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SET C - COMMUNITY MEDICINE ANSWERS

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SECTION I - Long Essay Questions (2 x 10 = 20 marks)

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Q1. Define screening. Discuss criteria for screening, evaluation of a screening test and application in cervical cancer and congenital hypothyroidism. (10 marks)

1. The condition should be an important health problem
2. There should be a recognizable latent or early symptomatic stage
3. Natural history of the condition should be adequately understood
4. There should be an accepted treatment for patients with recognized disease
5. Facilities for diagnosis and treatment should be available
6. A suitable, valid, and reliable screening test should be available
7. The test should be acceptable to the population
8. The cost should be economically balanced in relation to expenditure on medical care as a whole
9. Case-finding should be a continuing process, not a one-time project
10. There should be an agreed policy on whom to treat as patients

• Validity = ability to measure what it is supposed to measure (sensitivity + specificity)
• Reliability = ability to give consistent results on repeated application
• Yield = amount of previously unrecognized disease brought to treatment
• Lead time = interval between detection by screening and clinical presentation

• Screening test: Pap smear (cytology), VIA (Visual Inspection with Acetic Acid), VILI, HPV DNA testing
• Target group: Women aged 30-65 years (every 3-5 years)
• National programme: Under NPCDCS, opportunistic screening at health facilities
• Rationale: Long pre-invasive CIN stage (10-15 years) allows early detection and treatment
• Treatment: Cryotherapy, LEEP, cone biopsy

• Screening test: TSH or T4 measurement from dried blood spot (heel prick) on filter paper, taken on day 3-5 of life
• Ideal as it has a long asymptomatic window before irreversible intellectual disability
• Treatment: Levothyroxine, if started within 2 weeks of birth, prevents cretinism completely
• Included in national newborn screening programmes

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Q2. Describe demographic transition and its effect on health care planning in India with emphasis on ageing, dependency ratio and maternal-child health services. (10 marks)

• India's elderly population (60+) is projected to reach 20% by 2050
• Increase in non-communicable diseases (CVD, diabetes, cancers, dementia)
• Health system shift: from infectious disease to chronic disease management
• Need for geriatric care services, long-term care facilities, rehabilitation
• Increased burden on social security and pension systems

• Total dependency ratio = (Population <15 + Population >65) / Working age population (15-64) x 100
• Currently India has a "demographic dividend" window (large working-age population)
• Young dependency ratio is falling; old-age dependency ratio is rising
• This transition creates a window of economic opportunity BUT requires investment in health, education, and employment
• Eventually, old-age dependency will increase healthcare expenditure significantly

• With falling TFR (now ~2.0 near replacement level), MCH services need reorientation
• Demand for antenatal care, safe delivery, postnatal care remains high in states still in Stage II-III
• Shift from quantity (spacing, limiting births) to quality of MCH care
• Increased focus on: nutrition (anaemia in pregnancy), institutional deliveries (JSSK, JSY)
• Child survival programmes become increasingly important as IMR falls but NCD burden rises
• Adolescent health needs to be addressed as a bridge for the next generation

• Two-tier burden: states like Kerala/Tamil Nadu need geriatric services; UP/Bihar still need MCH services
• Need for Universal Health Coverage addressing both ends of the spectrum
• Ayushman Bharat, AB-HWCs reoriented to provide comprehensive primary care
• Workforce planning must accommodate both geriatric medicine and MCH specialists
• Urban-rural disparities in transition must guide resource allocation

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SECTION II - Short Essay Questions (8 x 5 = 40 marks)

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Q1. A block has poor full immunization coverage. Prepare a microplan including due list, session planning, cold chain and defaulter tracking. (5 marks)

1. Due List Preparation (1 mark)
   • Prepare list of all eligible beneficiaries: pregnant women and children 0-2 years
   • Sources: MCTS (Mother & Child Tracking System), ANMOL app, birth records, village health registers
   • Calculate expected beneficiaries = live births per month + carryover defaulters
   • Categorize: due for 1st dose, due for subsequent doses, dropouts
2. Session Planning (1 mark)
   • Map all villages/habitations in the block
   • Determine session sites (AWC, Sub-centre, school)
   • Frequency: At least 1 session/village/month; weekly sessions for large villages
   • Timing: Fixed day, fixed site immunization (routine immunization day = Tuesday/Friday)
   • ANM responsible for each site; supervisor to monitor
3. Cold Chain Management (1 mark)
   • Vaccines stored at ILR (Ice-lined Refrigerator) at PHC level: +2°C to +8°C
   • Deep Freezers at district level: -15°C to -25°C
   • Vaccine carriers with ice packs for field sessions
   • Cold chain equipment maintenance schedule
   • VVM (Vaccine Vial Monitor) to check vaccine potency
   • Avoid freeze-sensitive vaccines (DPT, Hepatitis B, TT) being frozen
4. Defaulter Tracking (1 mark)
   • Identify defaulters from due list vs. vaccinated list comparison
   • MCTS-based tracking: SMS alerts, ASHA outreach
   • Home visits for defaulters by ASHA/AWW within 3 days of missed session
   • Maintain drop-out rate = (1st dose - last dose) / 1st dose x 100; target <10%
   • Intensified outreach sessions in areas with clustering of defaulters
5. Monitoring & Evaluation (1 mark)
   • Calculate Full Immunization Coverage (FIC) = children fully immunized / total eligible x 100; target >90%
   • Monthly review by MO-PHC
   • Rapid Household Survey for validation
   • Supervisory visits with checklists

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Q2. A community survey shows mean Hb 9.8 g/dL among pregnant women. Discuss classification, public health significance and intervention package. (5 marks)

• India has one of the highest rates of anaemia in pregnant women (~50-60% NFHS-5)
• Maternal complications: increased risk of PPH, cardiac failure, sepsis, maternal death
• Fetal/neonatal complications: IUGR, low birth weight, preterm delivery, perinatal mortality
• Cognitive and physical development impairment in children born to anaemic mothers
• WHO criterion: If >40% prevalence = severe public health problem
• A community mean of 9.8 g/dL implies many women are severely anaemic

1. Supplementation: Daily IFA tablets (180 tablets) during pregnancy + 42 days postpartum; IFA syrup for children
2. Deworming: Single dose Albendazole 400 mg in 2nd trimester
3. Dietary diversification: Promotion of iron-rich foods (green leafy vegetables, jaggery, lemon)
4. Fortification: Consumption of fortified rice and wheat flour through PDS
5. Treatment: Oral iron for mild-moderate; IV iron sucrose for severe (Hb 5-8 with poor tolerance); blood transfusion for Hb <5 g/dL or symptomatic
6. ANC contact: Early registration (within 12 weeks), at least 4 ANC visits with Hb testing at each
7. Testing: Point-of-care Hb testing with HemoCue/Saheli at health and wellness centres

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Q3. Calculate chi-square from a 2x2 table conceptually and state when it is used in community medicine. (5 marks)

• E(a) = (a+b)(a+c) / N
• E(b) = (a+b)(b+d) / N
• E(c) = (c+d)(a+c) / N
• E(d) = (c+d)(b+d) / N

• If χ² > 3.84, association is statistically significant at 5% level

1. Testing association between exposure and disease (case-control, cross-sectional studies)
2. Comparing proportions between two groups (e.g., vaccination rates in rural vs. urban)
3. Evaluating effectiveness of an intervention (pre-post comparison)
4. Assessing statistical significance in epidemiological studies
5. Used in Chi-square test for goodness of fit
6. NOT used for: continuous variables (use t-test), paired data (use McNemar), or when expected frequency <5 in >20% cells (use Fisher's exact test)

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Q4. Prepare a waste management plan for a primary health centre including segregation, storage, transport and final disposal. (5 marks)

• Central storage area at PHC: separate, lockable, well-ventilated, labeled "Biomedical Waste"
• Yellow bag waste: stored max 48 hours (summer), 72 hours (winter)
• Sharps containers: three-fourths full seal rule
• No mixing of biomedical and general waste

• Non-reusable, leak-proof bags tied securely with color-coding maintained
• Transported in closed, labeled vehicles
• Route and frequency must be predetermined
• Handled by trained personnel with PPE (gloves, masks, gumboots)
• Collection by authorized CBWTF (Common Biomedical Waste Treatment Facility)

• Monthly reporting to SPCB (State Pollution Control Board) via online portal
• Waste register maintained (Form 3) - quantity generated, collected, treated
• Annual report submission
• Training of all HCW (health care workers) in biomedical waste handling

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Q5. A 6-month-old child has weight-for-age below -3 SD and bilateral pedal oedema. Classify and describe community-level management. (5 marks)

• Weight-for-age < -3 SD = Severe Underweight/Severe Acute Malnutrition (SAM)
• Bilateral pedal oedema = Kwashiorkor (or marasmic-Kwashiorkor if also severely wasted)
• WHO classification: Severe Acute Malnutrition with complications (oedema is always SAM)
• MUAC: <11.5 cm for 6-59 month children also indicates SAM

• Bilateral pitting pedal oedema (pathognomonic)
• Moon face, misery, flaky paint dermatosis, hair changes (flag sign)
• Hepatomegaly, irritability
• Weight: may appear deceptively normal due to oedema

1. Identification/Screening:
   • ASHA/AWW screen using MUAC tape and weighing scale monthly
   • Refer all SAM children to NRC (Nutritional Rehabilitation Centre)
2. NRC Management (Facility-based for complicated SAM):
   • Phase 1 - Stabilization (Days 1-7): F-75 therapeutic milk, treat infections (Amoxicillin), correct electrolytes (no IV fluids unless shocked), manage hypoglycaemia, hypothermia
   • Transition Phase (Days 8-14): F-100 or RUTF introduction
   • Phase 2 - Rehabilitation: F-100 or RUTF (Ready-to-Use Therapeutic Food = Plumpy'Nut), catch-up growth
3. RUTF-based Outpatient (for uncomplicated SAM):
   • Weight-based RUTF sachets dispensed weekly
   • Criteria for discharge: MUAC ≥12.5 cm, no oedema, 15% weight gain maintained for 2 weeks
4. Community Follow-up (1 mark):
   • AWC supplementary nutrition (SNP) under ICDS
   • Kishori Shakti/POSHAN Abhiyaan counselling for mother
   • Vitamin A supplementation, deworming
   • Immunization catch-up
   • Behaviour Change Communication (BCC) on complementary feeding
   • MAM children to AWC for take-home rations

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Q6. A researcher reports p value = 0.03 for association between indoor air pollution and COPD. Interpret in terms of statistical significance and clinical relevance. (5 marks)

• p-value = probability of obtaining the observed result (or more extreme) by chance alone, assuming the null hypothesis is true
• Here, p = 0.03 means there is a 3% probability that the observed association between indoor air pollution and COPD occurred by chance
• Since p < 0.05 (conventional threshold of significance), the result is statistically significant
• We reject the null hypothesis (H₀: no association between indoor air pollution and COPD)
• The association is unlikely to be due to chance

• A statistically significant result may NOT be clinically significant (especially in large samples)
• A clinically significant result may not reach statistical significance in small samples
• For this study: must report Odds Ratio (OR) with 95% CI
  • OR = 1.1 (statistically significant but clinically trivial)
  • OR = 3.5 (statistically significant AND clinically meaningful)

• 95% CI should not include 1.0 (which would mean no association)
• Narrow CI = precise estimate (large sample); wide CI = imprecise (small sample)
• Even with p = 0.03, if CI is wide (e.g., 1.01-8.5), the true effect is uncertain
• Conclusion: p = 0.03 indicates the association is real (not due to chance), but clinical relevance requires examination of effect size (OR/RR), biological plausibility, confounding control, and dose-response relationship

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Q7. A coastal district faces cyclone threat. Prepare disaster management plan focusing on vulnerable groups, water safety and disease surveillance. (5 marks)

• Early Warning System: IMD alerts to district authorities 48-72 hours prior
• Community awareness, mock drills
• Pre-positioning of medicines, ORS, chlorine tablets, vaccines

• Identification: Elderly, disabled, pregnant women, children <5, chronically ill, below poverty line families
• Evacuation: Priority evacuation via trained ASHA/AWW, police; evacuation shelters pre-designated (schools, panchayat buildings at higher ground)
• Shelters: Ensure universal accessibility (ramps for disabled), breastfeeding corners, separate areas for women
• Pregnant women: Delivery kits in shelters, skilled birth attendants, referral linkages
• Medicines: Chronic disease patients - ensure 30-day supply before evacuation

• Post-cyclone: all surface water presumed contaminated
• Water testing: E. coli and total coliform testing of all water sources
• Purification: Chlorination of water tanks (residual chlorine 0.5 mg/L), use of ORS kits, water purification tablets
• WASH: Temporary sanitation units in relief camps, handwashing stations
• Advise boiling water for drinking; avoid raw foods
• Mobile water tankers with treated water

• Activate Integrated Disease Surveillance Programme (IDSP) with daily 'S' (syndromic), 'P' (presumptive), 'L' (laboratory) forms
• Alert diseases post-cyclone: Cholera, typhoid, leptospirosis, malaria, dengue, acute diarrhoeal disease, conjunctivitis, skin infections
• Establish temporary disease reporting posts in relief camps
• Rapid Response Teams (RRT) deployed: investigate any cluster of illness within 24 hours
• Mass chemoprophylaxis if indicated (e.g., doxycycline in leptospirosis outbreaks)
• Immunization: Cholera vaccine (oral), Hep A vaccine in high-risk groups
• Health workers deployed with daily reporting to district surveillance officer

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Q8. A country has high life expectancy but rising obesity and diabetes. Discuss epidemiological transition and prevention strategy. (5 marks)

1. Age of Pestilence and Famine - High mortality from infections and malnutrition; low LE
2. Age of Receding Pandemics - Decline in infectious disease mortality; LE rises to 30-50 years
3. Age of Degenerative and Man-made Diseases - NCDs (CVD, cancer, diabetes) dominate; LE >50 years

• Nutritional transition: shift from whole grains to processed, calorie-dense foods
• Physical inactivity: sedentary jobs, motorized transport, screen time
• Urbanization
• Reduced breastfeeding, increased formula feeding in infancy
• Stress, sleep disruption

• Policy-level: sugar tax, restrictions on junk food advertising to children
• Urban planning: promote walkable cities, cycling tracks
• School nutrition programmes, physical activity in schools

• Population-based: WASH, dietary guidelines, mass media campaigns
• High-risk: intensive lifestyle modification for pre-diabetics (metformin if indicated)
• Target: 5-7% weight loss reduces diabetes incidence by 58% (Diabetes Prevention Program)

• Mass screening: NPCDCS population-based screening for diabetes, hypertension at HWCs
• HbA1c monitoring, annual retinal examination, foot examination
• Treat to target: HbA1c <7%, BP <130/80

• Prevent complications: neuropathy, nephropathy, retinopathy, CVD
• Cardiac rehabilitation, dialysis access, limb salvage programmes

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SECTION III - Short Answer Questions (10 x 3 = 30 marks)

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Reasoning-Based Questions (3 marks each)

• Prevalence = Incidence × Duration of disease
• Chronic diseases (diabetes, TB, hypertension) have long duration (years to decades), so even with the same incidence, cases accumulate in the community
• Acute diseases (cholera, common cold) resolve quickly (days to weeks), so cases leave the prevalent pool rapidly
• In chronic disease: slow removal (low recovery/death rates) → high stock of existing cases
• Example: Incidence of diabetes = 5/1000/year; duration = 20 years → Prevalence = 100/1000 (10%)
• Formula: P ≈ I × D (valid when prevalence is low and rate is stable)

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• p-value only tells whether an association is statistically significant; it does NOT tell the magnitude of effect
• CI provides point estimate + range of plausible values at a given confidence level (usually 95%)
• CI gives clinical importance: a p < 0.05 with OR = 1.05 (CI: 1.001-1.10) is statistically significant but clinically negligible
• CI reflects sample size and precision: narrow CI = large study, precise estimate; wide CI = small study, imprecise
• CI allows comparison across studies (used in meta-analyses)
• p-value is binary (significant/non-significant); CI is continuous and more informative
• When CI excludes the null value (1.0 for OR/RR; 0 for mean difference) → statistically significant, same conclusion as p<0.05

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• ORS works on the principle of sodium-glucose co-transport in the intestinal mucosa
• Glucose enhances sodium absorption via SGLT-1 (sodium-glucose cotransporter-1) on enterocytes; water follows osmotically
• This transport mechanism is preserved even during cholera/secretory diarrhoea because the absorptive cells (villous tip cells) remain intact; only secretory (crypt) cells are over-stimulated
• Net result: absorption of sodium, glucose, and water EXCEEDS ongoing losses when ORS is given adequately
• WHO low-osmolarity ORS (245 mOsm/L): Na⁺ 75 mmol/L, Glucose 75 mmol/L, K⁺ 20 mmol/L, Citrate 10 mmol/L
• Low-osmolarity ORS reduces stool output by ~20% and vomiting compared to older high-osmolarity ORS
• Principle: Replaces fluid and electrolytes lost in stool; glucose accelerates absorption

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• Community diagnosis = systematic assessment of the health status, needs, and determinants of health of a defined population (analogous to clinical diagnosis before treatment)
• Identifies priority health problems and their magnitude in the community
• Determines distribution by person, place, and time - who is affected, where, when
• Identifies risk factors and determinants - guides choice of interventions
• Establishes baseline data against which programme effectiveness can be measured
• Ensures equitable allocation of scarce resources to those with greatest need
• Prevents planning based on assumptions rather than evidence
• Example: If community diagnosis reveals high malnutrition among tribal children, resources are directed to them rather than a general population approach

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• Adolescents (10-19 years) form 21% of India's population - a critical window of opportunity
• Maternal pathway: Adolescent girls with poor nutrition (anaemia, stunting) → low birth weight babies → stunted children → perpetuates cycle of malnutrition across generations
• Behavioural pathway: Health behaviours (smoking, alcohol, physical activity, dietary habits) established in adolescence persist into adulthood and influence parenting practices
• Early marriage/pregnancy: Adolescent pregnancy = higher maternal and infant mortality; delaying marriage improves educational attainment and child health outcomes
• Mental health: Mental disorders often onset in adolescence; untreated depression/anxiety affects parenting quality
• RKSK (Rashtriya Kishor Swasthya Karyakram): India's adolescent health programme addresses nutrition, reproductive health, substance abuse, mental health, injuries and NCDs
• Breaking the intergenerational cycle of poverty, malnutrition, and poor health requires investing in adolescents today

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Direct Questions (3 marks each)

1. Nutrition: Screening for anaemia and malnutrition; weekly IFA (Iron Folic Acid) supplementation through WIFS (Weekly Iron and Folic Acid Supplementation) programme; biannual deworming
2. Reproductive and Sexual Health: Life skills education, menstrual hygiene, contraception counselling, prevention of early marriage and teen pregnancy; Adolescent Friendly Health Clinics (AFHC) at CHC/DH level
3. Prevention and Management of Substance Misuse, Mental Health, Injuries/Violence, NCDs, and Non-communicable diseases: Peer education (Peer Educator model), Rashtriya Kishor Swasthya Karyakram community-based interventions through peer educators, counselling at AFHCs

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• TFR is the average number of children that would be born to a woman over her entire reproductive lifetime (15-49 years) if she were to experience the age-specific fertility rates of a given year throughout her childbearing years, and she were to survive from birth to the end of her reproductive period
• Formula: TFR = Sum of Age-Specific Fertility Rates (ASFRs) for ages 15-19, 20-24, 25-29, 30-34, 35-39, 40-44, 45-49 × 5 (the 5-year interval)
• TFR is a period measure - does not follow a cohort
• Replacement level TFR = 2.1 (2 children to replace parents + 0.1 for child mortality)
• India's TFR (NFHS-5, 2019-21): 2.0 (below replacement level nationally, though state variations exist)
• TFR is the best summary measure of current fertility in a population

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1. Full Immunization Coverage (FIC): Percentage of children aged 12-23 months who have received all scheduled vaccines (BCG, 3 doses OPV, 3 doses DPT, 1 dose measles/MR) - target >90%; NFHS-5: 76.4% nationally
2. Dropout Rate (DPT1-DPT3 dropout): = (DPT1 vaccinated - DPT3 vaccinated) / DPT1 vaccinated × 100 - measures attrition between first and last dose; target <10%; high dropout indicates programme failure in follow-up
3. Missed Opportunity Rate / Defaulter Rate: Proportion of eligible children who visit a health facility but are not vaccinated, OR proportion who received 1st dose but did not complete the schedule; also DPT1-Measles dropout and Routine Immunization session holding rate

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1. Civil Registration System (CRS): Compulsory registration of births, deaths, marriages, stillbirths under Registration of Births and Deaths Act 1969; data compiled by Registrar General of India (RGI); most direct source but incomplete in rural areas
2. Sample Registration System (SRS): Continuous demographic survey by Registrar General of India; dual record system (independent enumeration + retrospective survey); provides IMR, CBR, CDR, TFR at national and state level - most reliable source for vital rates
3. Census of India: Decennial census (every 10 years) provides data on population size, age-sex distribution, literacy, housing; indirect source for vital events; used to calculate dependency ratios, sex ratio, population projections

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1. Equitable Distribution: PHC should be available to all people regardless of their ability to pay, geographical location, social status, or gender; emphasis on underserved populations (rural, tribal, slum dwellers)
2. Community Participation: Communities must be involved in planning, implementation, and evaluation of their own health care; health is not done TO communities but WITH them; promotes ownership, sustainability
3. Intersectoral Coordination: Health improvement requires collaboration between multiple sectors: agriculture (nutrition), education (literacy), water/sanitation, housing, social welfare; health sector alone cannot achieve health for all

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SECTION IV - Difficult MCQs (10 x 1 = 10 marks)

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• Mean ± 1 SD = 68.3%
• Mean ± 2 SD = 95.4%
• Mean ± 3 SD = 99.7%

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• Mean: affected by outliers
• Range: entirely determined by extremes
• Median: middle value, not affected by extreme scores
• Standard deviation: affected by outliers

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• CBR: crude birth rate (does not account for age-sex structure)
• GFR: general fertility rate
• Net Reproduction Rate (NRR): Average number of daughters born to a woman who will survive to replace her mother; NRR = 1 means exact replacement; NRR < 1 = below replacement
• Stillbirth rate: mortality indicator

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• Assertion is TRUE: In case-control studies, we cannot calculate RR directly because we sample based on disease (outcome), not exposure; we cannot determine incidence rates
• Reason is TRUE and CORRECTLY EXPLAINS the assertion: Because cases and controls are selected based on disease status, the denominator (population at risk over time = incidence) cannot be determined; hence OR is used as an approximation of RR (valid when disease is rare - rare disease assumption)

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• Effective treatment = patients survive longer but are not cured
• Prevalence = Incidence × Duration - if incidence unchanged but duration increases (patients live longer with disease), prevalence rises
• This is Increased survival/duration - treatment keeps patients alive longer, increasing the pool of prevalent cases

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Summary Score Sheet