Practice questions CPH exam with correct answers

Public health laws approved by city or county boards must be - correct answer approved by referendum Sensitivity - correct answer true positive rate; proportion of positives correctly identified as such; A/A+C Specificity - correct answer true negative rate; probability of testing negative if the disease is truly absent; D/B+D A confounding variable - correct answer is associated with exposure; it can strengthen or weaken Rate data such as the number of events occurring in a specified period of time are often described by which probability distribution? - correct answer The Poisson distribution is often used to describe count data and can be used to describe rate data by including an offset term for the denominator of the rate. The number of independent events needed for selecting the appropriate probability model is specified by the: - correct answer Probability distributions are based on the number of independent events. Degrees of freedom (to vary) are used as the specification of the number of events that can vary. If we are predicting a parameter (which is a fixed value), only the number of events minus 1 can vary and the final event would then have to be a specific value, it cannot vary and is thus not an independent event. Enteric pathogens - correct answer bacteria of the intestines traditional indicator of microbiological water quality - correct answer fecal coliform bacteria Health Impact Assessment - correct answer a combination of procedures, methods, and tools by which a policy, program or project may be judged as to its potential effects on the health of a population, and the distribution of those effected within the population