INI-CET 2026 Practice Questions

Q: Health data from 15 nations investigates the relationship between per capita tobacco consumption and national COPD prevalence, revealing a strong positive correlation. Which study type best describes this?

Ecological study. ***Ecological study*** - An ecological study assesses the relationship between exposure and outcome at the **population level** rather than the individual level, using data aggregated across nations as in this example. - The unit of analysis is the **entire population** (15 nations), making it the correct classification for this type of correlational research. *Case control study* - Requires individual-level data by identifying subjects based on the presence or absence of the **outcome** (COPD) and looking back for the **exposure** (tobacco). - It is not used to analyze aggregate national-level data like per capita consumption metrics. *Cohort study* - Involves following a group of individuals over time to determine if exposure leads to the subsequent development of the outcome. - Because this study assesses prevalence and consumption across nations simultaneously at the population level, it does not involve the prospective follow-up characteristic of a cohort study. *Cross sectional study* - Analyzes individual-level data to capture a snapshot of exposure and disease at a single point in time. - Because this study uses group-level (nations) data rather than individual subject data, it is specifically referred to as an ecological study, not a cross-sectional study.

Q: A new screening test is evaluated in a population of 1,000 individuals. Of these, 100 individuals are known to have the disease. The test correctly identifies 90 of the diseased individuals, while 50 non-diseased individuals are false positive. Based on the data below, what is the Positive Predictive Value (PPV) of this screening test? Screening Test Diseased Non-Diseased Test Positive 90 50 Test Negative 10 850 Total 100 900

64%. ***64%*** - The **Positive Predictive Value (PPV)** is calculated by the formula: **True Positives / (True Positives + False Positives)**. - Plugging in the values from the table: **90 / (90 + 50) = 90 / 140 ≈ 0.643**, which is approximately **64%**. *90%* - This represents the **Sensitivity** of the test, calculated as **True Positives / (True Positives + False Negatives)** (90 / 100). - It measures the ability of a test to correctly identify individuals who actually have the disease. *98%* - This calculation is incorrect and does not correspond to standard diagnostic test parameters. - A value this high would imply nearly perfect predictive capability, which is not supported by the data provided. *47%* - This value is likely obtained by calculating the **Negative Predictive Value (NPV)** incorrectly or using the wrong denominator. - It does not represent the probability that a person with a positive test result truly has the disease.

Q: In a defined population, approximately 67% of all stroke cases are attributable to uncontrolled hypertension. If hypertension were adequately managed, 2/3rd of stroke burden could be eliminated. This is an example of:

Population attributable risk. ***Population attributable risk*** - This measure represents the **proportion of disease in the total population** that can be attributed to a specific exposure, which is directly applicable to the scenario where 67% of stroke cases are linked to hypertension. - It estimates the **potential impact** of a public health intervention, such as eliminating hypertension, on the total disease burden in the population. *Relative risk* - This is a ratio of the **incidence in the exposed group** compared to the incidence in the unexposed group. - It measures the **strength of the association** between a risk factor and an outcome, rather than the proportion of the disease attributable to the risk factor. *Attributable risk* - Often called **Risk Difference**, this measure calculates the actual difference in incidence rates between exposed and unexposed groups. - It does not account for the **prevalence of the exposure** in the entire population, unlike population attributable risk which considers the total disease burden. *Odds Ratio* - This statistical measure determines the odds of an exposure occurring in cases compared to the odds of exposure in controls, commonly used in **case-control studies**. - It is an estimate of relative risk (when disease is rare) but does not quantify the **portion of population disease** caused by the risk factor.

Q: On investigating an outbreak, an epidemiologist plots epidemic curve of acute febrile illness showing successive clusters separated by approximately 1 incubation period apart. Which of the following diseases shows this pattern of propagated spread?

Measles. ***Measles*** - This infectious disease typically exhibits a **propagated epidemic curve** because it is transmitted directly from person-to-person through respiratory droplets. - Successive waves of cases appear at intervals corresponding to the **incubation period**, as susceptible individuals are infected by the initial index cases, leading to secondary and tertiary generations of transmission. *Salmonellosis* - Usually presents as a **point-source epidemic**, where multiple individuals are exposed simultaneously to a single contaminated food or water source. - The epidemic curve typically shows a **rapid rise and fall** in cases rather than the progressive waves characteristic of person-to-person transmission. *Typhoid* - Like other foodborne or waterborne illnesses, it frequently follows a **common-source or continuous-source pattern** of exposure rather than serial transmission chains. - While secondary spread is possible in poor sanitation settings, the classic presentation is a **sharp peak** resulting from ingestion of contaminated materials. *Food poisoning* - Characteristically results from a **common-source outbreak**, where all affected individuals consume a shared, contaminated food item within a short window. - These cases typically cluster together within a timeframe defined by the **incubation period** after a single meal, rather than showing extended, wave-like generation periods.

Q: Under the RMNCH+A programme, a state is categorized in the "Red" zone. Which criterion is likely responsible for this classification?

IMR exceeding the national average by 20% or more. ***IMR exceeding the national average by 20% or more*** - In the RMNCH+A framework, states are categorized into high-priority districts or zones based on health performance indicators, where the **Red zone** represents the most critical performance gap requiring intensive intervention. - Classification into the Red zone is typically triggered when key indicators like the **Infant Mortality Rate (IMR)**, **Maternal Mortality Ratio (MMR)**, or **Total Fertility Rate (TFR)** significantly lag behind the national average, specifically defined as exceeding the benchmark by **20% or more**. *MMR lower than the national benchmark* - Having a lower Maternal Mortality Ratio is considered a **positive indicator** of health performance, which would likely classify a region into a higher-performing category like the **Green zone**. - High-performing states are prioritized for sustainability and resource allocation, rather than being identified as needing urgent, intensive corrective action like the Red zone. *Institutional delivery rate meeting the nationally accepted threshold* - Meeting or exceeding the **institutional delivery** threshold indicates robust access to skilled birth attendance, which is a successful programmatic outcome. - This metric is used to track progress and identify areas of success, not to flag the most underperforming states that fall into the **Red zone**. *Full immunization coverage achieving the desired target* - Achieving **full immunization coverage** targets demonstrates effective implementation of public health outreach and infrastructure. - States performing well on immunization are categorized as **Green** or stable, as they are meeting the program’s developmental milestones rather than failing critical population health benchmarks.

Q: A 34-year-old female, G2P1, with a history of pre-eclampsia in her previous pregnancy, comes for her first ANC visit at 12 weeks. What is the most appropriate intervention for prevention of pre- eclampsia in her current pregnancy?

Low-dose aspirin. ### ***Low-dose aspirin*** - Per ACOG and USPSTF guidelines, **low-dose aspirin** (81 mg/day) is recommended for the prevention of pre-eclampsia in high-risk women starting between 12 and 28 weeks of gestation (ideally before 16 weeks). - A history of **pre-eclampsia** in a previous pregnancy is a high-risk factor that mandates prophylactic treatment to reduce morbidity. *Low-dose aspirin with Low Molecular Weight Heparin (LMWH)* - There is no clinical indication for the routine addition of **LMWH** to aspirin for pre-eclampsia prevention unless the patient has a diagnosed **thrombophilia** or **antiphospholipid syndrome**. - Adding anticoagulation unnecessarily increases the risk of bleeding complications without clear benefit in reducing pre-eclampsia related outcomes. *Low calcium intake* - Current evidence-based guidelines recommend **calcium supplementation** for high-risk populations, specifically in areas with low dietary calcium intake, rather than restricting it. - Studies show that **calcium supplementation** (1–2 g/day) helps reduce the risk of pre-eclampsia, whereas "low" intake is not a therapeutic intervention. *Low salt intake* - Routine **sodium restriction** is not recommended for pregnancy as it does not prevent pre-eclampsia or gestational hypertension. - Maintaining a normal, balanced diet is advised; significant salt restriction may lead to inadequate fetal nutrition without maternal benefit.

Question 1

Assertion: In a nested case-control study, incidence rates can be derived from the parent cohort.
Reason: Nested case-control studies have the ability to estimate relative risk accurately.

Accepted Answer

Both assertion and reason are correct, but they are unrelated

Answer

Both assertion and reason are correct, and the reason is the correct explanation of the assertion

Answer

Assertion is correct, but the reason is incorrect

Answer

Assertion is incorrect, but the reason is correct

Question 2

Health data from 15 nations investigates the relationship between per capita tobacco
consumption and national COPD prevalence, revealing a strong positive correlation. Which study
type best describes this?

Accepted Answer

Ecological study

Answer

Case control study

Answer

Cohort study

Answer

Cross sectional study

Question 3

A new screening test is evaluated in a population of 1,000 individuals. Of these, 100 individuals
are known to have the disease. The test correctly identifies 90 of the diseased individuals, while 50
non-diseased individuals are false positive. Based on the data below, what is the Positive
Predictive Value (PPV) of this screening test?
Screening Test Diseased Non-Diseased
Test Positive 90 50
Test Negative 10 850
Total 100 900

Accepted Answer

64%

Answer

90%

Answer

98%

Answer

47%

Question 4

In a defined population, approximately 67% of all stroke cases are attributable to uncontrolled
hypertension. If hypertension were adequately managed, 2/3rd of stroke burden could be
eliminated. This is an example of:

Accepted Answer

Population attributable risk

Answer

Relative risk

Answer

Attributable risk

Answer

Odds Ratio

Question 5

Which statement is correct regarding assessment of heterogeneity in meta-analysis?

Accepted Answer

It evaluates the degree of variability in results across the combined studies

Answer

It directly quantifies and corrects for publication bias

Answer

It automatically removes confounding variables from individual studies

Answer

It computes the incidence rate of the outcome across all populations

Question 6

On investigating an outbreak, an epidemiologist plots epidemic curve of acute febrile illness
showing successive clusters separated by approximately 1 incubation period apart. Which of the
following diseases shows this pattern of propagated spread?

Accepted Answer

Measles

Answer

Salmonellosis

Answer

Typhoid

Answer

Food poisoning

Question 7

On evaluating an influenza vaccine, it demonstrated an efficacy of 95% in randomized controlled
trials and an effectiveness of 90% in post-marketing surveillance studies. Which of the following
statement is incorrect?

Accepted Answer

The vaccine confers absolute and complete protection against influenza infection

Answer

Vaccinated individuals demonstrate a 95% reduction in disease risk vs unvaccinated

Answer

Vaccinated individuals show a 90% reduction in influenza risk in real-world settings

Answer

Vaccine effectiveness can be lower than efficacy in real-world settings

Question 8

Which of the following statement is correct with respect to the Pearl Index?

Accepted Answer

Number of accidental pregnancies per 100 woman-years of contraceptive use

Answer

Number of accidental pregnancies in 100 women using a contraceptive for 1 year

Answer

Number of live births per 100 woman-years

Answer

Number of pregnancies including abortions per 100 couples

Question 9

Under the RMNCH+A programme, a state is categorized in the "Red" zone. Which criterion is
likely responsible for this classification?

Accepted Answer

IMR exceeding the national average by 20% or more

Answer

MMR lower than the national benchmark

Answer

Institutional delivery rate meeting the nationally accepted threshold

Answer

Full immunization coverage achieving the desired target

Question 10

A 34-year-old female, G2P1, with a history of pre-eclampsia in her previous pregnancy, comes for
her first ANC visit at 12 weeks. What is the most appropriate intervention for prevention of pre-
eclampsia in her current pregnancy?

Accepted Answer

Low-dose aspirin

Answer

Low-dose aspirin with Low Molecular Weight Heparin (LMWH)

Answer

Low calcium intake

Answer

Low salt intake

INI-CET 2026

Community Medicine

Obstetrics and Gynecology