Public Health Dentistry Revision #2

1. The purpose of double blinding in clinical trials is to

Avoid observer and subject bias

Achieve comparability between study and control

Avoid observer bias

Avoid subject bias

Question 1 of 20

2. Test used to represent difference in heights of students in two different classes in school

Unpaired t test

ANOVA

Chi square

Paired T test

Question 2 of 20

3. Application of Incubation period is all EXCEPT

To prevent infection to the contacts of the infected person

To differentiate co-primary cases from secondary cases

To find out time for isolation

To find out time for Quarantine

Question 3 of 20

4. Adjuvant used in DPT vaccine is

Copper

Magnesium

Zinc

Aluminium

Question 4 of 20

5. Term Colorado stain was given by

Knutson

Greene

Dean

McKay

Question 5 of 20

6. If mean is less than the median, than the data is said to be

Normal distribution

Negatively skewed

Positively skewed

Equitable distribution

Question 6 of 20

7. Bias can be eliminated by all except:

Matching

Multivariate analysis

Randomization

Blinding

Question 7 of 20

8. Sequence of contents in scientific report of oral health survey:

Introduction, Aim, materials and methods, results

Introduction, Materials and methods, result, discussion

Review of literature, Aim, methods and material, results

Aim, Materials and methods, result, conclusion

Question 8 of 20

9. A standard z score is related to?

Score which is away from mean

Measure of central tendency

None of the above

Score which is away from median

Question 9 of 20

10. Anti-calculus agent in toothpaste is

Cocoamidopropyl

Pyrophosphate

Fluoride

Lauryl sulphate

Question 10 of 20

11. Dmf index measures

Rate of caries

Cumulative caries experience

None of the above

Oral hygiene Status

Question 11 of 20

12. Which is not an epidemiological method of population survey

Ecological studies

Correlational studies

Twin studies

Community trials

Question 12 of 20

13. Savlon contains

Cetrimide + butyl alcohol

Cetrimide + Chlorhexidine + butyl alcohol

Cetrimide + Cetavlon

Cetrimide + Chlorhexidine

Question 13 of 20

14. Which of the following statements about confidence limits/ interval is true:

Less variable the data, wider will be the confidence interval

Sample size does not affect the confidence interval

Smaller the confidence level larger will be the confidence interval

95% confidence interval will cover 2 standard errors around the mean

Question 14 of 20

15. A Path finder survey for oral health needs to be done at 12 sites for 4 index age groups at each site. What should be the sample size for the survey

1500

300

1200

400

Question 15 of 20

16. In a community trial, every 5th house in a village was selected for sampling. This type of sampling is called as

Cluster sampling

Simple random sampling

Stratified random sampling

Systematic random sampling

Question 16 of 20

17. Age was found to be a factor affecting the relation of diabetes mellitus and periodontics

Information Bias

Selection Bias

Confounding Bias

Sampling Bias

Question 17 of 20

18. In epidemiology, a sample is:

A group of people in a small area

Small group of people representing the population

Represents a small group of people of low socio-economic status

Represents each individual

Question 18 of 20

19. Anganwadi Worker (AWW) is appointed for population

30000

5000

1000

20000

Question 19 of 20

20. Simplest commonly used method of measuring variation in a population is

Range

Median

Mean

Question 20 of 20