External Reference Pricing

External Reference Pricing

External reference pricing (ERP) is a policy that uses prices of the same or comparable medicine in other jurisdictions as benchmarks for a domestic price or reimbursement decision. The reference-country basket, product match, price basis, exchange rate and aggregation rule determine the resulting figure. This page shows the calculation and explains why a foreign list price is not a direct measure of local value or what a payer ultimately pays.

What is being referenced

A policymaker first identifies the product, strength, formulation, package and point in the supply chain to compare. A per-package price may need conversion to a common dose or treatment course, and taxes, wholesale margins and dispensing fees may have to be handled consistently. Countries can use ERP in different ways, including an initial price ceiling or a periodic reassessment under local rules.

Design choice	Questions to answer	Why it changes the benchmark
Reference basket	Which countries qualify and why?	A high-price or low-price basket changes the result.
Product match	Same molecule, strength, presentation and pack?	Unlike units produce misleading comparisons.
Price type	Ex-factory list, retail, reimbursement or net transaction?	Confidential rebates and margins change actual payment.
Conversion	Which exchange rate and observation date?	Currency movements can change a local-currency value.
Aggregation	Lowest, average, median or another rule?	The same basket yields different limits.
Review	How often and with what missing-price rule?	Availability and timing influence subsequent decisions.

ERP differs from internal reference pricing, which benchmarks against medicines or therapeutic alternatives within one country. It also differs from health technology assessment or value-based pricing, which considers comparative benefits, costs and other decision criteria. An ERP benchmark may be one input into negotiation rather than the final reimbursed amount.

Calculate a reproducible benchmark

Suppose a fictional authority compares an identical course of a medicine in three countries. Country A reports 100 units of its currency, converted at 0.90 home-currency units per foreign unit, giving $100\times0.90=90$ home-currency units. Countries B and C report equivalent home-currency prices of 100 and 140. The aligned basket is therefore 90, 100 and 140 per course.

Its lowest price is 90, median is 100, and unweighted arithmetic mean is $(90+100+140)/3=110$. If a fictional rule sets a domestic ceiling at 95% of the median, the ceiling is $0.95\times100=95$ home-currency units per course. This is an invented rule and does not represent a current country's policy.

Spreadsheet item	Illustrative formula	Result
Converted country A price	=100*0.90	90 home-currency units per course.
Aligned basket	90, 100, 140	Same product, unit and price basis assumed.
Lowest observed price	=MIN(90,100,140)	90.
Median observed price	=MEDIAN(90,100,140)	100.
Unweighted mean	=AVERAGE(90,100,140)	110.
Fictional ceiling	=0.95*MEDIAN(90,100,140)	95.

The exchange rate is quoted in home currency per unit of country A's currency; reversing that quote would require division instead. The equality of courses, prices before tax and currency dates is assumed only for teaching. If country C's price were absent, the authority would need a documented rule for missing observations rather than silently treat it as zero.

Why list and net prices can diverge

Publicly available list prices may not reflect confidential discounts, rebates, tender results or managed agreements. A list-price benchmark can therefore compare amounts that no payer actually pays. Transparency of a price label does not establish comparability of contracts, eligible populations or included services.

A net price in another jurisdiction may be unavailable or legally confidential, so analysts should state the observed price basis and avoid implying that the ERP calculation estimates actual savings. Domestic procurement, taxes, patient cost sharing and distribution costs also affect whether a lower benchmark changes household affordability. A published foreign price cannot be substituted directly into a local budget model without the relevant contract and volume.

Economic and access consequences

ERP can give purchasers an external anchor when pricing information is limited. Yet manufacturers and purchasers may respond to the system: timing a launch, changing public list prices or negotiating confidential terms can affect the set of observable prices. If several countries reference one another, a change in one price may propagate through later reviews, subject to each country's rules.

These possible responses are mechanisms to investigate, not guaranteed effects of a particular policy. Evaluating ERP requires a credible counterfactual and measures of net spending, medicine availability, launch timing, patient access and relevant health outcomes. A lower official ceiling may save money for one purchaser but also change supply or reimbursement terms; neither direction should be assumed without evidence.

Suppose the fictional ceiling of 95 instead of a proposed list amount of 120 were actually applied to 10,000 identical courses, with no other changes. The simple gross difference is $(120-95)\times10{,}000=250{,}000$ home-currency units. It is not an observed budget saving: net prices, uptake, mix, supply and administration may differ, and the 120 proposal is not necessarily the counterfactual transaction price.

Interpreting a cross-country comparison

The purpose is a defensible domestic decision, not a claim that every medicine should have the same price everywhere. Income, market size, procurement systems and health needs vary across countries. Rules may pursue affordability or bargaining power while creating access or distributional trade-offs that require monitoring.

• Match the product: Compare equivalent strength, pack, dose and treatment duration.
• Name the price basis: List, net, retail and reimbursement amounts have different meanings.
• Document the basket: Country selection and missing-price rules can dominate the result.
• Check currency units: An exchange rate's direction, date and variability affect conversion.
• Separate benchmark and payment: A calculated ceiling is not proof of a final net price.
• Monitor access: Price changes should be considered alongside availability, uptake and patient burden.

Sources and further reading

The WHO guideline on country pharmaceutical pricing policies discusses ERP among policy tools and distinguishes it from internal reference pricing. A WHO account of reference pricing in Georgia illustrates an actual jurisdictional application, while the European Commission simulation study examines cross-country interactions. All basket amounts, exchange rates and ceiling rules above are original teaching assumptions.