WHO Global Oral Data Bank, 1986-96: An Overview of Oral Health Surveys at 12 Years of Age

Article excerpt

Introduction

The WHO Global Oral Data Bank (GODB) was established in 1969 to meet the need for information on oral health status and disease trends upon which to base WHO's Oral Health programme (ORH). Currently, the GODB contains 1850 data sets on dental caries for 178 countries. Over the years, it has become the main international reference for global oral health epidemiology. Data on oral health are used in a variety of ways: to assess country, regional, and global situations; to guide programmes; and in planning and monitoring (1).

Each data set is checked by WHO for standard criteria and methodology before being accepted for entry into the GODB. The data bank thus satisfies requests for the collection of internationally available, clearly defined information on oral health (2), and the demand that the collection and presentation of such data be standardized (3). Also, the GODB accumulates relevant information from sources that generally do not appear in the scientific literature, e.g. reports prepared for ministries of health. Furthermore, WHO recommends that countries conduct regular oral health surveys every 5 years if possible, so that changes in oral health patterns and trends can be identified early enough for appropriate and timely planning or replanning of services.

This Update reviews the dental caries data available in the GODB, and which were collected in the period 1986-96 for the index age of 12 years (1). Only national surveys and those regional surveys from which acceptable national estimates could be made were chosen.

Materials and methods

The information in the GODB is collected from the following sources:

-- reports on surveys using the WHO standard epidemiological methods, including those which use the pathfinder methodology, as described in Oral health surveys: basic methods (4);

-- articles on oral health in the MEDLINE database provided that they meet the WHO criteria and methodology requirements and can be summarized in the standard format; and

-- official reports from WHO regional offices, ministries of health, and research institutions which use WHO standard methods.

Over the period 1986-96, a total of 307 surveys of 12-year-old children were included in the GODB. These are classified as national surveys, regional or local surveys, or as surveys with only limited information. In this Update we have included from the total set the following types of data:

-- national data obtained through random sampling, from national pathfinder studies, or from national registers; and

-- regional data considered by local authorities and WHO to be adequate as a basis for reliable national estimates.

If more than one survey fulfilled these criteria for any country only the latest is cited here.

Data presented include the percentage of the sample affected, the decayed, missing, filled teeth (DMFT) index and, if available, its decayed teeth (DT), missing teeth (MT) and filled teeth (FT) components. Two classifications of Member States have been used to present the data. First, by WHO region: African, the Americas, Eastern Mediterranean, European, South-East Asia, and Western Pacific, and second, according to the criteria in the World economic and social survey 1994 (5), in which countries are classified as developing, developed market economies, or economies in transition.

Results

Representative oral health surveys at 12 years of age in the GODB

Of the 307 surveys included in the GODB over the period 1986-96, 80 are reported here and provide data for 42% of WHO Member States. Originally, Member States in the GODB were subdivided simply as developing or highly industrialized, a classification that highlighted sharp contrasts in caries prevalence and trends. The more recent economic classification into three categories has further sharpened these contrasts. Subdividing the data according to country category, the 17 surveys from developed market economies represent 68% of these countries and the data from the eight countries with economies in transition represent 36% of such countries. …