# Chapter 3: Measures of Morbidity & Mortality Used in Epidemiology Flashcards

1
Q

What is a count?

A

The # of cases involved of a disease
Ex: cases of influenza reported in Westchester County; college dorm residents who had mononucleosis; stomach cancer patients who were foreign born; traffic fatalities in the borough of Manhattan during a 24-hr period

2
Q

Ratio? Types?

A

A value obtained by diving the 1 quantity by another

• Simple-sex
• Demographic
• Sex ratio at birth
3
Q

Proportions?

A

A type of ratio in which the numerator is part of the denominator. Can be expressed as a percentage.
Formula: A/ (A+B)
Ex: A is 1,1150 (# of African American boys)
B is 3,180 (# of white boys)
1150/ (1150+3180)= 0.2318 = 23.2%

4
Q

Simple sex ratio

A
```# of male cases to female cases
Ex: Out of 1000 car fatalities, 950 were men, 50 were women. What's the SSR? (950/50 = 19/1 M to F)```
5
Q

Demographic sex ratio

A

SSR * 100

Ex: (151,781,326/156,964,212)* 100 = 96.7

6
Q

Sex ratio at birth

A

SSR * 1000

Ex:

7
Q

Rate? Elements?

A

A type of ratio. The denominator involves a measure of time. Consists of num/deno in which both are calculated in units of time.

• Disease frequency count
• Unit size of the population at risk
• Time period during which the event occurs
8
Q

Prevalence?

A

of existing cases of a disease or health condition in a population at some designated time

• Describes burden of illness in a pop.
• Guides allocution of resources
• Outcome measures often expressed as 10^n
9
Q

What is point prevalence?

A

Prevalence at a point in time
Ex: (# of persons ill/total # in the group) from July 13-15
41,837 people were asked if they smoke, 6,234 said yes (6,234/41,837) = 14.9% is the point prevalence

10
Q

What is period prevalence?

A

Prevalence during a period in time. # of cases in a period of time.
Ex: Have you ever been diagnosed by a physician as having any form of cancer, other than skin cancer?
41,837 people were asked, 2,293 said yes (2293/41837) = 5.5% is the period prevalence

11
Q

What is BMI?

A

Body mass index; a measure of obesity

12
Q

Incidence?

A

the number of instances of illnesses commencing, or of persons falling ill, during a given period in a population. A measure of the risk of a specified health-related events

13
Q

Incidence rate?

A

the rate of development of a disease in a group over a certain time period; period included in the denominator
-(# of new cases/total pop. at risk) * 10^n
-time: the period during which the cases accrue
Ex: 1,085 new cases of breast cancer among 37,105 women.
1085/37105= 0.02924/8 (yrs.)= 0.003655*100,000= 365.5 cases per 100,000 women (ask for help???)

14
Q

Population risk?

A

the denominator for incidence rates; those members of a population who are at risk for contracting a specific disease or adverse health outcome

15
Q

Attack rate?

A

(AR) is an alternative for the incidence rate. Used when the nature of the disease is such that a population is observed for a short time period, often as a result of specific exposure
Ex: 87 people ate turkey for dinner and 63 became ill and the rest didn’t. What’s the AR?
AR= ill/ (ill+well)100; (ill/total)100
63/ (63+24)*100= 72.4%

16
Q

Cumulative incidence?

A

incidence expressed as a proportion of a cohort or group at risk; # of new cases of disease occurring over a time period in population at risk at beginning of interval

• the proportion of of at risk pop. who develop the disease
• estimates the risk of developing the disease
17
Q

Incidence density?

A

the average PERSON-TIME incidence rate; an incidence measure used when members stored in a pop. or study group are under observation for different lengths of time
-Subjects enter/exit the candidate pop. at varying times
-Recruited to study over time
Subjects are “lost to follow up”and don’t complete the study

18
Q

What’s the interrelationship between prevalence and incidence?

A

The prevalence of a disease (P) is proportional to the incidence rate (I) * the duration (D) of a disease

19
Q

What are crude rates?

A

Summary rates based on the actual # of events in a pop. over a given time period
Ex: Look at Exhibit 3-5 on pg. 310-311

20
Q

Crude birth rate?

A
```# of live births during a specified period of time (1 yr.) per the resident pop. during the midpoint of the time period
Ex: 3,945,875 babies were born in the US in 2016 in the US when the pop. size was 323,127,513
3,945,875/323,127,513= 12.2 per 1000```
21
Q

General fertility rate?

A

average # of children born in a time period. Expressed as 1000 women per age (whatever age given)

22
Q

Total fertility rate?

A

the average # of children that would be born per woman if all women lived to the end of their childbearing years and bore children according to a given set of age specific fertility rates

23
Q

Fetal mortality?

A

Spontaneous intrauterine death of the fetus at any time during the pregnancy

24
Q

Fetal death rate

A

of fetal deaths after 20 weeks gestation or more/# of live births plus fetal deaths (20 weeks gestation or more). Expressed as rate per 1,000 live births and fetal deaths

25
Q

Late fetal death rate?

A

fetal deaths after 28 weeks gestation or more

26
Q

Fetal death ratio?

A

(# of fetal deaths after gestation of 20 weeks or more/ # of live births during a yr.) * 1,000 live births

27
Q

Infant mortality death rate?

A

(# of infant deaths in a yr./# of live births in a yr.) * 1000 live births
Ex: there were 23,161 infant deaths and 3,945,875 live births in a year
(23,161/3,945,875)*1000= 5.87 per 1000 live births

28
Q

Neonatal mortality rate?

A

(# of infant deaths under 28 days of age/# of live births) * 1000 live births
-“neo” means new. When the baby is new to the world (aka newborn)

29
Q

Postneonatal mortality rate?

A

(# of infant deaths from 28-365 days after birth/# of live births) * 1000 live births

30
Q

Maternal mortality rate?

A

of maternal deaths ascribed to childbirth per 10,000 or 100,000 live births

31
Q

What are specific rates?

A

A type of rate based on a particular subgroup of the pop. defined
Ex: in terms of race, sex, or age

32
Q

Cause specific rate?

A

a rate that specifies events, such as deaths according to their cause
Ex: assault, chronic liver disease, environment, etc. 1

33
Q

Age specific rates?

A

a rate for a specific age group. The numerator and denominator apply to the same age group* 100,000

34
Q

Proportional mortality ratio?

A

the # of deaths w/in a pop. due to a specific disease or cause/total # of deaths in pop.

35
Q

A

summary measures of the rate of morbidity and mortality in a pop. which statistical procedures have been applied to remove the effect of differences in composition of the various pops.

36
Q

Direct method?

A

a rate adjustment that applies specific rates for a group to a standard pop.

37
Q