World Suffering Index

Event list methodology

Experimental estimates · v0.2

How the estimates work

Each event uses a source count and one representative condition course. All numerical intensity assignments are provisional; the reasoning is visible here and in every report.

The common calculation

USU = count × average days × 24 × average intensity ÷ 47.25

Count

Use reported cases, episodes or a clearly dated population cohort. Keep the source definition and reporting window. Do not silently substitute all affected people for the population actually modeled.

Duration

Assign one average course in days to each counted case or person. Clinical duration ranges can inform a representative choice; they do not establish a measured event-specific mean.

Intensity

Use one combined score from 0 to 10: 0 means no included negative experience and 10 an extreme, overwhelming experience. The assigned score averages across people and elapsed hours, including relief and sleep.

Consistency

The same condition template applies across events. Every dengue report uses five days at intensity 3; both flood reports use 30 days at intensity 2. Pain, fear and other concurrent symptoms are represented jointly, rather than added as separate scores.

The reporting unit

What is one USU?

For event list v0.2, one USU is defined by a stipulated six-hour kidney-stone pain reference trajectory totaling 47.25 intensity-hours, equivalent to an average intensity of 7.875 over those six hours.

We use linear weighting (p = 1): doubling the assumed count, duration or intensity doubles the result. Intensity scores 2, 3 and 4 imply approximately 25%, 38% and 51% of the reference’s average hourly intensity. These are model assumptions, not observed clinical ratios.

The reference makes the scale concrete. It does not establish that different people or forms of distress are empirically equivalent. Read about the USU research framework.

Three shared condition templates

Why these durations and intensities?

Sources support symptom descriptions and, where available, typical duration windows. The exact numerical intensity is our judgment in every template.

Dengue: acute symptoms

5 days · average intensity 3 / 10

WHO describes acute symptoms lasting 2-7 days. Five days is a rounded representative choice inside that interval, not a measured mean for any listed outbreak. Later fatigue is excluded. [S2]

Fever, headache, body/joint aches and nausea support a meaningful acute symptom burden. Assigned intensity 3 is a working average across the whole day, including relief and sleep. It is lower than a severe-pain peak. WHO does not establish the value 3 or its ratio to the reference. [S2]

Excluded: Later fatigue, prolonged recovery, separate severe-case templates, caregiver distress, unreported infections and post-death loss.

Flood displacement: initial distress

30 days · average intensity 2 / 10

We assign the same 30-day initial course to each reported flood-displaced person. Continuing displacement in Brazil in June 2024 and difficult conditions in Pakistan in October 2022 support a multiweek scenario. Neither source measures a 30-day cohort mean; keeping the same course is a consistency choice, not evidence that recovery takes equally long. [S6] [S10]

WHO describes anxiety, sadness, sleep problems and other distress after emergencies. Assigned intensity 2 represents a modest whole-day average across the selected cohort, including relief and people with little distress. This provisional mapping to the pain reference is especially weak; WHO supplies no numeric conversion. [S7]

Excluded: Injury and disease episodes, bereavement, later mental-health effects, distress outside the selected cohort and post-death loss.

Chikungunya: acute symptoms

8 days · average intensity 4 / 10

CDC describes acute symptoms typically resolving within 7-10 days. Eight days is a rounded representative choice inside that interval, not the observed mean for this outbreak. Persistent joint symptoms are excluded. [S4]

CDC describes potentially severe, debilitating joint symptoms; Paraguay's adult suspected-case definition included incapacitating joint pain or arthritis. These support testing a higher average than dengue. Assigned intensity 4, and the 4:3 ratio, remain model judgments rather than measured equivalence. [S3] [S4]

Excluded: Persistent/recurrent joint pain, rare complications as separate profiles, caregiver distress, unreported infections and post-death loss.

How to read and compare entries

Compare the included experience

Every headline is cumulative USU for its stated cases or cohort under the common formula. Counts, reporting periods and omitted consequences differ. The table orders model outputs; it is not a comprehensive ranking of the world’s events.

A reporting period is not an assumed course

A case can be reported within a window while its modeled course extends beyond it. The flood entries assign a 30-day course to their respective reported populations; neither represents 30 days of observed follow-up or a calendar-year total.

Keep deaths and missing values visible

Deaths remain separate from USU, with their source population and date. A broader event death count may accompany a narrower modeled cohort. Missing data are shown as unavailable, not zero.

Do not sum the rows

Populations and time can overlap, including Brazil’s dengue outbreak and the Rio Grande do Sul floods. No overlap adjustment is applied. Excluded suffering is unestimated; the totals are not guaranteed lower bounds.

Uncertainty and alternative assumptions

Source counts can miss or misclassify cases, and reporting practices differ across settings. Assumed duration and intensity can be substantially wrong. Multiplying averages simplifies individual variation and associations between duration and severity.

Each report includes two simple alternative duration/intensity scenarios. These are not confidence intervals or a complete uncertainty analysis. Some event orderings reverse under these alternatives.

No causal baseline is fitted. Individual symptom trajectories and fatal-case truncation are not reconstructed. The figures describe assigned event-related experiences, not causally identified excess burden.

A versioned starting point

Event list v0.2 adds Pakistan floods, Bangladesh dengue and Mexico dengue to the four entries in v0.1. Duration, intensity and the reference unit are unchanged. The displacement duration explanation now covers both flood contexts. This calculation series remains separate from the earlier USU research pilots and the manuscript’s more detailed simulations. Existing pilot values retain their original definitions.

A condition-template revision applies to all linked event list events. Material changes receive a new method or data version and a visible note. Source counts and original definitions stay available with each release.

All inputs & assumptionsCalculated event list CSVResearch background

Sources for the event list

Event list method v0.2 · Prepared 5 October 2026