In January 2024, the Dutch National Health Care Institute (Zorginstituut Nederland) published a comprehensive update to its Guideline for Economic Evaluations in Healthcare, the first since 2016. More than just a procedural refresh, this revision marks a deliberate methodological elevation of the societal perspective and introduces new standards aligned with cutting-edge health economics research.
Our blog provides a scientific synthesis of the key updates, their rationale and how they position the Netherlands at the methodological frontier of health technology assessment (HTA).
Economic evaluation methodology is not static. Over the last decade, advances in uncertainty analysis, costing methods, trial-based statistics and spillover effects (e.g., caregiver burden) have revealed gaps in older frameworks. Furthermore, persistent misapplications, such as limited use of probabilistic models or undervaluation of informal care, necessitated clear corrective action.
The revision is underpinned by:
- Empirical research on societal preferences (e.g., de Boer et al., 2023; John et al., 2019)
- Theoretical advances in discounting and VOI modelling (Attema et al., 2018; Fenwick et al., 2020)
- Consultation with over 30 HTA stakeholders, including academic centres, pharmaceutical firms, and policy bodies
- Alignment with good practice recommendations from ISPOR and other HTA networks (ISPOR Task Forces, 2020)
Key Scientific Changes and Their Justification
1. Lower Discount Rate for Costs (3%)
The prior 4% cost discount rate assumed a 2.5% annual growth in the consumption value of health — a figure now considered overestimated. New empirical estimates suggest a more modest growth (0.6–2.9%) in Dutch willingness-to-pay (WTP) for health warranting a reduction to 3%. This aligns with best practice in intertemporal welfare economics and improves comparability with neighbouring countries.
2. Mandatory Probabilistic Analysis and VOI Modelling
Non-linear models using deterministic averages often produce biased cost-effectiveness results. The updated guideline mandates probabilistic base-case analysis and introduces VOI (Expected Value of Perfect/Partial Information) into the reference case — making the Netherlands one of the first jurisdictions to do so. VOI is essential in quantifying decision uncertainty and guiding efficient future research investment.
3. Inclusion of Informal Caregiver QoL Effects
While caregiver costs were previously included, their quality-of-life (QoL) impacts were not. New literature supports quantifying these using EQ-5D-5L and scenario-based modelling, capturing spillover effects essential to the societal perspective.
The guideline endorses the carer disutility method, though it notes limitations in current instruments for caregiver well-being.
4. Indirect Medical Costs Now in Base Case
Previously handled in scenario analysis, indirect unrelated future medical costs (e.g., treatment of comorbidities in extended survival) are now required in the base case. This corrects for asymmetry: life tables and utility estimates assume continued general health system use, so associated costs must be reflected.
5. Expert Elicitation: Clear Standards Introduced
Building on guidance from Iglesias et al. (2016), the updated guideline imposes strict reporting for expert judgement:
- Disclosure of conflicts of interest
- Separation of qualitative opinion and quantitative elicitation
- Mathematical aggregation of quantitative responses
This enhances reproducibility and mitigates bias, critical in early-phase or rare disease evaluations.
6. Trial-Based Economic Evaluations: New Statistical Guidance
Trial-based evaluations now receive tailored guidance on:
- Addressing clustering, missing data, baseline imbalances, and skewness
- Applying bootstrapping and sensitivity analyses to empirical data
- Ensuring consistency with model-based evaluations when using trial inputs
7. Updated Costing Manual with Expanded Categories
Reflecting 2022 cost data, the new manual now includes:
- Diagnostics, mental health services, drug administration
- Non-health sectors: education and justice (essential for evaluating interventions in social care, behavioural health)
This update supports more precise valuation of cross-sectoral impacts, a necessity in interventions targeting the elderly, youth, or vulnerable populations.
The Dutch guideline remains distinctive in prescribing a true societal perspective — a stance that encompasses direct and indirect healthcare costs, productivity losses (via the friction cost method), informal care and caregiver QoL and education, justice and other externalities
This contrasts with many jurisdictions (e.g., NICE, IQWiG) which primarily adopt a payer perspective, often excluding broader costs.
The guideline’s accompanying research agenda prioritises:
- Recalibration of WTP thresholds (currently €20k, €50k, €80k/QALY) — outdated since 2015
- Development of a preference-based generic well-being instrument — critical for assessing non-curative or long-term social interventions (e.g., ASCOT, ICECAP-A, EQ-HWB; Brazier et al., 2022)
These measures may eventually complement or supplement EQ-5D in areas like elder care, mental health, and public health.
The 2024 Dutch guideline reinforces the country’s reputation as a methodological leader in HTA, thanks to:
- Commitment to the full societal perspective
- Mandating VOI and probabilistic analysis
- Integration of cross-sectoral impacts
- Proactive stakeholder consultation and academic rigour
These changes not only raise the scientific bar for submissions to Zorginstituut Nederland but also provide a blueprint for international best practice, especially as HTA bodies across Europe contemplate more holistic approaches to cost-effectiveness.