Epidemiology for English speaking students / Tasks for Seminars / Seminar 1 Epidemiologic measures / Tasks 1

Task 1

According to data listed in Table 1

1. Calculate the rates of prevalence and incidence of rheumatism among Moscow’s population in 1998

2. Identify and explain the causes of discrepancy between the values of prevalence and incidence rates of rheumatism in Moscow’s population in 1998 and in the period under review.

3. Reveal the epidemiological meaning of the prevalence and incidence rates of rheumatism and scarlet fever morbidity of Moscow’s population in 1998

Table 1. Morbidity due to rheumatism among Moscow’s population in 1992-1998 in prevalence and incidence rates per 100 000 population

years	population	Number of patients		Prevalence 0/0000	Incidence 0 /0000
		Total	New cases
1992	9044600	2689	40	29.7	0.4
1993	8837050	2290	45	25.9	0.5
1994	8792900	2161	48	246	0.5
1995	8792900	2045	39	23.3	0.4
1996	8755100	1999	45	22.8	0.5
1997	8690900	1942	46	22.3	0.5
1998	8690800	1832	55	???????	???? ??

Task № 2

According to data listed in Table 3:

1. Calculate the incidence rate of morbidity due to scarlet fever among Moscow’s population in 1998.

2. State and validate your reasons for the possibility of calculating the prevalence rate using tabulated data

3. State and prove your arguments about the expediency of evaluating scarlet fever morbidity with the help of the period prevalence rate

4. Reveal the epidemiological meaning of the scarlet fever morbidity rate of Moscow’s population in 1998

Table 3 Scarlet fever morbidity rate for Moscow’s residents in 1992-1993 per 100000 population

Year	Population	Cases revealed	Morbidity (incidence rate)
1992	9044600	6653	73,6
1993	8337050	7700	87,1
1994	8/92900	7990	90,9
1995	3792900	6831	78,3
1996	8755100	7465	85,3
1997	8690900	5726	65,9
1998	8690800	9353	??????

Task № 3

According to data listed in Table.4:

1. Calculate the proportion of children up to 14 years of age among cases of acute viral hepatitis in the Russian Federation in 2005.

2. Indicate what data (absolute numbers or incidence rates ) you have chosen for calculations. Explain the reason.

3. Indicate if it is possible using data from Table 1.4 to calculate the value of incidence rate of acute viral hepatitis among adults (over 14 years of age), their proportion among the sick. Calculate possible rates. Explain your decision.

Table 4 Morbidity due to acute viral hepatitis in the Russian Federation in 2005

Total		Children up to 14 years of age
Absolute number	Per 100 000 population	Absolute number	Per 100 000 population
64967	44.94	13307	57.65

Task №4

According to data listed in Table5:

1. Calculate the proportion of hepatitis A, B and C cases among acute viral hepatitis cases in the Russian Federation in 2005.

2. Indicate what data (absolute numbers or incidence rates ) you have chosen for calculation. State your reason.

Table 5 Morbidity with acute viral hepatitis in the Russian Federation in 2005

	Total		Children up to 1 4 years of age
	Absolute number	Per 100 000 population	Absolute number	Per 100 000 population
Acute viral hepatitis
	64967	44.94	64967	44.94
Including hepatitis A
	43433	30.05	12246	53.05
Hepatitis B	12379	8.56	438	1.90
Hepatitis С	6455	4..47	179	0.78