NEET-PG 2019 — Community Medicine
11 Previous Year Questions with Answers & Explanations
Which measure indicates the diagnostic power of a test to correctly identify those with a disease?
What is the most peripheral level of the healthcare system where the Reproductive and Child Health Programme is implemented?
Which research method is most appropriate for studying the progression of a disease over time?
Which of the following is not an epidemiological indicator?
Which health center is located in the remotest area for planning and management of health schemes?
Which type of study determines the odds ratio?
Contact isolation is done for:
For the population of 10,000, how much area is required per year for a trench method sanitary landfill pit of 2m depth?
Which vaccine requires annual updates due to frequent antigenic changes?
Most peripheral unit for planning of family planning and other services under RCH program is
NEET-PG 2019 - Community Medicine NEET-PG Practice Questions and MCQs
Question 1: Which measure indicates the diagnostic power of a test to correctly identify those with a disease?
- A. Negative predictive value
- B. Specificity
- C. Sensitivity (Correct Answer)
- D. Positive predictive value
Explanation: ***Positive predictive value*** - It refers to the probability that subjects with a positive test result truly have the disease, highlighting the test's **diagnostic accuracy** [1]. - A high positive predictive value indicates that the test is effective at diagnosing the disease in the population tested. *Sensitivity* - Sensitivity measures the ability of a test to correctly identify those with the disease (true positives), but does not account for the test result's predictive capability [1]. - It is important for screening, but **not directly the diagnostic power** for those already tested. *Negative predictive value* - This indicates the probability that subjects with a negative test result truly do not have the disease, focusing on true negatives rather than correct diagnosis of the condition [1]. - While informative, it does not assess the ability to correctly diagnose the disease when the result is positive. *Specificity* - Specificity is the measure of a test's ability to correctly identify those without the disease (true negatives), not diagnosing the disease accurately among those tested [1]. - It is essential for determining false positives but not for assessing the overall diagnostic power of a test. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. (Basic Pathology) introduces the student to key general principles of pathology, both as a medical science and as a clinical activity with a vital role in patient care. Part 2 (Disease Mechanisms) provides fundamental knowledge about the cellular and molecular processes involved in diseases, providing the rationale for their treatment. Part 3 (Systematic Pathology) deals in detail with specific diseases, with emphasis on the clinically important aspects., pp. 253-254.
Question 2: What is the most peripheral level of the healthcare system where the Reproductive and Child Health Programme is implemented?
- A. Anganwadi Center
- B. Sub-center (Correct Answer)
- C. District Level
- D. Block Level
Explanation: ***Sub-center*** - The **Sub-center** is the most peripheral and first contact point between the primary healthcare system and the community. - It is where basic Reproductive and Child Health (RCH) services, including **antenatal care**, **immunization**, and **family planning**, are delivered directly to the population. *Anganwadi Center* - **Anganwadi Centers** primarily focus on providing nutritional support, preschool education, and some health-related awareness. - While they support RCH efforts (e.g., distributing supplements), they are not the main implementing level for comprehensive RCH services but rather a community-level support structure. *District Level* - The **District Level** (e.g., District Hospitals) serves as a referral center and provides specialized RCH services, monitoring, and program management. - It is a higher tier that supervises and supports RCH programs, but the direct implementation at the community level happens below this. *Block Level* - The **Block Level** (e.g., Community Health Centers) provides comprehensive primary healthcare services and acts as a referral point for Primary Health Centers. - While it plays a significant role in RCH service delivery and supervision, the services are actually implemented to the community at the Sub-center level, which is administratively below the block.
Question 3: Which research method is most appropriate for studying the progression of a disease over time?
- A. Cohort Study (Correct Answer)
- B. Cross sectional study
- C. Randomized Control Trials
- D. Interventional Studies
Explanation: ***Cohort Study*** - A **cohort study** observes a group of individuals over a period of time, allowing researchers to track the **natural progression of a disease** from exposure through onset and various stages. - This design is ideal for investigating the **incidence** of disease and identifying risk factors over time. *Cross sectional study* - A **cross-sectional study** assesses exposure and outcome at a **single point in time**, providing a snapshot. - It cannot establish temporality or observe disease progression, as it does not follow individuals over time. *Randomized Control Trials* - **Randomized controlled trials (RCTs)** are primarily designed to evaluate the **effectiveness of interventions** or treatments by comparing outcomes between an experimental group and a control group. - While they follow participants over time, their main goal is not to study the natural progression of an untreated disease. *Interventional Studies* - **Interventional studies** involve manipulating an exposure or treatment to observe its effect, often to test a hypothesis about a causal relationship. - While they track outcomes over time, their focus is on the impact of the intervention rather than the natural history or progression of a disease without intervention.
Question 4: Which of the following is not an epidemiological indicator?
- A. None of the options (Correct Answer)
- B. ABER
- C. Annual falciparum incidence
- D. Annual parasite index
Explanation: ***None of the options*** - All listed options—**ABER (Annual Blood Examination Rate)**, **Annual parasite index**, and **Annual falciparum incidence**—are indeed widely recognized and utilized **epidemiological indicators**, particularly in the context of malaria surveillance and control. - As such, there is no option presented that is *not* an epidemiological indicator. *ABER* - **ABER (Annual Blood Examination Rate)** is an epidemiological indicator used to assess the annual number of blood smears examined per 1000 population. - It helps to measure the **intensity of surveillance** and case detection efforts in a given area for diseases like malaria. *Annual parasite index* - The **Annual Parasite Index (API)** is an epidemiological indicator that measures the number of confirmed malaria cases per 1000 population per year. - It is crucial for assessing **malaria endemicity** and the burden of the disease in a specific region. *Annual falciparum incidence* - **Annual falciparum incidence** is an epidemiological indicator specifically tracking the number of *Plasmodium falciparum* malaria cases per 1000 population per year. - This indicator is essential for monitoring the **severity and transmission of the most dangerous form of malaria**.
Question 5: Which health center is located in the remotest area for planning and management of health schemes?
- A. Anganwadi
- B. Block centre
- C. Sub-centre (Correct Answer)
- D. PHC
Explanation: ***Sub-centre*** - A **sub-centre** is the most peripheral and first contact point between the primary healthcare system and the community, usually located in the **remotest areas**. - It serves a population of 3,000-5,000 (3,000 in tribal/hilly areas). - It plays a crucial role in the planning and management of various health schemes at the grassroots level, focusing on basic healthcare services like immunization, antenatal care, and health education. *Anganwadi* - An **Anganwadi** is part of the Integrated Child Development Services (ICDS) program, primarily focusing on nutritional and preschool education services for children and expectant/nursing mothers. - While important for community welfare, it is not a health center under the formal healthcare delivery system. *Block centre* - A **Block centre** (Community Health Centre/CHC) serves a larger population of approximately 80,000-120,000 people at the block level. - It provides secondary healthcare and referral services but is not the remotest point of contact for basic healthcare planning. *PHC* - A **Primary Health Centre (PHC)** serves a population of about 20,000-30,000 people and is located at the intermediate level between sub-centres and CHCs. - While PHCs coordinate health scheme management, they are not positioned in the remotest areas—sub-centres occupy that role.
Question 6: Which type of study determines the odds ratio?
- A. Case control (Correct Answer)
- B. Cohort
- C. Cross sectional
- D. RCT
Explanation: ***Case control*** - **Case-control studies** compare individuals with a disease (cases) to individuals without the disease (controls) and look back in time to identify previous exposures. - The **odds ratio** is the primary measure of association used in case-control studies, quantifying the odds of exposure among cases versus controls. *Cohort* - **Cohort studies** follow groups of individuals over time, some exposed to a risk factor and some not, to determine the incidence of a disease. - They typically determine **relative risk**, which is the ratio of incidence rates in exposed versus unexposed groups. *Cross sectional* - **Cross-sectional studies** assess the prevalence of disease and exposure at a single point in time. - They primarily measure **prevalence** and can be used to calculate a **prevalence odds ratio**, but they do not establish temporality between exposure and outcome. *RCT* - **Randomized controlled trials (RCTs)** are interventional studies where participants are randomly assigned to an intervention or control group to determine the effectiveness of a treatment or exposure. - The main measure of effect in RCTs is often the **relative risk reduction**, **absolute risk reduction**, or **number needed to treat**, rather than the odds ratio for observational exposure.
Question 7: Contact isolation is done for:
- A. Mumps
- B. MRSA (Correct Answer)
- C. Diphtheria
- D. Typhoid
Explanation: ***MRSA*** - **Methicillin-resistant *Staphylococcus aureus* (MRSA)** is transmitted primarily through direct contact with infected patients or contaminated environmental surfaces, necessitating **contact isolation** measures. - These measures include the use of **gloves and gowns** upon entering the patient's room to prevent spread. *Mumps* - Mumps is a viral infection primarily transmitted via **respiratory droplets**, requiring **droplet isolation** rather than contact isolation. - The virus spreads through coughing and sneezing, necessitating measures like wearing a surgical mask. *Diphtheria* - Diphtheria, caused by *Corynebacterium diphtheriae*, is spread through **respiratory droplets** from close contact with an infected person, requiring **droplet isolation**. - This typically involves wearing a mask and sometimes eye protection. *Typhoid* - Typhoid fever is a **fecal-oral disease** caused by *Salmonella Typhi*, transmitted through contaminated food and water. - While proper hand hygiene is crucial, it generally does not require specific isolation precautions beyond **standard precautions** in a hospital setting for most patients.
Question 8: For the population of 10,000, how much area is required per year for a trench method sanitary landfill pit of 2m depth?
- A. 3 acres
- B. 4 acres
- C. 2 acres
- D. 1 acre (Correct Answer)
Explanation: ***1 acre*** - For a **trench method sanitary landfill** with a 2m depth, the required area per year for a population of 10,000 is approximately **1 acre**. - This estimation accounts for the typical volume of solid waste generated by this population size and the compaction achieved in well-managed landfills. *3 acres* - An area of **3 acres** would be significantly larger than typically required for a population of 10,000 for a 2m deep trench landfill. - This might be needed for a much larger population, less compaction, or a shallower landfill depth. *4 acres* - **4 acres** is an excessive amount of land for the stated population and landfill depth, suggesting inefficiency or a miscalculation in waste volume or density. - Such a large area would likely imply either very low waste compaction or a much larger population than specified. *2 acres* - While closer than 3 or 4 acres, **2 acres** is still generally more than what is needed for a 10,000 population with a 2m deep trench landfill. - This could be considered if the waste generation rate is higher than average or if compaction is less efficient.
Question 9: Which vaccine requires annual updates due to frequent antigenic changes?
- A. Measles
- B. Rubella
- C. Influenza (Correct Answer)
- D. BCG
Explanation: ***Influenza*** - The influenza virus undergoes frequent **antigenic drift** and **antigenic shift**, which are changes in its surface proteins (hemagglutinin and neuraminidase). - These constant changes necessitate annual updates to the influenza vaccine to match the circulating strains predicted for the upcoming flu season. *Measles* - The measles virus is **antigenically stable**, meaning it does not frequently change its surface proteins. - Due to its stability, a highly effective and long-lasting vaccine can be produced, and annual updates are not required. *Rubella* - The rubella virus is also **antigenically stable**, similar to measles. - A single vaccine, usually given as part of the MMR (Measles, Mumps, Rubella) vaccine, provides long-term immunity without the need for annual revision. *BCG* - The Bacillus Calmette-Guérin (BCG) vaccine targets *Mycobacterium tuberculosis* and is not subject to frequent antigenic changes. - It is a live-attenuated vaccine that provides long-lasting immunity, and annual boosters or updates are not necessary.
Question 10: Most peripheral unit for planning of family planning and other services under RCH program is
- A. PHC
- B. District
- C. Sub-centre (Correct Answer)
- D. Block/ Taluka
Explanation: ***Sub-centre*** - The **Sub-centre** is the most peripheral and first contact point between the primary healthcare system and the community. - It serves a population of 3,000-5,000 people and is responsible for delivering basic health services, including **family planning** and **RCH (Reproductive and Child Health) services**, directly to the community. *PHC* - A **Primary Health Centre (PHC)** is a more central facility, serving a larger population (20,000-30,000) and acting as a referral unit for 6 sub-centres. - While PHCs provide comprehensive primary care, the **planning and direct delivery** at the grassroots level occur at the Sub-centre. *District* - The **District level** involves overarching planning, supervision, and resource allocation for health services within the entire district. - It is not the most peripheral unit for direct service delivery or planning with the community. *Block/Taluka* - The **Block/Taluka level** often corresponds to a Community Health Centre (CHC) or block-level administrative health office. - These facilities supervise PHCs and manage health programs for a larger administrative block, but are not the immediate point of contact for service planning with the community.