Question

Measures of Disease Frequency (Chapter 2)

In 2009, President Obama launched a nationwide initiative to end homelessness in the U.S. by 2020. The homeless are a vulnerable population with limited access to health care and poor health outcomes. In order to allocate sufficient federal and local resources to eliminate homelessness, U.S. cities conduct an annual survey to estimate the number of homeless persons living within major cities. The City of Boston’s Emergency Shelter Commission (ESC) conducted a survey of homelessness on the night of January 25, 2017. Volunteers counted the number of homeless persons living on the streets, in emergency shelters for individuals or families, in domestic violence programs, in residential mental health or substance abuse programs, transitional housing, and in specialized programs.

1. Which of the following best describes the homeless population in the City of Boston?

a. Dynamic population

b. Fixed population

2. Which of the following describes the homeless population that took part in the ESC survey on January 25^th?

a. Dynamic population

b. Fixed population

3. The 2015 Homeless Census counted 3,456 homeless persons in Boston. The 2016 homeless census counted 3,384 homeless persons in Boston. The size of the population in Boston was 665,984 in 2015 and 673,184 in 2016. From 2015-2016, did the burden of homelessness:

a. Increase

b. Decrease

c. Stay the same (2015: .52%, 2016 0.50%)

d. Cannot determine from this information

4. What do you consider to be the biggest limitation in the homeless survey and why?

a. Time of year (winter)

b. Survey conducted one time annually, not more frequently

c. Survey unlikely captured all homeless persons

d. Survey captures prevalence, not incidence of homelessness

Answer 1

Fixed population: In a fixed population membership is relatively permanent and perhaps defined by some event. Once a person experiences the defining event they remain part of that population as long as they are alive.

Dynamic population: In a dynamic population, membership is defined by current status, so membership is not necessarily permanent. A person is a member of the population as long as they meet the definition of the population, and they cease to be a members of the population when they no longer meet the definition. Note that a person can be a member, leave, and then become a member again.

Que1.

This is an example of dynamic population. Because if a person own a house then he is not a part of this population.

Que.2

Fixed population.

Because the homeless population that took part in the ESC survey on January 25th does not change. Even though person own house after that date. But he is homeless on 25 th jan. He is part of that population as long as he is alive.

Que.3

Proportion of homeless in 2015 = 3456 / 665,984 = 0.0052

Proportion of homeless in 2016 = 3384 / 673184 = 0.0050

Since proportion in 2016 is less than 2015. Burden of homeless decreases from 2015 to 2016.

Que.4

Survey unlikely captured all homeless persons.