On-line learning resources

Cal package e-books

Coggan D, Rose G, Epidemiology for the uninitiated: http://www.bmj.com/epidem/epid.html

A good introductory text Schoenbach V. Understanding the Fundamentals of

Epidemiology http://www.epidemiolog.net/evolving/TableOfContents.htm

This book contains lots of interesting material, with lectures, tutorials problems and solutions.

A CAL Package

Accessing the Cal

website to downloadhttp://www.personal.dundee.ac.uk/~cdvflore/

on teaching computersAll programmes

contentsdescriptive epidemiology, demography, RCT, cohort

studies, case-control studies, surveys introduction to statistics and data analysis questionnaire design, screening

Sources of routine data

Professor Iain Crombie

Data required

Size / characteristics of populationHealth event data

MortalityMorbidity

Other data

Why we need routine data descriptive epidemiology

disease frequencies by person, place and timemeasuring burden of disease for planning

demography other types of study

what happens to• people who smoke• people with high blood pressure

Early routine data in England

deaths recorded in early 16th Century by parishto count plague deaths from 1563 weekly bills of mortality published christenings also recorded1629 other causes of death recorded

1662

John Graunt of Londonmember of the Royal Society tailor first to draw scientific conclusions from statistical data

estimates of population size life table- law of mortality statistical association time series representative sample careful assessment of error repeated testing of ideas

died in poverty

1620 - 1674

Graunt’s analyses

male mortality higher that female (14:13)infant mortality very high

• one third had died by age of 5

seasonal variation in mortalityplague killed more than had been realisedepidemic of ricketts

Population CensusPeriodic count of number and characteristics of

people by regionEvery 10 yrs in UK since 1801 (except 1941)Office for National Statistics (ONS) in England &

Wales; General Registrar Office (GRO) in ScotlandOccur in most developed countries

Scotland Population 2011: single years of age

1946

1965

1986

Birth, death, marriage and divorce registration

Legal requirement Close relative (legal informant) must

register births and deathsPopulation estimates (and

projections)

Trends in births and birth rate

Marriages by type

% brides and grooms unable to write:sign with an X

Divorces

Mortality

All deaths registered within 5 daysRegistered medical practitioner must

issue medical certificate of cause of deathBasis of national mortality statistics

Death certification Must list condition / sequence of

conditions leading to deathPart I: Direct / underlying cause of death and

conditions leading to itPart II: Significant condition contributing to

death but not part of actual sequence

Immediate cause

Underlying cause

Arriving at the cause

Death was caused byI (a) Immediate causeI (b) Due toI (c) Due toII Other contributing disease

a) generalised metastasesb) bronchopneumoniac) lung cancer

Lung cancer is the underlying cause of death

Death certification Person AIa UraemiaIb Acute retention of urineIc Benign prostatic

hypertrophyII....................

Person BIa Hepatic failureIb Bile duct obstructionIc Carcinoma of head of

pancreasII Diabetes mellitus

What are the underlying causes of death?

Coding disease: ICD-10

International Statistical Classification of Diseases and Health Related Problems, 10th revision

Produced by WHO for coding morbidity/ mortality‘to promote international comparability in the

collection, classification, analysis and presentation of mortality and morbidity statistics’

ICD-10 examples

A05.1 Botulism

C15.3 Malignant neoplasm –

upper third of oesophagus

Q03 Congenital hydrocephalus

S60.417 Abrasion of left little finger

T40.0x1Poisoning by opium (accidental)

More coding

Person AIa Traumatic shockIb Multiple fracturesIc Pedestrian hit by truckII....................

V04.1

Person BIa Acute anaemiaIb Bleeding oesophageal

varicesIc Portal hypertensionII Cirrhosis of liver

K74.6

Population data + Death data

death rates age group disease long term trends

published data national international (WHO)

Morbidity

Contact with health care systemDisease-specific reporting Disease registersPopulation-based surveys

Receiving care

Awaiting care

Ill but not seeking help

Healthy

Iceberg concept of disease

Some of the statutory notifiable infectious diseases…

Anthrax, cholera, plague, measles, meningitis, mumps, rubella, rabies, TB, typhus

Health care contacts

Hospital inpatient data with ICD10 coded admission codes (Scottish Morbidity Records)AdministrativeDemographicClinical

GP data registers

Accuracy of disease coding

death fairly good diagnostic fashion

hospital discharge often correct

general practice many hard to diagnose conditions

Disease registers

Identify individualsWith a feature in commonLongitudinal (updated systematically)Based on a (geographically) defined population

Early disease registers

Leprosy, Norway, 1856 Blind persons, Britain, 1937 Cancer, Massachusetts, 1927 Psychiatric patients, Denmark, 1940 Tuberculosis, ?, ?

marked increase in Registries after 1950

Lepers’ squint: Lunna Kirk, Shetland

Early disease registers

• Leprosy, Norway, 1856• Blind persons, Britain, 1937• Cancer, Massachusetts, 1927• Psychiatric patients, Denmark, 1940• Tuberculosis, ?, ?

• marked increase in Registries after 1950

The Cancer Registry Most countries maintain some form of cancer register

many cover only part of a country

Co-ordinated by the European Network of Cancer Registries

the International Association of Cancer Registries

UK – 100% coverage from 1970 NHS funded

Frequency of types of cancer: men, UK, 2009

Frequency of types of cancer: women, UK, 2009

Age distribution of all cancers: cases and rates

Other disease registers

ankylosing spondylitis brittle bone disease cerebral palsy congenital anomalies coronary heart disease cystic fibrosis Creutzfeltd-Jakob disease diabetes

What do most of these diseases have in common?

Uses of registries To measure amount of disease (incidence / prevalence)

Temporal trends

Patient follow-up

To measure outcomes (eg cancer survival)

Service organisation / delivery/ evaluation

Research and clinical audit

Studies of disease causation

Heterogeneity of registers

size quality

completeness of recording accuracy of information

purpose cost continuity of funding

Population-based surveys

Ad hocDifferent methods

Physical examination, questionnaire, face to face interview, telephone survey

Different populationsLocal, national

Examples Scottish Health survey

alcohol, diet, exercise, smoking, blood pressure, obesity also in England

General Household Surveyhousing type, education, family structure, income, alcohol

Living Costs and Food Surveymerged from National Food Survey and Family Expenditure

Survey. Was called Expenditure and Food Surveyhousehold food consumption, demographics, goods,

services

Obesity prevalence by age and gender

SHS 2010

Prevalence of obesity by SIMD quintile

SHS 2010

General household survey 2010: types of cigarette

General household survey 2010: household size

General household survey 2010: consumer durables

Record Linkage uses personal identifiers to link

mortality hospital discharge prescribing (Tayside) laboratory tests (Tayside)

to examine predictors of mortality quality of careadverse drug reactions

Other dataSocio-economic

Unemployment benefitIncome supportCrime statistics

EnvironmentalAir pollutionRoad accidentsDrinking water

What you should know routine data collections systems needed

descriptive epidemiology and demography many types of data collection systems

huge amount of data available some compulsory, many voluntary demographic, disease, economic, behavioural

data sets vary in completeness and accuracy census data good death certificate data good nationally funded schemes usually good others: good to not very good