ASSET-HE-EE-CI-002-001 · Version 1.1.0

Cost-of-Illness Study Design Map

Choose the burden question, perspective, epidemiological approach and estimation route, then audit what the study can legitimately claim.

Burden ≠ savings. Estimated economic burden is not automatically avoidable expenditure, recoverable savings, cost-effectiveness or priority. A cost-of-illness study describes burden; it does not by itself establish the value of an intervention.

1. Define the study purpose

Primary purpose Perspective Condition / health problem Population and geography Currency / price year Observation period / horizon

2. Choose the epidemiological and costing design

Epidemiological approach Cost-estimation approach Attribution method Affected cases / persons

Do not mix prevalence- and incidence-based quantities in the same total unless the reconciliation is explicit and methodologically justified.

3. Set the cost boundary

Direct healthcare costs Direct non-healthcare costs Productivity losses Informal-care costs

Mean attributable cost per affected person Uncertainty scenario (%)

4. Design integrity checks

Condition, population, geography and period are explicit. Included cost categories match the stated perspective. Cost categories are mutually exclusive; missing values are not treated as zero. Attribution separates condition-related/excess costs from unrelated use. Population scaling and denominators are documented and reconciled. Uncertainty in quantities, unit values and attribution is examined.

5. Study design output

Select Build design to generate the audit summary.

Interpretation safeguards

A descriptive burden estimate does not establish that all observed costs are caused by the condition.
Attributable/excess-cost studies require a defensible counterfactual or attribution method.
Prevalence-based studies describe costs occurring in a period; incidence-based studies follow costs associated with new cases over a defined course.
Perspective determines which costs belong in the study; excluded or shifted costs should be disclosed.
Productivity and informal-care valuation require explicit methods and can overlap with other categories if boundaries are poorly defined.
Large burden does not imply equivalent savings are achievable through prevention or treatment.
COI results do not establish cost-effectiveness, affordability, equity or priority.