Which of the following viral diseases is least commonly reported in India?
What is the BMI classification for an obese person?
In a developing country, the prevalence of diabetes mellitus is increasing at an annual rate of 1.8%. Using epidemiological principles similar to the Rule of 70, approximately how many years will it take for the diabetes prevalence to double, and what are the primary healthcare planning implications of this growth rate?
In the context of demographic studies, how is 'population explosion' defined in terms of growth rate?
Which of the following demographic characteristics can be GENERALLY assessed from the visual structure of a population pyramid without requiring precise statistical calculations?
Pearl's index is defined as the number of unintended pregnancies per:
Infant mortality rate in India is per 1000 live births?
Randomization is done to reduce?
What is a limitation of the case fatality rate?
Which of the following statements about incidence is false?
NEET-PG 2013 - Community Medicine NEET-PG Practice Questions and MCQs
Question 21: Which of the following viral diseases is least commonly reported in India?
- A. Japanese B encephalitis
- B. Lassa fever (Correct Answer)
- C. KFD
- D. Dengue
Explanation: ***Lassa fever*** - **Lassa fever** is endemic to West Africa, with the **multimammate rat** being its primary reservoir. - Cases of Lassa fever are **extremely rare** in India, primarily limited to travel-related instances due to the geographical distribution of the disease and its vector. *Japanese B encephalitis* - **Japanese B encephalitis (JBE)** is a significant public health concern in India, particularly in endemic regions. - It is a mosquito-borne viral disease, and **vaccination programs** are ongoing to control its spread. *KFD* - **Kyasanur Forest Disease (KFD)** is an endemic viral hemorrhagic fever primarily found in the **Karnataka state of India**. - It is transmitted by **ticks**, making it a regionally significant but recognized viral disease within India. *Dengue* - **Dengue** is one of the most commonly reported and widespread viral diseases in India. - It is a **mosquito-borne** illness with frequent outbreaks occurring across various parts of the country.
Question 22: What is the BMI classification for an obese person?
- A. Less than 18.5
- B. 18.5-24.9
- C. 25-29.9
- D. ≥30 (Correct Answer)
Explanation: ***≥30*** - A **Body Mass Index (BMI)** of **30 kg/m² or higher** is the standard WHO classification for **obesity**. - This classification indicates a significant accumulation of body fat that poses increased health risks including cardiovascular disease, type 2 diabetes, and certain cancers. *Less than 18.5* - A BMI in this range indicates that an individual is **underweight**, which also carries potential health risks associated with insufficient body mass. - This is the opposite end of the spectrum from obesity. *18.5-24.9* - This range represents a **healthy weight** or **normal BMI**, indicating a balanced proportion of weight to height. - Individuals in this category generally have the lowest health risks associated with body weight. *25-29.9* - A BMI within this range indicates **overweight**, which is a precursor to obesity if lifestyle changes are not made. - While not categorized as obese, it still carries increased health risks compared to a normal BMI.
Question 23: In a developing country, the prevalence of diabetes mellitus is increasing at an annual rate of 1.8%. Using epidemiological principles similar to the Rule of 70, approximately how many years will it take for the diabetes prevalence to double, and what are the primary healthcare planning implications of this growth rate?
- A. 30-35 years
- B. 35-46 years (Correct Answer)
- C. 25-30 years
- D. 20-25 years
Explanation: ***35-46 years*** - Using the **Rule of 70**, divide 70 by the annual growth rate (1.8%): 70 / 1.8 ≈ **38.89 years**. This value falls within the 35-46 year range. - The doubling of diabetes prevalence within this timeframe necessitates significant **healthcare planning implications**, including increased demand for diagnostic services, medications, and specialized care, as well as focused preventative measures. *30-35 years* - This range is too low, as the calculated doubling time of approximately **38.89 years** is longer than this range. While close, this timeframe underestimates the actual time needed for prevalence to double. *25-30 years* - This range is significantly lower than the calculated doubling time of approximately **38.89 years**, meaning it underestimates the time required for diabetes prevalence to double by about 9-14 years. *20-25 years* - This range is far too low, as the calculated doubling time of approximately **38.89 years** is much longer. This timeframe would suggest a much higher annual growth rate than the stated 1.8%.
Question 24: In the context of demographic studies, how is 'population explosion' defined in terms of growth rate?
- A. > 2% (Correct Answer)
- B. 0.5% - 1.0%
- C. 1.5% - 2.0%
- D. 1.0% - 1.5%
Explanation: ***> 2%*** - A **population explosion** is generally defined as a rapid and significant increase in population size, typically characterized by an annual growth rate exceeding **2%**. - This rate indicates a **doubling time** of approximately 35 years or less, leading to substantial demographic changes. - In the context of Indian demographics, this definition is particularly relevant to the period of rapid population growth experienced in the mid-20th century. *0.5% - 1.0%* - A growth rate in this range is considered **moderate** or even **low** for many developing countries and would not be indicative of a "population explosion." - This rate represents a relatively **stable** or slowly increasing population, not the rapid surge implied by the term. *1.5% - 2.0%* - While a 1.5% to 2.0% growth rate is significant, it often falls short of the threshold typically associated with a "population explosion," which implies a more **accelerated** and **unsustainable** rate of increase. - Many countries with this growth rate face challenges, but it's generally not classified as an "explosion" unless other contextual factors are extreme. *1.0% - 1.5%* - A growth rate between 1.0% and 1.5% is considered a **moderate** rate of population increase. - This range does not signify the rapid and often unmanageable growth implied by the term **population explosion**.
Question 25: Which of the following demographic characteristics can be GENERALLY assessed from the visual structure of a population pyramid without requiring precise statistical calculations?
- A. Exact male-to-female population ratios
- B. Life expectancy (Correct Answer)
- C. Immigration and emigration rates
- D. Crude birth rate per 1,000 population
Explanation: ***Life expectancy*** - A population pyramid visually represents the age and sex distribution of a population, which allows for a general inference of **life expectancy** based on the pyramid's shape. - A pyramid with a broad base and rapidly tapering top suggests **lower life expectancy**, while one with a more rectangular shape in older age cohorts indicates **higher life expectancy**. *Exact male-to-female population ratios* - While the pyramid shows the proportion of males and females in each age group, determining **exact numerical ratios** for the entire population from a visual glance is difficult. - Precise calculation would require **specific data values** for each bar. *Immigration and emigration rates* - Population pyramids can sometimes show **"bulges" or "indents"** in specific age groups that might hint at past large-scale migration. - However, **direct assessment of rates** (e.g., how many people per 1,000 immigrated or emigrated) from its visual structure alone is not possible. *Crude birth rate per 1,000 population* - The **width of the base** of the pyramid gives a general idea of the birth rate, with a wider base indicating higher births. - However, to determine the **exact crude birth rate per 1,000**, specific statistical data is required, not just a visual assessment of the pyramid's shape.
Question 26: Pearl's index is defined as the number of unintended pregnancies per:
- A. Per 100 woman years (Correct Answer)
- B. Per 10 woman years
- C. Per 1000 woman years
- D. Per 50 woman years
Explanation: ***Per 100 woman years*** - The **Pearl Index** is a common measure of the effectiveness of contraception. - It is calculated as the number of unintended pregnancies per **100 woman-years** of exposure to a contraceptive method. *Per 10 woman years* - This metric represents too small a population and duration to provide a statistically reliable measure of contraceptive effectiveness. - Using 10 woman-years as the denominator would inappropriately inflate the Pearl Index value, making methods appear less effective than they are. *Per 1000 woman years* - While a larger denominator provides greater statistical power, the standard definition of the Pearl Index specifically uses **100 woman-years**. - Expressing it per 1000 woman-years would make the index numerically smaller, potentially leading to misinterpretation if not clearly stated. *Per 50 woman years* - This denominator is not the standard convention for calculating the **Pearl Index**. - It would result in a different numerical value for the index, making direct comparisons with commonly reported Pearl Index values challenging.
Question 27: Infant mortality rate in India is per 1000 live births?
- A. 25
- B. 55
- C. 60
- D. 34 (Correct Answer)
Explanation: ***34*** - As per the **Sample Registration System (SRS)** data around **2012-2013**, India's **Infant Mortality Rate (IMR)** was reported as **34 deaths per 1,000 live births**. - This represents the number of infant deaths (before completing one year of age) per 1,000 live births in a given year. - This was the approximate national average used for the NEET-2013 examination period. *25* - This figure represents a lower IMR than the national average for India during 2012-2013. - While some progressive states like Kerala had achieved IMR closer to this figure, it was not the overall national rate at that time. *55* - This figure is higher than the reported national IMR for India in 2012-2013. - India's IMR had already declined below this level due to improved maternal and child health programs under NRHM (National Rural Health Mission). *60* - This value represents a historical estimate from earlier years (pre-2010). - By 2012-2013, India had made significant progress in reducing infant mortality from these higher historical levels through better healthcare access and immunization coverage.
Question 28: Randomization is done to reduce?
- A. Recall bias
- B. Selection bias (Correct Answer)
- C. Berksonian bias
- D. Reporting bias
Explanation: ***Selection bias*** - **Randomization** ensures that each participant has an equal chance of being assigned to any study group, which helps to distribute both known and unknown confounding factors evenly. - This process minimizes **selection bias** by promoting comparability between groups, making it more likely that any observed differences are due to the intervention rather than pre-existing differences. *Recall bias* - **Recall bias** occurs when there are systematic differences in the way participants remember or report past exposures or events, often seen in retrospective studies. - While randomization helps control for confounding, it does not directly prevent participants from inaccurately recalling information. *Berksonian bias* - **Berksonian bias** is a form of selection bias where the probability of being admitted to a hospital (or selected into a study) is affected by the presence of a co-morbidity, leading to a distorted association between diseases. - Randomization aims to balance characteristics *within* the study groups once participants are recruited, but it doesn't address biases related to the initial selection into the study population from a larger source. *Reporting bias* - **Reporting bias** refers to selective revealing or suppression of information, either by study participants (e.g., social desirability bias) or by researchers (e.g., only reporting positive findings). - Randomization helps ensure internal validity by creating comparable groups, but it does not prevent individuals from selectively reporting outcomes or experiences.
Question 29: What is a limitation of the case fatality rate?
- A. Not useful in acute infectious disease
- B. Not related to virulence
- C. Time period not specified (Correct Answer)
- D. It is not related to survival rate
Explanation: ***Time period not specified*** - The **case fatality rate (CFR)** is sometimes presented without a clear time frame, making it difficult to compare across different studies or diseases. - A CFR calculated over **24 hours** is vastly different from one calculated over **30 days** or **one year**, yet both could be presented simply as "CFR" *Not useful in acute infectious disease* - The CFR is highly **useful** in acute infectious diseases, as it directly measures the **severity** and immediate impact of an outbreak. - It helps public health officials understand the **lethality** of an infectious agent and aids in resource allocation and intervention strategies. *Not related to virulence* - **Case fatality rate** is directly related to **virulence**, as it reflects the proportion of affected individuals who die from the disease. - A higher CFR indicates a more **virulent pathogen** or a more severe disease process. *It is not related to survival rate* - The **case fatality rate** is inherently linked to the **survival rate**; they are complementary measures. - If the CFR is X%, then the associated survival rate is (100 - X)%, representing the proportion of cases that do not die from the disease.
Question 30: Which of the following statements about incidence is false?
- A. Does not include unit of time (Correct Answer)
- B. It is a rate
- C. Numerator includes new cases
- D. Denominator includes population at risk
Explanation: ***Does not include unit of time*** - This statement is false because **incidence** is defined as the number of **new cases** of a disease over a specific period of time in a population at risk. - Therefore, it inherently includes a **unit of time** (e.g., per year, per month), making this option incorrect as a characteristic of incidence. *It is a rate* - **Incidence is a rate** because it quantifies the speed at which new cases of a disease occur within a population. - It expresses the number of new events (cases) per unit of population at risk over a specified time period. *Numerator includes new cases* - The **numerator of incidence** specifically counts the number of **new cases** of a disease that develop during a defined observation period. - This distinguishes it from prevalence, which includes all existing cases. *Denominator includes population at risk* - The **denominator for incidence** comprises the **population at risk** of developing the disease during the observation period. - Individuals who already have the disease or are immune are typically excluded from the denominator.