WHODAS 2.0 12-item: functioning and disability assessment

What this assessment is

The 12-item WHO Disability Assessment Schedule 2.0, or WHODAS 2.0 12-item, is a brief measure of difficulty with everyday functioning.

It samples six areas of life and produces an overall disability score. It is designed to work across health conditions rather than for one diagnosis.

The short form has 12 items. It is not the 36-item WHODAS 2.0, which provides more detailed domain scores.

Version always matters.

WHODAS describes functioning during the past 30 days. It does not diagnose a medical or mental health condition.

Environments can disable.

Who it was designed for

The World Health Organization developed WHODAS 2.0 for adults with or without health conditions. Its framework is linked to the International Classification of Functioning, Disability and Health.

The international development study involved people from multiple countries, languages, cultures, and health settings. That broad testing supports cross-condition use, although every translation and population still needs appropriate validation.

The 12-item form can be self-administered, completed in an interview, or answered by a proxy who knows the person well.

The respondent type matters. A proxy's view may differ from the person's own experience, so the two should not be treated as interchangeable without noting who answered.

Respondent type matters.

How it is administered

The form asks how much difficulty the person had during the past 30 days because of health conditions.

It usually takes about five minutes. The standard response scale has five levels, from no difficulty to extreme difficulty or inability.

Current WHO scoring templates code those levels from 0 to 4. Some older manuals and datasets use 1 to 5 coding. The two conventions produce different raw ranges and must not be mixed.

Do not combine them.

Use the same form, respondent type, coding convention, and language when comparing results over time.

What it measures

The 12 items sample six areas of functioning:

• cognition, including understanding and communication
• mobility
• self-care
• getting along with other people
• life activities, including household and work roles
• participation in society

The short form includes two items from each area. Its main result is an overall functioning score.

Two items are not enough to provide the same domain detail as the 36-item form. Do not treat the short form as six complete two-item diagnostic subscales.

How scoring works

WHODAS 2.0 supports simple and complex scoring.

With current 0-to-4 response coding, simple scoring adds the 12 ratings. The total ranges from 0 to 48. A higher total indicates greater reported difficulty with functioning.

Complex scoring uses item-response-theory weights and converts the result to a 0-to-100 scale. Zero indicates no reported disability and 100 indicates the greatest disability represented by the scoring model.

The simple 0-to-48 total and complex 0-to-100 score are not interchangeable. A service should label the method and keep it consistent.

Name the method.

Methods must match.

Older 1-to-5 coding produces a raw sum from 12 to 60 before any transformation. Do not compare that number directly with a current 0-to-48 simple score.

Follow the official WHO WHODAS guidance for the chosen form and scoring method, including missing responses.

How to interpret a WHODAS 12-item score

A higher score indicates greater difficulty with everyday functioning during the past 30 days.

The result is global. It can show that functioning is affected, but the short form provides limited information about exactly where or why.

There are no universal WHODAS 12-item cutoffs that diagnose mild, moderate, or severe disability across all conditions and populations. Percentiles, averages, or thresholds from one study should be labeled with their population and purpose.

Context always matters.

For repeated assessment, use the same coding and scoring method. A decrease can suggest improved functioning, but the amount of change that matters depends on the condition, setting, and purpose.

Scores can diverge.

Review individual responses when a specific area needs attention. A global total can hide a serious problem in one domain.

What the score cannot tell you

WHODAS cannot identify the condition that caused a functional difficulty.

It cannot distinguish physical, mental, cognitive, environmental, or social causes on its own. It also cannot determine eligibility for benefits or services without the rules of the relevant program.

A low total does not rule out a major problem in one part of life. A high total does not show that difficulty is permanent.

The result cannot replace a diagnosis, examination, occupational assessment, or conversation about the person's goals and environment.

Evidence and limitations

WHODAS 2.0 was developed through international field studies and has been evaluated across many conditions. Its condition-neutral design makes it useful when several health problems affect functioning together.

The 12-item form reduces burden but loses detail. It is best suited to a brief overall view. The 36-item form is more appropriate when reliable domain-level information is needed.

Self-report can be affected by expectations, mood, support, accommodations, and the environment. Proxy reports add another perspective but may not match the person's own ratings.

Functioning is contextual.

Support changes function.

Scoring conventions are a practical source of error. Always report the form, coding direction, scoring method, respondent, and recall period beside the result.