PUBLIC HEALTH

Question 1

Define the following terms in your own words

a. Cost-effectiveness analysis –

b. Evidence-based public health –

c. Infectious (communicable) disease –

d. Zoonotic disease –

e. Posttraumatic stress disorder –

f. Psychiatric epidemiology –

Question 2

What are the three elements of the epidemiologic triangle?

Question 3

Calculate the sensitivity, specificity, positive predictive value (or predictive value +) and negative predictive value (or predictive value
-) for the data in the following table (NOTE: Pay attention to the
labels on the rows and columns, and be sure to show all your work.):

Screening test positive Screening test negative

Gold standard: disease present 58 13

Gold standard: disease absent 9 176

Question 4

How do the trends for overweight and obesity in the United States
compare for children and adolescents versus adults?

Cost-effectiveness analysis

Cost- effectiveness analysis is a term used in health services field to refer to an economic analysis method that compares relative outcomes and costs of courses of action (Altman&Bland,1994).

CEA= Health gain cost

Health gain from a measure (premature births averted, years of life or sight- years gained)
Evidence-based public health

It involves a strong base of knowledge on disease distribution and frequency, disease consequences and determinants, and on the effectiveness, efficacy and safety of interventions as well as their costs.
Infectious (communicable) disease

A communicable, transmissible or infectious disease involves clinically evident illness (symptoms or medical signs) that is as a result of infection, growth or presence of pathogenic biological agent in the host body.
Zoonotic disease

This refers to an infectious disease that is transmissible between species or vectors in humans and animals.
Posttraumatic stress disorder

PTSD refers to a grave anxiety disorder which initiates after experiencing an event that leads to psychological trauma. Although not frequent, the effects of PTSD are enduring (Ogden et al. 2002).

                                                Psychiatric epidemiology

This is field that attempts to assess the prevalence, etiology and conceptualization of mental illness in communities. It is a subsection of epidemiology and it is difficult since the present knowledge is poor.

Elements of the Epidemiologic Triangle

The epidemiologic triangle refers to infectious disease causation traditional model. It has the environment, host and external agent. The agent and host come together to cause disease in the host.

Sensitivity

Sensitivity = true positives

True positives + false negatives

=58/71= 0.817

Specificity

Specificity =true positives

True negatives + false positives

58/185= 0.314

Positive predictive value

PPV =True Positives

True Positives + False positives

58/67 =0.866

Negative predictive value

NPV = True Negatives

True Negatives + False Negatives

176/189 =0.931

Overweight and Obesity trends

      Recently, there has been a rapid emergence of childhood obesity and this will impact greatly on public health, as the overweight children grow in to overweight adults (Ogden et al. 2002).The prevalence of obesity and overweight among children has reduced.

References

Altman, D.G., &Bland, J.M. (1994). “Diagnostic tests. 1: Sensitivity and specificity”. BMJ          308 (6943): 1552.

Ogden, C.L., et al. (2002). Prevalence and trends in overweight among U.S. children and       adolescents, 1999-2000. JAMA 288:1728-32.