MAGENT

Katz index of activities of daily living (ADL)

The Katz index of activities of daily living (ADL) looks at six basic self-care activities: bathing, dressing, toileting, transferring, continence and feeding. In the form used here, each activity done independently counts 1 and each dependent activity counts 0, so the count runs from 0 to 6. Magent's calculator adds the six yes/no answers you supply and returns that count, based on Katz's index.

Not a medical device. Not a diagnosis or dosing recommendation.

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What is the Katz index?

Katz and colleagues described the index in 1963 while studying older and chronically ill people. They noticed that people tend to lose and regain basic self-care activities in a fairly consistent order, and they built the index around six of them.

The 1963 paper sorted people into letter grades, A to G, according to which activities they could do alone. The 0 to 6 count that most people now call the Katz score is a later convention: it simply counts the independent activities. Magent's calculator uses that count and doesn't assign the letter grades.

Independent here means doing the activity without supervision, direction or personal help from another person.

The Katz index count

Katz count = bathing + dressing + toileting
           + transferring + continence + feeding

each activity: 1 if independent, 0 if dependent
count 0 to 6

Exact expression the calculator uses:

Katz Index of ADL = bathing_independent + dressing_independent + toileting_independent + transferring_independent + continence_independent + feeding_independent; each 1 if independent; max 6 (Katz 1963)

Inputs

InputIndependent means, in brief
bathing_independentWashes by sponge, shower or tub without another person's help
dressing_independentFetches clothes and puts them on; help with shoelaces alone doesn't count against this
toileting_independentGets to the toilet, on and off, sorts out clothing and cleans up
transferring_independentGets in and out of bed and a chair; leaning on something for support is fine
continence_independentFully controls bladder and bowels
feeding_independentGets food from plate to mouth; someone else cutting up meat beforehand is fine

These are short paraphrases. Each input is true (independent) or false (dependent), and you decide which. The calculator doesn't observe anyone.

How the calculation works

  1. Judge each activity. Decide whether the person does it without another person's supervision or help.
  2. Count. Each independent activity adds 1.
  3. Report. The result is a number from 0 (dependent in all six) to 6 (independent in all six).

The calculator returns the count and the six components. It doesn't add bands or labels, because later sources group the count in different ways.

Worked examples

These use Magent's own expected values for the calculator.

Example 1: dependent in all six

  1. Every activity false.
  2. Count 0 out of 6.

Example 2: independent in bathing alone

  1. Bathing true, the other five false.
  2. Count 1.

Example 3: independent in three activities

  1. Bathing, dressing and toileting true; transferring, continence and feeding false.
  2. Count 3.

Example 4: independent in all six

  1. Every activity true.
  2. Count 6.

History of the Katz index

Katz S, Ford AB, Moskowitz RW, Jackson BA and Jaffe MW published the index in JAMA in 1963, in "Studies of illness in the aged. The index of ADL: a standardized measure of biological and psychosocial function". Their letter grades reflected the order in which activities were lost. Later forms turned the six activities into yes/no items and counted them, which is the version this calculator follows.

When it's used

The count is recorded when staff want a quick, repeatable description of basic self-care, for example on admission, before discharge or at follow-up.

Where it's used

Geriatric wards, rehabilitation units, nursing homes and home care.

Who uses it

Nurses, geriatricians, occupational therapists and care staff. The calculator adds the six answers.

Limits of the calculation

  • It covers six basic activities. It doesn't cover cooking, shopping, managing money or other instrumental activities.
  • Each activity is a yes/no, so it can miss partial changes.
  • The count isn't Katz's original letter grade.
  • It doesn't decide on care level, placement or a rehabilitation plan.
  • This page doesn't say what a result means for a particular person.

Clinical decisions belong to a qualified clinician who knows the patient.

  • Modified Rankin grades overall disability after stroke on a single scale.
  • Braden scores pressure injury risk, which partly reflects mobility and activity.
  • The Barthel Index is a separate 0 to 100 score with more items and graded points; it isn't the same as this count.

Glossary

  • ADL: activities of daily living, the basic tasks of self-care.
  • Independent: done without supervision, direction or personal help from another person.
  • Transferring: moving between bed and chair.
  • Instrumental activities: more complex tasks such as cooking or shopping, not covered here.

Common mistakes

  • Counting supervision as independent. Needing someone to watch or prompt counts as dependent.
  • Calling the count Katz's 1963 score. The 1963 paper used letter grades; the count is a later form.
  • Adding bands. Later sources group the count differently, and the calculator applies none.
  • Mixing it up with the Barthel Index. They're different scores.

Source

Katz S, et al. Studies of illness in the aged. The index of ADL: a standardized measure of biological and psychosocial function. JAMA. 1963;185(12):914-919. DOI: 10.1001/jama.1963.03060120024016. PMID: 14044222

Frequently asked questions

What are the six Katz activities?

Bathing, dressing, toileting, transferring, continence and feeding.

What is the highest Katz count?

6, meaning independent in all six activities.

Did Katz's 1963 paper use a 0 to 6 score?

No. The 1963 paper used letter grades A to G. The 0 to 6 count of independent activities is a later way of scoring the same six activities, and it's what this calculator returns.

Does using a walking aid make someone dependent?

Not for transferring: leaning on an object for support still counts as independent. Help from another person counts as dependent.

Is the Katz index the same as the Barthel Index?

No. The Barthel Index is a separate 0 to 100 score.