VITAL DATA Nigel Paneth

FIVE COMPONENTS OF VITAL DATA Vital data are defined as major events in the population that are required by law (in many jurisdictions) to be reported to governmental authority. The five generally accepted components of vital data are: BIRTHS DEATHS FETAL DEATHS MARRIAGES DIVORCES

BIRTHS Important as a denominator to epidemiologists, as a numerator (birth-rate, fertility-rate) to demographers Subsets of births (e.g. low birthweight) often of importance to epidemiologists because of their high risk

DEATHS The major outcome of interest to epidemiologists. The overall death rate is of interest to demographers, the cause-specific rates to epidemiologists.

FETAL DEATHS Not always considered vital data, because rules on registration are so varied. Tend to be under-reported almost everywhere, regardless of legal requirements. Great variation in minimum gestational age required for reporting. (In most US states, about 20 weeks)

MARRIAGES AND DIVORCES Neither of the above used as outcomes much by epidemiologists, though often of interest as exposures affecting health.

POPULATION Although not labeled as vital data, counts of the population from CENSUS data are essential to epidemiologists as denominators for death and disease rates.

NINE USES OF VITAL DATA 1. MEASURING THE BURDEN OF DISEASE. How do cause-specific mortality rates compare to each other? 2. HISTORICAL PATTERNS OF DISEASE How have death rates changed over centuries? 3. SECULAR TRENDS IN DISEASE How are death-rates changing now?

MORE USES OF VITAL DATA 4. GEOGRAPHIC DIFFERENCES How do countries or regions differ in mortality? 5. DEFINING ACUTE EPIDEMICS Can we detect sudden changes in disease? 6. DEFINING NEW DISEASES Can we detect new diseases in vital data?

MORE USES OF VITAL DATA 7. ASSESSING MEDICAL CARE Can we compare death rates in populations receiving different kinds of medical care? 8. ENVIROMENTAL EXPOSURES Can we compare death rates in regions exposed to different ecological exposures? 9. POLITICAL USES (AND MISUSES) Can we persuade politicians to support public health measures based on vital data?

DEFINING EPIDEMICS (Albert Camus’ The Plague).. the bare statement that 302 deaths had taken place in the third week of the plague failed to strike the public's imagination. For one thing, all 302 deaths might not have been due to plague. Also, no one in the town had any idea of the average weekly death-rate in ordinary times. The population of the town was about 200,000. There was no knowing if the present death-rate were really so abnormal. This is, in fact, the kind of statistics that nobody ever troubles much about - notwithstanding that its interest is obvious. The public lacked, in short, standards of comparison.

CAUSE OF DEATH CERTIFICATION IMMEDIATEUNDERLYINGCONTRIBUTORY Myocardial infarction Coronary heart disease Diabetes Epidural hemorrhage Motor vehicle accident Alcohol intoxication Pneumocystis pneumonia AIDSIV drug abuse

EXAMPLES OF THE USES OF VITAL DATA

RECOGNIZING PATTERNS OF DISEASE WHAT ARE THESE EPIDEMICS?

EARLY USES OF DEATH DATA Florentine dowry fund Typhoid fever decline

HISTORICAL TRENDS IN DISEASE Cancer Heart Disease Overall mortality Infant mortality Maternal mortality AIDS

GEOGRAPHIC VARIATIONS Breast Cancer Cervical cancer

DETECTING NEW DISEASE PATTERNS Changing death rates in asthma

ASSESSING THE EFFECTS OF MEDICAL CARE Neonatal tetanus immunization Newborn intensive care Effect of infant transport

THE POLITICS OF VITAL DATA Yalow letter about South African mortality