Epidemiology: Measures of Mortality

Vocabulary flashcards covering core epidemiological concepts, equations, and measures of mortality based on Chapter 4 of Gordis Epidemiology.

Annual All-Cause Mortality Rate

The measure of annual deaths in a population from all causes, calculated as $\frac{\text{No. of deaths from all causes in } 1 \text{ year}}{\text{No. of persons in the population at midyear}} \times 10^n$.

Case Fatality

A measure of disease severity and lethality, calculated as $\frac{\text{No. of individuals dying during a specified period after onset}}{\text{No. of individuals with specified disease}} \times 10^n$.

Proportionate Mortality

The proportion or share of total deaths caused by a specific disease over a specified time period, calculated as $\frac{\text{No. of deaths from a specific disease in } 1 \text{ year}}{\text{Total no. of deaths in } 1 \text{ year}} \times 10^n$.

Years of Potential Life Lost (YPLL)

A measure of premature mortality calculated by subtracting each deceased person's age at death from a predetermined age (such as $75\,\text{years}$ in the United States) and summing the results across a population.

Underlying Cause of Death

The disease or injury which initiated the train of morbid events leading directly or indirectly to death, or the circumstances of the accident or violence which produced the fatal injury.

Direct Age Adjustment

A method used to compare mortality between populations by applying age-specific mortality rates from each population to a single standard population structure.

Indirect Age Adjustment

An age-adjustment method used when age-specific death counts are unavailable or in occupational studies, where general population age-specific death rates are applied to a study population to calculate expected deaths.

Standardized Mortality Ratio (SMR)

The ratio of observed deaths in a study population to expected deaths if the population had the same age-specific risk as a general reference population, calculated as $\text{SMR} = \frac{\text{Observed Deaths}}{\text{Expected Deaths}} \times 100$.

Cohort Effect

Variations over time in health characteristics or disease rates among groups of individuals defined by a shared experience, such as decade of birth or exposure era.

Impairment

Any loss or abnormality of psychological, physiological, or anatomical structure or function.

Disability

Any restriction or lack of ability (resulting from an impairment) to perform an activity in the manner or within the range considered normal for a human being.

Handicap

A disadvantage for a given individual, resulting from an impairment or disability, that limits or prevents the fulfillment of a role that is normal depending on age, sex, and social and cultural factors.

Disability-Adjusted Life Year (DALY)

A metric quantifying disease burden equal to one lost year of healthy life, calculated as the sum of years of life lost to premature death (YPLL) and years lived with disability (YLD).

Epidemiologic Transition

A long-term shift in global mortality patterns where communicable diseases decline while noncommunicable diseases become the primary cause of death.