Community Medicine — Non-Communicable Disease, NMC MBBS licence examination syllabus (Nepal Medical Council).
Non-communicable disease and health promotion
Four behaviours drive four diseases — which is what makes prevention tractable.
Non-communicable diseases are now a leading cause of death almost everywhere, including in countries that have not finished dealing with infection and undernutrition. That combination — a double burden — is the defining public health problem of this region, and it lands on health systems that were designed for episodic infectious illness and are now being asked to manage conditions that last for decades.
The encouraging structure underneath is that four major disease groups share four modifiable behavioural risk factors. One policy on tobacco reduces cancer, cardiovascular disease and chronic lung disease at once. That shared aetiology is why NCD prevention is efficient in a way that infectious disease control, with its organism-by-organism approach, often is not.
🩺 Where this lives: Non-communicable disease is a major driver of poverty in countries without universal coverage. A diagnosis of diabetes or heart disease means paying for medication every month for the rest of a life, usually out of pocket, often after selling land or borrowing. Families make rational decisions to stop treatment for a condition producing no symptoms. That is not non-adherence in the way clinicians usually mean it — it is a household budget decision, and understanding it changes what a useful consultation looks like.
💡 A note on numbers. This chapter contains no prevalence figures, mortality percentages or Nepal-specific NCD statistics. These come from STEPS survey rounds and national reports and change between them, so a figure quoted here would be stale and a student reproducing it could be marked wrong. Take current values from the national STEPS survey and Department of Health Services reports. The levels of prevention, the prevention paradox and screening criteria are covered in the Epidemiology chapter; clinical management sits in the Medicine chapters.
The epidemiological transition
The classical transition describes a shift from infectious disease and undernutrition towards chronic disease as countries develop. What actually happens in low- and middle-income countries is less tidy: the old burden does not disappear, so tuberculosis, diarrhoeal disease and malnutrition persist alongside rising diabetes, hypertension and cancer. NCDs also tend to appear at younger ages and to be diagnosed later here, so the years of productive life lost are greater.
Four diseases, four risk factors
WHY THE SHARED RISK FACTORS MATTER SO MUCH
THE FOUR DISEASE GROUPS
Cardiovascular disease — including stroke, which is the
dominant NCD killer in much of South Asia
Cancer
Chronic respiratory disease
Diabetes
THE FOUR BEHAVIOURAL RISK FACTORS
TOBACCO — smoked and smokeless
UNHEALTHY DIET — particularly SALT, and increasingly
sugar and processed food
PHYSICAL INACTIVITY
HARMFUL ALCOHOL USE
THESE PRODUCE THE INTERMEDIATE RISK FACTORS you measure in
clinic: raised blood pressure, raised blood glucose,
abnormal lipids, and overweight.
THE STRATEGIC CONSEQUENCE: because the behaviours are
shared, a single intervention acts on several diseases at
once. Reducing tobacco use lowers lung cancer, myocardial
infarction, stroke and COPD together. Reducing dietary salt
lowers blood pressure and therefore stroke — and stroke
matters enormously here.
ALSO REMEMBER THE ENVIRONMENTAL CONTRIBUTORS that the
"four by four" framing can obscure: HOUSEHOLD AIR
POLLUTION from solid cooking fuel is a major cause of
chronic lung disease in women who have never smoked, and
outdoor air pollution contributes to cardiovascular and
respiratory disease. These are covered in the
Environmental Health chapter.
Population and high-risk strategies
💡 Exam angle: this is the most examinable idea in the chapter, and it is counterintuitive. A population strategy shifts the whole risk distribution a little — salt reduction, tobacco taxation, clean air. Each individual gains almost nothing noticeable, yet the total number of events prevented is large, because most cases arise from the many people at moderate risk rather than the few at extreme risk. A high-risk strategy finds and treats those at greatest danger, which helps each of them substantially but misses the bulk of future cases. You need both, and the population approach is usually cheaper and reaches people who never attend a clinic.
Tobacco control
Two points are specific to this region. First, smokeless tobacco — chewed and applied preparations — is widely used and is not a safe alternative; it is a major cause of oral cancer, and it is often not counted as "smoking" when you ask. Second, of all the available measures, price is the single most effective, and it works disproportionately on the two groups most worth protecting: young people and those on low incomes.
Delivering chronic care
WHY CHRONIC CARE FAILS, AND WHAT HELPS
THE MODEL MISMATCH
Health services built for infectious illness expect a
patient to arrive unwell, be treated, and leave better.
Chronic disease requires the opposite: an asymptomatic
person, mostly self-managing, returning indefinitely.
THE PRACTICAL BARRIERS — ask about these directly
COST of lifelong medication, paid out of pocket
DISTANCE and time away from work to attend
DRUG STOCK-OUTS at the local facility
NO SYMPTOMS to prompt or reward adherence
Absent or fragmented records, so nobody sees the trend
WHAT IMPROVES IT
PROTOCOL-BASED care that a non-specialist can deliver
reliably
TASK-SHIFTING to nurses and community health workers,
which extends reach where doctors are scarce
Fixed-dose combinations and simplified regimens
Reliable supply chains — a perfect prescription is
worthless if the drug is unavailable next month
Patient education aimed at understanding, since the
treatment relieves nothing the patient can feel
Integration with existing services rather than parallel
vertical programmes
AND NOTE THE OVERLAP WITH INFECTION: diabetes substantially
increases tuberculosis risk, and TB and NCD services often
see the same patients — which is an argument for
integration rather than separation.
Clinical reasoning: four scenarios
🔍 Case 1 — treating only the extreme
ScenarioA district plans to reduce stroke by screening and treating only those with the very highest blood pressures, arguing that resources should target those at greatest risk.
Key questionWhere do most strokes actually come from?
ReasoningMost cases arise from the large number of people at moderate risk rather than the small number at extreme risk. A high-risk strategy helps each person found, but prevents fewer events in total than a modest shift in the whole population.
AnswerCombine both: continue case-finding and treatment, but add population measures such as salt reduction and tobacco control, which are cheaper and reach those who never attend a clinic.
🔍 Case 2 — "she isn't compliant"
ScenarioA woman with diabetes and hypertension has stopped her medication. She lives four hours from the clinic, the local facility has had no stock for two months, and the drugs cost a significant share of household income. She is labelled non-compliant.
MislabellingThese are system failures, not patient failures.
ReasoningCost, distance and stock-outs are the classic barriers to chronic care. Her decision is rational given her circumstances, and calling it non-compliance stops anyone from fixing the actual problem.
AnswerAsk about cost, distance and supply explicitly. Simplify the regimen, use fixed-dose combinations where available, arrange care closer to home through task-shifting, and address the stock-out through the supply system.
🔍 Case 3 — the man who does not smoke
ScenarioA man with an oral ulcer that has not healed for two months says he has never smoked. Tobacco use is recorded as none, and the ulcer is treated as an aphthous ulcer.
Question not askedDoes he chew tobacco?
ReasoningSmokeless tobacco is widely used and frequently not reported as "smoking". It is a major risk factor for oral cancer, and a non-healing oral ulcer is a red flag.
AnswerAsk specifically about chewed and applied tobacco preparations, examine the mouth thoroughly, and refer a persistent ulcer for biopsy rather than treating it empirically.
🔍 Case 4 — a programme that changed nothing
ScenarioA district runs health education sessions urging people to eat less salt and exercise more. Two years later, blood pressure in the population is unchanged. The conclusion drawn is that people are not motivated.
Alternative readingEducation alone rarely changes behaviour at scale.
ReasoningAdvice competes with price, availability and environment. Where salt is cheap and abundant in processed and preserved foods, and where there is nowhere safe to walk, information does not translate into behaviour.
AnswerCombine education with structural measures — reformulation and labelling of food products, taxation, and environmental changes that make the healthier option the easier one. Education supports policy; it rarely substitutes for it.
Commonly confused
Confusion
The distinction
Why it matters
Transition vs double burden
Old burden persists alongside the new
Systems must handle both at once.
Behavioural vs intermediate risk factors
Behaviours produce raised BP, glucose, lipids
Intervening earlier is cheaper.
Population vs high-risk strategy
Whole-distribution shift versus targeting
Most cases come from moderate risk.
Individual benefit vs total benefit
The prevention paradox
Explains why population advice feels pointless.
Smoked vs smokeless tobacco
Smokeless is not safe and is under-reported
Major cause of oral cancer here.
Non-compliance vs system failure
Cost, distance, stock-outs
The label prevents the fix.
Education vs structural measures
Advice competes with price and environment
Education supports policy, rarely replaces it.
Episodic vs chronic care model
Asymptomatic lifelong self-management
Requires a different service design.
Rapid revision
MUST-KNOW FACTS
1. NCDs are now a leading cause of death worldwide.
2. The EPIDEMIOLOGICAL TRANSITION shifts burden from infection to chronic disease.
3. Low-income countries carry a DOUBLE BURDEN — both at once.
4. NCDs appear at YOUNGER ages and are diagnosed later here.
5. THE FOUR DISEASES: cardiovascular, cancer, chronic lung, diabetes.
6. STROKE is the dominant NCD killer in much of South Asia.
7. THE FOUR BEHAVIOURAL RISK FACTORS: TOBACCO, DIET, INACTIVITY, ALCOHOL.
8. They produce the intermediate factors: raised BP, glucose, lipids, weight.
9. Shared risk factors mean one intervention acts on several diseases.
10. HOUSEHOLD AIR POLLUTION causes lung disease in never-smokers.
11. POPULATION STRATEGY shifts the whole distribution slightly.
12. HIGH-RISK STRATEGY finds and treats those at greatest risk.
13. MOST CASES ARISE FROM THE MODERATE-RISK MAJORITY.
14. Population measures are cheaper and more equitable.
15. They reach people who never attend a clinic.
16. Both strategies are needed together.
17. TOBACCO is the largest single preventable cause of death.
18. SMOKELESS TOBACCO IS NOT SAFE — a major cause of ORAL CANCER.
19. It is frequently not reported when you ask about "smoking".
20. PRICE and TAXATION are the most effective tobacco measures.
21. Also: smoke-free places, advertising bans, warnings, cessation support.
22. Brief advice from a clinician works — ask and advise routinely.
23. CHRONIC CARE requires a different model from episodic care.
24. Barriers: COST, DISTANCE, STOCK-OUTS, no symptoms, no records.
25. "Non-compliance" is often a household budget decision.
26. TASK-SHIFTING and PROTOCOL-BASED care extend reach.
27. Fixed-dose combinations and simple regimens help adherence.
28. A perfect prescription is worthless without reliable supply.
29. DIABETES increases TUBERCULOSIS risk — integrate services.
30. NCDs push families into poverty through out-of-pocket spending.
31. Education alone rarely changes behaviour at population scale.
32. Take all prevalence figures from the current STEPS survey.
💡 Exam angle: the two highest-yield ideas are the population-versus-high-risk comparison, and the "four by four" structure that explains why shared risk factors make prevention efficient. Both are reasoning rather than recall — and both come up in policy questions where the tempting answer is to target only the sickest.
Syllabus points
The epidemiological transition
The double burden of disease
The four major NCD groups
The four behavioural risk factors
Behavioural versus intermediate risk factors
Why shared risk factors make prevention efficient
Population versus high-risk strategy
Why most cases come from moderate risk
Tobacco control measures
Smokeless tobacco and oral cancer
Why chronic care needs a different model
Cost, distance and stock-outs
Task-shifting and protocol-based care
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