NR503 Midterm Exam : Population Health, Epidemiology & Statistical Principles Question 1 The population of a city on February 15, 2005, was 36,600. The city has a passive surveillance system that collects hospital and private physician reports of influenza cases every month. During the period between January 1 and April 1, 2005, 2,200 new cases of influenza occurred in the city. Of these cases, 775 persons were ill with influenza according to surveillance reports on April 1, 2005. The monthly incidence rate of active cases of influenza for the 3-month period was: 4 per 1,000 population 17 per 1,000 population 20 per 1,000 population 39 per 1,000 population 130 per 1,000 population Question 2 What would be the effect on age-specific incidence rates of uterine cancer if women with hysterectomies were excluded from the denominator of incidence calculations assuming that most women who have had hysterectomies are older than 50 years of age. The rates in all age groups would remain the same. Only rates in women older than 50 years of age would tend to decrease.