AIAPGET Community Medicine, Research Methodology & Health Policy Syllabus

Differentiate kwashiorkor from marasmus.

Kwashiorkor = severe protein deficiency with adequate calories; features edema, fatty liver, skin/hair changes, preserved subcutaneous fat. Marasmus = severe deficiency of both calories and protein; features gross wasting, no edema, "old man" face.

List the four major nutritional deficiency disorders of public health importance in India.

Protein-energy malnutrition (PEM), vitamin A deficiency (nutritional blindness), iron deficiency anaemia, and iodine deficiency disorders (IDD).

What are the permissible/standard indicators of safe drinking water turbidity and residual chlorine?

Turbidity should be <1 NTU (acceptable up to 5 NTU). Free residual chlorine should be at least 0.5 mg/L after 1 hour of contact to ensure disinfection.

What is the breakpoint chlorination?

The point at which chlorine demand of water is fully met; chlorine added beyond this appears as free residual chlorine, which provides disinfection. The dip-and-rise pattern marks the breakpoint.

Define the demographic cycle / its five stages.

Stage 1: High stationary (high birth & death). Stage 2: Early expanding (high birth, falling death). Stage 3: Late expanding (declining birth, low death). Stage 4: Low stationary (low birth & death). Stage 5: Declining (death exceeds birth).

What is the demographic dividend?

Economic growth potential resulting from a shift in a population's age structure, when the working-age population (15-64) is larger than the dependent (non-working) population.

Define crude birth rate (CBR) and crude death rate (CDR).

CBR = (live births in a year / mid-year population) x 1000. CDR = (deaths in a year / mid-year population) x 1000.

What is the dependency ratio?

Dependency ratio = (population aged <15 + population aged >=65) / population aged 15-64, usually x100. It expresses the burden on the productive age group.

Differentiate qualitative (categorical) from quantitative (numerical) data.

Qualitative data describe categories/attributes - nominal (no order, e.g., blood group) or ordinal (ordered, e.g., disease grade). Quantitative data are measurable numbers - discrete (counts) or continuous (e.g., height, weight).

Differentiate probability from non-probability sampling, with examples.

Probability sampling: every unit has a known non-zero chance of selection (simple random, systematic, stratified, cluster, multistage) - allows generalization. Non-probability: selection by convenience/judgement (convenience, quota, purposive, snowball) - prone to bias.

Differentiate a cohort study from a case-control study.

Cohort: starts with exposure, follows forward to outcome (prospective), measures incidence and relative risk; good for rare exposures. Case-control: starts with outcome (disease), looks backward at exposure, measures odds ratio; good for rare diseases and quicker/cheaper.

What is the hierarchy of study designs by strength of evidence (ascending)?

Case report/series < ecological < cross-sectional < case-control < cohort < randomized controlled trial < systematic review/meta-analysis (highest).

Define a randomized controlled trial (RCT) and its key feature.

An experimental study in which participants are randomly allocated to intervention or control groups. Randomization plus blinding minimizes confounding and bias, making it the gold standard for assessing causality/efficacy.

How are relative risk and odds ratio calculated and interpreted?

Relative Risk (RR) = incidence in exposed / incidence in unexposed (cohort). Odds Ratio (OR) = ad/bc from a 2x2 table (case-control). Value >1 = positive association, =1 = no association, <1 = protective.

What is the formula for mean, and when is the median preferred?

Mean = sum of all observations / number of observations. The median (middle value) is preferred over the mean when data are skewed or contain outliers, as it is not distorted by extreme values.

Define mode and state when a dataset is bimodal.

The mode is the most frequently occurring value in a dataset. A dataset is bimodal when two values occur with the highest equal frequency.

What is standard deviation and what does it measure?

SD = square root of the variance = sqrt[ sum(x - mean)^2 / (n-1) ]. It measures the average dispersion/spread of observations around the mean.

Define the coefficient of variation (CV) and its use.

CV = (standard deviation / mean) x 100. It is a unit-free measure used to compare variability between two datasets with different units or widely different means.

In a normal distribution, what percentage of observations fall within 1, 2 and 3 SDs of the mean?

Approximately 68.3% within +/-1 SD, 95.4% within +/-2 SD, and 99.7% within +/-3 SD of the mean (the empirical/68-95-99.7 rule).

Define type I and type II errors.

Type I (alpha) error = rejecting a true null hypothesis (false positive). Type II (beta) error = failing to reject a false null hypothesis (false negative). Power = 1 - beta.

What is a p-value and the conventional level of significance?

The p-value is the probability of obtaining the observed result (or more extreme) if the null hypothesis is true. By convention, p < 0.05 is considered statistically significant.

When is a chi-square test used versus a Student's t-test?

Chi-square test: association between two categorical (qualitative) variables. Student's t-test: comparison of means between two groups for quantitative data that are normally distributed.

Define sensitivity and specificity of a screening test.

Sensitivity = ability to correctly identify those WITH disease = TP / (TP + FN). Specificity = ability to correctly identify those WITHOUT disease = TN / (TN + FP).

What are the four basic ethical principles of biomedical research?

Autonomy (respect for persons/informed consent), Beneficence (do good), Non-maleficence (do no harm), and Justice (fair distribution of benefits and burdens).

What are the essential elements of informed consent in research?

Disclosure of purpose, procedures, risks and benefits; comprehension by the participant; voluntariness (no coercion); competence to consent; and the right to withdraw at any time without penalty.

What is the role of an Institutional Ethics Committee (IEC) in research?

To review research protocols involving human participants for scientific validity and ethical acceptability, protect participants' rights/safety/well-being, and provide ongoing monitoring; in India it follows ICMR guidelines.

What are the key components of a research protocol?

Title, introduction/background, review of literature, objectives/hypothesis, methodology (study design, population, sampling, variables, data collection, analysis plan), ethical considerations, budget/timeline, and references.

Name the Indian government mission promoting AYUSH and state what AYUSH stands for.

The National AYUSH Mission (NAM), under the Ministry of AYUSH. AYUSH = Ayurveda, Yoga & Naturopathy, Unani, Siddha, and Homoeopathy (also includes Sowa-Rigpa).

Under which Act and schedules are Ayurvedic, Siddha and Unani drugs regulated in India?

The Drugs and Cosmetics Act, 1940 (and Rules 1945). ASU drugs are regulated chiefly under Chapter IVA, with Schedule T (GMP for ASU drugs) and Schedule E(1) (list of poisonous substances under Ayurvedic/Siddha/Unani systems).

What are the three tiers of the public healthcare delivery system in rural India and their population norms?

Sub-Centre (SC) for 5,000 population (3,000 in hilly/tribal), Primary Health Centre (PHC) for 30,000 (20,000 tribal), and Community Health Centre (CHC) for 120,000 (80,000 tribal) - the first referral unit with specialists.