Bottom Line:
ADLs (activities of daily living) are the basic necessary daily self-care tasks people are required to perform such as bathing, dressing, toileting, grooming, and self-feeding. They are sometimes called Basic Activities of Daily Living (BADLs) to differentiate them from IADLs (instrumental activities of daily living) which are slightly more complex tasks that people are required to perform in order to live independently in society. These include shopping, banking, housework, and cooking among others.
Memory Aids:
BADLs – DEATH
D – dressing
E – eating (specifically feeding oneself, but not necessarily cooking or chewing or swallowing)
A – ambulation (walking and transferring)
T – toileting (including cleaning oneself afterwards)
H – hygiene (showering, grooming, combing/styling hair)
IADLs – SHAFT
S – shopping
H – housekeeping
A – accounting (including banking, management of finances)
F – food preparation
T – telephone use (or another communication device) and transportation (driving or using the bus or calling a taxi)
Details:
The concept of ADLs originates from geriatrics and was proposed in the late 50s by Sidney Katz and his team at the Benjamin Rose Hospital. They studied hip fracture patients and tried to identify physical functions that could help prognosticate patient outcomes. Their work was published in a 1959 paper which, at least for me, was not readily accessible for free. The study stressed that the person should be able to perform the activity completely independently. For example, dressing included getting the clothes out of the drawer or closet, putting them on, fastening the buttons, etc. Walking was required to be done without the aid of a cane or walker. There were some exceptions allowed i.e. assistance tying shoes was OK, getting someone else to prepare the food was OK as long as the patient was able to feed themselves, and so forth. They noted a hierarchy of complexity in these activities with bathing being the most complex and self-feeding being the least. Katz and colleagues developed a scoring system called the “Katz Index of Independence in Activities of Daily Living”. It’s scored out of 6 with 0 being the worst and 6 being the best. The categories are scored 0 or 1 and include: bathing, dressing, toileting, transferring, continence and feeding.
Wikipedia’s article on the subject has a nice way of thinking about BADLs as those things “many people do when they get up in the morning and get ready to go out of the house: get out of bed, go to the toilet, bathe, dress, groom, and eat”. Another helpful way to think of these activities is those things which are learned as a child. It should be noted that there may be an individual or cultural component to these tasks. Some tasks are more complex at baseline in different cultures. Clothing may be more difficult to put on, self-feeding implements may be more difficult to use, toileting practices may be more difficult, etc.
Lawton and Brody advanced this concept a bit further in 1969 with a paper in the Gerontologist outlining activities which allowed people to function independently in society, otherwise known as IADLs. There is a bit more flexibility with this list as it will depend on the culture and society the person lives in. As with the BADLs, there is a scoring system with each item scored 0 or 1. The total score will depend on the exact number of categories used, but a reasonable list can be found here. The categories listed are: telephone use, shopping, food preparation, housekeeping, laundry, transportation, medication use, and personal finances. It should also be noted that some of these activities can be performed in conjunction with someone else i.e. a spouse or child or something like that without it counting against their score. One nice way to think about IADLs is that they are those tasks which we learn as adolescents.
Both of these scoring systems have revolutionized the way we think about geriatrics, but also multiple other areas including dementia, disability, etc. They are widely used by physicians, occupational therapists, social workers and many others not just to prognosticate, but to determine social assistance needs, long term care requirements, even insurance costs.
References:
Original Katz 1959 BADLs article
Katz Index of Independence in Activities of Daily Living scale
Lawton and Brody 1969 IADLs article
Lawton and Brody Instrumental Activities of Daily Living scale
Wikipedia ADLs page