The Measurement of Disability in the Elderly: A Systematic Review of Self-Reported Questionnaires

JAMDA 15 (2014) 150.e1e150.e9

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Review

The Measurement of Disability in the Elderly: A Systematic Review of Self-Reported Questionnaires Ming Yang MD, Xiang Ding MS, Birong Dong MD * The Center of Gerontology and Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan, China

a b s t r a c t Keywords: Disability systematic review self-reported outcome questionnaire elderly

Objective: To analyze the contents and formats of general self-reported questionnaires on disability that are designed for and/or are widely applied in the elderly population to depict a complete picture of this field and help researchers to choose proper tools more efficiently. Methods: A broad systematic literature search was performed in September 2013 and included the following databases: MEDLINE, EMBASE, CINAHL, PsycINFO, and PROQOLID. The publication language was limited to English and Chinese. Two review authors independently performed the study selection and data extraction. All of the included instruments were extracted and classified using the International Classification of Functioning, Disability, and Health framework. Results: Of 5569 articles retrieved from the searches and 156 articles retrieved from the pearling, 22 studies (including 24 questionnaires) fulfilled the inclusion criteria. From these, 42 different domains and 458 items were extracted. The most frequently used questionnaire was the Barthel Index followed by the Lawton and Brody Instrumental Activities of Daily Living Scale and the Katz Index of Activities of Daily Living, respectively. The contents and formats of the questionnaires varied considerably. Activities and participation were the most commonly assessed dimensions. In addition, the Activities of Daily Living, mobility and the Instrumental Activities of Daily Living Scale were the most common domains assessed among the included questionnaires. Conclusions: Among the 24 included questionnaires, the most frequently used questionnaires were the Barthel Index, Lawton and Brody Instrumental Activities of Daily Living Scale, and Katz Index of Activities of Daily Living. The content and format of the questionnaires varied considerably, but none of the questionnaires covered all essential dimensions of the International Classification of Functioning, Disability, and Health framework. Ó 2014 - American Medical Directors Association, Inc. All rights reserved.

Disability is a common condition worldwide. The prevalence of disability varies among studies, depending on the criteria used, but generally increases with advancing age.1e3 According to the World Health Organization (WHO) and the World Bank, over 1 billion people (approximately 15% of the world’s population) live with a form of disability, and 2% to 4% of this population have significant difficulties in functioning.1 The prevalence of disability is 8.9% in the group aged 15 to 49 years, 20.6% in the group aged 50 to 59 years, and 38.1% in the group aged 60 years and over.1 As the population ages, disability is becoming an increasingly important concept because of its adverse effects on health outcomes, health care costs, and quality of life.2 Hence, the measurement of disability plays an M.Y. and X.D. contributed equally to this work. The authors declare no conflict of interest. * Address correspondence to Birong Dong, MD, The Center of Gerontology and Geriatrics, West China Hospital, Sichuan University, No.37 Guoxue Lane, Chengdu, Sichuan, China. E-mail address: [email protected] (B. Dong).

increasingly important role in public health and research on the aging population. It is clear that health measurements must be based on a specific conceptual framework; thus, the concept of disability must be clearly defined. Unfortunately, although disability, as a term, has been commonly used in social science, public health, and clinical practice for nearly 50 years, disability as a concept lacks a consensus definition and unique diagnostic criteria.3e6 The earliest and most prominent conceptual model on disability was developed by Nagi.7 In his model, disability [defined as having problems in activities of daily life (ADL)] began with a pathology (eg, diseases or injuries), with impairments (dysfunction or structural abnormalities in specific body systems), and functional limitations (restrictions in basic physical actions) as intervening steps. This model was subsequently modified by Verbrugge and Jette5; they theorized that many extra-individual factors (eg, medical care and social and environmental factors) could influence entire pathway between pathology, impairment, functional limitations, and disability. On the basis of such work, the WHO

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developed the International Classification of Impairments, Disabilities, and Handicaps in 1980, which was subsequently replaced by the International Classification of Functioning, Disability, and Health (ICF) in 2001.8 The ICF provides a common method for describing and coding various elements of functioning and disability and advances the understanding and measurement of function, but the ICF itself is not a tool for measuring disability.8 According to the ICF, in this review, disability is “an umbrella term, covering impairments, activity limitations, and participation restrictions.”8 The term includes multiple dimensions: self-care [ADL and instrumental activities of daily living (IADL)], emotion, cognition, social participation, physical ability, sensory ability, and communication, among others.8,9 Measurements in this field reflect the evolution of the concept of disability. Initially, the questionnaires focused on impairments (eg, physical and sensory abilities). Attention then shifted toward measuring self-care ability (eg, ADL and IADL) and later moved to an assessment of environmental factors and social participation (eg, community life and communication services).3,10,11 To date, the measurement of disability has principally been built using 2 types of information: self-reported and observation of performance. Both methods have their own merits and disadvantages. Self-reported measurements of disability have a long history and wide application. 11 Self-reported measurements are low-cost and easy to use. However, the measures are based on respondents’ perceptions of their own functioning, which may sometimes be either overestimated or underestimated. Furthermore, the results may be affected by the presence of cognitive impairment or depression, language, education, and culture.12 Unlike self-reported measurements, performance-based measurements test the actual, not perceived, ability of respondents. Generally, performance-based measurements have excellent face validity and reproducibility and are sensitive to change. However, such measurements depend on the cooperation of respondents. These measurements typically require special equipment and rigorous standardization and, therefore, are time- and money-intensive.12,13 Moreover, Rozzini et al indicated that a performance-based measure may detect a functional limitation before it becomes measurable by self-reported questionnaires.14 Nevertheless, a more recent systematic review found moderate to large correlation coefficients between self-reported and performance-based measures when they assess the same domain of disability.15 In addition, proxy reported information (typically by the caregivers of older adults) can be used to assess the functioning of specific persons who are unable to respond themselves (eg, patients with cognitive impairment). In this review, we focus on self-reported questionnaires. Current disability questionnaires, which are usually applied as outcome measures by clinicians, serve a variety of purposes. Some apply to a particular disease (disease-specific questionnaires), whereas others are broadly applicable (general questionnaires); some measure only functional limitations (eg, mobility), whereas others have a broader scope and cover multiple dimensions of disability; some are screening scales, whereas others are clinical rating scales; and some are designed for inpatients, whereas others are designed for community dwellings.10,11 In addition, for researchers in social science or public health, disability questionnaires can be used as tools to define a specific population worthy of study. When deciding to assess disability, researchers and clinicians usually face a wide, sometimes confusing array of options. Even if limited to self-reported measurements, many questionnaires are available. For example, there were over 100 ADL scales described in the literature.11 In addition, application-related issues (eg, scales used, time to administer) and psychometric properties (eg, reliability and validity), as well as translation into relevant languages, need to be taken into account. On the other hand, most of these questionnaires or scales were designed

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for the general population, and few of them are particularly developed for older people. As we know, some items (eg, work ability, running ability, etc.) in the questionnaires for the general population may be not suitable for older patients. Therefore, the aim of this review is to summarize general selfreported questionnaires on disability that is designed for and/or widely applied in the elderly to draw a complete picture of this field and help geriatricians or researchers to choose proper tools more efficiently in clinical practice or research investigating functioning and/or disability. Methods Unlike other literature reviews, a systematic review is defined as a review that systematically searches for, appraises, and synthesizes research evidence, often adhering to guidelines on the conduct of a review.16 In this review, we followed standard systematic review methodology as listed in the handbook of the Center for Reviews and Dissemination17 and reported our findings following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement guidelines for reporting systematic reviews and metaanalyses.18 Literature Search A broad systematic literature search was performed in the following databases: MEDLINE (1950 to September 9 2013), EMBASE (1974 to September 9, 2013), CINAHL (1982 to September 9, 2013), and PsycINFO (1950 to September 9, 2013). The search terms for the MEDLINE search included MESH terms as well as free text terms on disability (ie, “disability,” “disablement,” or “disable”), functional impairment or limitation (ie, “functional impairment*,” “functional limitation*,” “functional capacit*,” “functional performance*,” “loss of function,” “functional abilit*”, “physical limitation*” or “functional status”), older individuals (ie, “elderly,” “older,” “elder,” “aged,” or “geriatric*”), and questionnaires (“questionnaires,” “health status indicators,” “task performance and analysis,” “weight and measures,” “disability evaluation,” or “functional assessment”). All MESH terms were exploded. The terms were properly modified, if necessary, when searching other databases. We also searched the Patient-Reported Outcome and Quality of Life Instruments Database on September 9, 2013 using the following search terms: “functioning” or “function” or “disability.” In addition, we hand-searched the reference lists of the included articles and relevant reviews or systematic reviews to identify additional studies. Study Selection The following inclusion criteria were used to select relevant articles.
The study design was cross-sectional or longitudinal and reported the development or modifications of the original questionnaire and/or the initial validation of the original questionnaire.
The included participants were elderly patients (60 years and over).
Questionnaires not originally developed for use in the elderly population were only included if they were applied in ten or more published papers.
We included full structured questionnaires with standardized questions and answer options that were self-administered. We also included interviewer-administered questionnaires only if the information was self-reported. Some questionnaires could

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be administered either by self or by proxy; these were included as well.
According to the ICF,8 we included questionnaires that contained at least 1 of the following dimensions: body functions (eg, mental functions, sensory functions and pain, voice and speech functions); body structures (eg, structures of the nervous system, structures related to movement); activities and participation (eg, communication, mobility, self-care, community, and social life); and environmental factors (eg, support and relationships).
Only those questionnaires with published evidence for validity and reliability were included.
Only publications in English and Chinese were included. The exclusion criteria were as follows:
Studies aimed at 1 specific patient population (eg, arthritis, diabetes, stroke, and dementia); and
Disease-specific questionnaires. The study selection process was separately piloted by 2 independent reviewers (M.Y. and D.X.). Any disagreement in this process was resolved by discussion or consultation of the third reviewer (B.R.D.). All titles and abstracts were screened, and the decisions to include or exclude studies were recorded (0 ¼ excluded, 1 ¼ included, 2 ¼ order for full text assessment). Subsequently, the full texts of the papers marked 1 and 2 were screened again according to the inclusion and exclusion criteria listed above to determine the final inclusion. In addition, during the process of screening, we recorded the names of questionnaires that were not initially developed for the elderly and then searched the databases again with the name of the questionnaire as well as MESH terms and free text terms of the elderly. Those questionnaires widely used in the elderly were added as potentially eligible candidates, and the full-texts of these papers were also screened to determine the final inclusion. Data Extraction We created standardized data extraction forms to record the relevant information extracted from the original articles. The forms included the following information: name of questionnaires, target population, application settings, number and labeling of domains, number of items, type of scale, number of response options, range of scores, anchors, type of scoring, recall period, and time to administer. The data were extracted by two reviewers (M.Y. and D.X.) separately, and the results were compared by M.Y. Discrepancies were resolved by checking the original papers or consulting the third reviewer (B.R.D.) when necessary. Data Analysis Content analysis of the domain labels was conducted to synthesize the data. The domains were independently grouped into broad dimensions (as described above) by two reviewers (M.Y. and D.X.). The level of agreement was calculated using Cohen’s Kappa coefficient. Disagreements were then resolved by consulting the third reviewer (B.R.D.). After the categorization of all of the domains had been decided, the frequency of domains per dimension was calculated. A brief content analysis was also performed for the populations for which the questionnaires were designed as well as for the application setting, number of items, type of scoring, recall period, and time to administer. Furthermore, to estimate the frequency of the included questionnaires in the elderly, we searched MEDLINE and EMBASE with the name of the included questionnaires as well as the MESH terms and free text terms of the elderly and restricted the

publication types to “article”; the number of the records for each questionnaire was calculated, and the results were compared. Results Literature Search The electronic search identified a total of 7990 hits. Among them, 3891 papers were found in MEDLINE, 3367 in EMBASE, 293 in CINAHL, and 439 in PsycINFO. After removing duplicates, a total of 5569 papers were available for screening (Figure 1). Study Selection The study selection procedure is described in Figure 1. After screening the titles and abstracts, 141 potentially eligible studies were identified. There was an initial agreement of 87% on the included studies (n ¼ 122). After discussion, full agreement was reached. The second search identified further 12 studies as potentially eligible candidates (the method was described above). Moreover, 3 additional candidates were identified through hand searches of the reference lists. After studying the full text articles of the 156 studies, 134 studies were excluded. The most frequent reasons for exclusion were as follows: the questionnaire was disease-specific (n ¼ 37); the questionnaire was not self-reported (n ¼ 36); the article used the questionnaire as an outcome measure only (did not describe the development or initial validation) (n ¼ 32); the questionnaire was duplicated with a different name (n ¼ 19); and the questionnaire was published in languages other than English and Chinese (n ¼ 6). As a result, 22 studies (including 24 questionnaires)19e40 were included in the final review. Among them, 2 studies19,33 included 2 questionnaires each. Content Analysis Table 1 provides an overview of the 24 included questionnaires. Thirteen questionnaires (54%; questionnaires 3, 5, 7, 8, 10, 11, 15e20, 22) were developed for the elderly. The other 11 questionnaires (46%; questionnaires 1, 2, 4, 6, 9, 12e14, 21, 23, 24) were not originally designed for the elderly but are widely used in the elderly population. According to our search results, most of the included questionnaires were used in less than 100 studies conducted in the elderly (Table 2). Overall, the most frequently used questionnaire in the elderly was Barthel Index (BI) of Activities of Daily Living (questionnaire 1), which was applied in more than 2000 studies, followed sequentially by Lawton and Brody Instrumental Activities of Daily Living Scale (LB-IADL; questionnaire 11) and Katz Index (KI) of Activities of Daily Living (questionnaire 8). Of these three studies, only LB-IADL was developed in the elderly population (Table 2). Interestingly, some questionnaires specifically designed for the elderly (questionnaires 3, 17-19) were rarely used in this population. Disability can be defined based on the degree of difficulty with a task (marked as “difficulty”), the degree of dependence on people or devices (marked as “dependence”), or the frequency of performing a task (marked as “frequency”). In this review, we found that 11 questionnaires (46%; questionnaires 1, 3, 5, 8, 9, 11, 12, 16e18, 21) assessed dependence; 6 questionnaires (25%; questionnaires 2, 14, 15, 20, 21, 24) assessed difficulty; 1 questionnaire (4%; questionnaire 4) assessed frequency; 4 questionnaires (17%; questionnaires 6, 10, 19, 22) assessed both difficulty and frequency; and 2 questionnaires (8%; questionnaires 7 and 12) assessed both dependence and difficulty. Domains measured in different questionnaires varied from each other. The number of domains per questionnaire ranged from 1 to 6. After the removal of the duplicate domains, a total of 42 domains were identified. ADL, mobility, and IADL were the most frequent

M. Yang et al. / JAMDA 15 (2014) 150.e1e150.e9

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Fig. 1. Study selection flow chart.

assessed domains in the included questionnaires. The domains that appeared multiple times are listed in Table 3. All other domains appeared only once. The domains were grouped into 4 broad dimensions based on the ICF: “body functions”; “body structures”; “activities and participation”; and “environmental factors”. The interrater reliability of the initial independent coding of the 42 domains was high, with a Cohen’s Kappa of 0.835 (P < .001) and 94% total accordance. After agreement on discrepancies, the number of domains per dimension was as follows: body functions, n ¼ 10; body structures, n ¼ 0; activities and participation n ¼ 31; and environmental factors, n ¼ 1 (Table 4). All included questionnaires measured the dimension “activities and participation.” Eleven of the questionnaires (questionnaires 3, 5, 10, 11, 13, 17, 18, 19, 22, 23, 24) assessed “body function” as well. Only 1 questionnaire, the Winchester Disability Rating Scale-2 (questionnaire 22), assessed “activities and participation,” “body function,” and “environmental factors” simultaneously. However, none of the included questionnaires assessed “body structures” (Table 4). Format Analysis Overall, 458 items were included in the studied questionnaires. The number of items per questionnaire ranged from 3 to 54 (Table 1). An analysis of the 458 items revealed 7 different types of answer options, the most common of which was a 5-point scale. Nearly all of the included questionnaires were ordinal scales, with the exception of Katz Index of ADL (a nominal scale) and the Rosow-Breslau Functional Health Scale (a Guttman scale).

Twelve questionnaires (50%; questionnaires 1e5, 7, 11, 13, 15, 16, 20, 21) were scored by calculating the sum of items; 6 questionnaires (25%; questionnaires 8, 9, 14, 17, 22) required no score; 2 questionnaires (8%; questionnaires 7 and 13) calculated the total score with formulas; 2 questionnaires (8%; questionnaires 23 and 24) calculated the total score either through summing the score of each item or with computer; and 2 questionnaires (8%; questionnaires 10 and 19) did not report the method of scoring (Table 1). The majority of the included questionnaires (questionnaires 1, 2, 4, 6-8, 10e13, 15e22) were developed for clinical application; three questionnaires (questionnaires 3, 9, 14) were developed for survey; and the remaining three questionnaires (questionnaires 5, 23, 24) could be applied in either clinical practice or survey. Twelve (50%) questionnaires in the review reported the recall periods. Among these 12 questionnaires, 6 (questionnaires 2, 6, 15, 22-24) measured disability in the past month before assessing; 1 (questionnaires 8) measured in the past 2 weeks; 3 (questionnaires 7, 11, 12) in the past week; and 2 (questionnaires 4 and 18) used different recall periods for different items. Thirteen (54%) questionnaires (questionnaires 4, 6, 9, 10, 13e15) were self-administered; four (17%; questionnaires 2, 3, 8, 11) were interviewer-administered; 5 (21%; questionnaires 1, 5, 7, 12, 16) questionnaires were either self- or interviewer-administered; and 2 (8%; questionnaires 23 and 24) questionnaires could be administered by patients, interviewers, or proxies. In addition, the time to administer the questionnaire was described in 8 questionnaires (questionnaires 1, 3, 5, 6, 10, 18, 23, 24) and ranged in time from 2 to 42 minutes.

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Table 1 Summary of the Included Questionnaires Labeling of Domains

Number of Items

Type of Scale

Number Range of Scoring Scores of Response Options

Recall Period

Mode of Time to Administer Administration (min)

Dependence

1

ADL

10

Ordinal

0,5,10,15 0e10

Sum

Unclear

2e10

Difficulty

1

ADL

8

Ordinal

0e2

0e16

Sum

N/A

Dependence

3

20

Ordinal

1e5

20e100

Sum

10e15

Interviewer

Clinical

Frequency

2

15

Ordinal

0e3

0e45

Sum

3 or 6 mo N/A

Self

The elderly

Clinical or survey

Dependence

5

29

Ordinal

3 to 0

Unclear

42

Self or interviewer

6.Functional Status Questionnaire (FSQ)29

Ambulatory patients

Clinical

Difficulty or frequency

6

34

Ordinal

0e4, 1e6, or 1e4

Specific The past formula month

15

Self

7.Groningen Activity Restriction Scale (GARS)28 8.Katz’s Index of ADL (KI)27

Non-institutionalized elderly The elderly with hip fracture Adults living in the community

Clinical

18

Ordinal

1e3

18e54

Sum

N/A

Clinical

Dependence 2 and difficulty Dependence 1

Physical risk; mental risk; social risk Daily activities; social activities ADL; mobility; communication; mental functions; IADL ADL; I ADL; Mental health; work performance; social activity; quality of interaction ADL; IADL

The past month Unclear

Self or interviewer Interviewer

6

Nominal

None

None

None

Survey

Dependence

4

Ordinal

None

None

None

10.Late Life Function and Disability The elderly living in the Clinical Instrument (LLFDI)38 community The elderly Clinical 11.Lawton and Brody Instrumental Activities of 33 Daily Living Scale (LB-IADL) Clinical 12.London handicap scale (LHS)34 Stroke patients

Difficulty or frequency Dependence

2

Ordinal

1e5

Ordinal

1e3, 1e4, `8e61 or 1e5

Mobility; physical 6 independence; occupation; social integration; orientation; economic selfsufficiency Mobility; kitchen; 22 domestic; leisure

Ordinal

1e6

Ordinal

0,1

Ordinal

None

Ordinal Ordinal

Guttmann None

Target Population

1.Barthel Index (BI)31

Patients in Clinical rehabilitation service Patients receiving Clinical primary care The elderly in hospital Survey and community

4.Frenchay Activities Index (FAI)30

Stroke patients

5.Functional Autonomy Measurement System (SMAF)36

2.Brief disability questionnaire (BDQ)23 3.Elderly At Risk Rating Scale (EARRS)37

9.Lambeth Disability Screening Questionnaire (LDSQ)22

13. Nottingham Extended Activities of Daily Living scale (NEADL)27 14.The OECD long-term disability questionnaire (OLDQ)25 15.Pepper Assessment Tool for Disability (PAT-D)37 16.Physical Self-Maintenance Scale (PSMS)33 17.Rosow-Breslau Functional Health Scale (RBFHS)32

Application Type of Settings Assessment

1

Difficulty or dependence

6

ADL

Mobility; self-care; 25 domestic duties; occupation Disability; 48 function IADL 8

Stroke patients

Clinical

Dependence

4

Adults living in the community

Survey

Difficulty

2

The elderly

Clinical

Difficulty

3

The elderly

Clinical

Dependence

1

Physical function; 16 sensorial function ADL; IADL; 19 mobility ADL 6

The elderly

Clinical

Dependence

1

Mobility

3

87 to 0 Sum

0e100

The past week The past 2 wk Unclear

N/A

Self or interviewer Interviewer

N/A

Self

Unclear

25

Self

The past week

N/A

Interviewer

0e1

Specific The past formula week

N/A

Self or interviewer

0e22

Sum

Unclear

N/A

Self

None

None

Unclear

N/A

Self

1e5

19e95

Sum

N/A

Self

1e5

6e30

Sum

The past month Unclear

N/A

None

Unclear

N/A

Self or interviewer Self

0e100

None

Not report Sum

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Number of Domains

Questionnaire Number, Name of Questionnaire

The elderly

Clinical

Dependence

6

19.Short Form of the Late-Life Function and Disability Instrument (SF-LLFDI)39 20.Tokyo Metropolitan Institute of Gerontology Index of Competence (TMIG-IC)24

The elderly living in the Clinical community

Difficulty or frequency

2

The elderly living in the Clinical community

Difficulty

3

21.Townsend Disability Scale (TDS)20 22.Winchester disability rating scale 2 (WDRS-2)21

Adults

Clinical

Dependence

2

The elderly living in the Clinical community

Difficulty or frequency

4

23.World Health Organization Disability Assessment Schedule (WHODAS) 2.0 full version19

Adults

Clinical or survey

Difficulty

6

24.World Health Organization Disability Assessment Schedule (WHODAS) 2.0 short version19

Adults

Clinical or survey

Difficulty

6

OECD, Organization for Economic Cooperation and Development; N/A, not available.

Physical disability; 54 symptoms of aging; self-esteem; social satisfaction; depression; personal control Disability; 23 function Instrumental self- 13 maintenance; effectance; social role ADL; IADL 9 18 ADL; sensorial function; depression; social support 36 Cognition; mobility; self-care; getting along; life activities; participation in society 12 Cognition; mobility; selfcare; getting along; life activities; participation in society

None

The past 15 month or current

Self

0e100

Not report

Unclear

N/A

Self

0,1

0e13

Sum

Unclear

N/A

Self

Ordinal

0e2

0e18

Sum

Unclear

N/A

Self

Ordinal

None

None

None

The past month

N/A

Self

Ordinal

1e5

36e180

Sum

The past month

20

Self, interviewer or proxy

Ordinal

1e5

12e60

Sum

The past month

5

Self, interviewer or proxy

Ordinal

1e4

Ordinal

1e5

Ordinal

None

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18.Self-evaluation of life function (SELF) scale35

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Table 2 The Frequency of Use of the Included Questionnaires in the Elderly

Table 4 Classification of the Contents of the Included Questionnaires (Based on ICF)

Abbreviation of Questionnaire

Number of Records

BI LB-IADL KI FAI NEADL FSQ LHS PSMS SMAF LLFDI TMIG-IC GARS WHODAS 2.0 (full version) WDRS-2 WHODAS 2.0 (short version) BDQ PAT-D OLDQ TDS LDSQ SF-LLFDI RBFHS EARRS SELF

2562 1787 534 156 72 62 51 49 37 35 31 27 26 25 24 23 15 13 11 10 9 7 6 3

BI, Barthel Index; BDQ, brief disability questionnaire; EARRS, Elderly At Risk Rating Scale; FAI, Frenchay Activities Index; FSQ, Functional Status Questionnaire; GARS, Groningen Activity Restriction Scale; KI, Katz Index; LB-IADL, Lawton and Brody Instrumental Activities of Daily Living Scale; LDSQ, Lambeth Disability Screening Questionnaire; LHS, London Handicap Scale; LLFDI, Late Life Function and Disability Instrument; NEADL, Nottingham Extended Activities of Daily Living scale; OLDQ, Organization for Economic Cooperation and Development Long-Term Disability Questionnaire; PAT-D, Pepper Assessment Tool for Disability; PSMS, Physical SelfMaintenance Scale; RBFHS, Rosow-Breslau Functional Health Scale; SELF, Selfevaluation of life function Scale; SF-LLFDI, Short Form of the Late-Life Function and Disability Instrument; SMAF, Functional Autonomy Measurement System; TMIG-IC, Tokyo Metropolitan Institute of Gerontology Index of Competence; TDS, Townsend Disability Scale; WDRS-2, Winchester Disability Rating Scale-2; WHODAS, World Health Organization Disability Assessment Schedule.

Discussion This systematic review identified a large number of questionnaires for measuring disability in the elderly. Approximately one-half of the included questionnaires were specifically designed for the elderly; the others were not developed for the elderly but were widely applied in the elderly population. The BI, LB-IADL, and KI were the most popular tools in the field. The content and format of the questionnaires varied considerably. ADL, mobility and IADL were the most common domains assessed among the included questionnaires. When analyzed according to the framework of the ICF, all questionnaires measured “activities Table 3 Domains (as Described by the Authors) that Appeared Multiple Times in the Included Questionnaires Labeling of Domains

N

ADL Mobility IADL Self-care Cognition Depression Getting along Life activities Occupation Participation in society Sensorial function Social activities

10 8 6 3 2 2 2 2 2 2 2 2

ADL, activities of daily living; IADL, instrument activities of daily living.

Abbreviation of Questionnaire BDQ BI EARRS FAI FSQ GARS KI LB-ADL LDSQ LHS LLFDI NEADL OLDQ PAT-D PSMS RBFHS SELF SF-LLFDI SMAF TDS TMIG-IC WDRS-2 WHODAS 2.0 full version WHODAS 2.0 short version

Body Body Activities and Functions Structures Participation

C C

C C C C C C C C C C C C C C C C C C C C C C C

C

C

C C

C C C

C C C

Environmental Factors

C

BI, Barthel Index; BDQ, brief disability questionnaire; EARRS: Elderly At Risk Rating Scale; FAI, Frenchay Activities Index; FSQ, Functional Status Questionnaire; GARS, Groningen Activity Restriction Scale; KI, Katz Index; LB-IADL, Lawton and Brody Instrumental Activities of Daily Living Scale; LDSQ, Lambeth Disability Screening Questionnaire; LHS, London Handicap Scale; LLFDI, Late Life Function and Disability Instrument; NEADL, Nottingham Extended Activities of Daily Living scale; OLDQ, Organization for Economic Cooperation and Development Long-Term Disability Questionnaire; PAT-D, Pepper Assessment Tool for Disability; PSMS, Physical SelfMaintenance Scale; RBFHS, Rosow-Breslau Functional Health Scale; SELF, Selfevaluation of life function Scale; SF-LLFDI, Short Form of the Late-Life Function and Disability Instrument; SMAF, Functional Autonomy Measurement System; TMIG-IC, Tokyo Metropolitan Institute of Gerontology Index of Competence; TDS, Townsend Disability Scale; WDRS-2, Winchester Disability Rating Scale-2; WHODAS, World Health Organization Disability Assessment Schedule.

and participation.” Some of the questionnaires measured “body function” as well. Only one questionnaire (Winchester Disability Rating Scale-2) measured “environmental factors,” none of the questionnaires measured “body structure.” The lack of questionnaires exploring “body structure” may be due to the exclusion of disease-specific questionnaires in this review. An analysis of the format revealed that most of the questionnaires were ordinal scales. The most common answer option was a 5-point Likert scale. Our review indicates that there is no consensus on the content and format of questionnaires on disability in the elderly. This lack of consensus is partly due to the absence of a standard definition and unique diagnostic criteria. Most of the included questionnaires were published before 2001, at which time the ICF8 was established. The ICF provides a well-accepted conceptual model of disability and advances the understanding and measurement of disability. As the well-known International Classification of Diseases classifies the diagnoses of diseases, the ICF classifies functioning and disability. Both of the two classifications belong to the WHO family of international health classifications. The ICF can be used as a scientific tool for consistent, internationally comparable information about disability, and help clinicians, researchers, and decision-makers understand and assess disability systematically.8 Nevertheless, the ICF is neither a questionnaire nor a survey instrument; the ICF is merely a classification system that can provide a standard for defining and measuring disability. Therefore, the development of better tools to measure disability more accurately is needed. As an example,

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WHO-DAS 2.019 was developed recently based on the ICF; however, it did not assess environmental factors and may need improvement. It is important to acknowledge that disability is a complex and multidimensional construct; for example, the ICF includes 1454 categories.8 Hence, it is impossible to create a single questionnaire that encompasses all categories. However, it seems to be reasonable and practical to develop a tool covering all dimensions of the ICF, (ie, body function, body structure, activities and participation, and environmental factors). Missing any of the 4 dimensions might cause underestimation of the prevalence and influence of disability. In this review, we found that most of the questionnaires focused on activities and participation but omitted other important concepts, such as environmental factors. As a result, disability could be underestimated with these tools. More specifically, when focusing on activities and participation, we determined that some concepts in this dimension, (eg, ADL, mobility, and IADL attracted most of the researchers’ attention). Other concepts, such as “participation in society,” are rarely measured in the included questionnaires. This exclusion makes it more difficult to compare results between different studies. In our opinion, if a questionnaire does not cover all dimensions of the ICF or if it only measures some domains of a dimension, it would be appropriate to specify the term of disability more accurately to avoid misleading readers. For example, 1 study may apply the Physical SelfMaintenance Scale to measure ADL, whereas another study may apply the Rosow-Breslau Functional Health Scale to measure mobility, but both of the studies report “disability” as the outcome. The use of “disability” in both of these contexts is inappropriate because “disability” refers to totally different contents in the 2 studies; it would be better to report the measured characteristic as “ADL disability” and “mobility disability”, respectively. Traditionally, disability can be defined as having difficulty with a task or as needing help with a task. Using 2 different methods to rate disability could have a substantive impact on the prevalence of disability in the elderly. For example, Jette41 reported that using questionnaires phrased in terms of experiencing difficulty with an activity can produce significantly higher estimates of disability than those phrased in terms of needing help. In fact, there is evidence that combining questions about difficulty and dependence might more fully depict the continuum of disability in older people.10 In this review, we identified 11 questionnaires assessing “dependence,” 6 assessing “difficulty,” and 2 that assessed both “dependence” and “difficulty.” Researchers can choose different types of questionnaires according to specific purposes. However, questionnaire users should pay more attention to this issue when making cross-study comparisons of disability. Another factor that can significantly influence estimates of disability is the recall period. As we know, many individuals experience fluctuations in functional status over time. If a research aims to measure “acute disability” or to detect the change in functional status over time, it would be appropriate to set the recall period at a relatively short time (eg, “past week”). If the objective is to measure chronic or long-term disability, a longer recall period (eg, “past 3 months”) might be needed. Approximately one-half of the included questionnaires reported the recall period, which ranged from “past week” to “past 1 month.” The selection of the appropriate recall period is dependent on the research aims and objectives; no consensus has been achieved on this issue. However, there is evidence that the accuracy rate of recall decreases as the duration of the recall period increases.42 Again, special attention is warranted when making cross-study comparisons. It is obvious that 1 questionnaire cannot meet all assessment and evaluation needs for a particular population. Developing new questionnaires will not change this fact. An alternative is to use

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a combination of existing questionnaires to provide a more comprehensive and accurate picture of disability.43 However, the variety and number of available questionnaires makes it difficult for clinicians and researchers to decide which one to choose for their purpose. Our review provides a broad overview of disability assessment in the elderly and can be used to guide the selection. Clinicians and researchers should consider the intended purpose of measurement (eg, clinical trials or survey), the content (eg, ADL, mobility, or IADL), the setting (eg, hospital, nursing home, or community), and the application (eg, time of administration, mode of scoring, and recall period) before selecting appropriate questionnaires from this review. The measurement properties also need to be considered once a potential questionnaire has been chosen. All questionnaires included in this review presented evidence of their validity and reliability. However, because of the large number of the clinimetric studies, we plan to report such values in another review. Study Limitations Potential biases in the review process were as follows. First, although we adhered to the rigorous methods of systematic review, we included only publications in English and Chinese. This language selection might cause selection bias. Second, in this review, a “widely used” questionnaire was arbitrarily defined as a questionnaire that was cited in at least 10 studies. Questionnaires, such as Global Activity Limitation Index,44 that were cited less than 10 times, were excluded. This method might also induce selection bias. Third, the subscales (parts of certain questionnaires) that seemed to be eligible were not included because they were not full questionnaires. For example, the Physical Functioning Scale,45 a part of the Medical Outcomes Study Short-Form 36, was excluded. Last, the content of the individual items in the included questionnaires was not analyzed. Conclusions This review identified 24 self-reported disability questionnaires that were developed for or widely used in the elderly. From these, 42 different domains and 458 items were extracted. The most frequently used questionnaire was the BI followed by the LB-IADL and KI. ADL, mobility, and IADL were the most common outcomes applied in this field. The content and format of the questionnaires varied considerably, but none of the questionnaires covered all of the essential dimensions of the ICF. Activities and participation were the most commonly assessed dimensions. It is difficult to decide which questionnaire is the best, but this review offers useful information by comparing the content and format of each questionnaire for selecting appropriate questionnaires for different purposes. Acknowledgments This study is part of the research project named Geriatric Comprehensive Assessment and Health Care Service System in Chinese Elderly, which was funded by National Department Public Benefit Research Foundation by Ministry of Health P. R. China (No. 201002011). The sponsor has no role in the design, methods, data collection, analysis and preparation of paper. References 1. WHO. World report on disability. Malta: World Health Organization; 2011. 2. Topinkova E. Aging, disability and frailty. Ann Nutr Metabol 2008;52:6e11. 3. Alves LC, Leite IDC, Machado CJ. The concept and measurement of functional disability in the elderly population: A literature review. Ciencia e Saude Coletiva 2008;13:1199e1207.

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4. German PS. Measuring functional disability in the older population. Am J Public Health 1981;71:1197e1199. 5. Verbrugge LM, Jette AM. The disablement process. Soc Sci Med 1994;38:1e14. 6. Ebrahim S. Disability in older people: A mass problem requiring mass solutions. Lancet 1999;353:1990e1992. 7. Nagi SZ. Some conceptual issues in disability and rehabilitation. In: Sussman M, editor. Sociology and Rehabilitation. Washington, DC: American Sociological Association; 1965. p. 110e113. 8. WHO. International Classification of Functioning, Disability and Health (ICF). Geneva: World Health Organization; 2001. 9. Dale C, Prieto-Merino D, Kuper H, et al. Modeling the association of disability according to the WHO International Classification of Functioning, Disability and Health (ICF) with mortality in the British Women’s Heart and Health Study. J Epidemiol Community Health 2012;66:170e175. 10. Gill TM. Assessment of function and disability in longitudinal studies. J Am Geriatr Soc 2010;58:S308eS312. 11. McDowell I. Measuring Health: A Guide to Rating Scales and Questionnaires. 3rd ed. New York: Oxford University Press; 2006. 12. Daltroy LH, Phillips CB, Eaton HM, et al. Objectively measuring physical ability in elderly persons: The Physical Capacity Evaluation. Am J Public Health 1995; 85:558e560. 13. Reuben DB, Siu AL. An objective measure of physical function of elderly outpatients. The Physical Performance Test. J Am Geriatr Soc 1990;38: 1105e1112. 14. Rozzini R, Frisoni GB, Ferrucci L, et al. The effect of chronic diseases on physical function. Comparison between activities of daily living scales and the Physical Performance Test. Age Ageing 1997;26:281e287. 15. Coman L, Richardson J. Relationship between self-report and performance measures of function: A systematic review. Can J Aging 2006;25:253e270. 16. Grant MJ, Booth A. A typology of reviews: An analysis of 14 review types and associated methodologies. Health Inform Libraries J 2009;26:91e108. 17. Systematic Reviews. CRD’ s Guidance for Undertaking Reviews in Healthcare. York: Center for Reviews and Dissemination, University of York; 2009. 18. Moher D, Liberati A, Tetzlaff J, Altman DG. Preferred reporting items for systematic reviews and meta-analyses: The PRISMA statement. BMJ 2009;339: 332e336. 19. Üstün T, Kostanjsek N, Chatterji S, Rehm J. Measuring Health and Disability: Manual for WHO Disability Assessment Schedule WHODAS 2.0. Malta: WHO Press; 2010. 20. Townsend P. Poverty in the United Kingdom: A Survey of Household Resources and Standards of Living. Berkeley and Los Angeles: University of California Press; 1979. 21. Oliveri S, Carpenter IG, Demopoulos G. Validity and reliability of the Winchester disability rating scale (2): A comprehensive screening instrument for the elderly in the community. Gerontology 1994;40:319e324. 22. Patrick DL, Darby SC, Green S, et al. Screening for disability in the inner city. J Epidemiol Community Health 1981;35:65e70. 23. Von Korff M, Ustun TB, Ormel J, et al. Self-report disability in an international primary care study of psychological illness. J Clin Epidemiol 1996;49:297e303. 24. Koyano W, Shibata H, Nakazato K, et al. Measurement of competence: Reliability and validity of the TMIG Index of Competence. Arch Gerontol Geriatr 1991;13:103e116.

25. McWhinnie JR. Disability assessment in population surveys: Results of the O.E.C.D. Common Development Effort. Rev Epidemiol Sante Publique 1981;29:413e419. 26. Nouri F, Lincoln N. An extended activities of daily living scale for stroke patients. Clin Rehabil 1987;1:301e305. 27. Katz S, Ford AB, Moskowitz RW, et al. Studies of illness in the aged. The Index of ADL: A standardized measure of biological and psychosocial function. JAMA 1963;185:914e919. 28. Kempen GI, Suurmeijer TP. The development of a hierarchical polychotomous ADL-IADL scale for noninstitutionalized elders. Gerontologist 1990;30: 497e502. 29. Jette AM, Davies AR, Cleary PD, et al. The Functional Status Questionnaire: Reliability and validity when used in primary care. J Gen Intern Med 1986;1: 143e149. 30. Wade DT, Legh-Smith J. Langton Hewer R. Social activities after stroke: Measurement and natural history using the Frenchay Activities Index. Int Rehabil Med 1985;7:176e181. 31. Mahoney FI, Barthel DW. Functional evaluation: The Barthel Index. Md State Med J 1965;14:61e65. 32. Rosow I, Breslau NA. Guttman health scale for the aged. J Gerontol 1966;21: 556e559. 33. Lawton MP, Brody EM. Assessment of older people: Self-maintaining and instrumental activities of daily living. Gerontologist 1969;9:179e186. 34. Harwood RH, Gompertz P, Ebrahim S. Handicap one year after a stroke: Validity of a new scale. J Neurol Neurosurg Psychiatry 1994;57:825e829. 35. Linn MW, Linn BS. Self-evaluation of life function (self) scale: A short, comprehensive self-report of health for elderly adults. J Gerontol 1984;39: 603e612. 36. Hebert R, Carrier R, Bilodeau A. The functional autonomy measurement system (SMAF): Description and validation of an instrument for the measurement of handicaps. Age Ageing 1988;17:293e302. 37. Donald IP. Development of a modified Winchester disability scaledThe elderly at risk rating scale. J Epidemiol Community Health 1997;51:558e563. 38. Jette AM, Haley SM, Coster WJ, et al. Late life function and disability instrument: I. Development and evaluation of the disability component. J Gerontol Biol Med Sci 2002;57:M209eM216. 39. McAuley E, Konopack JF, Motl RW, et al. Measuring disability and function in older women: Psychometric properties of the late-life function and disability instrument. J Gerontol Biol Med Sci 2005;60:901e909. 40. Rejeski WJ, Ip EH, Marsh AP, et al. Measuring disability in older adults: The International Classification System of Functioning, Disability and Health (ICF) framework. Geriatr Gerontol Int 2008;8:48e54. 41. Jette AM. How measurement techniques influence estimates of disability in older populations. Soc Sci Med 1994;38:937e942. 42. Gill TM, Gahbauer EA. Evaluating disability over discrete periods of time. J Gerontol Biol Med Sci 2008;63:588e594. 43. Huijbregts MPJ, Gruber RA. Functional outcome measurement in the elderly. Orthop Phys Ther Clin 1997;6:383e401. 44. van Oyen H, Van der Heyden J, Perenboom R, Jagger C. Monitoring population disability: Evaluation of a new Global Activity Limitation Indicator (GALI). Sozialund Präventivmedizin/Social and Preventive Medicine 2006;51:153e161. 45. Ware JE Jr, Sherbourne CD. The MOS 36-item short-form health survey (SF-36). I. Conceptual framework and item selection. Med Care 1992;30:473e483.