What is the common threshold for statistical significance in hypothesis testing?
Spot map is used for?
In a clinical study examining the relationship between weight and height in pediatric patients, what is the maximum possible value of the correlation coefficient if the correlation is very strong?
What is the type of sampling used when a random sample is taken from distinct groups within a population, such as religious groups like Hindus, Muslims, and Christians?
Which of the following is a Category A bioterrorism agent?
NVBDCP includes all except ?
A patient sustained an injury to the right leg in a road traffic accident and his leg was amputated. This is?
One PHC covers how much population in hilly area?
Descending order of cancer prevalence in males in India?
The most important sandfly-transmitted disease in India is-
NEET-PG 2013 - Community Medicine NEET-PG Practice Questions and MCQs
Question 81: What is the common threshold for statistical significance in hypothesis testing?
- A. 0.01
- B. 0.02
- C. 0.03
- D. 0.05 (Correct Answer)
Explanation: ***Correct: 0.05*** - A **p-value of 0.05 (or 5%)** is the most widely accepted and **conventional threshold** for statistical significance in most scientific fields, including medicine - This represents a **5% probability** of observing the results if the **null hypothesis** were true (Type I error or α level) - This is the **standard alpha level** taught in biostatistics and most commonly used in medical research *Incorrect: 0.01* - While 0.01 indicates **higher statistical confidence** (1% chance of Type I error), it is more stringent than the standard threshold - Used in studies requiring **greater certainty** or where false positives have severe consequences - Not the most common or default threshold in general hypothesis testing *Incorrect: 0.02* - A p-value of 0.02 represents a **2% chance of Type I error** - While statistically valid, it is **not a conventional alpha level** for most hypothesis tests - Not the standard threshold taught or applied in medical statistics *Incorrect: 0.03* - A p-value of 0.03 represents a **3% chance of Type I error** - This is **not a standard choice** for statistical significance testing - Not the conventionally prescribed alpha level in biostatistics
Question 82: Spot map is used for?
- A. Local distribution of disease (Correct Answer)
- B. Rural-urban variation
- C. National variation
- D. None of the options
Explanation: ***Local distribution of disease*** - A **spot map** visually represents the geographic distribution of individual cases of a disease or health event. - Each 'spot' on the map corresponds to the exact location where a case occurred, making it ideal for identifying **clusters** or patterns of disease within a specific area. *Rural-urban variation* - While a spot map could potentially show cases in both rural and urban settings, its primary purpose is not to specifically highlight the differences between these two broad categories. - Other types of **thematic maps** or **statistical analyses** are better suited for assessing rural-urban variations. *National variation* - A spot map would be impractical for showing national variation in detail, as it would require plotting individual cases across an entire country, leading to an overly cluttered and uninterpretable image. - **Choropleth maps**, which use shading or colors to represent data for predefined geographic areas (like states or provinces), are more appropriate for illustrating national trends or variations. *None of the options* - This option is incorrect because the primary use of a spot map aligns directly with illustrating the **local distribution of disease**.
Question 83: In a clinical study examining the relationship between weight and height in pediatric patients, what is the maximum possible value of the correlation coefficient if the correlation is very strong?
- A. 0
- B. +1 (Correct Answer)
- C. +2
- D. No correlation
Explanation: ***+1 (perfect positive correlation)*** - A correlation coefficient of **+1** indicates a perfect positive linear relationship between two variables, meaning as one variable increases, the other increases proportionally. - This value represents the **maximum possible strength** for a positive correlation. *0* - A correlation coefficient of **0** indicates no linear relationship between two variables. - This would contradict the premise that the correlation is "very strong". *+2 (invalid value for correlation coefficient)* - The correlation coefficient, also known as Pearson's r, can only range from **-1 to +1**. - A value of +2 is outside this possible range and is therefore an **invalid value**. *No correlation (not possible for strong correlation)* - **No correlation** implies a correlation coefficient of 0 or close to 0. - This directly contradicts the statement that there is a **very strong correlation** between weight and height.
Question 84: What is the type of sampling used when a random sample is taken from distinct groups within a population, such as religious groups like Hindus, Muslims, and Christians?
- A. Simple random
- B. Stratified random (Correct Answer)
- C. Cluster
- D. Systematic random
Explanation: ***Stratified random*** - This method involves dividing the population into **distinct, non-overlapping subgroups (strata)** based on a shared characteristic (e.g., religious groups). - A **random sample** is then drawn from each stratum, ensuring representation from all groups. *Simple random* - Involves selecting individuals entirely at **random** from the entire population, with each individual having an equal chance of being chosen. - It does not guarantee representation from specific subgroups within the population. *Systematic random* - This method selects individuals at **regular intervals** from a randomly ordered list of the population (e.g., every 10th person). - While it offers a degree of randomness, it does not specifically account for or ensure representation of distinct subgroups. *Cluster* - This method involves dividing the population into **clusters (natural groupings)**, usually geographically, and then randomly selecting entire clusters to sample. - Unlike stratified sampling, where individuals are selected from each stratum, cluster sampling involves sampling all individuals within chosen clusters.
Question 85: Which of the following is a Category A bioterrorism agent?
- A. Brucella
- B. Q fever
- C. Typhus fever
- D. Anthrax (Correct Answer)
Explanation: ***Anthrax*** - **Anthrax**, caused by *Bacillus anthracis*, is classified as a **Category A** bioterrorism agent due to its high mortality rate, ease of dissemination, and potential for major public health impact. - It can manifest as cutaneous, inhalational, gastrointestinal, or injectional forms, with **inhalational anthrax** being the most lethal. *Brucella* - **Brucella** species cause brucellosis, which is classified as a **Category B** bioterrorism agent. - While it can be debilitating, it generally has a lower mortality rate and less public health impact than Category A agents. *Q fever* - **Q fever**, caused by *Coxiella burnetii*, is another **Category B** bioterrorism agent. - It causes a flu-like illness and can have chronic complications but is not as severe or easily disseminated as Category A agents. *Typhus fever* - **Typhus fever**, caused by *Rickettsia prowazekii* (epidemic typhus) or *Rickettsia typhi* (murine typhus), is a **Category B** bioterrorism agent. - It can cause severe illness but is not among the highest-priority agents like anthrax, smallpox, or botulism.
Question 86: NVBDCP includes all except ?
- A. Filariasis
- B. Malaria
- C. Kala-azar
- D. Yellow fever (Correct Answer)
Explanation: ***Yellow fever*** - Yellow fever is a **viral hemorrhagic fever** transmitted by infected mosquitoes, primarily **Aedes aegypti**. - While a significant public health concern, it is **not included in India's National Vector-Borne Disease Control Programme (NVBDCP)**, as it is not endemic to India. *Filariasis* - **Lymphatic filariasis** (elephantiasis) is a major vector-borne disease in India, caused by parasitic worms transmitted by mosquitoes. - It is a key component of the NVBDCP, which focuses on its elimination through **mass drug administration** and vector control. *Malaria* - **Malaria**, caused by Plasmodium parasites transmitted by Anopheles mosquitoes, is a cornerstone of the NVBDCP. - The program actively implements strategies for **case detection, treatment, vector control**, and preventing outbreaks. *Kala-azar* - **Kala-azar** (visceral leishmaniasis) is a severe parasitic disease transmitted by **sandflies**, making it a vector-borne disease. - It is one of the six diseases targeted by the NVBDCP for elimination, particularly in endemic regions of India.
Question 87: A patient sustained an injury to the right leg in a road traffic accident and his leg was amputated. This is?
- A. Handicap
- B. Impairment (Correct Answer)
- C. Disease
- D. Disability
Explanation: ***Impairment*** - An **impairment** refers to a problem in body function or structure, such as the loss of a limb or organ. - The amputation of the leg is a direct loss of a **body part**, fitting the definition of an impairment. *Handicap* - A **handicap** refers to a disadvantage for an individual, resulting from an impairment or disability, that limits or prevents the fulfillment of a role that is normal for that individual. - It describes the **social consequences** of the impairment, not the physical loss itself. *Disease* - A **disease** is a disorder of structure or function in a human, animal, or plant, especially one that produces specific symptoms or that affects a specific location and is not simply a direct result of physical injury. - While the accident caused the injury, the loss of the leg is a direct physical result, not an **ongoing pathological process** like a disease. *Disability* - A **disability** is a restriction or lack of ability to perform an activity in the manner or within the range considered normal for a human being, as a result of an impairment. - It describes the **functional limitation** that arises from the impairment, such as difficulty walking, rather than the physical loss itself.
Question 88: One PHC covers how much population in hilly area?
- A. 50000
- B. 10000
- C. 20000 (Correct Answer)
- D. 30000
Explanation: ***20000*** - In **hilly, tribal, or difficult areas**, one PHC is generally established for a population of **20,000**. - This lower population coverage is due to challenges in accessibility and the dispersed nature of communities in such regions. - As per **Indian Public Health Standards (IPHS)**, PHCs in difficult terrains serve smaller populations to ensure better healthcare access. *50000* - This figure does not correspond to standard PHC or CHC coverage norms. - A **Community Health Centre (CHC)** typically covers a population of **1,20,000** and serves as a referral unit for four PHCs. - CHCs provide specialist services including surgery, obstetrics & gynecology, pediatrics, and medicine. *10000* - This figure does not match the population coverage of any standard health facility under the Indian health system. - A **Sub-Centre** in hilly/tribal/difficult areas covers approximately **3,000 population**, while in plain areas it covers **5,000 population**. - Sub-Centres are the most peripheral contact point between the primary healthcare system and the community. *30000* - This figure represents the population covered by a Primary Health Centre (PHC) in **plain areas**. - The population coverage is higher in plain areas due to better infrastructure, road connectivity, and accessibility compared to hilly regions. - As per IPHS norms, PHCs in plains serve larger populations than those in difficult terrains.
Question 89: Descending order of cancer prevalence in males in India?
- A. Oral > lung > pharynx > esophagus
- B. Pharynx > lung > oral > esophagus
- C. Lung > oral > pharynx > esophagus (Correct Answer)
- D. Esophagus > oral > stomach > lung
Explanation: ***Lung > oral > pharynx > esophagus*** - This order represents the **most common cancer prevalence pattern** in Indian males according to **ICMR-NCDIR** population-based cancer registries. - **Lung cancer** ranks highest nationally, strongly associated with **smoking** (bidi and cigarette use). - **Oral cavity cancer** is extremely prevalent in India due to **tobacco chewing, betel quid, and gutka consumption**. - **Pharyngeal cancer** and **esophageal cancer** follow, also linked to tobacco and alcohol use. - Regional variations exist, but this order reflects **national-level data** for Indian males. *Oral > lung > pharynx > esophagus* - While **oral cancer prevalence is very high** in India (competing with lung cancer in some regions), at the **national aggregate level**, lung cancer typically ranks first. - This order may be accurate for **specific regions** with high tobacco chewing prevalence but does not represent the overall national pattern. *Pharynx > lung > oral > esophagus* - **Pharyngeal cancer** is less prevalent than both **lung and oral cancers** in Indian males. - This sequence incorrectly places pharyngeal cancer at the top, which contradicts **Indian cancer registry data**. *Esophagus > oral > stomach > lung* - This order is incorrect as **esophageal and stomach cancers** are significantly less prevalent than **lung and oral cancers** in Indian males. - **Lung cancer consistently ranks at or near the top** in Indian male cancer statistics, making this order epidemiologically inaccurate.
Question 90: The most important sandfly-transmitted disease in India is-
- A. Kala azar (Correct Answer)
- B. Typhus
- C. Relapsing fever
- D. Plague
Explanation: ***Kala azar*** - **Kala azar**, or **visceral leishmaniasis**, is a severe parasitic disease endemic to India, transmitted primarily by *Phlebotomus argentipes* sandflies. - It is characterized by fever, **splenomegaly**, hepatomegaly, and can be fatal if untreated, making it a major public health concern. *Typhus* - **Typhus** is caused by Rickettsial bacteria and is typically transmitted by lice or fleas, not sandflies. - Symptoms include fever, rash, and headache, differing significantly from the visceral symptoms of Kala azar. *Relapsing fever* - **Relapsing fever** is caused by *Borrelia* bacteria and is transmitted by ticks or lice, not sandflies. - It is characterized by recurring episodes of fever, distinct from the progressive symptoms of Kala azar. *Plague* - **Plague** is caused by *Yersinia pestis* and is primarily transmitted by **fleas** carried by rodents. - It presents with buboes, fever, and sepsis, which are different from the clinical manifestations of sandfly-borne diseases.