10 - AIIMS november 2002 community medicine mcqs - part 4

15q: as per the world health organization guidelines, iodine deficiency disorders are endemic in a community if the prevalence of goiter in school age children is more than ?

a. 1 %
b. 5 %
c. 10 %
d. 15 %

answer b. 5 %

16q: a 46 year old female presented at the eye OPD in a hospital. Her vision in the right eye was 6/60 and in the left eye is 3/60. under the national programme for control of blindness, she will be classified as ?

a. socially blind
b. low vision
c. economically blind
d. normal vision

answer b. low vision

17q: the visual acuity used as a cut off for differentiating “normal” from “abnormal” children in the school vision screening programme in India is ?

a. 6/6
b. 6/9
c. 6/12
d. 6/90

answer b. 6/9

18q: when a diagnostic test is used in series mode then ?

a. sensitivity increases but the specificity decreases
b. specificity increases but the sensitivity decreases
c. both sensitivity and specificity decreases
d. both sensitivity and specificity increases

answer b. specificity increases but the sensitivity decreases

19q: the active immunity offered by tetanus toxoid is effective in nearly ?

a. 25 % of patients
b. 50 % of patients
c. 75 % of patients
d. 100 % of patients

answer d. 100 %

9 - AIIMS november 2002 community medicine mcqs - part 3

11q: prevalence of a disease :

a. is the best measure of the disease frequency in etiological studies
b. can only be determined by a cohort study
c. is the number of new cases in a defined population
d. describes the balance between incidence,mortality and recovery

answer d. describes the balance between incidence,mortality and recovery

12q: in a controlled trial to compare two treatments , the main purpose of randomization is to ensure that :

a. the two groups will be similar in prognostic factors
b. the clinician does not know which treatment the subjects will receive
c. the sample may be referred to a known population
d. the clinician can predict in advance which treatment the subjects will receive

answer a. the two groups will be similar in prognostic factors

13q: a randomized trial comparing the efficacy of two drugs showed a difference between the two with a p value of less than 0.005. in reality however the two drugs do not differ . this is therefore an example of ?

a. type 1 error ( alpha error )
b. type 2 error ( beta error )
c. 1- alpha
d. 1- beta

answer a. type 1 error ( alpha error )

14q: the number of patients required in a clinical trial to treat a specific disease increases as :

a. the incidence of the disease decreases
b. the significance level increases
c. the size of the expected treatment effect increased
d. the drop out rate increases

answer d. the drop out rate increases