Mapping global availability of WHO Essential Medicines List drugs across country income tiers, procurement systems, and facility types
Since 1977, the WHO Model List of Essential Medicines has defined the minimum set of drugs a functioning health system needs to satisfy the priority healthcare needs of its population. The 23rd Model List (2023) contains roughly 500 medicines, selected biennially by an independent Expert Committee using an explicit, evidence-based procedure rather than commercial or political criteria.
Every application to add or remove a medicine from the Model List is scored against three explicit pillars:
• Public health relevance — is the target condition a significant cause of morbidity or mortality, and does treating it materially change population health outcomes? • Comparative efficacy and safety evidence — the application must present systematic review-grade evidence (ideally Cochrane-standard) showing the medicine performs as well as or better than existing alternatives already on the list, with an acceptable adverse-event profile. • Comparative cost-effectiveness — the incremental cost per outcome gained is weighed against alternatives; a medicine need not be the cheapest, but its cost must be justified by its incremental benefit in typical low-resource settings.
Applications are submitted by academic groups, WHO technical programs, NGOs and occasionally manufacturers, then reviewed publicly with a comment period before the Expert Committee meets. Committee membership is deliberately independent of industry funding, and members must declare conflicts of interest before deliberation.
The WHO Model List is explicitly a template, not a mandate. Each country is expected to adapt it into a National Essential Medicines List that reflects local disease burden, treatment protocols, and what the national formulary and insurance schemes can realistically finance and distribute.
A straight copy of the WHO list is rarely appropriate: disease burden varies enormously by region (e.g., visceral leishmaniasis medicines matter in East Africa and South Asia but not in most high-income NEMLs), and national manufacturing or import capacity constrains what can realistically be stocked.
Most NEMLs are also linked directly to reimbursement — national health insurance schemes and public hospital formularies typically only pay for or stock NEML-listed products, which makes the adaptation process a de facto rationing decision. Countries with strong pharmaceutical regulatory authorities (e.g., South Africa's SAHPRA, India's CDSCO) tend to update their NEML close to the WHO's two-year cycle; many lower-capacity ministries of health revise theirs only every 4–6 years, meaning newer WHO-listed medicines — including some cancer therapies and newer antiretrovirals added in the 2020s — take years to reach national formularies.
Health Action International and WHO jointly developed a standardized survey methodology in 2003, now used in more than 50 countries, to make medicine pricing and availability comparable across health systems by measuring a common basket of medicines against a shared reference price.
Surveyors visit a stratified sample of public facilities, private retail pharmacies, and (where relevant) mission/NGO outlets across urban and rural areas, recording the price of a standard basket of roughly 30–50 medicines spanning acute and chronic conditions.
Each observed unit price is divided by the corresponding Management Sciences for Health international reference price (drawn from competitive tenders and non-profit supplier catalogs) to produce a price ratio per medicine per outlet; the median across all sampled outlets of a given sector is the Median Price Ratio (MPR).
An MPR of 1.0 means the local price matches the international reference; MPRs of 2–6 are common for originator brand products in the private sector of low- and middle-income countries, while generic equivalents typically cluster around 1–2. This gap — not availability alone — is often the single largest driver of unaffordability for patients paying out of pocket.
Because roughly 50–90% of medicine spending in low-income countries is out-of-pocket, an MPR of 4× on an originator antihypertensive can push a month's treatment beyond a full day's wage — even when the medicine is technically "available" on the pharmacy shelf.
Availability is measured separately from price: a surveyor simply records whether a specific essential medicine is physically present and in-date at the point of care on the day of the visit. The public/private split in this metric is one of the most consistent findings across two decades of WHO/HAI surveys.
Public facility stockouts are driven less by list design than by supply-chain and financing failures: forecasting errors, delayed tendering, currency shocks affecting import costs, weak last-mile cold-chain logistics, and periodic stock-outs of specific manufacturers even when the medicine itself is not in short global supply.
The private sector, in contrast, is stocked by profit-motivated retailers who can source flexibly and pass costs to the patient, so availability is consistently higher but at the price ratios documented in the pricing survey stage. The net effect is a two-tier access system within the same country: patients wealthy enough to pay private prices get near-certain access, while those depending on public facilities face a coin-flip on any given clinic visit — a pattern documented repeatedly across sub-Saharan Africa, South Asia, and parts of Latin America.
Layering the pricing and availability data by WHO region produces a clear gradient: the WHO African Region and parts of the South-East Asia Region consistently report the lowest public-sector availability and the highest relative prices, while the European and Western Pacific high-income clusters approach near-universal coverage.
The gap is not simply "poor countries have less" — it compounds across the entire pipeline covered by the earlier stages. A low-income country may have a well-designed NEML on paper, but weak procurement financing means tenders go unfilled; weak logistics mean even successfully procured stock does not reach rural clinics; and high private MPRs mean patients who face a public stockout often cannot afford the private alternative.
Insulin is a frequently cited case: although insulin has been on the WHO EML since 1977, WHO surveys have repeatedly found that roughly half of people with type 1 diabetes in low-income countries lack reliable year-round access, and where available, prices can consume a substantial share of household income. Essential antibiotics for childhood pneumonia and sepsis show similar patterns, with pediatric-appropriate formulations (dispersible tablets, pediatric suspensions) stocked even less reliably than adult formulations of the same drug.
WHO's headline estimate — roughly 2 billion people, about 1 in 3 globally — lack reliable access to essential medicines is not evenly distributed poverty; it is concentrated in exactly the regions where this gap analysis shows compounding failures across selection, financing, procurement, and last-mile logistics.
Armed with granular gap data, health ministries and international partners can target interventions at the specific failure point rather than the system as a whole — pooling demand to negotiate lower prices, mandating generic substitution at the pharmacy counter, and channeling scarce financing toward the lowest-coverage tiles first.
Pooled procurement mechanisms — the PAHO Strategic Fund, the Global Fund's Pooled Procurement Mechanism, and UNICEF Supply Division — aggregate national demand across dozens of countries into single large tenders, giving even small low-income buyers the negotiating leverage of a single very large purchaser and driving unit prices toward the manufacturing cost floor.
Price negotiation frameworks pair this leverage with transparency: publishing achieved tender prices lets other countries benchmark their own procurement and avoid overpaying relative to peers of similar income tier.
Generic substitution policy — allowing or requiring pharmacists to dispense a WHO-prequalified generic in place of a prescribed originator brand — is often the single fastest lever available to a health ministry, typically cutting retail prices 40–60% without waiting for a new procurement cycle, provided a prequalified generic supplier already exists for that molecule. Together, these three levers are what move a red critical-gap tile toward teal high-coverage status over a period of a few budget cycles rather than decades.