UPSC-CMS 2017 Practice Questions

Q: Which one of the following is FALSE regarding confounding factor in epidemiological studies ?

Distributed equally between study and control groups. ***Distributed equally between study and control groups*** - A **confounding factor** is, by definition, **not equally distributed** between study (exposed) and control (unexposed) groups, as this unequal distribution leads to the observed bias. - If a potential confounder were equally distributed, it would not distort the relationship between the exposure and the outcome. *Source of bias is interpretation* - Confounding is a source of **bias in interpretation** because it can create a spurious association or mask a true one between an exposure and an outcome. - It leads to an incorrect conclusion about the causal relationship, even if the data collection itself was accurate. *Associated both with exposure and disease* - For a variable to be a confounder, it must be **associated with the exposure** being studied (e.g., smoking is associated with alcohol consumption). - It must also be an **independent risk factor for the disease** outcome (e.g., alcohol consumption is an independent risk factor for esophageal cancer). *Independent risk factor for disease in question* - A confounder must be an **independent risk factor** for the disease outcome, separate from its association with the primary exposure. - This means it influences the disease risk regardless of the exposure being investigated.

Q: Denominator in calculation of case fatality rate is:

Total number of cases due to the disease concerned. ***Total number of cases due to the disease concerned*** - The **case fatality rate (CFR)** measures the **proportion of deaths** among individuals diagnosed with a specific disease. - The denominator for CFR is defined as the **total number of confirmed cases** of that disease in a given population and time period. - Formula: CFR = (Deaths from disease / Total cases of disease) × 100 *Total number of hospital admissions* - This value represents the total number of individuals admitted to the hospital, which may include patients with various conditions, not just the specific disease of interest. - Using this as the denominator would incorrectly dilute the severity of the disease in question by including individuals not directly affected by it. *Total number of deaths due to all causes* - This figure encompasses all deaths in a population, regardless of cause, and is typically used in calculations like the **crude death rate**. - It does not specifically relate to the severity or outcome of a particular disease and therefore cannot serve as the denominator for case fatality. *Total number of deaths due to the disease concerned* - This value represents the **numerator** in the calculation of the case fatality rate, as it quantifies the number of deaths attributable to the specific disease. - Using it as the denominator would lead to a calculation of 100% if the number of deaths equals the number of cases, which would be incorrect for CFR calculations.

Q: An important measure of communicability of a disease is

Secondary attack rate. ***Secondary attack rate*** - The **secondary attack rate** quantifies the probability of infection among **susceptible contacts** of a primary case. - It is a direct measure of the **person-to-person transmissibility** or **communicability** of an infectious disease within a defined population. - Calculated as: (Number of cases among contacts / Total number of susceptible contacts) × 100 *Incidence rate* - The **incidence rate** measures the rate at which **new cases** of a disease occur in a population over a specified period. - While related to disease spread, it does not specifically describe transmission from an existing case to a close contact. *Prevalence rate* - The **prevalence rate** measures the **proportion of individuals** in a population who have a disease at a specific point in time or over a period. - It reflects the burden of existing disease but provides no direct information about how easily the disease spreads from one person to another. *Case fatality rate* - The **case fatality rate** (CFR) indicates the **proportion of individuals** diagnosed with a disease who die from that disease. - It is a measure of the **severity or lethality** of a disease, not its communicability or transmissibility.

Q: Which of the following statements is NOT correct regarding case fatality rate?

One of the measures related to virulence. ***One of the measures related to virulence*** - This statement is **incorrect**. The **case fatality rate (CFR)** is a measure of the **severity of a disease** within a specific population of affected individuals, typically related to a specific outbreak or period. - While it reflects disease severity, it is not a direct measure of **virulence**, which describes the pathogen's ability to cause damage to the host and is an intrinsic property of the infectious agent itself. *It is the ratio of deaths to cases expressed as percentage* - This is a **correct definition** of the case fatality rate (CFR), calculated as the number of deaths from a disease divided by the total number of cases of that disease, expressed as a percentage. - It quantifies the proportion of individuals diagnosed with a specific disease who ultimately die from it. *Very useful indicator for both acute and chronic diseases* - This statement is **correct**. The case fatality rate is a valuable indicator for assessing the severity and impact of both **acute diseases** (e.g., infectious outbreaks) and **chronic diseases** (e.g., cancer survival). - It helps in understanding the prognosis and lethality of a condition in affected individuals. *Variation can occur for the same disease because of changes in the agent factors* - This statement is **correct**. Case fatality rates for the same disease can vary significantly due to changes in **agent factors** (e.g., strain virulence, drug resistance), host factors (e.g., age, immune status), and environmental factors (e.g., access to healthcare). - For example, different strains of influenza can have varying case fatality rates due to differences in their inherent pathogenicity.

Q: Farmer's lung is caused by the inhalation of:

Grain dust with actinomycetes. ***Grain dust with actinomycetes*** - **Farmer's lung** is a type of **hypersensitivity pneumonitis** caused by inhaling dust from moldy hay or other agricultural products contaminated with **thermophilic actinomycetes**. - These bacteria trigger an immune response in the lungs, leading to inflammation and respiratory symptoms. *Cotton fibre dust* - Inhalation of **cotton fiber dust** is associated with **byssinosis**, a different occupational lung disease. - Byssinosis typically presents with chest tightness and shortness of breath, often worse on the first day of the work week. *Sugarcane dust* - Exposure to **sugarcane dust** can lead to **bagassosis**, another form of hypersensitivity pneumonitis. - While similar in mechanism to farmer's lung, the specific antigen is different (from sugarcane rather than moldy hay). *Silica dust* - Inhalation of **silica dust** causes **silicosis**, a chronic, progressive occupational lung disease characterized by pulmonary fibrosis. - Silicosis is common in miners, quarry workers, and others exposed to silica, and it is not a hypersensitivity reaction but a direct fibrotic response.

Q: Suraksha Clinics are conducted under the aegis of which National Health Programme?

Reproductive and Child Health Programme. ***Reproductive and Child Health Programme*** - **Suraksha Clinics** (also known as Surakshit Matritva Suraksha or SMS Clinics) are established under the **Reproductive and Child Health (RCH) Programme** to provide comprehensive **maternal and child health services**. - These clinics offer services including **antenatal care (ANC), postnatal care (PNC), institutional deliveries, family planning**, and management of complications during pregnancy and childbirth. - They are part of India's efforts to ensure **safe motherhood** and reduce maternal and infant mortality rates. *National AIDS Control Programme* - This program focuses on **HIV/AIDS prevention, care, and treatment** through services like counseling, testing (ICTC), and antiretroviral therapy (ART centers). - While it operates various specialized centers for HIV care, **Suraksha Clinics are not part of NACP** but are specifically for maternal and child health. *Iodine Deficiency Disorders Programme* - This program aims to prevent **iodine deficiency** through universal salt iodization and monitoring of IDD prevalence. - It does not involve clinic-based maternal health services like Suraksha Clinics. *Revised National Tuberculosis Control Programme* - This program (now National TB Elimination Programme) is dedicated to **tuberculosis diagnosis, treatment, and control** through DOTS and other strategies. - It operates designated microscopy centers (DMCs) and treatment facilities, not Suraksha Clinics for maternal care.

Q: In a normal distribution, Mean ± 2 S.D. contains

95.4 % values. ***95.4 % values*** - According to the **empirical rule** (or 68-95-99.7 rule) for normal distributions, approximately **95.4%** of data falls within two standard deviations of the mean. - This interval covers from (Mean - 2 S.D.) to (Mean + 2 S.D.) and represents the likelihood of a value falling in this range. *68.3 % values* - This percentage corresponds to the data contained within **Mean ± 1 S.D.** in a normal distribution, not Mean ± 2 S.D. - It signifies that roughly two-thirds of all observations lie within one standard deviation from the mean in a bell-shaped curve. *91.2 % values* - This value is not a standard percentage associated with common multiples of standard deviations (1, 2, or 3) from the mean in a normal distribution. - It does not correspond to any universally recognized interval like ±1 S.D., ±2 S.D., or ±3 S.D. *99.7 % values* - This percentage represents the data contained within **Mean ± 3 S.D.** in a normal distribution. - It indicates that almost all (99.7%) of the data points are expected to fall within three standard deviations from the mean.

Q: Infant Mortality Rate is expressed per:

1000 live births. ***1000 live births*** - The **Infant Mortality Rate (IMR)** specifically measures the number of deaths of infants **under one year of age** per **1,000 live births** in a given population. - This definition is crucial for accurately assessing and comparing infant health outcomes across different regions and over time. *1000 pregnancies* - This option would include pregnancy losses that are not considered live births, such as **stillbirths** and miscarriages, which are distinct statistical measures. - The IMR specifically focuses on infants who were born alive and subsequently died within their first year of life. *100,000 live births* - While some rates might be expressed per 100,000 (e.g., maternal mortality ratio), **infant mortality rate** is universally standardized to a base of **1,000 live births**. - Using 100,000 live births would result in a disproportionately small and less intuitive number for IMR comparisons. *1000 under five children* - This definition refers to the **Under-5 Mortality Rate (U5MR)**, which includes deaths of children from birth up to their fifth birthday. - The IMR is a narrower measure, specifically focusing on infants who die **before their first birthday**.

Q: Which of the following tests is NOT used for checking quality of pasteurisation of milk?

Orthotoluidine test. ### ***Orthotoludine test*** * The **Orthotoluidine test** is used to detect residual **chlorine** in drinking water. * It is not employed to assess the quality of pasteurization in milk, which focuses on enzyme inactivation and microbial reduction. ### *Phosphatase test* * The **phosphatase test** is the most widely accepted and reliable method for checking the adequacy of **pasteurization** in milk. * It works by detecting the activity of **alkaline phosphatase**, an enzyme naturally present in raw milk that is destroyed at pasteurization temperatures. ### *Coliform count* * The **coliform count** is an indicator of **post-pasteurization contamination** or inadequate sanitation. * While not a direct measure of the pasteurization process itself, a high coliform count suggests a failure in hygiene after heating, indicating poor overall quality control. ### *Standard Plate count* * The **Standard Plate Count (SPC)**, also known as the **aerobic plate count**, measures the total number of viable microorganisms in milk. * A reduction in SPC after pasteurization indicates the effectiveness of the heat treatment in killing bacteria, making it an indirect measure of pasteurization efficiency and overall microbial quality.

Q: Which of the following are the components of epidemiological triad?

Agent, host and environmental factors. ***Agent, host and environmental factors*** - The **epidemiological triad** is a traditional model that explains disease causation by focusing on the interaction between an infectious **agent**, a susceptible **host**, and the **environment** that brings them together. - Understanding these three components helps to analyze and prevent the spread of diseases. *Sensitivity, specificity and predictive value* - These terms relate to the **performance and accuracy of diagnostic tests**, assessing how well a test identifies true positives and true negatives. - They are measures used in the evaluation of screening programs and diagnostic procedures, not directly in the causation model. *Prevalence, incidence and attack rate* - These are **measures of disease occurrence** or frequency within a population, used to quantify the burden of disease. - While essential for understanding disease patterns, they describe the *results* of the disease process rather than the *factors* causing it. *Time, place and person distribution* - These refer to the **descriptive epidemiology** aspects of disease, outlining **who** is affected, **where** they are, and **when** the disease occurs. - These elements characterize disease patterns but are not the fundamental components responsible for disease causation in the epidemiological triad model.

Question 1

Which one of the following is FALSE regarding confounding factor in epidemiological studies ?

Accepted Answer

Distributed equally between study and control groups

Answer

Source of bias is interpretation

Answer

Associated both with exposure and disease

Answer

Independent risk factor for disease in question

Question 2

Denominator in calculation of case fatality rate is:

Accepted Answer

Total number of cases due to the disease concerned

Answer

Total number of hospital admissions

Answer

Total number of deaths due to all causes

Answer

Total number of deaths due to the disease concerned

Question 3

An important measure of communicability of a disease is

Accepted Answer

Secondary attack rate

Answer

Incidence rate

Answer

Prevalence rate

Answer

Case fatality rate

Question 4

Which of the following statements is NOT correct regarding case fatality rate?

Accepted Answer

One of the measures related to virulence

Answer

It is the ratio of deaths to cases expressed as percentage

Answer

Very useful indicator for both acute and chronic diseases

Answer

Variation can occur for the same disease because of changes in the agent factors

Question 5

Farmer's lung is caused by the inhalation of:

Accepted Answer

Grain dust with actinomycetes

Answer

Cotton fibre dust

Answer

Sugarcane dust

Answer

Silica dust

Question 6

Suraksha Clinics are conducted under the aegis of which National Health Programme?

Accepted Answer

Reproductive and Child Health Programme

Answer

Iodine Deficiency Disorders Programme

Answer

National AIDS Control Programme

Answer

Revised National Tuberculosis Control programme

Question 7

In a normal distribution, Mean ± 2 S.D. contains

Accepted Answer

95.4 % values

Answer

68.3 % values

Answer

91.2 % values

Answer

99.7 % values

Question 8

Infant Mortality Rate is expressed per:

Accepted Answer

1000 live births

Answer

1000 pregnancies

Answer

100,000 live births

Answer

1000 under five children

Question 9

Which of the following tests is NOT used for checking quality of pasteurisation of milk?

Accepted Answer

Orthotoluidine test

Answer

Phosphatase test

Answer

Coliform count

Answer

Standard Plate count

Question 10

Which of the following are the components of epidemiological triad?

Accepted Answer

Agent, host and environmental factors

Answer

Sensitivity, specificity and predictive value

Answer

Prevalence, incidence and attack rate

Answer

Time, place and person distribution

UPSC-CMS 2017

Community Medicine