Epidemiology - Ch. 3

An epidemiologic survey of roller-skating injuries in Metroville, a city with a population of 100,000 (during the midpoint of the year), produced the following data for a particular year:Number of skaters in Metroville during any given month: 12,000Roller-skating injuries in Metroville: 600Total number of residents injured from roller-skating: 1800Total number of deaths from roller-skating: 90Total number of deaths from all causes: 900The cause-specific mortality rate from roller-skating was:

90/100,000 × 100,000.

An epidemiologic survey of roller-skating injuries in Metroville, a city with a population of 100,000 (during the midpoint of the year), produced the following data for a particular year:Number of skaters in Metroville during any given month: 12,000Roller-skating injuries in Metroville: 600Total number of residents injured from roller-skating: 1800Total number of deaths from roller-skating: 90Total number of deaths from all causes: 900The proportional mortality ratio (%) due to roller-skating was:

90/900 × 100.

An epidemiologic survey of roller-skating injuries in Metroville, a city with a population of 100,000 (during the midpoint of the year), produced the following data for a particular year:Number of skaters in Metroville during any given month: 12,000Roller-skating injuries in Metroville: 600Total number of residents injured from roller-skating: 1800Total number of deaths from roller-skating: 90Total number of deaths from all causes: 900The crude death rate for all causes was:

900/100,000 × 100,000.

Calculation of the standardized mortality ratio is an example of the direct method of age adjustment.

False

A prerequisite for using the direct method of age adjustment is that the age-specific death rates in the study population must be stable.

True

For a chronic disease of low incidence and long duration, prevalence of the disease increases relative to incidence.

True

The crude death rate is defined as the number of deaths in a given year divided by a reference population (during the midpoint of the year) times 100,000.

True

The incidence rate of a disease is defined as the number of new cases of the disease over a time period divided by the total population (at risk) during the same time period times a multiplier (e.g. 100,000).

True

The point prevalence of a disease is defined as the number of persons ill divided by the total number in the group at a point in time.

True

When the duration of a disease becomes short and the incidence is high, the prevalence becomes similar to incidence.

True

Blood pressure measurements on adult males 30-39 years of age were obtained in a survey of a representative sample of Twin Cities households. To compare the frequency of hypertension in the white and nonwhite populations surveyed, the most appropriate measure is the:

race-specific prevalence.

The incidence of a disease is five times greater in men than in women, but the prevalence shows no sex difference. The most likely explanation is that:

the duration of the disease is greater in women

The risk of acquiring a given disease during a time period is best determined by:

the incidence rate (cumulative incidence) for that disease in a given period of time.

Successful treatment programs that would shorten the duration of a disease primarily affect:

the prevalence of the disease.

The major disadvantage of crude rates is that:

they do not permit comparison of populations that vary in composition.