ArticlePDF AvailableLiterature Review

World Health Organization Disability Assessment Schedule 2.0: An International Systematic Review

Abstract and Figures

Purpose: This systematic review examines research and practical applications of the World Health Organization Disability Assessment Schedule (WHODAS 2.0) as a basis for establishing specific criteria for evaluating relevant international scientific literature. The aims were to establish the extent of international dissemination and use of WHODAS 2.0 and analyze psychometric research on its various translations and adaptations. In particular, we wanted to highlight which psychometric features have been investigated, focusing on the factor structure, reliability, and validity of this instrument. Method: Following Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) methodology, we conducted a search for publications focused on “whodas” using the ProQuest, PubMed, and Google Scholar electronic databases. Results: We identified 810 studies from 94 countries published between 1999 and 2015. WHODAS 2.0 has been translated into 47 languages and dialects and used in 27 areas of research (40% in psychiatry). Conclusions: The growing number of studies indicates increasing interest in the WHODAS 2.0 for assessing individual functioning and disability in different settings and individual health conditions. The WHODAS 2.0 shows strong correlations with several other measures of activity limitations; probably due to the fact that it shares the same disability latent variable with them. Implications for Rehabilitation WHODAS 2.0 seems to be a valid, reliable self-report instrument for the assessment of disability. The increasing interest in use of the WHODAS 2.0 extends to rehabilitation and life sciences rather than being limited to psychiatry. WHODAS 2.0 is suitable for assessing health status and disability in a variety of settings and populations. A critical issue for rehabilitation is that a single “minimal clinically important .difference” score for the WHODAS 2.0 has not yet been established.
Content may be subject to copyright.
REVIEW
World Health Organization disability assessment schedule 2.0: An international
systematic review
Q4 Stefano Federici
a
, Marco Bracalenti
a
, Fabio Meloni
a
and Juan V. Luciano
b,c
a
Department of Philosophy, Social & Human Sciences and Education, University of Perugia, Perugia, Italy;
b
Teaching, Research & Innovation
Unit, Parc Sanitari Sant Joan De D
eu, St. Boi De Llobregat, Spain;
c
Primary Care Prevention and Health Promotion Research Network (RedIAPP),
Madrid, Spain
Q1
ABSTRACT
Purpose: This systematic review examines research and practical applications of the World Health
Organization Disability Assessment Schedule (WHODAS 2.0) as a basis for establishing specific criteria for
evaluating relevant international scientific literature. The aims were to establish the extent of international
dissemination and use of WHODAS 2.0 and analyze psychometric research on its various translations and
adaptations. In particular, we wanted to highlight which psychometric features have been investigated,
focusing on the factor structure, reliability, and validity of this instrument.
Method: Following Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) method-
ology, we conducted a search for publications focused on whodasusing the ProQuest, PubMed, and
Google Scholar electronic databases.
Results: We identified 811 studies from 94 countries published between 1999 and 2015. WHODAS 2.0 has
been translated into 47 languages and dialects and used in 27 areas of research (40% in psychiatry).
Conclusions: The growing number of studies indicates increasing interest in the WHODAS 2.0 for assess-
ing individual functioning and disability in different settings and individual health conditions. The
WHODAS 2.0 shows strong correlations with several other measures of activity limitations; probably due
to the fact that it shares the same disability latent variable with them.
äIMPLICATIONS FOR REHABILITATION
WHODAS 2.0 seems to be a valid, reliable self-report instrument for the assessment of disability.
The increasing interest in use of the WHODAS 2.0 extends to rehabilitation and life sciences rather
than being limited to psychiatry.
WHODAS 2.0 is suitable for assessing health status and disability in a variety of settings and
populations.
A critical issue for rehabilitation is that a single minimal clinically important .differencescore for the
WHODAS 2.0 has not yet been established.
ARTICLE HISTORY
Received 16 April 2016
Revised 4 August 2016
Accepted 8 August 2016
Published online 222
KEYWORDS
WHODAS 2.0; systematic
review; PRISMA; disability
measurement; ICF; DSM-5
Introduction
The International Classification of Functioning, Disability and Health
(ICF) [1] describes functioning and disability as the outcome of a
complex, multidimensional interaction between a persons health
condition(s) and context (environmental and personal factors).
Positive or neutral aspects of those interactions are referred to as
functioning; negative aspects as disability. More specifically, dis-
ability can be described as arising out of limitations on activity
and restrictions on participation that are determined by the inter-
action between bodily functioning, structural impairments, and an
unhelpful context. Unlike previous classification systems, the ICF
does not describe disability exclusively from the viewpoint of
health professionals; instead it uses the biopsychosocial
approach.This represents a new paradigm,[2] shifting from the
previous ICIDH: International Classification of Impairments,
Disabilities, and Handicaps,[3] which failed to integrate the social
model of disability.[4,5] The ICIDH precisely followed Nagis
pathological model of disability [6,7]hugely influential in the
United States from the 1960s,[8] and which was also the basis for
the disablement processof Verbrugge and Jette [9]medicaliz-
ing disability.[10] Conversely, the ICF focuses on the context-
dependent impact of disability on a persons functioning and is
neutral with respect to the etiopathological aspects of disability.
This implies that the ICF is indifferent towards the hierarchical
order of possible health states based on medical standards, mov-
ing away from being a consequence of disease classification.[1]
This complex, dynamic, multidimensional, and contested con-
cept of disability [11] has profound implications for the measure-
ment of disability. Any empirical measurement of disability
assumes an operational definition that tells us what to observe
and how to describe it.[12] While the ICF model does provide
standardized language with which to frame disability and a com-
prehensive conceptual description of health related states, it does
not provide specific operationalization of the more general con-
cepts associated with disability for developing questions.[13]
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
CONTACT Stefano Federici stefano.federici@unipg.it Department of Philosophy, Social & Human Sciences and Education, University of Perugia, Piazza G.
Ermini 1, Perugia 06123, Italy
Supplemental data for this article can be accessed here
ß2016 Informa UK Limited, trading as Taylor & Francis Group
DISABILITY AND REHABILITATION, 2016
http://dx.doi.org/10.1080/09638288.2016.1223177
For example, in a bilingual context where the second language
is a sign language, deafness would emerge only as an impairment
(i.e., as a structural and functional body dysfunction). However, in
contexts where this sign language is only spoken by a minority,
deafness would be considered not only as an impairment but also
as a restriction on participation.[14,15] In this case, a disability
assessment tool designed to evaluate restrictions on participation
would register little evidence of disability in the bilingual context
and, in contrast, much greater disability in the monolingual con-
text, despite the similar epidemic diffusion of deafness in the two
contexts.[16]
In recognition of this context dependency, the ICF does not
prescribe specific measurement tools; as Zola argued,[17] any
attempt to identify standard indices of disability represents a futile
attempt to define disability as a fixed, dichotomous concept
rather than as the fluid, continuous experience it is in practice.
Although disability is neither a fixed nor dichotomous concept,
this does not mean it cannot be measured: the clearness of the
purpose of the measurement ensures identification of the most
suitable tools.
Another well-known paradox in measuring disability arises from
the fact that an individuals understanding of his or her well-being
may not accord with the evaluations of medical experts. Sen [18]
has noted the conceptual difference between perception and
observation of health. There is often discrepancy between an indi-
viduals subjective view of his or her health, based on personal per-
ceptions, and the views of doctors or professionals, which are
based on objective data.[19] Many people with severe disability
often claim that they have an acceptable or even good quality of
life, although there is a widespread assumption that if people have
a disability they cannot enjoy a state of well-being.[20,21] Albrecht
and Devlieger [22] stated that the disability paradoximplies that
personal experience with disability is an important aspect of any
assessment of disability and hence assessments of it should com-
bine objective observations with subjective, self-report data.
In June 1999, in order to address the issue of an effective
assessment of disability, the World Health Organization (WHO) dis-
seminated a beta version of a generic assessment instrument: the
WHO Disability Assessment Schedule II (WHODAS II). WHODAS II
provided a cross-cultural, standardized method for measuring limi-
tations and restrictions on individualsactivities and participation
in their society in a way which was independent of medical diag-
nosis. The beta version of WHODAS II was based on the WHO
Psychiatric Disability Assessment Schedule [23] which was
designed to assess the extent of disability associated with a psy-
chiatric condition; it was developed for use in a field trial phase
(version 3.1a Phase Two). A guide to using WHODAS II was pub-
lished in 2004.[24] The publication of the Manual in 2010 [25]
marked the final version, which is referred to under the acronym
WHODAS 2.0.
WHODAS 2.0 was developed from a large pool of ICF items
which were subjected to field trials in 19 countries.[26] ICF experts
reviewed all the psychometric and qualitative data from these tri-
als and selected 36 items to represent the ICFs six activity and
participation domains:
Cognition understanding and communicating (six items).
Mobility moving and getting around (five items).
Self-care hygiene, dressing, eating, and being alone (four
items).
Getting along interacting with other people (five items).
Life activities domestic responsibilities, leisure, work, and
school (eight items).
Participation joining in community activities (eight
items).
A 12-item version consisting of two items from each domain
(Understanding and communicating, items 3 and 6; Getting
around, items 1 and 7; Self-care, items 8 and 9; Getting Along
with People, items 10 and 11; Life activities, items 2 and 12;
Participation in society, items 4 and 5) was also produced. Scores
on the 12-item version account for 85% of the variance in scores
on the full 36-item version. Seven paper-based versions of
WHODAS 2.0 were developed:
Three 36-item versions: Interview-administered, self-admin-
istered, and proxy-administered (knowledgeable
informants).
Three 12-item versions: Interview-administered, self-admin-
istered, and proxy-administered.
One 12 þ24-item version, interview-administered.
A version designed specifically for use with children (WHODAS-
Child) was developed in 2013 by the DSM-5 Impairment/Disability
workgroup.[27] This version uses phrasing which is easily under-
stood by children and their families, and consistent with the basic
descriptions of child disability in the children and youth version of
the ICF.[28]
Unlike the most commonly used measuring instruments,
WHODAS 2.0 rates disability from the respondents subjective per-
spective. The respondent is asked to indicate how much
difficultyhe or she experiences (none, mild, moderate, severe,
and extreme) in the normal performance of a given activity, taking
into account the use of support or assistive devices and/or the
help of a caregiver (aids) where applicable. For any item rated
greater than none, a follow-up question is used to elicit informa-
tion about the frequency with which difficulty is experienced. The
respondent is asked on how many days in the last 30 he or she
experienced difficulty; responses are given on a five-point scale:
(1) only 1 day; (2) up to a week ¼from 2 to 7 d; (3) up to 2 week-
s¼from 8 to 14 d; (4) more than 2 weeks ¼from 15 to 29 d; (5)
every day ¼30 d.
Next, the respondent is asked how much the difficulties have
interfered with his or her life. Respondents are asked to answer
with reference to the following:
1. Degree of difficulty (increase in effort, discomfort or pain,
slowness, or changes in the way the person does the
activity).
2. Health conditions (disease or illness, injury, mental or emo-
tional problems, or problems related to alcohol or drug
abuse).
3. The last 30 d.
4. Averaging goodand baddays.
5. The way in which he or she normally performs the activity.
6. Items that refer to activities not experienced in the past 30 d
are not rated.
The structure and features of WHODAS 2.0 i.e., its context
invariance and independence from medical diagnosis, and equiva-
lence of the six domains of functioning and disability are con-
ceptually compatible not only with the biopsychosocial approach
and the ICF but also with the atheoretical and polythetic model of
the Diagnostic and Statistical Manual of Mental Disorders (DSM)
developed by the American Psychiatric Association (APA).[29,30]
The context-dependent nature of psychiatric disorders means that
the patients perspective on his or her own functioning is particu-
larly relevant to psychiatric assessment.[29] Self-evaluations are a
better method of capturing an individuals experiences and con-
textual background than a professionals assessment, which may
be influenced by his or her cultural bias.
It is, therefore, not surprising that the first edition of WHODAS,
the WHO Psychiatric Disability Assessment Schedule,[23] was spe-
cifically designed to assess the level of disability associated with a
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
2 S. FEDERICI ET AL.
psychiatric condition. Its prevalent use in the psychiatric context
explains why the fifth edition of the DSM indicates the WHODAS
2.0 as the most suitable tool for the assessment of functioning in
psychiatric patients.
In the last 15 years, the WHODAS 2.0 has also acquired greater
significance in collecting prevalence data on disability. In order to
harmonize disability statistics worldwide, a workgroup [31] was
formed to plan and implement analyses of the six measure ques-
tions developed by the Washington Group on Disability Statistics
(WG) [32]formed as a result of the United Nations International
Seminar on Measurement of Disability that took place in New
York in June 2001: the WHODAS 2.0 six domains of activity and
participation, and the World Health Survey modules.[33] Disability
question short sets were outlined [31] that overcame the limita-
tions of the six WG census questions. Although created on the
basis of the ICF framework, the WG short questions discard con-
textual factors, indeed. Incorporating the six domains into the WG
questions enable studying the lived experience of health beyond
measuring the consequence of diseases.[2]
Purpose
The aim of this systematic review was to examine the use of
WHODAS 2.0 in international scientific literature between 1999 and
2015. In particular, we analyzed the version, language, and psycho-
metric properties of the WHODAS 2.0 as well as the countries and
research fields in which it has been used. We also analyzed the
design, purpose, and results of studies using WHODAS 2.0.
Method
This study followed the checklist in the Preferred Reporting Items
for Systematic Reviews and Meta-Analyses (PRISMA) statement
(www.prisma-statement.org).[34,35]
Eligibility criteria
We considered books, book chapters, conference papers, confer-
ence proceedings, instruction manuals, and journal articles for
which the full text or abstract was published in at least one of the
five major European languages (English, Spanish, Portuguese,
German, and French) and which focused on at least one of the
WHODAS versions developed since 1999. Studies which explicitly
reported use of the WHO Psychiatric Disability Assessment
Schedule (WHODAS-I or WHO/DAS) [23] or the WHO Short
Disability Assessment Schedule (WHODAS-S) [36] were excluded
from analysis. We also excluded studies whose bibliography only
included reference to WHO 1988 [23] or Janca et al.[36] Finally, we
excluded doctoral dissertations and work published without an
abstract in one of the five major European languages cited above.
Information sources
We identified publications by searching the PubMed, EBSCO, and
Google Scholar electronic databases, and by scanning reference
lists of pertinent review articles, editorials, and hand-
books.[2426,3772] The last search was run on 31 December
2015.
Search
We used the following search terms in all fields: (whodas OR who-
das OR who/das OR world health organization disability assess-
ment schedule).
Study selection
Eligibility assessment was performed independently in a blinded,
standardized manner by authors S. F. and M. B. The first screening
was based on the article abstracts. The next selection was based
on the full text of the documents. Disagreements between
reviewers were resolved by discussion to reach a consensus.
Data collection process
We developed a data extraction sheet. This was pilot-tested on
eleven randomly-selected included studies and refined accord-
ingly. S. F. and M. B. extracted the data from the included studies
and checked them. Disagreements were resolved by discussion
between the authors.
Data items
Information was extracted on (1) year of publication; (2) study
design (i.e., cross-sectional study, longitudinal study, review, etc.);
(3) country where the study was conducted; (4) research field; (5)
sample size; (6) sample type (i.e., general population, older people,
depressed people, etc.); (7) purpose of the study; (8) WHODAS 2.0
version used (i.e., 12-item, 36-item, etc.); (9) language in which
WHODAS 2.0 was used; (10) psychometric properties of WHODAS
2.0; (11) other measures used in the study; (12) publication type
(i.e., journal article, conference proceedings, etc.) (see
Supplementary Table S1).
Results
Study selection
The number of publications retrieved from each electronic data-
base was as follows, ProQuest: 709, PubMed: 522, Google Scholar:
4588 a total of 5819 publications. By following up references
from relevant review articles, editorials and handbooks, we identi-
fied an additional 23 papers that met the inclusion criteria. Taking
duplication into account, there were 4681 records; 3427 were dis-
carded because the abstract was not available in one of the five
major European languages (English, Spanish, Portuguese, German,
and French) or did not focus on the content of interest, or
because the product was only web content (e.g., blogs, discussion
boards, web documents, etc.). The full texts of the remaining 1254
citations were examined in more detail and as a result an add-
itional 443 studies which did not meet the inclusion criteria were
excluded from the analysis.
The remaining 811 records met inclusion criteria and were
included in the systematic review. The selection process is sum-
marized in a flow diagram according to PRISMA [34] guidelines
(Figure 1).
Study characteristics
We investigated the following variables in the 811 selected stud-
ies: study design; country where the study was conducted;
research area; sample size; sample type (e.g., general population,
older people, etc.); purpose of the study; the WHODAS 2.0 version
used; the language in which WHODAS 2.0 was used; the psycho-
metric properties of WHODAS 2.0 where reported; the other meas-
ures used in the study; publication type (i.e., journal article,
conference proceedings, etc.). Supplementary Table S1 summa-
rizes the information extracted from the selected studies (see sub-
section Data itemsabove); Supplementary Table S2 displays
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
WHODAS 2.0: AN INTERNATIONAL SYSTEMATIC REVIEW 3
frequencies (number and percentage) for the six main study char-
acteristics of the included studies: year of publication; study
design; country where the study was conducted; research field;
WHODAS 2.0 version used; publication type.
The number of included studies increased from 1999 onwards.
More than 50% of the studies were published between 2013 and
2015. This percentage remains unchanged (>50% in the last three
years) even when studies in the field of psychiatry (n¼328; 40%)
are excluded on the grounds that the release in 2013 of DSM-5
[29]which recommends WHODAS 2.0 for assessment of disabil-
ity in adults aged 18 years and older with mental disorders
might have affected the global trend (Figure 2; Supplementary
Table S2).
Ninety-four percent (n¼762) of the publications were journal
articles (Supplementary Table S1); 4% (n¼29) were conference
proceedings [72100]; 2% book chapters (n¼16) [71,101115];
0.4% (n¼3) books [24,25,116]; and 0.1% (n¼1) an encyclopedia
term [117] (Supplementary Table S2).
The research groups responsible for the selected studies came
from 94 countries. The most heavily represented countries
(responsible for 571 studies, 44%) were the United States of
America (n¼162, 12%), Australia (n¼81, 6%), Spain (n¼77, 6%),
Italy (n¼69, 5%), India (n¼66, 5%), the Netherlands (n¼62, 5%),
and China (n¼54, 4%) (Supplementary Tables S1 and S2).
According to the Manual for WHO Disability Assessment
Schedule,[25] WHODAS 2.0 is available in more than 30 languages.
We found that WHODAS 2.0 was administered in 47 languages and
dialects; the following is a list of the first reported translations in
each case: Amharic,[118] Arabic,[119] Bengali,[120] Chinese,[121]
Danish,[122] Dari,[123] Dutch,[124] English,[125] Estonian,[126]
Farsi,[127] French,[128] Georgian,[129] German,[130] Greek,[131]
Haitian Creole,[132] Hebrew,[133] Hindi,[134] Indonesian,[135]
Italian,[136] Japanese,[137] Kannada,[138] Kinyarwanda,[139]
Korean,[140] Krio,[141] Latvian,[83] Luganda,[142] Lusoga,[143]
Malayalam,[144] Nepali,[145] Norwegian,[146] Polish,[147]
Portuguese,[148] Russian,[149] Slovenian,[150] Spanish,[151]
Swedish,[152] Tamil,[153] Thai,[154] Tok Pisin,[155] Turkish,[156]
Twi,[157] Ukrainian,[149] Urdu,[158] Xhosa,[159] Xitsonga,[160]
Yoruba,[161] and Zulu [162] (Supplementary Table S1).
Information about the types of study is presented in
Supplementary Tables S1 and S2: 60% (n¼483) were cross-sec-
tional studies; 11% (n¼89) were longitudinal studies; 8% (n¼61)
were randomized controlled trials; 4% (n¼36) reviews; 5% (n¼41)
theoretical or evaluative research; 3% (n¼27) follow-up studies;
3% (n¼22) non-randomized controlled trials; 2% (n¼17) random-
ized clinical trials; 1% (n¼10) study protocols; 1% (n¼7) qualita-
tive studies; 1% (n¼6) data comparisons; 1% (n¼6) guides; 0.4%
(n¼3) agreement studies (study of agreement between two or
more judges belonging to a focus group or to an expert panel);
0.2% (n¼2) case studies; and 0.1% (n¼1) Delphi surveys.
WHODAS 2.0 was used in 27 research fields; most frequently in
psychiatry (n¼328, 40%);[27,41,50,53,54,68,71,79,8385,9194,97,
102,109,110,115,118,121,122,123,128,129,132,145,155158,161,
163457] geriatrics (n¼122, 15%);[90,95,100,106,111,120,127,137,
138,153,154,458567] neurology (n¼74, 9%) [51,58,64,69,74,76,77,
81,88,89,98,99,568629]; disability and rehabilitation (n¼71, 9%;
[2426,44,52,5557,73,78,80,82,96,104,107,108,116,117,119,126,
134,136,143,150,152,630675]), health sciences (n¼45, 6%) [39,59,
60,103,105,112,114,133,142,160,162,676709]; and epidemiology
(n¼29, 4%).[48,70,87,101,159,710733] Together, these fields
accounted for 83% of all studies (n¼670). References for each of
the 27 research fields are reported in Supplementary Table S1 and
frequencies (number and percentage) for each field are displayed
in Supplementary Table S2.
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
Figure 1. Four-phase
Q8 flow diagram of the systematic review according to PRISMA.[34]
4 S. FEDERICI ET AL.
Taken together, the research studies involved thousands of
participants worldwide (Supplementary Table S1). Several studies
recruited subjects cross-sectionally or longitudinally in cohorts
from international surveys (e.g., European Study on the
Epidemiology of Mental Disorders ESEMeD [176,177,182,195,201,
205207,235,236,366,413]; WHO Study on global AGEing and adult
health SAGE [120,162,473,491,511,529,552,565,676,686,687,724,
734,735]; 10/66 Dementia Research Group [90,100,111,153,212,489,
501,508,514,516518,531534,536,540,548550,555,557,564]) or
national surveys (e.g., the Netherlands Study of Depression and
Anxiety NESDA [58,282,285,286,295,296,313,314,363,367,373,
430432,435437,440,441]).
Thirty percent (n¼244) of the selected studies did not report
which version of WHODAS 2.0 was administered.[3844,47,49,50,
5864,6769,72,74,75,78,80,83,85,87,91,9395,9799,102,106108,
122,132,155,158,168170,174,175,181,183,184,190,192,195,197,199,
200,204,208,211,222,225,229,234,244,246249,252,258,262,263,
270272,275285,287,288,298,299,301308,312,314320,327329,
334,336,337,341,345,357,358,363,366,370373,375377,386,388,394,
399,400,405,407,409,412,414,417419,421,430,431,434,437,438,441,
443,445447,455,458,459,461,465,468,469,476,477,496,497,500,501,
504507,512,513,516518,521,523,526,534,537539,541,547,551,
566569,574,575,581,582,585,598,599,601,603,619,626,636,641,645,
647,648,652,663,665,666,676,677,681683,685,688,693,695,696,704,
706,708710,721,725,726,728,729,733,735751]
Thirty percent (n¼248) used the 36-item version of WHODAS
2.0 [2426,45,46,48,51,5357,65,66,70,71,76,77,81,82,86,88,89,96,
101,103,110,112,114121,124,125,127,130,131,136138,143,144,
146148,150153,156,159,160,163,164,167,189,196,198,203,210,213,
217220,223,226228,232,233,240,242,243,253,254,265,266,268,269,
286,290,295,296,300,310,311,313,331,332,335,338,339,348,349,351,
361,367,374,385,395,398,403,408,410,411,423,432,435,436,439,440,
462,466,467,472,480,486,487,490,509,510,522 ,524,525,528,530,546,
560,572,573,577,579,583,586,588597,600,602,604618,622625,
627,629,631,632,634,638,639,644,649,650,657,659,660,662,668670,
672674,679,680,690692,700,702,705,713,722,752799]; 29%
(n¼244) the 12-item version [2426,37,48,52,55,73,79,84,90,92,100,
105,109,111,114,116,117,123,129,134,137,141,142,145,157,162,166,
171,180,185,186,188,191,194,209,212,215,221,224,237239,241,245,
250,251,256,257,260,261,264,265,267,273,274,289,291294,297,309,
322326,333,342344,353,354,356,359,360,364,365,368,369,379,
382384,387,389393,396,401,402,404,420,422,424428,442,444,
449,451454,456,460,463,464,470,473475,478,479,481485,488,
489,491494,498,499,508,511,514,515,519,520,527,529,531533,536,
540,542545,549,550,552,553,555559,561565,570,571,576,578,
584,586,587,620,621,628,630,635,637,642644,646,651,653655,658,
661,664,667,675,678,686,687,689,690,692,694,699,701,703,707,711,
712,715720,723,724,727,731,732,734,800827]; and 1% (n¼6)
WHODAS-Child.[27,139,828831]
Three percent (n¼24) of the selected studies administered the
World Mental Health (WMH) Survey Initiative version, WMH-
WHODAS.[104,133,161,176179,193,201,202,205207,216,321,355,
397,416,429,671,730,832834] The WMH Survey Initiative is a pro-
ject organized by the Assessment, Classification, and
Epidemiology (ACE) Group at the WHO and its purpose is to
obtain accurate information about the prevalence and correlates
of mental disorders, substance use disorder, and behavioral disor-
ders in countries in all WHO regions (http://www.hcp.med.harvard.
edu/wmh/). WMH-WHODAS is a modified version of WHODAS 2.0
which was added to the revised version of the Composite
International Diagnostic Interview (WMH-CIDI), a comprehensive,
structured diagnostic interview for assessing mental disorders.
[177]
Finally, 7% (n¼61) of the studies administered a subset of
WHODAS 2.0 items selected for their relevance to the research in
question.[113,126,128,135,149,154,165,172,173,182,187,214,230,231,
235,236,255,259,330,340,346,347,350,352,362,378,380,381,406,413,
415,433,448,450,457,471,495,502,503,535,548,554,580,584,631,633,
640,656,684,697,698,714,835843]
Forty-eight of the 811 selected studies reported the psycho-
metric properties of WHODAS 2.0.[24,25,80,86,121,124,125,130,136,
137,139,143,144,151,156,188,206,207,254,268,269,322324,332,502,
520,549,550,571,577,587,595,622,623,638,640,650,660,671,679,711,
723,736,764,769,799,812]
Internal consistency: Twenty-eight studies [25,121,124,125,130,
136,137,139,144,151,156,254,268,269,324,520,549,571,577,595,622,
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
Figure 2. Number of selected studies published per year.  although the last search was run on 31 December 2015, eight journal articles
[53,285,313,499,556,598,656,689] dated 2016 matching our criteria were already available online.
WHODAS 2.0: AN INTERNATIONAL SYSTEMATIC REVIEW 5