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). œDiagnostic 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.