ORIGINAL RESEARCH
Quan i ying Knowledge o Alzheime ’s Disease:
An Analysis o he Psychome ic P ope ies
o he Alzheime ’s Disease Knowledge Scale
Guille mo Ga cia-Ribas .Elena Ga cı
´a-A celay .Alonso Mon oya .
Jo ge Mau ino .Ja ie Balles e os
Recei ed: No embe 16, 2020 / Accep ed: Janua y 6, 2021 / Published online: Janua y 29, 2021
ÓThe Au ho (s) 2021
ABSTRACT
In oduc ion: The Alzheime ’s Disease Knowl-
edge Scale (ADKS) is one o he mos popula
ins umen s o assessing a pe son’s knowledge
ega ding Alzheime ’s disease (AD). The objec-
i e o his s udy was o explo e ADKS i em
cha ac e is ics wi h i em esponse heo y (IRT)
p ocedu es.
Me hods: A nonin e en ional web-based s udy
was conduc ed. A nonpa ame ic IRT p ocedu e,
Mokken analysis, was used o explo e he
unde lying la en s uc u e o he ADKS and
ADKS i em cha ac e is ics ega ding scalabili y
and iola ions o he mono one homogenei y
(MH) model. A andom-e ec s me a-analysis
was implemen ed ha combined ADKS sco es
om independen s udies.
Resul s: A o al o 447 employees o a pha -
maceu ical company pa icipa ed in he s udy.
The mean ADKS sco e was 21.2 (SD 2.8). Mok-
ken analysis showed ha mos ADKS i ems (22
o 30) do no i o any scale and can be con-
side ed o be scale independen . Two i ems (#1:
pa icula ly p one o dep ession; #20: dep es-
sion can be mis aken o AD) i o a domain
ela ing o dep ession, ano he wo i ems (#2:
men al exe cise can p e en AD de elopmen ;
#8: bene i o psycho he apy) can be ela ed o
po en ial p e en ion and imp o emen , and
ou i ems (#12: poo nu i ion can make he
symp oms wo se; #18: high choles e ol may
inc ease he isk o AD; #26: high blood p essu e
may inc ease he isk o AD; #27: genes can only
pa ially accoun o AD de elopmen ) i o a
isk ac o domain. As expec ed om hose
esul s, nei he he o e all scale (H= 0.033) no
i s i ems showed app op ia e scalabili y index
alues, sugges ing ha ADKS does no i o a
MH model. Ele en i ems showed iola ions o
he assump ions o he MH model. The me a-
analy ical a e age sco e was 21.78 (95% CI
20.67–22.90), wi h heal hca e p o essionals and
ca egi e s showing he highes le els o AD
knowledge.
Conclusion: Al hough he ADKS does no p e-
sen a unidimensional s uc u e, i s indepen-
den i ems oge he p o ide a comp ehensi e
spec um o in o ma ion ega ding AD
knowledge.
G. Ga cia-Ribas
Depa men o Neu ology, Hospi al Uni e si a io
Ramo
´n Y Cajal, Mad id, Spain
E. Ga cı
´a-A celay (&)J. Mau ino
Medical Depa men , Roche Fa ma, Mad id, Spain
e-mail: [email p o ec ed]
A. Mon oya
Medical A ai s, Neu oscience, Ho mann-La Roche
Limi ed, Mississauga, ON, Canada
J. Balles e os
Depa men o Neu osciences and CIBERSAM,
Uni e si y o he Basque Coun y, Leioa, Spain
Neu ol The (2021) 10:213–224
h ps://doi.o g/10.1007/s40120-021-00230-x
Keywo ds: Alzheime ’s disease; Alzheime ’s
Disease Knowledge Scale; Knowledge;
Psychome ic assessmen
Key Summa y Poin s
Why ca y ou his s udy?
Lack o knowledge and misconcep ions
abou Alzheime ’s disease a e c i ical
p oblems a ound he wo ld.
Imp o ing he public’s unde s anding o
Alzheime ’s disease may acili a e ea ly
diagnosis, educe s igma abou he
disease, and p omp a discussion o he
needs o pa ien s and hei amilies.
Wha was lea ned om he s udy?
The Alzheime ’s Disease Knowledge Scale
is a sel - a ed ques ionnai e ha assesses
wha people know abou Alzheime ’s
disease in di e en key domains. In
addi ion o i s good psychome ic
p ope ies, i is an easy- o-implemen and
eliable ool o e alua ing knowledge
gaps in laype sons, ca egi e s, and
heal hca e p o essionals.
DIGITAL FEATURES
This a icle is published wi h digi al ea u es,
including a summa y slide, o acili a e unde -
s anding o he a icle. To iew digi al ea u es
o his a icle go o h ps://doi.o g/10.6084/
m9. igsha e.13526369.
INTRODUCTION
Alzheime ’s disease (AD) leads o i e e sible
p og essi e cogni i e impai men . I is he mos
common ype o demen ia, a ec ing millions o
people wo ldwide [1,2].
Al hough in o ma ion abou cogni i e
impai men has been widely dissemina ed
h ough nume ous awa eness campaigns and
educa ional p og ams, se e al s udies ha e
e ealed di e en gaps in he public’s knowl-
edge ega ding demen ia and AD [3–6]. Ade-
qua e AD knowledge h oughou socie y could
lead o ea lie iden i ica ion o his diso de in
he popula ion, which would esul in ea lie
app op ia e heal hca e o people wi h demen-
ia and would dec ease he s igma associa ed
wi h AD [3]. In addi ion, unde s anding peo-
ple’s pe cep ions o AD can be c ucial when
ca ying ou speci ic psychosocial in e en ion
s a egies [3].
Va ious ins umen s ha e been de eloped o
assess knowledge o demen ia and AD, includ-
ing he Alzheime ’s Disease Knowledge Tes
(ADKT), he Uni e si y o Alabama Alzheime ’s
Disease Knowledge Tes o Heal h P o essionals
(UAB-ADKT), he Demen ia Quiz (DQ), he
Knowledge abou Memo y Loss and Ca e es
(KAML-C), he Alzheime ’s Disease Knowledge
Scale (ADKS), he Demen ia Knowledge Assess-
men Tool Ve sion 2 (DKAT2), he Demen ia
Knowledge 20 (DK-20), and he Uni e si y o
Jae
´n Alzheime ’s Ca e Scale (UJA ACS) [7–9].
The ADKS is one o he mos widely used o
hese ins umen s [3]. I is a 30-i em ques ion-
nai e ha measu es wha people know abou
AD ac oss se en c i ical knowledge domains:
isk ac o s (six i ems), symp oms (4 i ems),
assessmen and diagnosis (4 i ems), disease a-
jec o y (4 i ems), li e impac (3 i ems), ea -
men and managemen (4 i ems), and
ca egi ing (5 i ems) [10]. The ADKS has ade-
qua e psychome ic p ope ies and is designed
o be adminis e ed o he gene al public,
pa ien s, ca egi e s, and heal hca e p o ession-
als [8,10].
We aimed o achie e a g ea e unde s anding
o he psychome ic cha ac e is ics o he ADKS
by applying nonpa ame ic i em esponse he-
o y (IRT) p ocedu es o he esponses ob ained
om an anonymous su ey. To ou knowledge,
his is he i s ime ha a s udy has ocused on
ADKS i em cha ac e is ics ins ead o using clas-
sical app oaches ha ely on he eliabili y and
alidi y o he o al ADKS sco e.
214 Neu ol The (2021) 10:213–224
METHODS
S udy Design and Pa icipan s
A nonin e en ional, c oss-sec ional, sel -com-
ple ed, web-based s udy ( he CONOCE s udy)
was conduc ed among employees o a pha ma-
ceu ical company in Spain (Roche Fa ma SA).
This s udy was conduc ed in acco dance wi h
he Good Clinical P ac ice Guidelines o he
In e na ional Con e ence on Ha monisa ion
and wi h he e hical p inciples o he Decla a-
ion o Helsinki. I was app o ed by he in es-
iga ional e iew boa d o he Hospi al
Uni e si a io Ramo
´n y Cajal, Mad id, Spain
( e e ence code: 372). In o med consen was
ob ained om all subjec s. Pa icipan s we e
in i ed o pa icipa e om Decembe 2019 o
Feb ua y 2020.
S udy P ocedu es
Pa icipan s answe ed ques ions ega ding
demog aphic da a and comple ed he ADKS.
Each ADKS i em is a s a emen ha can be
ei he alse ( alue 0) o ue ( alue 1) [10].
‘‘T ue’’ is he co ec esponse o 18 i ems,
whe eas he emaining 12 i ems a e e e se
sco ed, so ‘‘ alse’’ is he co ec esponse o
hose i ems. A highe sco e indica es be e
knowledge ega ding AD.
S a is ical Analyses
Con inuous a iables we e desc ibed using
means and s anda d de ia ions, and ca ego ical
a iables using equencies and pe cen ages. A
nonpa ame ic IRT p ocedu e—Mokken analy-
sis—was used o explo e he unde lying mea-
su emen s uc u e o he ADKS and how well i
i s o he mono one homogenei y (MH) model,
which allows people o be anked on AD
knowledge based on hei o al ADKS sco es.
Among o he c i e ia, he MH model assumes
unidimensionali y o he la en cons uc mea-
su ed wi h he scale, as assessed wi h Loe-
inge ’s scalabili y coe icien s [11]. Scalabili y
coe icien s desc ibe he deg ee o which indi-
idual i ems (H
i
), pai s o i ems (H
ij
), and he
o e all se o i ems (H) o m a scale ha can be
used o ank people on hei abili y (knowledge)
ega ding he la en ai being measu ed (AD
knowledge). Scalabili y coe icien s e lec he
a io o he obse ed Gu man e o equency
(inadequacy wi h which he achie emen le el
is ma ched o he di icul y o he i em being
measu ed) o he expec ed Gu man e o e-
quency (i.e., based on chance alone) o a pai o
i ems [12,13]. When da a i well o he MH
model, H
i
alues a e posi i e and ange om
ze o o 1, whe e a alue o 1 indica es no
Gu man e o s and alues close o ze o indi-
ca e many Gu man e o s. To de ine an
app op ia e unidimensional scale, each one o
he 30 ADKS i ems was equi ed o ha e a scal-
abili y coe icien (H
i
)o C0.30 and an o e all
scale scalabili y index (H)o C0.30 [14]. We
ex ac ed he published e ec sizes o he ADKS
om p e ious s udies (mean alues, s anda d
de ia ions, and sample sizes) and combined
hem wi h ou own esul s using a andom-e -
ec s me a-analysis o a i e a an es ima e o
he o e all AD knowledge and how his
knowledge di e ed be ween popula ion sub-
g oups [15].
We pe o med he s a is ical analyses wi h R
e sion 4.0 (h ps://c an. -p ojec .o g/) using
he lib a ies ‘‘mokken’’ o IRT and ‘‘me a o ’’ o
he andom-e ec s me a-analysis [11,16,17].
RESULTS
A o al o 447 subjec s pa icipa ed in he s udy.
Mos pa icipan s we e aged be ween 18 and
50 yea s (78%), emale (65%), and had a bach-
elo ’s o mas e ’s deg ee (89%). Fo y- wo
(9.4%) pa icipan s epo ed ha ing a i s -de-
g ee ela i e wi h AD. Demog aphic cha ac e -
is ics o he sample a e shown in Table 1.
O e all AD Knowledge
The mean ADKS sco e was 21.2 (SD 2.8; 95% CI
20.9–21.4). Fo ou i ems (ca egi ing domain:
‘‘in o med decisions’’ and ‘‘di icul ies wi h sel -
ca e;’’ isk ac o s domain: ‘‘a isk o high
blood p essu e’’ and ‘‘a isk o high choles-
e ol’’), less han 50% o he answe s we e
Neu ol The (2021) 10:213–224 215
co ec . Figu e 1shows he ADKS i ems anked
by pe cen age o co ec answe s (‘‘pe cen co -
ec ’’) a e e e sing he sco es o in e se
i ems.
Figu e 2shows he equency dis ibu ion o
sco es along he obse ed ange (13–29 poin s);
50% o he obse a ions occu be ween he
sco e alues o 19 and 23 (which he e o e co -
espond o he 25% and 75% pe cen iles o he
ADKS sco e dis ibu ion, espec i ely).
Unde lying S uc u e o he ADKS
and I em Cha ac e is ics
Mos o he ADKS i ems (22 o 30) do no i o
any scale and can be conside ed o be scale
independen . Two i ems (#1 and #20) i o a
knowledge domain ela ed o dep ession,
ano he wo i ems ( #2 and #8) a e ela ed o AD
p e en ion and eco e y, and ou i ems (#12,
#18, #26, and #27) i o a knowledge domain
ela ed o isk ac o s. Table 2shows he esul s
o he au oma ed i em selec ion p ocedu e
(AISP) ha was implemen ed o asce ain he
knowledge domains co e ed by he ADKS in he
cu en su ey.
As expec ed om hose esul s, nei he he
o e all scale (H= 0.033) no i s i ems showed
app op ia e scalabili y indices. No i em had a
scalabili y index H
i
C0.30, and indices we e in
ac qui e low, sugges ing ha he ADKS does
no i a MH model. Mo eo e , 11 i ems iola ed
assump ions o he MH model (Table 2).
Me a-analysis o he ADKS Sco es
Table 3shows he main cha ac e is ics and
e ec sizes o he s udies ha ha e epo ed
ADKS mean sco es (including he p esen
s udy). Figu e 3displays a o es plo wi h indi-
idual and combined ADKS sco es. The com-
bined esul has a ela i ely high mean sco e
(mean 21.78; 95% CI 20.67–22.90) ha di e s
signi ican ly among subg oups (Q es = 11.35
on 4 d ; p alue = 0.02), wi h heal h p o es-
sionals p esen ing he highes mean sco e (11
da a poin s, mean ADKS = 22.9), ollowed clo-
sely by ca egi e s (3 da a poin s, mean ADKS =
21.6). A s udy conduc ed by Ba al e al. ound
ha s uden s ob ained he lowes sco es (ADKS
sco e = 15.4), whe eas he subg oup o heal h
p o essionals yielded he highes sco es in a
s udy by Ca pen e e al. (ADKS sco e = 27.4)
[10,18].
DISCUSSION
The ADKS belongs o a g oup o psychome ic
scales ha aim o assess knowledge ega ding
AD, as his can assis wi h he de elopmen o
psychoeduca ional cu icula and in e en ions
o demen ia ca e [7]. The o iginal alida ion o
he ADKS included di e en popula ions in he
USA (college s uden s, olde adul s wi h no
cogni i e impai men , demen ia ca egi e s, and
heal hca e p o essionals), and he scale was also
applied o o alida ed by s udying college s u-
den s in Sou h Ko ea and Nepal, ca egi e s in
he Ne he lands, he Uni ed Kingdom, and
Table 1 Demog aphic cha ac e is ics o he s udy sample
(n= 447)
n%
Gende
Female 292 65.3
Age, yea s
B30 66 14.8
31–40 113 25.3
41–50 170 38.0
51–60 93 20.8
[60 5 4.7
Educa ion
Seconda y 23 5.1
Voca ional aining 26 5.8
Bachelo ’s deg ee o equi alen 167 37.4
Mas e ’s deg ee o equi alen 203 45.4
PhD o equi alen 28 6.3
AD ca egi e 42 9.4
AD Alzheime ’s disease
216 Neu ol The (2021) 10:213–224
Sou h Ko ea, and heal hca e p o essionals in
Aus alia, B azil, China, India, Malaysia, and
Spain [8,10,18–27]. I was also adminis e ed o
laypeople in B azil, and was included as a
knowledge esou ce on he websi e o he Alz-
heime ’s Associa ion in he USA [26,28].
Despi e some c i icisms o he ADKS ha a e
linked o dicho omous i em assessmen ,
e e se-sco ed i ems, and a likely ceiling e ec
o some i ems, his is cu en ly one o he ew
alida ed scales o be used ei he a he in e -
en ion planning s age o as a signal o ou -
come measu e when e alua ing in e en ions
o he o e all knowledge o demen ia [7,8,29].
Because he ADKS was designed o es ima e he
o e all knowledge ega ding AD, no an
unde lying cons uc o dimension, se e al
common psychome ic s a is ics such as in e -
nal eliabili y o analyses o dimensional s uc-
u e a e no as ele an as hey migh be o
o he scales ha a e used o e alua e he e ec-
i eness o in e en ions [7,8].
Ou s udy shows ha he ange o pe cen
co ec alues o ADKS i ems and he nea -
symme ic dis ibu ion o o e all sco es may
suppo i s use ulness o ela i es o people
wi h cogni i e impai men who a e seeking a
neu ological e alua ion, and o guide he psy-
choeduca ional e o s o demen ia suppo
g oups [10]. Howe e , he esul s o he IRT
app oach do no suppo scale unidimension-
ali y o he anking o subjec s ac oss a con in-
uum o AD knowledge. The AISP indica es ha
he unde lying s uc u e o he ADKS does no
i he o iginally heo ized domains. I ins ead
sugges s ha i ems a e independen , which is
ele an o a gene al knowledge scale ha is
used o de ec knowledge gaps, bu no o
anking indi iduals.
Ca pen e e al. [10] de eloped he ADKS in
2009 o inco po a e new scien i ic unde s and-
ing abou AD in o he ADKT. All measu es
equi e pe iodic upda es o keep pace wi h
de elopmen s and new in o ma ion eme ging
om he apidly e ol ing ield o cogni i e
diso de s. In hei sys ema ic e iew o AD
knowledge ou come measu es, Spec o e al.
ecommend he de elopmen o a
Fig. 1 Alzheime ’s Disease Knowledge Scale: co ec answe s
Neu ol The (2021) 10:213–224 217
con empo a y ins umen ha inco po a es
i ems ela ing o biopsychosocial and pa ien -
cen e ed models o AD ca e [7]. Ou esul s do
no suppo he use o he o al ADKS sco e o
meaning ully ank people acco ding o hei AD
knowledge, as he da a did no i wi h he MH
model. Howe e , e en hough he IRT esul s
indica e ha he ADKS is no sui able o e al-
ua ing people a he indi idual le el, i does no
di ec ly ollow ha g oup mean sco es based on
knowledge acc ued om mul iple independen
i ems a e no sui able o compa ing popula ion
subg oups in e ms o hei AD knowledge, as
ou me a-analy ical esul s show. In ac , wha
migh be a gued is ha he ADKS is a use ul
ou come measu e o e alua ing he e ec i e-
ness o in e en ions. When Ha ink e al.
e alua ed an e-lea ning cou se o demen ia
ca egi e s, hey did no ind a signi ican di -
e ence be ween subjec s andomized o he
expe imen al psychoeduca ional in e en ion
(n= 37, mean ADKS sco e = 24.37, SD = 2.94)
and hose andomized o he con ol in e en-
ion (n= 46, mean ADKS sco e = 24.39, SD =
2.90) [20]. The mean di e ence (MD) was no
signi ican ly di e en be ween g oups (MD
-0.02, 95% CI -1.30 o 1.26) and did no
show a signi ican change a ou mon hs om
baseline (n= 83, mean ADKS sco e = 24.28,
SD = 3.35). Howe e , e en gi en he se ious
doub s ega ding he use o ADKS as an ou -
come measu e o e alua e in e en ions,
knowledge o he co ec ness o esponses may
be use ul when designing and de eloping
in e en ions aimed a imp o ing AD knowl-
edge among ca egi e s and heal h p o ession-
als—aims ha also guided he de elopmen o
he ADKS [10].
This s udy has se e al limi a ions. The e is
pa icipan sel -selec ion bias; i is possible ha
he su ey ended o a ac he mos mo i a ed
esponden s o hose who we e mos knowl-
edgeable abou AD. In addi ion, ca ying ou
he s udy in only one company may ha e lim-
i ed he gene alizabili y o he indings o o he
heal hca e communi ies, o e en he gene al
popula ion.
Fig. 2 Alzheime ’s Disease Knowledge Scale: dis ibu ion o sco es
218 Neu ol The (2021) 10:213–224
Table 2 Co ec answe s, esul s om he Mokken au oma ed i em selec ion p ocedu e, scalabili y coe ficien s, and
mono one homogenei y model iola ion coun s o he Alzheime ’s Disease Knowledge Scale (n= 447)
I em no. and wo ding Co ec
answe s
n(%)
AISP Scalabili y
coe ficien
No. o
significan
iola ions
1. People wi h AD a e pa icula ly p one o dep ession 327 (73) 3 0.057 0
2. I has been scien ifically p o en ha men al exe cise can p e en a
pe son om ge ing AD
334 (75) 2 0.047 1
3. A e symp oms o AD appea , he a e age li e expec ancy is
6–12 yea s
249 (56) 0 0.015 0
4. When a pe son wi h AD becomes agi a ed, a medical examina ion
migh e eal o he heal h p oblems ha caused he agi a ion
277 (62) 0 -0.006 1
5. People wi h AD do bes wi h simple ins uc ions, gi ing one s ep
a a ime
432 (97) 0 0.003 1
6. When people wi h AD begin o ha e di ficul y aking ca e o
hemsel es, ca egi e s should ake o e igh away
156 (35) 0 0.045 1
7. I a pe son wi h AD becomes ale and agi a ed a nigh , a good
s a egy is o y o make su e ha he pe son ge s plen y o
physical ac i i y du ing he day
274 (61) 0 -0.004 1
8. In a e cases, people ha e eco e ed om AD 398 (89) 2 -0.002 2
9. People whose AD is no ye se e e can benefi om psycho he apy
o dep ession and anxie y
398 (89) 0 0.054 1
10. I ouble wi h memo y and con used hinking appea s suddenly,
i is likely due o AD
283 (63) 0 0.019 0
11. Mos people wi h AD li e in nu sing homes 334 (75) 0 -0.008 1
12. Poo nu i ion can make he symp oms o AD wo se 385 (86) 1 0.073 0
13. People in hei 30s can ha e AD 341 (76) 0 0.039 0
14. A pe son wi h AD becomes inc easingly likely o all down as he
disease ge s wo se
377 (84) 0 0.031 0
15. When people wi h AD epea he same ques ion o s o y se e al
imes, i is help ul o emind hem ha hey a e epea ing
hemsel es
343 (77) 0 0.034 0
16. Once people ha e AD, hey a e no longe capable o making
in o med decisions abou hei own ca e
203 (45) 0 0.063 0
17. E en ually, a pe son wi h AD will need 24 h supe ision 365 (82) 0 0.006 1
18. Ha ing high choles e ol may inc ease a pe son’s isk o
de eloping AD
149 (33) 1 0.092 0
19. T emo o shaking o he hands o a ms is a common symp om
in people wi h AD
340 (76) 0 -0.006 3
Neu ol The (2021) 10:213–224 219
CONCLUSION
Lack o in o ma ion and misconcep ions abou
AD a e s ill c i ical p oblems. Whe eas he ADKS
does no show he cha ac e is ics and dimen-
sionali y expec ed o a scale whose aim is o
e alua e a nonobse able la en ac o o con-
s uc , i does p esen a se o i ems ha oge-
he con ibu e o he o e all knowledge o AD,
and so i migh be use ul o e alua ing knowl-
edge gaps ega ding AD. As o iginally desc ibed,
he ADKS can be used wi h laypeople o ca e-
gi e s o de e mine wha hey know abou AD,
and by heal hca e p o essionals and suppo
g oups o guide psychoeduca ional e o s.
Table 2 con inued
I em no. and wo ding Co ec
answe s
n(%)
AISP Scalabili y
coe ficien
No. o
significan
iola ions
20. Symp oms o se e e dep ession can be mis aken o symp oms o
AD
288 (64) 3 0.060 0
21. AD is one ype o demen ia 297 (66) 0 -0.002 0
22. T ouble handling money o paying bills is a common ea ly
symp om o AD
335 (75) 0 0.048 0
23. One symp om ha can occu wi h AD is belie ing ha o he
people a e s ealing one’s hings
334 (75) 0 0.075 0
24. When a pe son has AD, using eminde no es is a c u ch ha can
con ibu e o decline
301 (67) 0 0.038 0
25. P esc ip ion d ugs ha p e en AD a e a ailable 410 (92) 0 0.015 0
26. Ha ing high blood p essu e may inc ease a pe son’s isk o
de eloping AD
149 (33) 1 0.064 0
27. Genes can only pa ially accoun o he de elopmen o AD 409 (92) 1 0.098 0
28. I is sa e o people wi h AD o d i e as long as hey ha e a
companion in he ca a all imes
412 (92) 0 0.005 1
29. AD canno be cu ed 424 (95) 0 0.052 0
30. Mos people wi h AD emembe ecen e en s be e han hings
ha happened in he pas
354 (79) 0 0.033 0
An AISP alue o ze o deno es an i em ha does no fi o any scale
AD Alzheime ’s disease, AISP au oma ed i em selec ion p ocedu e, MH mono one homogenei y
220 Neu ol The (2021) 10:213–224
ACKNOWLEDGEMENTS
The au ho s hank all Roche employees who
ook hei ime o comple e he su ey.
Funding. This s udy and he jou nals Rapid
Se ice Fee we e unded by Roche Fa ma Spain
Medical Depa men .
Au ho ship. All named au ho s mee he
In e na ional Commi ee o Medical Jou nal
Edi o s (ICMJE) c i e ia o au ho ship o his
a icle, ake esponsibili y o he in eg i y o
he wo k as a whole, and ha e gi en hei
app o al o his e sion o be published.
Au ho ship Con ibu ions. All au ho s
made subs an ial con ibu ions o he concep-
ion and design o he s udy, da a acquisi ion,
Table 3 A e age Alzheime ’s Disease Knowledge Scale sco es o di e en popula ions
S udy and yea Coun y Popula ion nMean ADKS (SD)
Ca pen e [10] USA S uden s
Olde adul s wi h no cogni i e impai men
Senio cen e s a
Demen ia ca egi e s
Heal hca e p o essionals
484
89
61
54
75
20.19 (3.59)
24.10 (2.95)
20.15 (4.10)
22.70 (4.27)
27.40 (1.89)
No dhus [19] No way Psychologis s 956 24.10 (2.50)
Smy h [22] Aus alia Heal hca e p o essionals 360 23.60 (3.26)
Ha ink [20] Ne he lands and UK Demen ia ca egi e s 83 24.28 (3.35)
Hughes [28] USA Alzheime ’s Associa ion websi e isi o s 552 23.11 (3.36)
Kim [21] Sou h Ko ea S uden s
Heal hca e p o essionals
Demen ia ca egi e s
422
64
89
19.29 (2.93)
21.56 (2.61)
17.93 (2.88)
Ma Nu i [23] Malaysia Pha macis s 445 19.05 (3.69)
Sulli an [8] Aus alia Heal hca e p o essionals 55 22.80 (2.89)
Amado [26] B azil Laypeople
Heal hca e p o essionals
899
515
20.50 (3.33)
23.46 (3.51)
Alac eu [24] Spain Pha macis s
Gene al p ac i ione s
578
104
22.95 (2.50)
24.40 (2.30)
S om [25] India Nu ses 15 19.50 (3.00)
Ba al [18] Nepal S uden s 385 15.45 (2.95)
Wang [27] China Gene al p ac i ione s 341 21.42 (2.73)
This s udy 2020 Spain Roche employees 447 21.16 (2.83)
ADKS Alzheime ’s Disease Knowledge Scale, SD s anda d de ia ion
Neu ol The (2021) 10:213–224 221
