Aida van Riel

I build health economic models that turn clinical evidence into decisions people can explain.

from trial data to decision model, one assumption at a time

Aida van Riel is a health economist based in Rotterdam, the Netherlands. She holds an MSc in Health Economics from Erasmus University Rotterdam, graduated cum laude, and builds cost-effectiveness, budget-impact and pricing models that turn clinical evidence into decisions people can explain.

Illustrated watercolour portrait of Aida van Riel, smiling, in a soft pink and cream palette
graduated cum laude
MSc Health Economics · Erasmus University Rotterdam

Why this work

01 / Why this work

Health economics lives between what we want to provide and what we can provide. Every model simplifies, every threshold reflects a choice, and every decision affects real people.I wanted to understand those choices well enough to question them. So I became a health economist.

good models answer questions. good economists question the answers.
02 / How I think

Four questions I ask before I trust the number.

A model can produce an answer. The interesting part is understanding what had to be true for that answer to hold.

01

What are we giving up?

A treatment can improve health and still not be the best use of a fixed budget.

Cost-effectiveness is not only about what a treatment adds. It is also about the health that could have been produced elsewhere with the same resources. That opportunity cost is what turns an ICER from a calculation into a decision.

QALYs · ICERs · opportunity cost · net monetary benefit
02

Which assumption is doing the work?

The base-case result is only the beginning.

A model can look precise while depending heavily on a handful of uncertain inputs or structural choices. I care less about whether the ICER is €31,842 than whether the conclusion survives plausible changes to the assumptions underneath it.

Deterministic sensitivity analysis · PSA · scenario analysis · structural uncertainty
03

What happens when the data stop?

Trial follow-up ends. The decision horizon usually does not.

Long-term outcomes often have to be extrapolated beyond the observed data. The choice of survival distribution, treatment-effect assumption, or time horizon can matter more than another decimal place in the observed estimate.

Survival extrapolation · partitioned survival · time horizons · treatment effect
04

Are we talking about value, price, or affordability?

They sound similar. They answer different questions.

A medicine can be cost-effective at a given price and still create an unaffordable budget impact at scale. It can also have a high list price without that price telling us much about its production cost. Value, price, and affordability belong in the same conversation, but they are not interchangeable.

Value based pricing · budget impact · affordability · access
Value
What is the health gain worth?

Value asks whether the benefits a medicine produces justify the resources used to provide it. In cost-effectiveness analysis, that often means comparing additional costs with additional QALYs and a reference threshold.

Price
What are we actually being asked to pay?

Price is the amount charged for the medicine. It may be a list price or a confidential net price, and it is not the same thing as either the medicine’s production cost or its value.

Affordability
Can the health system absorb the total bill?

Affordability asks what happens when the price is multiplied across everyone who may receive the treatment. Even a cost-effective medicine can create a budget impact that is difficult to absorb at scale.

a medicine can offer good value, have a high price, and still be unaffordable. all three can be true at once.
03 / Selected work

Six projects I worked on

01 / 06
Cost utility analysis · Access pricing

What should a new breast cancer therapy cost?

A new therapy entered the Dutch market at €13,695 per cycle. I built a partitioned survival model, a five-year budget impact model, and a cost-based access price using the ASCERTAIN framework, to test whether that price could be justified.

€1.11M per QALY gained≈14× the €80k reference threshold
4 files inside
ICER, cost per QALY gained
At the asking price, the ICER is approximately €1.11M per QALY, around fourteen times the €80k reference threshold. Reaching the threshold would therefore require a fundamentally different pricing arrangement, not a marginal discount.
Markov modelling · Survival extrapolation

Does the survival gain justify the additional cost?

A 20-year cohort Markov model built from trial data, with survival extrapolation and probabilistic uncertainty analysis.

20y simulated cycle by cycle
2 files inside
Markov state transitions
Progression-freestate 1
transition probability
Progressedstate 2
transition probability
Deathabsorbing
Cycle length 3 weeks20-year horizon
Costs and QALYs accumulate as the cohort moves between states. Probabilistic analysis and acceptability curves show how uncertainty shifts the decision across Dutch thresholds.
Market access · Global health financing

How do you build access when the market won’t?

A four-part access strategy for a medicine with strong public-health value but weak commercial incentives.

4 complementary access levers
1 file inside
Four levers, one access strategy
  1. 01
    Product-development partnerships
  2. 02
    Venture-philanthropy financing
  3. 03
    Tiered pricing & market access
  4. 04
    Regulatory pathway & risk mitigation
Four levers made the cut. The alternatives had to lose on evidence, not instinct: cost, timing, feasibility and implementation risk.
Funding strategy · Partnering

How do you finance the path to approval?

A first-in-class gene therapy faced $73M in development costs and a $30–50M funding gap. I built a financing strategy around sequencing partnership capital before an equity raise.

$73M estimated capital to approval
1 file inside
Sequencing capital around value creation
Capital required to approval$73M
Estimated funding gap$30 to 50M
Partnership firstupfront + milestones
Partnership capital first, equity raise later, after a potential value inflection. No immediate equity dilution, at the cost of sharing future economics.
Causal inference · Difference-in-differences · Heterogeneity

What happens at home when a migrant spouse leaves, or returns?

The 2008 crisis unexpectedly sent migrant workers home. I used that shock to study what changed for the spouses they returned to.

−1.39 points of mental distressfor wives when a migrant spouse returns
2 files inside
Effect on mental distress
Spouse returns
Spouse returns: effect on mental distress Change in mental distress when a migrant spouse returns: −0.87 overall (p = 0.163), +1.55 for men (p = 0.163), −1.39 for women (p = 0.012).
−0.87
overall
p = 0.163
+1.55
men
p = 0.163
−1.39
women
p = 0.012**
Spouse departs
Spouse departs: effect on mental distress Change in mental distress when a migrant spouse departs: −0.05 overall (p = 0.941), −1.95 for men (p = 0.088), +0.97 for women (p = 0.035).
−0.05
overall
p = 0.941
−1.95
men
p = 0.088
+0.97
women
p = 0.035**
Women show the clearest pattern: distress falls when a spouse returns, rises when one departs. The male estimates are less precisely estimated, not smaller.
Health financing reform · Equity

Why didn’t more insurance mean less out-of-pocket spending?

Coverage expanded rapidly. Financial protection did not. I looked at how targeting, benefit design and implementation pulled the two apart.

47% of enrolled households were not pooreligibility ran on an outdated poverty list
1 file inside
Coverage is not the same as protection
₹30,000
annual cap per household
hospital only
outpatient care and medicines excluded
2002 list
poverty census used to decide eligibility
no detectable fall
in out-of-pocket spending
The scheme expanded coverage, but weak targeting and a narrow benefit package limited how much financial risk it actually removed from households.
01 Cost utility analysis
Access pricing · Budget impact

What should a new breast cancer therapy cost?

A new therapy entered the Dutch market at €13,695 per cycle. I built a partitioned survival model, a five-year budget impact model, and a cost-based access price using the ASCERTAIN framework, to test whether that price could be justified.

ICER, cost per QALY gained
At the asking price, the ICER is approximately €1.11M per QALY, around fourteen times the €80k reference threshold. Reaching the threshold would therefore require a fundamentally different pricing arrangement, not a marginal discount.

A PI3Kα inhibitor entered the Dutch market at €13,695 per 28-day cycle. I built a cost-effectiveness evaluation using a partitioned survival model over a 20-year horizon from the societal perspective, alongside a budget-impact and pricing analysis.

At the asking price the treatment gained 0.394 QALYs at an incremental cost of €437,407: an ICER of roughly €1.11 million per QALY, far above the €80,000 reference threshold. Reimbursement at list price would add about €105 million to the Dutch drug budget over five years.

I then derived two alternative prices: a value-based threshold price, and a cost-based access price using the ASCERTAIN framework. Rather than treat the result as accept-or-reject, I explored what pricing conditions could make access defensible.

“Very impressive across the board: well written, with a very impressive methodology and an excellent description of the results.”

Assessor
04 / My project, in one interaction

How far would the price have to fall?

A new breast cancer medicine arrived in the Netherlands asking €13,695 for every 28 day cycle. My project asks what happens when the price a health system can justify and the price a manufacturer can justify are nowhere near each other.

before we start: the same medicine has three defensible prices, built from completely different logic

The asking price €13,695 What the manufacturer asks per cycle. A starting position, not a judgement about worth. the only one up for negotiation, so this is the one you will be changing
The access price €6,800 Built up from what it costs to research, make and supply, plus a defensible return. The manufacturer’s side of the argument. Fixed.
The value-based price €516 The most a payer could pay while still buying health at the €80,000 per QALY threshold. The health system’s side. Fixed.
drag the butterfly slider to lower the asking price
Price per cycle
€13,695
ICER, cost per QALY gained
€1,109,246
€516highest cost-effective price everything else stays fixed €13,695
Cost-effectiveness plane Extra cost per patient on the vertical axis against incremental QALYs gained on the horizontal axis. A dashed diagonal marks the €80,000 per QALY reference threshold: points below it are cost-effective. The dot shows the treatment at the selected price per cycle. cost-effective below this line above the cost-effectiveness threshold Extra cost per patient Incremental QALYs gained
ICER at each of the three prices per cycle
PricePrice per cycleICER, cost per QALY gained
The asking price€13,695€1,109,246
The access price€6,800€570,549
The value-based price€516€79,589
Still 13.9× the €80,000 reference threshold used in the analysis. The treatment reaches that threshold at approximately €516 per cycle. Keep dragging.

Four steps to the real question

01

Find the price consistent with cost effectiveness

Holding everything else in the model constant, the treatment reaches the €80,000 per QALY reference threshold at approximately €516 per cycle. That is about 96 percent below the original asking price of €13,695.

02

Price it from the other direction

I then used the ASCERTAIN framework to estimate a price based on research, manufacturing and supply costs, plus an allowable return. This produced a very different figure of approximately €6,800 per cycle.

03

The two prices are still far apart

€6,800 is the cost based access price from Step 02. It is estimated from research, manufacturing and supply costs, plus an allowable return.

But at €6,800 per cycle, the treatment is still above the cost effectiveness threshold. To reach that threshold, the price would need to be around €516 per cycle.

So the two approaches give very different answers:

  • €516 based on cost effectiveness
  • €6,800 based on the cost based pricing approach

That gap is the key finding.

04

So the conversation has to move beyond price

A simple discount may not be enough to close a gap this large. A managed entry agreement could instead bring price, spending and uncertainty into the same negotiation. That might mean a confidential net price, a limit on total spending, or payments linked to how the treatment performs.

The model does not decide which agreement is right. It shows why a different kind of agreement may be needed.

when two defensible prices are this far apart, the problem is no longer just the price.
05 / What others noticed

Two peo ple who checked the work

I can show you what I built. They can tell you how I worked.

“Her independence in conducting the research was highly positive, as was her attention to detail.”

In his words

No fundamental corrections to her research approach were necessary, and her attention to detail during data collection was highly positive.

She also applied a newly developed pricing model for which there is so far no reference in the literature. Where assumptions were needed, she made them explicit and justified them well.

I am more than happy to recommend her for positions in market access and health economics and outcomes research.

Portrait photo of Nicolas Xander
Nicolas Xander
Health Technology Assessment, Erasmus School of Health Policy and Management
Read the letter ↗

“Very impressive across the board.”

In his words

Well written, with a very impressive methodology and an excellent description of the results.

The methodology combined a cost effectiveness analysis, sensitivity analyses, an access based pricing model and a budget impact analysis. Many do just one or two of these, which makes her work all the more impressive.

It was clear that she was really on top of the literature, and took ownership of every part of it.

Portrait photo of Professor Hans van Kippersluis
Prof. dr. Hans van Kippersluis
Professor of Applied Economics, Head of Health Economics, Erasmus School of Economics
Read the letter ↗
06 / Where it comes from

Two countries, one question

Why does care reach some people and not others? I grew up seeing that question from two very different sides.

Ethiopia ኢትዮጵያ
my mother's side

Where I first understood why access matters.

I grew up knowing that healthcare can exist and still be out of reach, because of distance, cost, capacity, or what a family has to give up to get it.

Those trade-offs were real to people I knew long before I had words like access, affordability or financial protection for them.

That is where the question came from.

The Netherlands Nederland
my father's side

Where I learned how to examine the choices behind access.

In the Netherlands I encountered a health system that makes many of those choices unusually visible: evidence requirements, cost-effectiveness, severity, reimbursement and the limits of a finite budget.

Health economics gave me a way to take questions I already cared about and make them testable: to model the trade-offs, challenge the assumptions and ask whether resources could be used better.

That is where the question became a method.

07 / Keeping current

Four conversations I’m following

A running list of the questions, methods and shifts in HEOR I want to understand before they become standard practice.

tap one to see what it was about
ISPOR member

Rare disease forces an evidence problem: tiny populations, incomplete data and trials that may never look conventional. I was interested in where AI can genuinely strengthen real-world evidence, and where regulators will still need to see the reasoning behind the model.

A useful horizon scan of where HEOR is heading: changing evidence standards, new methods and the questions likely to shape reimbursement over the next few years. I keep this one as a map of what I should be learning next.

Senior HEOR practitioners on the skills they wish they had built earlier, and where technical competence stops being enough. I liked this one because it was aimed almost exactly at the stage I am in now.

The investor side of evidence generation: what has to be demonstrated before capital follows, and how reimbursement expectations can shape which technologies are investable long before they ever reach a patient.

sometimes keeping current means showing up.
Aida van Riel talking with other attendees at an ISPOR conference session
meeting people
Aida van Riel listening to a presentation at an ISPOR session
learning something new
08 / Off the clock

Other things that have my attention

Watercolour doodle of hiking boots and a mountain trail

Hiking

Give me a mountain, decent weather and a long trail and I’m happy. A good view at the end definitely helps.

Watercolour doodle of a green leafy plant

Nature

I just really like being outside. Parks, forests, beaches, long walks. I’m happiest when there’s something green around me.

Watercolour doodle of a dog

Animals

I’m the person who gets distracted by every animal I see. I love all of them, but dogs are definitely my biggest weakness.

Watercolour doodle of headphones and music notes

Music

My taste is genuinely all over the place. I’ve been told I have the music taste of an old woman, and when I find a song I love, old or new, I’ll play it on repeat for days.

Watercolour doodle of a snorkel mask and tropical fish

Snorkelling

Put me in warm water with a mask and I can disappear for hours. I somehow never get bored of seeing what’s underneath.

Watercolour doodle of a scuba diver

Diving

Still pretty new to this one. I got certified off the Perhentian Islands and immediately started thinking about where I could dive next.

Watercolour doodle of a laptop with a video timeline

Video editing

I started by editing the things I film while travelling to share with family and friends. Now I also make LinkedIn videos, product reviews and creator content for YouTube.

send me the clips, I’ll do the rest :)
Portrait photo of Julien from Soilytix
On the editing work
“I didn’t explain a lot, and she understood it pretty accurately. That’s pretty cool to see.”
Julien · Soilytix
09 / Contact

Looking for the next hard question.

I like problems that do not come with an obvious answer, and I am always interested in learning something new. My background is in health economics, but I am open to interesting work well beyond it. A thoughtful project, an ambitious company, a problem that needs figuring out, or simply a team doing something I have never done before can all get my attention.I learn quickly, work independently and genuinely enjoy getting into unfamiliar territory. If you are building something interesting and think I could add something to it, write to me.

Download CV
Aida van Riel Playing: Tezeta (Nostalgia) by Mulatu Astatke
2026