Respiratory Epidemics

Question 1

A woman with an acute respiratory syndrome is referred for a pulmonary function test. The results indicate that her forced expiratory volume (FEV) was measured at 1.89. If the mean FEV for women her age is 2.85 with a standard deviation of 0.53 how could you calculate the z-score to tell how different her score is from the population mean?
A) (1.89 – 2.85) / 0.53 = -1.81
B) (2.85 – 1.89) / 0.53 = 1.81
C) (1.89 – 0.53) / 2.85 = 0.48
D) (2.85 – 0.53) / 1.89 = 1.23
E) (0.53 – 1.89) / 2.85 = -0.48
F) (0.53 – 2.85) / 1.89 = -1.23

Answer 1

Correct answer is A.
A z-score is used to identify the difference between one score and the population mean (measured in units of standard deviation).
The calculation is: z = (score - mean) / standard deviation.

Question 2

A epidemiological research study is using a large, community-based sample to identify potential risk factors associated with the development of asthma. If the study reports a correlation coefficient of r=0.89 between the variables of obesity and asthma, how can this finding be interpreted?
A) Obesity causes asthma
B) Asthma causes obesity
C) There is a high, positive correlation between obesity and asthma
D) There is a low, positive correlation between obesity and asthma
E) There is a high, negative correlation between obesity and asthma
F) There is a low, negative correlation between obesity and asthma

Answer 2

Correct answer is C. Correlation coefficient measures the relationship between two continuous variables and falls between -1.0 and 1.0. It is important to understand that a correlation measures relatedness but not causation.

Question 3

If a group of researchers is interested in comparing the mean lung capacity in three groups of patients (e.g., healthy adults, patients with asthma, and patients with chronic obstructive pulmonary disease), what statistical analysis is most appropriate?
A) Independent t-test
B) Dependent t-test
C) One-way analysis of variance
D) Two-way analysis of variance
E) Chi-square
F) Pearson product coefficient

Answer 3

Correct answer is C. A one-way analysis of variance (ANOVA) is used to compare means and standard deviations of more than two groups.

A one-way analysis is used when there is one interval variable (e.g. lung capacity) and three nominal groups (e.g., healthy, asthma, COPD).

A two-way ANOVA is used when there are two variables compared across groups.

A t-test would be used when there are two groups of subjects.

Chi-square analysis would be used to compare groups of nominal variables.

Pearson product would be used if there were two continuous variables.

Question 4

If global healthcare agencies identify a new respiratory virus that spreads easily from person to person through coughing/sneezing and is found to cause serious illness worldwide, what would this be called?
A) Endemic
B) Epidemic
C) Outbreak
D) Pandemic

Answer 4

Correct answer is D. A Pandemic is the term used to describe a global disease outbreak.

Endemic refers to a disease condition that is normally found in a certain part of the population.

An outbreak is a disease that occurs in greater numbers than expected in a community or region during a particular period of time (e.g., season).

And an Epidemic is a disease that spreads rapidly to many people (but does not reach across wide geographical areas).

Question 5

A community clinic decides to keep track of the outbreak pattern for seasonal influenza by reviewing their own medical records over the past year. They calculate the total number of patients who tested positive for an influenza viral infection each month to determine that the peak time for flu activity in their community last year was the month of February. This calculation is best represented using which descriptive statistic?
A) Mean
B) Mode
C) Median
D) Range
E) Variance
F) Standard deviation

Answer 5

Correct answer is B. The mode is the descriptive statistic that is used to indicate the highest frequency of a variable (in this case, the largest number of cases, in a particular month)