Clinical review

A critique of the Barthel Index

Jan Dewing, Burford Community Hospital and Oxford Polytechnic

This article providesa critical review of apopular functionalindex, the BarthelIndex. The strengthsand weaknesses ofthe index with anemphasis on its useby nurses isconsidered and theneed to use this andother functionalindices for measuringdisability isaddressed.

T

Ms Dewing is LecturerPractitioner at BurfordCoinmunity Hospital andLecturer in the Departmentof Heakh Care Studies,Oxford Polytechnic

Correspondence to: MsDewing, BurfordCommunity Hospital,Sheep Street, Burford,Oxfordshire

he Barthel Index, originally calledthe Maryland Disability Index, was intro-duced in 1965 by Mahoney and Barthel. Itwas developed as a means of measuring theseverity of disability in people whose dis-ease interfered with independent movementof the limbs (Wylie and White, 1964). Useof the index has been extended to includemost physically disabling conditions. It iswidely used in the rehabilitation of peoplewho have suffered a stroke (Gibbon, 1991).Most critiques of the Barthel Index havestated that it is most useful where those as-sessed have paralysing conditions (Grangeret al, 1979a).

The index measures the functional statusin activities of daily living of people whoare physically disabled (Jacelon, 1986). Al-though it does not measure all the activitiesof daily living, a reasonable selection offunctional activities are included. The indexcontains 10 items. Fig. 1 shows the BarthelIndex as it currently stands. The activitiesin the index have been selected because oftheir perceived social importance. Similarly,the weighting of the items within the indexvaries according to the professionals'prioritization of the impact a deficit in eacharea would have on the person. Althoughthis achieves standardization it may not ac-curately represent the disabled person's realpriorities.

Using the indexThe index has been described as simple andeasy to use (Bowling, 1991). Scoring canbe carried out by any healthcare profes-sional, including nurses. Scorers need to betrained in its use but training has been re-ported to be quick. One study claimed thatscorers became sufficiently familiar withthe index after 2 months to become involv-ed in a research study to measure its relia-bility (Collin et al, 1988).

The scorer can either observe the dis-abled person and complete the index or askquestions of someone who has given physi-cal care to the person, i.e. the disabled per-son does not have to be seen directly by

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the scorer. In one report, scoring was carr-ied out with the help of relatives over thetelephone (Shinar et al, 1987). Each of the10 sections in the index is completed andassigned a score; the scores for all sectionsare then added together to provide a totalscore. Scoring takes between 30 secondsand 1 minute to carry out (Bowling, 1991).The index can be repeated at regular inter-vals to assess changes within a section andin the overall functional ability of the dis-abled person.

ReliabilityReliabihty can be defined as giving the sameresults for the same test conditions, evenif measured by different people over a per-iod of time (Cormack, 1984). The reliabilityof the Barthel Index cannot be establishedfrom the literature as the majority of studiesdo not include any of the guidelines usedby the authors for the scoring of each item.It is possible that each study used differentguidelines for scoring, which would affectthe scoring system.

Several studies have investigated the re-liability of the Barthel Index although theirmethodologies contain some weaknesses.Shinar et al (1987) examined theinterobserver reliability of the index. Theyused a sample of 18 people who were re-covering from a stroke. It should be notedthat the sample group contained peoplewho were fully cooperative and had noneglect of the affected side of the body oraphasia. A test and retest method was usedto check inter-rater reliability, in which theobservers moved between observing andrating different people. The observers wereresearch nurses specifically trained for thisstudy. The results showed general agree-ment, although some significant differenceswere found in the scores for personal hy-giene and toileting. Granger et al (1979b)has carried out several studies using theBarthel Index but reliability has not beenfully established as only medical recordswere used for scoring (Shinar et al, 1987).This method of observation does not take

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A critique of the Barthel Index

t. . .Jacelon (1986) hasstated tbat the BarthelIndex is generally notreliable for use withpeople who havecommunicationdeficits and changesin their mentalstatus.'

Fig. t. The Bai^hel Index

DATE

BOWELS0—incontinentI = occasional accident2=continent

BLADDER0 ^ incontinent or catherterised & unable to manageI ̂ occasional accident (max I Xper 24 hours)2=continent (for over 7 days)

GROOMINGO=needs helpI ̂ independent, face/hair/teeth/shaving

T O I L E T USE0=dependentl==needs some help, but can do something2—independent (on & off, dressing, wiping)

FEEDING0=unablel^needs help cutting, spreading butter etc2=independent

TRANSFER0=unableI = major help (1-2 people, physical)2=minor help (verbal or physical)3—independent

MOBILITY0—immobileI —wheel chair independent including corners etc2=walks with help of I person (verbal or physical)3—independent (but may use any aid, e.g. stick)

DRESSING0=dependentI —needs help, but can do about half unaided2=independent

STAIRS0 ~ unableI—needs help (verbal, physical, carrying aid)2=independent up and down

BATHING0—dependentI = independent

TOTAL

account of lnterobserver variations andpossible contextual differences.

Collin et al (1988) studied inter-rater re-liability (the reliability of seeking informa-tion rather than direct scoring) and the re-liability of self-reporting from the disabledperson. They concluded that the index wasa reliable measurement. However, it shouldbe noted that the sample group comprisedonly people with head injuries or strokes.

Nurses and occupational therapists carriedout the scoring. They appear to have beenless rigorously trained than the profession-als in Shinar's study, but their scoring abil-ities may be more representative of thoseof most clinical staff. However, the settingwas a specialist rehabilitation unit.

In the study by Collin et al, differencesin scoring were experienced in the items ontransferring, feeding, toileting, grooming

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A critique of the Barthel Index

^ When scored out of100, the scale providesa metric rating systemwhich is convenientfor statistical analysis(Jacelon, 1986).However, some usersof the scale now scoreout of 20 which cancause confusion. '

and dressing. This amounts to disagreementin half the total number of items from theindex that were tested. The authors suggest-ed that this may have been due to varyinglevels of skill between the observers and nothaving standardized tests to carry out, e.g.with feeding or dressing. These resultswould appear to question rather than con-firm reliability. Self-reporting in this studyraised predictable issues relating to self-per-ceived functional ability and ability as ob-served and perceived by the professional.The authors concluded that the index is notreliable where there is cognitive im-pairment. Further to this, Jacelon (1986) hasstated that the Barthel Index is generallynot reliable for use with people who havecommunication deficits and changes in theirmental status.

ValidityThe Barthel Index has also been widelytested for validity. Cormack (1984) definesvalidity as the ability to predict accuratelyon the basis of the measurements taken.This assumes that the measurements are re-liable. Wylie and White (1964) and Wylic(1967) compared the Barthel Index withother measures of disability that used data,including demographic factors, improve-ment over time, length of stay and finalmeasurements on discharge. The BarthelIndex was found to be valid both at a par-ticular point in time and as a measure ofimprovement over time.

As a result of validity testing, variousstudies have predicted the necessary mini-mal scores required at certain points duringrehabilitation to indicate that dischargehome will be a likely outcome Qacelon,1986). This index may therefore be a usefulindicator for clinical teams during rehabili-tation.

The Barthel Index has also been compar-ed with other measurements of functionalability. It compares favourably in most re-spects, although there are a few areas inwhich It does not compare favourably.When compared with the PULSES profile(another functional index), the Barthel In-dex was not sensitive to changes in func-tional ability related to general health, com-munication status and psychosocial status(Granger et al, 1979a); however, whencompared with the Katz Index and theKenny Self-Care Evaluation the Barthel In-dex was found to be equally valid. But onceagain the sample group in Granger's studywas composed entirely of people recoveringfrom stroke.

Strengths of the indexThe Barthe! Index is simple to understand.It is a compact index to carry out and istherefore not time-consuming. It is relative-ly simple to learn how to score and littletime IS needed to become proficient in usingthe index. When scored out of 100, the scaleprovides a metric rating system which isconvenient for statistical analysis (Jacelon,1986). However, some users of the scalenow score out of 20 which can cause con-fusion. The activities of daily living coveredby the Barthel Index are generally represen-tative of the overall functional abilities ofdisabled people. The index also seems toaccurately reflect changes in functional abil-ities to a certain level of sensitivity. Unlikesome other measurements, u is sensitive tochanges within each item and betweenitems (Jacelon, 1986).

The sections in the index cover most ofthe functional activities of daily living andprovide a baseline for more in-depth assess-ment by the healthcare team. The indexallows professionals and disabled peopleand their carers to assess progress over aperiod of time. It is adaptable in that anymember of the healthcare team or non-pro-fessional carer can be trained to score. Thefindings of the index are easily communi-cated, either in writing or verbally, toothers (Gibbon, 1991). The index is usefulin some research studies. It enables subjectswith approximately similar types of func-tional disability to be selected and allowsfor comparisons between subjects in thesame or different sample groups. It mayalso provide some information for clinicalaudit purposes.

The Barthel Index is only one exampleof a range of measurement scales that areavailable to assess functional disability.When used with people who are recoveringfrom stroke it appears to be as reliable andvalid as any other scale. It measures onlyphysical activities and does not include anyqualitative aspects of daily activities of liv-ing, such as being able to write or use atelephone. Although the Barthel Index isbeing more widely used for people withother disabilities and in a ranee of settings,Its use in this way requires further research.

Limitations to the Barthel IndexThe index uses a standardized assessmentformat which does not take into consider-ation individual factors in people or contex-tual differences. It assumes that observersare trained in using the scale and have accessto the guidelines for completing the index

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A critique of the Barthel Index

' The use of any scalein practice needs to beaccepted by thenursing team as awhole and not by onemember only, sucb asthe senior nurse. '

which are not always included on the scor-ing form. There appear to be several setsof guidelines, which do not always containthe same information or instructions forscorers. In some ways the items on the in-dex are too clear-cut to allow for variationsin functional abilities between individualsand over time. For example, the toiletingitems on bowels and bladder only look atthe functioning over the preceding week.The functional abihties of some disabledpeople may vary over a greater time spanthan 1 week and may be influenced by theenvironment and equipment available. Theend-points of the scoring system for eachitem are not true end-points as people'sabilities can change after the end-pointsused by the index (Bowling, 1991). Observ-ers who do not know the people they areassessing may not be aware of the usualfunctional abilities or the total range of abil-ity of those being observed and may scoreinaccurately. The index relies on the dis-abled person performing at their usual levelof functioning. It is assumed that this is themaximum level. People who may not befully aware of the implications of beingscored or do not choose to be fully activeor fully cooperate, for whatever reason,may be inaccurately scored. The alternativeis to score people when they are unawareof it, but this raises ethical questions.

Use of the indexAlthough the Barthel Index is becomingmore widely used, it is still mainly used inspecialist rehabilitation units. Members ofthe healthcare team who do not have anyknowledge of the index and its uses maytherefore find full participation in careplanning discussions difficult (Gibbon,1991). Professionals who use measurementtools such as the Barthel Index tend to as-sume, in their verbal and written communi-cations, that other professionals are famiharwith the scale in question. This is an unsafepractice because those who are not familiarwith it may ignore the information contain-ed within it or take on board this informa-tion without a clear understanding of howit was collected, which can then lead to theindex being used inappropriately. The useof this index or any other index should notbe seen as a substitute for individualizedpatient-centred assessments.

Implications for nursingA measurement scale that accurately as-sesses disability and handicap and can beused by all the healthcare professionals is

the ideal tool to contribute to the processof care planning. Unfortunately, such a tooldoes not yet exist, so nurses are making dowith those that are available. Research hasshown that the Barthel Index is comparableto other measurement scales. Nurses whowork with other professionals who usefunctional measurement scales or who wantto explore the use of them for nursingshould adopt a critical approach to suchscales. Several issues need to be addressed.

Nurses should be aware of the range ofliterature and research on measurementscales. They should also develop an ap-preciation of the quality of the research.The scale to be used should be thoroughlyinvestigated for reliability and validity. Theuse of any scale in practice needs to be ac-cepted by the nursing team as a whole andnot by one member only, such as the seniornurse. Similarly, nurses who are asked touse a measurement scale that is introducedby other professionals should question theuse of that scale. It may be that the otherprofessionals are aware of the limitationsof the scale but feel that a particular scaleis the best available at that time. Other pro-fessions cannot expect nursing to adoptmeasurement scales simply because theychoose to use them. However, nursingshould openly assess the suitability of anymeasurement scale regardless of which dis-cipline primarily uses it. It is important toremember that nurses are generally bestplaced to carry out the majority of func-tional assessments because of the nature oftheir contact with disabled people.

Nurses need to develop a critical ap-proach to the most appropriate use of theBarthel Index. It may be that this indexcould be mistakenly used as a means of cal-culating patient dependency or as a meansof nurse/patient allocation. The index wasnever intended for such use and it is totallyirresponsible for nurses to use it in this wayor to collude with other professionals whouse it out of context, e.g. as the criteria foradmission to nursing/residential homes.Using the index as a means of nurse/patientallocation is simply an elaborate task alloca-tion system. If nurses want to investigatethe use of the index for means other thanthat for which it was devised, they shouldundertake rigorous testing and evaluations.

A more functional issue needs to be con-sidered by nurses using measurement scalesfor the assessment of functional ability.There is little or no information containedin these measurement scales that cannot beobtained in normal practice from skilled

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A critique of the Barthel Index

^Independent living ismore dependent onthe patient'sperspectives andpsychological,environmental andsocial factors than onfunctional ability.'

healthcare professionals. The need to quan-tify disability and to measure it is a slightlyalarmine phenomenon. Concentrating onfunctional ability or disability can meanthat nurses and other healthcare profession-als are adopting a reductionist perspectiveto working with people who have disabilit-ies. Attempting to reduce and quantify theexperience of disability and handicap in theform of functional indices is following themedical model approach. Nurses need toquestion why they want to quantifypeople's experiences in this way.

McMillen Moinpour et al (1988) statethat the concept of functional status is im-portant in nursing because nurses are ofteninvolved in maintaining or improvingpeople's functional levels. These authors re-fer to functional status as a measure of thelevel of functioning in any of a variety ofareas such as physical status, intellectualstatus and social activity. While this takesa wider perspective of functional ability, itwould require nurses to make use of manyindices and assessment tools. The implica-tions of this are that not only would pa-tients be subjected to regular and repeatedtesting, but also there is the danger that thepatient's perspective would become less im-portant than the test outcomes.

It may be that nurses feel more comfort-able measuring functional abilities using in-dices like the Barthel Index than developingqualitative measures that are centredaround the patients' lived experiences andtheir perspectives of their own abilities(functional and others). This author wouldsuggest that the latter approach is more

compatible with nursing practice. If nursesare to be effective in their role they needto adopt a holistic framework. This in-cludes seeing the experiences of patients asthey see them, and not reducing andcompartmentalizing them into quantifiablemeasurable indices. Impairment, disabilityand handicap must be seen as a set of inter-related problems or needs if people withdisabilities are to live independently in thecommunity. Independent living is more de-pendent on the patient's perspectives andpsychological, environmental and socialfactors than on functional ability.

Bowling A (19911 Measurements of Health. OpenUniversity, Milton Keynes

Collin C, Wade DT, Davies S, Home V (1988) TheBarthel Index: a reliability study. Int] Disabtl Stud10: 61-3

Cormack DFS (1984) The Research Process in Nursing.Blackwell, Oxford

Gibbon B (1991) Measuring stroke recovery. NursTimes 87(441: 32-4

Granger CV, Albrecht GL, Hamilton BB (1979a) Out-come of comprehensive medical rehabilitation:measurement of PULSES Profile and the BarthelIndex. Arch Phys Med Rehabil 60: 145-54

Granger CV, Dewis LS, Peters NC, Sherwood CC,Barrett JE (1979b) Functional status measurementand medical rehabilitation outcomes. Arch Phy^Med Rehabil 57: 103-9

Jaceion CS (1986) The Barthel Index and other indicesof functional iibility. Rehtxbd Nurs 11: 9-11

Mahoney Fl, Barthel'DW (1965) Functional evalu-ation; the Barthel Index. Md Med} 14: 61-5

McMillen Moinpour C, McCorke R, Saunders J (1988)Measuring functional status. In: Stromberg MR,ed. Instruments for Clinical Nursing Research.Appleton and Lange, Norwalk

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Wylie CM (1967) Measuring the results of rehabilita-tion of patients with stroke. Public Health Rep 82:893-8

Wylie CM, White BK (1964) A measure of disability.^ Arch Environ Health 8: 834-9

KEY POINTS

There are many measurement scales available for the assessment of functionalability in people with physical disabilities. The Barthel Index is one that is gainingin popularity.

The index should be used appropriately in the context of individualized patientassessment and management of care and not as a substitute for interdisciplinarycare discussions.

The use of specific indices may exclude some professionals from care planning.Without the use of the correct guidelines and proper training, the index may beincorrectly used and scored.

The index should be used with patient groups in which reliability and validity havebeen demonstrated. It has not been tested for use as a dependency system oras a means of nurse/patient allocation.

Nurses need to consider the implications of using this and other functional indicesin their practice.

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