Basic Demography and Epidemiology

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					                                                Intermediate Level Module HI5

Module I5

Basic Demography and Epidemiology


This module will provide students with an understanding of basic ideas about demographic
and vital statistics. The ideas on this theme are largely quite basic, but they are pervasive,
in that they appear in various forms in many areas of public data collection e.g. in relation
to most household surveys.

The above material is closely related to the equivalent themes in epidemiology. Although
at first sight, “medical” issues might seem too specialised to appear in these notes, it will
again be seen that the ideas herein – sometimes first or best developed in the medical
context – are very generally applicable. Indeed it can be argued that any properly educated
layman, let alone a statistician, should be able to talk in terms of ratios or rates, prevalence,
incidence or risks without misusing or muddling the concepts!


Successful students will be able to:

       Explain basic concepts of demography and epidemiology needed to underpin later
        learning of general statistical work.
       Correctly utilise important general vocabulary, and apply the methods wherever

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                                               Intermediate Level Module HI5

       Recognise the usefulness of demographic and epidemiological ideas, while realising
        that such ideas usually need extension when data structures go beyond the most

Expected Outcomes

The main aim of the module is to introduce various basic ideas which underpin parts of the
trainees’ likely responsibilities, and to that extent it is an end in itself.   The module is
preparatory or foundational insofar as it is prerequisite for the demographic section of
Higher Module H1 which looks at the Life Table and various applications.          The present
module is primarily concerned with ideas that relate to good practice in data collection and
summary, whereas the material in H1 depends on – and develops an understanding of –
probability as the basis of Life Table calculations.

Of course surveys constitute one important element of public-sector data collection and
large parts of this module provide a complement to – but not a substitute for – a course on
survey methods.


Students attending this module would benefit by being familiar with the use of Excel and
with the use of the SSC-Stat Excel add-in. This would be equivalent to skills gained by
attending the Basic Level module B2 and the Intermediate Level module I2.

This module makes quite frequent reference to web-based sources of information, and it is
desirable that students participating in this module should have basic training,         and
regularly if not constantly have facilities and opportunities for good-quality access to some

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                                          Intermediate Level Module HI5

of the world-wide web’s fascinating, empowering and valuable information relevant to its

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                                                 Intermediate Level Module HI5


Session 01. Data Collection for Demographic and Vital Statistics:

Meaning of demography. Data sources: census, vital registration and surveys. Nature of
demographic data and usual need for very large samples. Data collection problems: frame,
non-response and measurement errors.             Uses and importance of demographic data.
Difficult concepts for data collection and analysis e.g. household and family. Difficult data
to elicit e.g. complete fertility histories.

Session 02. Data Collection for Epidemiological Statistics:

Meaning of epidemiology. Data sources, examples and discussion: routine data, cross-
sectional surveys, longitudinal and sentinel site studies, research approaches.

Session 03. Basic Summaries for Demographic Statistics:

Introduction to “demographic shorthand” use of algebraic symbols. Absolute vs. relative
numbers. Ratio, proportion and rate. Death rates introduced as being conceptually some
of the simplest demographic rates.         Age-specific death rates.   Data sources.   Mortality
rates. Mention of some other types of rates.

Session 04. Basic Summaries for Epidemiological Studies:

Attribute data & its importance in epidemiology. Point and period prevalence. Incidence
and relationship to prevalence. Risk, risk factors, comparison of risks. Brief introduction
to cohort and case-control studies and basic perceptions of risk therein. Confounding.

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                                               Intermediate Level Module HI5

Session 05. Preparing and Presenting Demographic Information - I:

Age-grouping conventions.        Age-misreporting.     Disaggregation and its data demands.
Reporting detailed data. Introduction to age-period-cohort issues.

Session 06. Preparing and Presenting Demographic Information - II:

Direct and indirect standardisation introduced and discussed in context of death rates.
Brief mention of other, more general applications of this idea.

Session 07. Preparing and Presenting Epidemiological Information - I:

Reference material with particular stress on the web-based “Supercourse”.                 Critical
approach to published results.     Reliability, repeatability, reproducibility, validity, accuracy
vs. precision, need to look critically at a whole profile of measurements. Sampling issues,
including sample size demand, for binary data.         Concepts involved in considering the
errors in binary data.

Session 08. Preparing and Presenting Epidemiological Information – II:

Causation: thinking about different degrees of complexity and indirectly in causal linkages.
Critique of arguments about causality. Place of experiments in under-pinning arguments
of causation. Clinical trials. Observational studies – Evans’ postulates.

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