The key to long-term care is functioning. Therefore, long-term care authorities have given considerable attention to defining and measuring minimal components of independent functioning.
There are four disability models traditionally used to measure ones inability to function independently in society. They are the Social Model (IADL’s), the Physical Model (ADL’s), the Mental Model (Cognitive Impairment), and the Medical Model (Injury or Sickness or medically necessary).
They are addressed in the order that one may traditionally lose them as they age (i.e. frailty).
There are many functions within the four models mentioned above that are important to independence, and indeed these functions seem to multiply and become more complex in modern urban societies.
These measures are designed to assess a broader range of functioning than ADLs by examining activities that require a greater degree of skill, judgment, and independence.
Because of this, people tend to have more difficulty performing IADLs than they do ADLs. And the vast majority of people having difficulty with ADLs also have difficulty with their IADLs.
There are more IADLs than ADLs and there is greater variation in which IADLs are included across assessment instruments.
Some of the IADLs assessed in the literature include the following:
- Shopping for personal items;
- Managing money;
- Using the telephone;
- Meal preparation;
- Medication management;
- Doing housework
IADLs provide important measures of need for support/assistance to live independently, but they cannot be as objectively measured as ADLs.
IADLs encompass both cognitive and physical function, but they also can include cultural/social biases.
In the natural progression of aging, IADLs become more difficult and are a traditional indicator of an early onset of a Physical (ADL) loss and/or Mental (cognitive impairment) loss.