Biostatistics worksheet exercises

1. An Introduction To Biostatistics

2. 2



Exercise Mark Evaluation
I
II
III
Average

Student name: ……………………………………………………………………………………………
Program :………………………………………………………………………………………………
Level : …………………………………………………………………………………………….

3. 3

Answer the following questions
Exercise I:
1. Choose the correct answer from each of the following:
1- Biostatistics deals with:
1. Individual’s life from birth to death
2. Events affecting life like marriage and education
3. Patient’s diagnostic and treatment
4. Both (1+2)

2- Biostatistics concerned with some indicators, except one
1. Demographic and vital events
2. Environmental health status
3. Patient’s status of admitting and discharging
4. (1)

3- We use the biostatics in:
1. Public health
2. Design and analysis of clinical trials in medicine
3. Both (1+2)
4. None of the above

4- The methods of data collection:
1. Records
2. Interview
3. Observation
4. All of the above

4. 4

5. Data in biostatistics termed as:
1. Census
2. Mortality
3. Morbidity
4. Variables

6. …….….. Can’t give measure the quantity but overall may sum to give a
relevant quality.
1. Rate
2. Censored data
3. Variable
4. Score

7. We use the……….. to detect the values above cut-off value.
1. Score
2. Censored data
3. Derived data
4. Categorical data

8. In order to have your data available on computer screen save it in
1. Image
2. Word document
3. Rich text
4. ASCII format

9. Uniform of Frequency distribution means:
1. One peak
2. Two peak
3. One form
4. No peaks

5. 5

2. Define:
1. Biostatistics:
……………………………………………………………………………………………………………………
……………………………………………………………………………………………………………………
2. Data:
……………………………………………………………………………………………………………………
……………………………………………………………………………………………………………………
3. Variables:
……………………………………………………………………………………………………………………
………………………………………… …………………………………………………………………………
4. Binary or Dichotomous Data:
……………………………………………………………………………………………………………………
……………………………………………………………………………………………………………………
5. Frequency distribution
……………………………………………………………………………………………………………………
……………………………………………………………………………………………………………………
6. Relative frequency
……………………………………………………………………………………………………………………
……………………………………………………………………………………………………………………

3. What’s the differences between:
1. Discrete data Vs continuous data
……………………………………………………………………………………………………………………
……………………………………………………………………………………………………………………
2. Nominal data Vs Ordinal data
………………………………………………………………………………………………………………………
………………………………………………………………………………………………………………………
3. Proportion Vs Percentage
………………………………………………………………………………………………………………………
………………………………………………………………………………………………………………………

6. 6

4. Numerical data Vs Categorical data
………………………………………………………………………………………………………………………
………………………………………………………………………………………………………………………
5. Qualitative data Vs Quantitative data
………………………………………………………………………………………………………………………
………………………………………………………………………………………………………………………

4. Use the box to define the type of each of the following data
1. ( ) Weight in Kg
2. ( ) Intelligent quotient
3. ( ) Sex (female/ male)
4. ( ) Height in cm
5. ( ) Number of patient/ year
6. ( ) Marital status (married, widowed, single)
7. ( ) Smoker (Yes, No)
8. ( ) Mother’s age
9. ( ) Blood pressure
10. ( ) Number of successful ablation treatment in a trial
11. ( ) Heart rate
12. ( ) Cholesterol level
13. ( ) Number of visits to a doctor
14. ( ) Degree of pain (severe, moderate, mild, none)
15. ( ) (True, false)








A Continuous data
B Discrete data
C Nominal data
D Ordinal data
E Derived data
F Dichotomous data

7. 7

5. Fill in the blanks
1. Biostatistics deals with
………………………………………………………, ………………………………………..…………… and
……………………………………………………… ……………………………………………….. …………….
2. Biostatistics applied in ……………………………………… ………………..………………….,
………………………………………………………………………… …………………………………… and
………………………………………………………………………… ………………… …………………………
3. Biostatistics concerned with many indicators as:
………………………………………………………………………………………………………………………
………………………………………………………………………………………………………………………
………………………………………………………………………………………………………………………
…………………… …………………………………………………………………………………………………
………………………………………………………………………………………………………………………
4. ……………………………………. and …………………………………data can be displayed
graphically which describes the …………………………………. Of occurrence in
the sample or population..
5. the most suitable graph to present continuous data is ………………………….
while for discrete data is …………………………………….
6. Mixture of two diagrams usually drawn by ………………………………………… ….
7. Vertical or horizontal rectangle with minimum and maximum value is
…………………………………………………..
8. Separate horizontal or vertical bars drawn for each category and the
length proportional to the frequency in that category best fits for
………………………………………… while continuous one best fits for
……………………………………………..
9. ……………………………….is circular and the …………………………….is
proportional to the frequency of the variable.
10. If both variables are numerical or ordinal , the relationship between
the two can illustrated using …………………………………………………………………..
and if one variable is categorical the ………………………………………………. best
fits for data representation.

8. 8

11. the shape of frequency distribution is ……………………………………….,
…………………………………………………………. Or …………………………………………..
12. in ………………………………… each observation is presented by one dot.
13. Ways of organizing and presenting data are ……………………………………….,
………………… …………………………………………….. and …………………………………………….
14. Tables in biostatistics are …………………………………….. ………………………….,
…………………………… …………..…………………… and ……… ………..…………………………..
6. Write on:
1. Free format











2. Distribution of data in single peak. Illustrate your answer with
diagrams.

9. 9

7. Name the following Diagrams

10. 10


8. Among 3253 Saudi women there 676 w omen have cancer.
Calculate:
1. Percentage of breast cancer
2. Proportion
3. Ratio








9. In a Clinical trial, the given observations are
a) with a given characteristic
b) without a given characteristic
So that:
Proportion=
Percentage =
Ratio =
Rate =

11. 11

Exercise II:
1. Choose the correct answers from the following:
1- The marks obtained by 9 students are:
(45, 32, 37, 46, 39, 36, 41, 48, and 36) the mean is:
1. 40
2. 360/9
3. 58
4. Both (1+2)

2- The median in these values (30,23,19,32,35,22,20,34,28,18,25) is
1. 22
2. 25
3. (22+20)/2
4. None of the above

3- The mode in these values (22,36,25,88,94,22,11,36,25,11,25) is
1. 25
2. 11
3. 36
4. None of the above

4-The range in these values (30, 45, 75, 80, and 100) is
1. 80
2. 60
3. 70
4. None of the above

5- For normal distribution we use:
1. Mean
2. Median
3. Percentiles
4. None

12. 12

6- For skewed distribution of data we use:
1. Mode
2. Median
3. Percentiles
4. All of the above

2. Define:
1. Mean:
……………………………………………………………………………………………………………………
……………………………………………………………………………………………………………………
2. Median:
……………………………………………………………………………………………………………………
……………………………………………………………………………………………………………………

3. Fill in the blanks
1. Statistical Parameters are:

1. ………. 1. ……………………………
2. ………. 2. ……………………………
3. ………. 3. ……………………………
4……………………………..
5. ……………………………
6. ……………………………

2. When a population follows a normal distribution, we can describe its
location and variability with two parameters………………… and ………………
3. When the population does not follow a normal distribution we can
describe it with ………………………. and ………………………………….
4. The Standard Normal distribution has a mean of ……………….………….and
a variance of ………………..………….
5. If the random variable, x, has a Normal distribution with mean, µ, and
variance, σ then the Standardized Normal Deviate (SND)
…………………..
a) Measures of …………………

b) Measures of ……………………...

13. 13

4. Write the formula for each of the following parameters:
1. Median for odd data number=
2. Median for even data number=
3. Mean (X) =
4. Range =
5. Standard Deviation (S) =
6. Variance (S
2
) =
7. 50
th
percentiles =
8. Mean Absolute Deviation (MAD) =

5. What percentages of subjects are included in 1, 2 or 3 s tandard
deviation from the mean?







6. Solve the following problems
1. The following data illustrates the Transcriptions Accuracy of Memorial
Health System. Count the Average:




Oct Nov Dec Jan Feb Mar Apr May June July
A 94.8 98 97.3 97 97.2 97.7 97.7 97.6 99 98.1
B 98 99 97 98.5 98.3 97.4 96 98 96.4 98.1
C 98.3 98.3 99.9 98.6 99.3 100 99.4 98.8 98.5 98.7
D 98.2 98.6 97.7 98 99.3 98.7 99.1 99 97.7 98.3
E 98.2 99.9 99.2 99.3 98.2 99.2 98.8 99.4 98.2 98.3
F 99.2 100 99.3 99.3 99.8 98.3 98.2 99.6 100 99.1
G 98.7 99.6 99.8 99.8 99.6 98.6 97 97.3 98.3 99
H 100 96.2 100 99.3 98.2 99.6 98.2 99.6 99.3 99

14. 14

2. Fourteen patients have the following lengths of stay:
2,3,4,1,4,16,4,2,1,5,4,3,6,1.
Calculate the mean, median, and mode?







3. The given data are for the period of stay in a hospital in one month
General Surgery 10
E.N.T 12
Orthopedics 18
Genitourinary 20
Count the Variance and Standard deviation?

15. 15

4. The following data illustrates blood cholesterol level for a Sample of 10
Persons
Complete the table and calculate variance, standard deviation, coefficient
variation.















5. Calculate range for the following data.
Data set: 100, 95, 125, 45, 70
Sorted value = 45, 70, 95, 100, 125





Person X X – X (X – X)
2

1 276
2 304
3 316
4 188
5 214
6 252
7 333
8 271
9 245
10 198
Total 2,597

16. 16

6. Calculate the Mean for (Small Population, N = 5)

Index (i) X
1 70
2 80
3 95
4 100
5 125
Total 470












7. The following data describe the blood sugar values for a small
population. Calculate the mean absolute deviation.

X
i
|X
i – µ|
80
70
95
100
125
Ʃ=470





8. Find the medians of the following data sets: {8, 7, 3, 5, 3}; {7, 8, 3,
6, 10, 10}.

17. 17

Exercise III:
1. On June 1, 170 inpatient service days were provided in a 200 bed
hospital. The bed occupancy ratio is:
1. 85%
2. 57%
3. 53%
4. 85%
5. None of the above

2. A 476927 people died from cancer. The population was 243394693,
the cancer mortality rate is:
1. 159.9 per 100000
2. 155.9 per 100000
3. 195.9 per 100000
4. 199.9 per 100000
5. None of the above

3 ……………………….. r ate is the ratio of deaths caused by anesthetic agent
during a period to the number of anesthetic administered, this related
to:
1. Cancer mortality rate
2. Mortality
3. Anesthesia death rate
4. postoperative rate
5. None of the above

4. The average number of days that inpatients discharged during the
period under consideration stayed in the hospital, Called:
1. Bed count
2. Average length of stay
3. Cancer rate
4. Mortality
5. None of the above

18. 18


5. The term refers to the sum of inpatient bed count days for each of the
days in the period under consideration. Called:
1. Bed count
2. Total bed count days
3. Bed turnover rate
4. Length of stay
5. None of the above

6. The hospital proportion of inpatient hospitalizations that end in death,
usually expressed as percentage, this related to:
1. Cancer mortality rate
2. Length of stay
3. Death rate
4. postoperative rate
5. None of the above

7. ……………………… m easures the risk of death for the cause under study in
a defined population during a given time period, this related to:
1. Cancer mortality rate
2. Length of stay
3. Death rate
4. postoperative rate
5. None of the above

8. The ratio of all infections in clean surgical cases to the number of
surgical operations is related to:
1. Postoperative infection rate
2. Length of stay
3. Anesthesia rate
4. Death rate
5. None of the above

9. The state of being diseased or the number of sick person or cases of
diseases in relation to a specific population, this related to:
1. Postoperative infection rate
2. Length of stay
3. Morbidity
4. Bed count
5. None of the above

19. 19


10. The number of calendar days a patient stays in the hospital, this
related to:
1. Bed count days
2. Length of stay
3. Average length of stay
4. Bed turnover rate
5. None of the above

11. It defined as the number of times a bed, on average, changes
occupant during a given period of time, this related to:
1. Bed count days
2. Length of stay
3. Morbidity rate
4. Bed turnover rate
5. None of the above

12. The number of available facility inpatient beds, both occupied and
vacant, on any given day, this related to:
1. Bed turnover rate
2. Length of stay
3. Morbidity rate
4. Bed count
5. None of the above

13. A unit of measure denoting the services received by one inpatient on
24-hours period, called:
1. Inpatient service day
2. Outpatient service day
3. Daily census
4. Average census
5. None of above

20. 20

14. During November, a hospital reported that (758) surgical operations
were performed. The infection control committee reported one
postoperative infection in a clean surgical case. According to the
formula, the postoperative infection rate for November is:
1. 0.1391
2. 1.1219
3. 0.1319
4. .01319
5. None of the above

15. A 200 bed hospital supplied the following information for the year
1999; Patients discharged and died (6500). The bed turnover rate is:
1. 33.5
2. 32.6
3. 23.5
4. 31.5
5. None of the above

16. If a hospital had 5 deaths and 400 discharges for a month, the gross
death rate is:
1. 1.24%
2. 1.25%
3. 1.22%
4. 1.64%
5. None of the above

21. 21

2. Write the formula that calculates each of the following:
1. Average daily census =
2. Average daily newborn census =
3. Bed count ratio =
4. Bed turnover rate =
5. Average Length of stay =
6. Postoperative Infection Rate =
7. Cancer Mortality Rate =
8. Bed Turnover Rate=
9. Crude birth rate=
10. General fertility rate=
11. Age-specific fertility rate =
12. Rate of natural increase (RNI) =
13. Incidence rate =
14. Prevalence rate =
15. Case fatality ratio =
16. Annual crude death rate =
17. Age specific death rate =
18. Maternal mortality rate =
19. Infant mortality rate =
20. Neonatal mortality rate =
21. Fetal mortality rate =

22. 22

3. Define:
1. Bed count days
………………………………………………………………………………………………………………………
………………………………………………………………………………………………………………………
2. Total bed count days
………………………………………………………………………………………………………………………
………………………………………………………………………………………………………………………

3. Total Length of stay
………………………………………………………………………………………………………………………
………………………………………………………………………………………………………………………
4. Morbidity
……………………………………………………………………………………………… ………………………
………………………………………………………………………………………………………………………
5. Death Rate (Mortality)
………………………………………………………………………………………………………………………
………………………………………………………………………………………………………………………
6. Length of stay (LOS)
………………………………………………………………………………………………………………………
………………………………………………………………………………………………………………………
7. Average Length of stay =
………………………………………………………………………………………………………………………
………………………………………………………………………………………………………………………
8. Bed count
……………………………………………………………………………………… ………………………………
………………………………………………………………………………………………………………………
9. Bed count ratio
………………………………………………………………………………………………………………………
………………………………………………………………………………………………………………………

23. 23

4. Solve the following problems
1- Hospital with (20) bassinets had 400 new born inpatient service days
during July. Count the Average daily census in July?



2- A (50) bed hospital that compiles 3846 inpatient services day for
September, Count the Average daily census?



3- During November, a hospital reported that 758 surgical operations
were performed; this infection control committee reported one
postoperative infection in a clean surgical case. Count the
Postoperative infection rate?



4- A hospital had 10 deaths and 800 discharge for a month. Count the
Mortality rate?

24. 24

5. The following table shoes, by age group, deaths in North Carolina
during 2001, the estimated population of North Carolina for 2001, and
the population of the United States for 2000. Use these data to compute
the 2001 age-adjusted death rate for North Carolina. Use the 2000 U.S
population as the standard population :
Age (Year) Population Deaths U.S Population
0-4 566.740 1.178 19.175.798
5-14 1.140.934 224 41.077.577
15-24 1.130.671 954 39.183.891
25-34 1.210.066 1.384 39.891.724
35-44 1.293.741 2.823 45.148.527
45-54 1.124.305 5.271 37.677.952
55-64 753.533 8.035 24.274.684
65 and over 986.115 51.863 34.991.753
Total 8.206.105 71.732 281.421.906

25. 25

6. Compute the basic measure of fertility, for Georgia 2000
Age of
women
(Year)
Number of
women in
Population
Number of
births to
women of
specified
age
Age-
specific
birth rate
per 1000
women
U.S
population
for year
2000
Standard
Population
based in
U.S
population
2000
Expected
births
Cumulative
fertility
rate
10-14 296.114 396 1.3 20.528.072 112.524 146 6.7
15-19 286.463 17.915 62.5 20.219.890 110.835 6.927 319.4
20-24 285.733 36.512 127.8 18.964.001 103.951 13.285 958.3
25-29 316.000 35.206 111.4 19.381.336 106.239 11.835 1.515.4
30-34 326.709 27.168 83.2 20.512.388 112.438 9.355 1.931.1
35-39 350.943 12.685 36.1 22.706.664 124.466 4.493 2.111.9
40-54 887.104 2.404 2.7 60.119.815 329.546 890 2.152.5
Total 2.749.066 132.286 182.432.166 1.000.000 46.931

1. Crude birth rate =


2. General fertility rate =


3. Age-specific fertility rate =

26. 26


7. The following annual data were reported for a certain geographic area:
Compute the following rates and ratios;
1. Crude death rate


2. Infant mortality rate



3. Fetal Mortality rate


4. Neonatal mortality rate

27. 27