, which aims to

include th

e most important populationsubgroups likely to have differing disease levels,

and to cover a standard number of subjects in

specific index age groups in any one location.

In this way, statistically significant and clinically

relevant information for planning is obtained at

minimum expense.


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This methodology is suitable for obtaining the

following information:

1. Prevalence of the various oral diseases affecting

the population.

2. Important variations in disease level, severity andneed for treatment in subgroups of the population.

3. A picture of the age profiles of oral diseases in the

population to provide information about severity and

progression of disease, and to give an indication as lowhether the levels are increasing or decreasing.


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Pathfinder Survey is classified! as either pilot or national.

Pilot Survey is one that includes only the most importantsubgroups in the population and only 1 or 2 index ages, usually

12 years and one other age group. Such a survey provides the

minimum amount of data needed to commence planning.

Additional data should then be collected in order to provide a

reliable baseline for the implementation and monitoring of

services.

National Pathfinder Survey incorporates sufficient examination

sites to cover all-important subgroups that may have differingdisease levels or treatment needs and at least three of index

ages. This type of survey design is suitable for the collection of

data for the planning & monitoring of services in all countries.


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Number of subjects

The number of subjects in each index age

group to be examined ranges from a minimum

of 25 to 50 for each cluster or sampling site,

depending on the expected prevalence and

severity of disease.


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An example of a sample design for a national

pathfinder survey for each index age or age group is as

follows:

Urban: 4 sites in capital city (4 x 25) = 100 2 sites in

each of 2 large towns (2x2x25) = 100

Rural: 1 site in each of-1 villages in different regions

(4 x 25) = 100

Total: 12 sites x 25 subjects = 300

Applying this cluster distribution to the entire

population (index ages like 12, 15,35 to 44, 65 to 74

years), the total sample is 4 x 300 = 1200.


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Index Age and Age Groups

Those recommended are 5 years for primary teeth,

12, 15, 35-44, 65-74 years for permanent teeth. In

each age group minimum of 25-50 subjects is to be

considered.3

5 years: This age is of interest in relation to levels of

caries in the primary dentition which may exhibit

changes over a shorter time span than thepermanent dentition at other index ages.


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12 years: This is the age at which children leaveprimary school, and is also the last age at which

reliable sample may be obtained easily through

the school system. At this age all permanent

molars would have erupted except the thirdmolars. This age is also chosen as the global

monitoring age for caries for international

comparisons and monitoring of disease trends.


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15 years: At this age the permanent teeth have

been exposed to th

e oral environment for 3 to 9years. The assessment of caries prevalence is

therefore often more meaningful than at 12 years

of age. This age is also important for the

assessment of periodontal disease indicators inadolescents.

35 to 44 years: This age group is the standard

monitoring group for health conditions of adults.

The full effect of dental caries, the level of severeperiodontal involvement and the general effects

of care provided can be monitored in this age

group.


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65 to 74 years: This age group has becomemore important with the changes in age

distribution and increases in life span. Data for

this group are needed both for planning

appropriate care for the elderly and formonitoring overall effects of oral care services.


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Scientific Method In Dental Epidemiology

1. Establishing the objective.

2. Designing the investigation.

3. Selecting the sample.4. Conducting the examinations.

5. Analyzing the data.

6. Drawing the conclusions.

7. Publishing the reports.


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Establishing the Objective

The surveyor must be absolutely clear about the

objective of the survey before considering its design.

Design is entirely dependent upon the objective of

th

e survey.In most of the survey, the objective can be stated in

the form of hypothesis which is to be tested. The

hypothesis can be the difference in external of the

dental disease between two different groups or in acase of clinical trials, that one method is then

another in preventing or treating a disease. The

object of the survey is then to test this hypothesis.


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Designing the Survey

This can be taken through different studies. They are:

Prevalence study also called as cross-sectional study:

It is the proportion of population suffering from a

particular disease in a given time in a given population.

It is useful to compare the diseases in population at

different time.

B. Incidence or longitudinal study: Where the amount

of new disease is a population is measured over a

period of time. This is usually expressed as the

proportion of that population which becomes affected

per unit time.


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Clinical trials:When a new treatment has been developed it is

important to provide the answer to two questions

before making decision.

Does it work?

Is it better than existing treatment?

To answer these questions, the clinical trial survey is

carried' out.


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Conducting the Examination

For scientific epidemiological study of dental

diseases and conditions, three aspects are of great

importance. They are ,

examination methods,

diagnostic aids and

diagnostic criteria.


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a.Ex

amination method:

The basic requirement is a chair preferably with

a headrest and source of illumination. The time for

examination may range from 30 seconds to one andhalf an hour depending upon the study.

Test and retest procedures are conducted to

minimize intra-examiner variability. Tests and

retests are examina-tion of patient two times andcomparing monthly. The intra-examiner variability is

minimized by training calibration session.


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b. Diagnostic aids:

According to WHO report on dental health

procedure, the diagnostic aids are plane mouth

mirror, sh

arp probe and sufficient day ligh

t.D

unning(1971) classifies the studies into 4 groups depending

upon the type of use of diagnostic aids.


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TYPE I: Complete examination with plane mouth

mirror and explorer under sufficient illumination

with full mouth radiographs. Additional diagnostic

aids are study cast, pulp testing and other

laboratory investigation.

Type II: Limited examination of patient with plane

mouth mirror and explorer under sufficient

illumination with bitewing X-rays and IOPA X-rays.

Type III: Examination of patient with plane mouth

mirror and explorer under good illumination. It is

commonly practiced.

Type IV: It is screening procedure, with the help of

a tongue depressor and available illumination.


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c. Diagnostic criteria:

These are the indices used for dental diseases.The indices should have the following properties:

Clarity

Simplicity

ObjectivityValidity

Reliability

Quantifiability

AcceptabilitySensitivity.


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Analysing the Data

This is done with the help of statistical

measurements, like range, mean deviation,standard deviation, mean, mode, median, bar

diagram, histogram.


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Drawing the Conclusion and Publishing the Report

This is taken under following headings:

a. Introduction: This tells about the diseases to be

studied.

b. Review of literature: Past literatures about the diseases

taken for survey are mentioned.

c. Materials and methods: This includes selection

and description of samples and methods used in

survey together with its criteria.

d.R

esults:Th

ese sh

ould be tabulated and illustrated asappropriate, with amplifications in the text.

e. Discussion and conclusion: The survey, its findings and

its conclusion are discussed at the discretion of the

survey.


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survey lecture

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