Validation of the Spanish Version of the Dementia Knowledge Assessment Tool 2

Abstract

Background:

There are currently no questionnaires to measure the knowledge of nurses about dementia or Alzheimer’s disease care in the Spanish language.

Objective:

To validate the Spanish version of the Dementia Knowledge Assessment Tool 2 (DKAT2-Sp).

Methods:

The DKAT2 was translated into Spanish and then back-translated. The new Spanish version was validated in a sample of 361 members of the nursing staff from 24 nursing homes and a sample of 297 nursing students in Spain. Psychometric properties were assessed through an item analysis, a Rasch analysis, differential item functioning analysis, construct validity (known groups), and internal consistency (Cronbach’s alpha).

Results:

The 21 items of the DKAT2-Sp fit the model well, showing a wide range of difficulty. Four items have differential items functioning between nursing professionals and students. The DKAT2-Sp shows acceptable internal consistency (Cronbach’s alpha = 0.76 for nursing professionals and 0.83 for students). Scores obtained in the known groups test were as hypothesized (Nursing home staff mean = 15.57 versus Nursing student mean = 12.85; p < 0.0001 for mean difference), supporting construct validity.

Conclusion:

The DKAT2-Sp is a reliable and valid questionnaire to measure knowledge about dementia in both nursing professionals and nursing students in Spanish-speaking contexts.

Keywords

Alzheimer’s disease dementia knowledge nursing care validation

INTRODUCTION

The most common form of dementia worldwide is Alzheimer’s disease (AD) (50–70% of cases) [1], followed by vascular dementia (12.5–25%) [2]. In Spain, there are approximately 600,000 people suffering from dementia, and around 400,000 with AD [3].

Quality of care for people with dementia should be based on the recommendations of clinical guidelines [4 –7]. An up-to-date knowledge of these recommendations and their context is an important issue for nursing practice. This knowledge can be measured; therefore, having validated tools is key to identifying knowledge gaps in health professionals, caregivers, and the general public [8].

A number of questionnaires and scales have been developed to measure knowledge about dementia care. These instruments have different psychometric properties and were targeted to different populations. The choice of the most appropriate instrument depends on its characteristics [8, 9].

By searching the literature, we identified four questionnaires to measure knowledge of AD, namely the Alzheimer’s Disease Knowledge Test (ADKT), 1988 [10]; the University of Alabama Alzheimer’s Disease Knowledge Test (UAB-ADKT), 1997 [11]; the Knowledge about Memory Loss and Care test (KAML-C), 2005 [12]; and the Alzheimer’s disease Knowledge Scale (ADKS), 2009 [13]. There are also four published questionnaires about knowledge on dementia: the Dementia Quiz (DQ) 1994 [14]; Dementia Knowledge 20 (DK-20) 2013 [15]; the Dementia Knowledge Assessment Tool Version 2 (DKAT2) 2013 [16]; and the Dementia Knowledge Assessment Scale (DKAS) 2015 [17, 18]. All of these questionnaires are written in English and were developed in English-speaking countries; there are no questionnaires for use in Spanish-speaking countries, even though dementia is also a major health problem in Spain and Ibero-American countries.

We selected the DKAT2 for translation and cultural adaptation into the Spanish context. This instrument was developed in Australia with the aim of providing a reliable and valid tool for measuring care workers’ knowledge of dementia. It is a three answer choice (Yes, No, I don’t know) questionnaire. The internal consistency of the DKAT2 with 21 items was good (Cronbach’s alpha = 0.79). DKAT2 includes items specific to late-stage dementia and is recommended for use in elderly care settings as a way to establish training needs and necessary information resources [16]. Also, this questionnaire has been translated into the Brazilian Portuguese language [19].

Therefore, the aim of our study was to adapt and validate the DKAT2 for a Spanish-speaking population and to examine its psychometric properties.

MATERIAL AND METHODS

Development of the Spanish version

Permission to use and translate the DKAT2 questionnaire was obtained from the authors. Two bilingual Nursing lecturers, whose mother language was Spanish, independently translated the DKAT2 into Spanish. The research team reviewed the different translations to resolve differences and ensure cultural adaptation, producing a single version (synthesis) from both translations. This first Spanish-version was back-translated by a bilingual nurse, whose mother language was English. The back-translated version was revised by the lead author of the original questionnaire, to ensure the quality of the translation, who made recommendations to improve two items. The team agreed on a final DKAT2 Spanish version (DKAT2-Sp) which maintains the structure and characteristics of the original questionnaire. The DKAT2-Sp questionnaire is shown in Table 1.

Table 1

Original (English) and Spanish version of the dementia knowledge assessment tool 2

DKAT2	DKAT2-Sp
Items^*	Items in Spanish
1. Dementia occurs because of changes in the brain (TRUE)	1. La demencia se produce debido a alteraciones en el cerebro
2. Brain changes causing dementia are often progressive (TRUE)	2. Los cambios cerebrales que causan demencia, a menudo, son progresivos
3. Alzheimer’s disease is the main cause of dementia (TRUE)	3. La enfermedad de Alzheimer es la principal causa de demencia
4. Blood vessel disease can also cause dementia (TRUE)	4. Las enfermedades de los vasos sanguíneos también pueden producir demencia
5. Confusion in an older person is almost always due to dementia (FALSE)	5. La confusión en una persona mayor, casi siempre, es debida a la demencia
6. Only older adults develop dementia (FALSE)	6. Solo las personas mayores desarrollan demencia
7. Knowing the likely cause of dementia can help to predict its progression (TRUE)	7. Conocer la causa probable de una demencia puede ayudar a predecir su progresión.
8. Incontinence always occurs in the early stages of dementia (FALSE)	8. La incontinencia siempre ocurre en las etapas tempranas de la demencia
9. Dementia is likely to limit life expectancy (TRUE)	9. La demencia es probable que limite la esperanza de vida.
10. When a person has late stage dementia, families can help others to understand that person’s needs (TRUE)	10. Cuando una persona está en una etapa avanzada de demencia, sus familiares pueden ayudar a otros a entender las necesidades de esa persona
11. People who have dementia may develop problems with visual perception (understanding or recognizing what they see) (TRUE)	11. Las personas que tienen demencia pueden desarrollar problemas de percepción visual (comprender y reconocer lo que ven)
12. Sudden increases in confusion are characteristic of dementia (FALSE)	12. Los aumentos repentinos del grado de confusión son característicos de la demencia
13. Uncharacteristic distressing behaviors may occur in people who have dementia (e.g., aggressive behavior in a gentle person) (TRUE)	13. Comportamientos perturbadores inusuales pueden ocurrir en personas con demencia (ej. Comportamiento agresivo en una persona tranquila)
14. Difficulty swallowing occurs in late stage dementia (TRUE)	14. La dificultad para la deglución ocurre en las etapas avanzadas de la demencia
15. Movement (e.g., walking, moving in a bed or chair) is limited in late stage dementia (TRUE)	15. La movilidad (ej. andar, moverse en la cama o un sillón) está limitada en las etapas avanzadas de demencia
16. Changing the environment (e.g., putting on a CD, opening or closing the blinds) will make no difference to a person who has dementia (FALSE)	16. Los cambios en el ambiente (ej. Poner un CD, abrir o cerrar las cortinas) no serán percibidos por una persona que tiene demencia
17. When a person who has dementia is distressed, it may help to talk to them about their feelings (TRUE)	17. Cuando una persona que tiene demencia está angustiada, puede ser útil hablarle sobre sus sentimientos.
18. It is important to always correct a person who has dementia when they are confused (FALSE)	18. Es importante corregir siempre a una persona con demencia cuando está confusa
19. A person who has dementia can often be supported to make choices (e.g., what clothes to wear) (TRUE)	19. A menudo, se puede ayudar a una persona con demencia a tomar decisiones (ej. Qué ropa llevar)
20. It is impossible to tell if a person who is in the later stages of dementia is in pain (FALSE)	20. Es imposible decir si una persona en etapas avanzadas de demencia tiene dolor
21. Exercise can sometimes be of benefit to people who have dementia (TRUE)	21. El ejercicio a veces puede ser beneficioso para las personas con demencia

^*Correct answer in brackets.

Psychometric testing

Before the main validation study, the questionnaire was piloted in a small sample of 19 nurses and assistant nurses from a nursing home, in order to test its comprehension and feasibility.

Two different samples were used to test the psychometric properties of the questionnaire. Inclusion criteria for sample 1 (nursing professionals) were: Registered Nurses (RNs) (4 years university degree), Assistant Nurses (ANs) (2 years diploma), and elderly care workers (1 year technical education) who work in 24 nursing homes in the province of Jaén (southern Spain). Inclusion criteria for sample 2 were: nursing students (2nd, 3rd, and 4th year) from the Faculty of Health Sciences of the University of Jaén (Spain). There were no exclusion criteria. All of the respondents participated on a voluntary basis. According to the methodological (sample size) recommendations for validation studies of the questionnaires, responses from 5 to 10 people per item were required. Since the DKAT2 has 21 items, a sample size of 210 was estimated as minimum [20].

Data collection procedure

Two instruments were used to collect the data: a questionnaire for participants’ demographic data and the DKAT2-Sp for assessing knowledge of dementia. Both questionnaires were self-administered by the participants.

Nursing homes

All of the directors of the nursing homes located in the province of Jaén (private or public administration) were asked to participate in the survey. Only one nursing home declined. After approval, enough questionnaires for all of the staff members were sent to each center. After two weeks, the completed questionnaires were collected.

Nursing students

Lecturers were informed and agreed to administer the questionnaires to their students during classes.

The study was performed from June 2016 to April 2017.

Ethics

The study was authorized by the Committee of Research Ethics of Jaén. Spanish Law of Data Protection was respected through the confidentiality and anonymity of the data.

Data analysis

Data were tabulated, coded, and cleaned in a spreadsheet the analysis. The total addition of the number of items with the correct answer was used to calculate the DKAT2-Sp score. The adjustment to the normal distribution of the score in DKAT2-Sp questionnaire was tested by the Kolmogorov-Smirnoff test and the histogram. The analysis included several methods: item analysis, Rasch model, validity, and reliability.

Item analysis

The analysis was performed for both samples. Two indices were calculated for each item: the difficulty index (percentage of correct answers), and the ignorance index (percentage of “I don’t know” answers) [20, 21]. According to the difficulty index, the items were classified into six categories: very easy (>90% correct answers); easy (75.1–90%); somewhat easy (50.1–75%); somewhat difficult (25.1–50%); difficult (10.1–25%); and very difficult (<10%).

The $\underline{Raschmodel}$ , based on the Item Response Theory (IRT) for psychometric validation of questionnaires, allows information on the performance of items and people to be differentiated. Rasch analysis was performed with the JMetrik software using the Joint Maximum Likelihood method [22]. Fit statistics were calculated: unweighted mean square of standardized residuals (UMS) (outfit) and weighted mean square of standardized residuals (WMS) (infit). Value 1 means a perfect fit, while outfit and infit values between 0.5 and 1.5 were acceptable [23]. The local independency between items was tested by using the Yen’s Q3 statistic [24]. Additionally, two differential item functioning analyses were conducted; the first between nursing professionals and nursing students, and the second between RNs and ANs. Effect size, with common OR and its 95% confidence interval were estimated, considering that an item has differential functioning when common OR <0.53 or >1.89 [25].

Construct $\underline{validity}$ was tested through the known groups method (groups with expected high and low knowledge on dementia care). The following four hypotheses were tested by Student’s t-test and one-way ANOVA: 1) Nursing professionals will achieve higher scores on the DKAT2-Sp than nursing students; 2) Registered nurses will achieve higher scores on the DKAT2-Sp than assistant nurses or elderly care workers; 3) Staff who have attended specific courses on dementia will achieve higher scores on the DKAT2-Sp than care versus those that have not; 4) Students with some experience in caring for family members with dementia will achieve higher scores on the DKAT2-Sp than those without such experience.

Reliability

Internal consistency of the questionnaire was estimated by Cronbach’s alpha.

RESULTS

Characteristics of participants

Sample 1 was composed of 361 members of nursing staff from 24 nursing homes (the response rate was 51.5%). Staff included RNs, ANs and elderly care workers. The total number of participants in Sample 2 was 297 students enrolled in a nursing degree program in the Faculty of Health Sciences in the University of Jaén (response rate 67.3%). Sample characteristics are depicted in Table 2.

Table 2

Sociodemographic characteristics of the samples

Variables	Nursing homes staff	Nursing students
	N = 361	N = 297
	Frequency (%)	Frequency (%)
Age (Mean; SD)	37.71; 1.26	21.82; 4.62
Gender
Female	342 (9.7%)	237 (79.8%)
Male	19 (5.3%)	57 (19.4%)
Professional category
Registered Nurses	69 (19.1%)
Assistant Nurses	242 (67.0%)
Elderly care workers	50 (13.9%)
Years of experience
<5 y	136 (37.8%)
5-15 y	175 (48.6%)
>15 y	49 (13.6%)
Have attending training courses on dementia
Yes	288 (79.8%)
No	72 (19.9%)
Know CPG
Yes	82 (22.7%)
No	238 (65.9%)
Year in nursing degree
2nd		119 (40.2%)
3th		84 (28.3%)
4th		93 (31.3%)
Experience caring for a family member with dementia
Yes		98 (33.0%)
No		199 (67.0%)

CPG, Clinical Practice Guideline.

Item analysis

Table 3 shows the difficulty and ignorance indices for the 21 items of the DKAT2-Sp. For nursing staff, there were 5 items considered to be very easy, 7 items that were easy, 8 items that were somewhat easy, and 1 item that was very difficult. For the nursing student sample, there were no items that were very easy, 5 items that were easy, 7 items that were somewhat easy, 8 items that were somewhat difficult and 1 item which was very difficult. Overall, students provided a lower percentage of correct answers than RNs and ANs in all of the items, but there were 4 items where the difference was very important (items 8, 11, 13, and 14).

Table 3

Item analysis of the DKAT2-Sp

	Nursing homes staff		Nursing students
Items index	Difficulty index %	Ignorance %	Difficulty index %	Ignorance index %
I 21	94.2	1.7	78.8	14.5
I 2	92.2	3.3	81.5	9.8
I 10	92.2	1.7	81.8	10.1
I 11	94	1.7	67.3	19.5
I 3	92.2	3.3	74.4	13.8
I 1	90	3.9	70.7	16.2
I 6	87	3	79.5	9.4
I 7	78.7	10	79.8	10.1
I 19	84	3.3	73.1	15.8
I 14	77.6	7.5	49.5	38.4
I 15	82	3	59.6	23.2
I 8	76.4	8.6	39.1	48.1
I 3	69.5	7.2	47.1	30.6
I 5	62.9	6.9	63.3	18.9
I 18	62.6	7.8	36.7	31.3
I 16	56.8	8.6	45.8	30.3
I 20	57.6	15.5	46.1	35
I 17	57.4	12.5	48.5	36
I 9	57.3	8	53.9	22.2
I 4	57.1	25.5	29.6	54.9
I 12	7.2	7.5	5.7	26.9

Items sorted from highest to lowest difficulty index in nursing home staff.

Rasch model

The Rasch analysis shows that all of the items fit the model well, because the values of WMS and UMS are between 0.61 and 1.2 (Supplementary Table 1). The items of the DKAT2-Sp cover a wide range of difficulty, from the easiest (Item 10 “When a person has late stage dementia, families can help others to understand that person’s needs” (true), difficulty: – 1.72) to the most difficult (Item 12 “Sudden increases in confusion are characteristic of dementia” (false), difficulty: 4.23). Figure 1 shows that the range of item difficulty overlaps with the range of ability of people to give the correct answer (Person density); this means that the 21 items of the questionnaire perform well.

Fig.1

The items map of the DKAT2-Sp. Right side shows the distribution of the scores obtained by people (expressed in Logit units) known as Person Density. Values higher than 0 denote high knowledge; values lower than 0 indicate low knowledge. Left side shows the distribution of the items according to their difficulty. Horizontal axis shows the items ordered from 1 to 21. Vertical axis shows the difficulty index of the items; higher values indicate more difficult items.

Differential item functioning

The analysis of differential item functioning (DIF) allows the determination of whether all of the items have an equally good performance in different populations. The questionnaire performs equally well with RNs and ANs because no item presents a significant amount of DIF. However, there are four items performing differently between nursing professionals and students: 2 favor the group of nursing staff (item 8 and 11), and another 2 favor the group of students (item 5 and 7) (Supplementary Table 2).

Construct validity

When the known-groups hypotheses were tested, we found that the DKAT2-Sp questionnaire scored higher in the groups where a higher degree of knowledge was expected in all cases (Table 4). Therefore, the DKAT2-Sp works as a good tool to identify people with high or low knowledge of dementia care.

Table 4

Construct validity of the DKAT2-Sp, comparing known groups with high or low expected level of knowledge on dementia care

Groups for comparison	Score in the scale	Statistic^*	p
Mean (Std. Dev.)
Category
Nursing homes staff (N = 351)	15.57 (2.60)	t = 11.31	p < 0.0001
Nursing students (N = 280)	12.85 (3.43)
Education
Registered Nurses (N = 68)	16.59 (2.20)	F = 6.66	p = 0.001
Assistant Nurses (N = 234)	15.32 (2.65)
Elderly care workers (N = 49)	15.35 (2.61)
Have attended some training course
Yes (N = 280)	15.87 (2.45)	t = 4.46	p < 0.0001
No (N = 70)	14.36 (2.87)
Students with experience in caring for family members with dementia
Yes (N = 94)	13.79 (2.98)	t = 3.28	p = 0.001
No (N = 184)	12.39 (3.55)

t, Student’s t-test; F, One-way analysis of variance.

Reliability

The DKAT2-Sp has adequate internal consistency (Cronbach’s alpha = 0.76 in the sample of nursing professionals and 0.83 in the sample of students). There was no item that, if deleted, increased the value of Cronbach’s alpha.

DISCUSSION

This study has focused on the cross-cultural adaptation and validation of the Spanish version of Dementia Knowledge Assessment Tool 2 (DKAT2) as a questionnaire that is useful to evaluate knowledge of dementia in those providing care [16]. The Spanish version, named DKAT2-Sp, shows good psychometric properties for validity and reliability. Internal consistency was acceptable (alpha: 0.76), slightly higher than found in the original study (0.67) [16]. Validity was tested by the known-groups method, like other studies: ADKS [13], AUB-ADKT [11], DK-20 [15], and DKAS [17]. DKAT2-Sp is able to differentiate correctly between people with high or low knowledge.

Our results fit well with those found in the original publication [16] as well as with the Brazilian Portuguese validation [19]. The DKAT2-Sp requires less than ten minutes to be answered, similar to the original version. This tool is available on the project’s website http://cuidsalud.com/en/inv/knowledge-alzheimer/.

Dementia is a worldwide health problem, but, to the best of our knowledge, there is no questionnaire in Spanish to measure knowledge about dementia care. Only a few questionnaires for the detection of dementia, cognitive impairment and memory problems have been translated and validated into Spanish, Portuguese, or Korean [19 , 26–29]. This paper reports on the first translation into Spanish and validation of a dementia knowledge questionnaire.

For the development of the Spanish version of the items, a sound method was used through translation, back-translation and proofreading by one of the authors of the original tool in order to ensure the semantic similarity of both versions. Also, the questionnaire was tested for comprehension in a small sample of RNs and ANs from a nursing home before the validation study was performed [20].

The DKAT2-Sp is quite similar to the original DKAT2 in structure and item wording. All items of the original questionnaire had semantic equivalence into Spanish. Therefore, it was not necessary to remove any item or perform major modifications for cultural reasons.

This questionnaire has been tested and validated in two different populations: nursing staff working in nursing homes and nursing students. This is not common in other studies to validate knowledge questionnaires that were developed in only one population. Most of the dementia knowledge questionnaires were validated in nurses (ADKT, DQ, AUB-ADKT, ADKS, DK-20, DKAT2) [10 , 13–16]. A few of them were tested on samples composed of nursing students (AUB-ADKT, ADKS) [11, 13] or medical students (ADKT) [10]. More recently, the DKAS has been tested with a few different groups: qualified nurses, health care professionals, health students, care workers, family carers and the general population, so it is currently the most widely-validated questionnaire [18].

Currently, it is proposed that methods based on the Item Response Theory (IRT), such as the Rasch model, be used in the validation studies of questionnaires, especially for knowledge questionnaires [30 –32]. The Rasch model allows for a separate measurement of items’ properties and respondents’ properties, providing researchers with important information to make decisions about the structure of the questionnaire. However, the IRT method has scarcely been used in studies involving questionnaires on Alzheimer’s disease or dementia [26 , 33]. Only one recent study used IRT for validation of the Korean version of the dementia questionnaire (Alzheimer’s Disease Knowledge Scale (ADKS-K)) [28]. In our study, analysis with the Rasch model showed that the DKAT2-Sp has an adequate range of difficulty of the items matching people’s ability, as shown on the item map. All of the items of the questionnaire fit well into the model, so the 21 items contribute to the measurement of the latent construct “knowledge on dementia”, as expected.

An important feature of the DKAT2-Sp is the three response options (Yes; No; I don’t know), which could be considered an advantage over questionnaires with only two response options [34, 35], because it allows respondents to explicitly declare their ignorance of a topic, without forcing them to choose the Yes or No option, avoiding the bias of correct responses by random. The ADKS [13] and AUB-ADKT [11] questionnaires have a different response format. By using the DKAT2-Sp, it is possible to identify topics on which there is erroneous knowledge (incorrect answers) and topics on which there is poor knowledge (don’t know answers). This is useful information for planning training programs for nurses or modifying the content of nursing student courses.

Our results show that most of the items of the DKAT2-Sp perform well for both nursing staff and students. There are only four items with differential functioning between the two groups. We have identified some items as especially difficult for students, such as those related to visual perception (I11), incontinence (I8), distressing behaviors (I13), and swallowing problems (I14).

Regarding the overall knowledge of dementia, as estimated by the DKAT2-Sp, our data show high scores in RNs (mean = 16.59; 78.9% of the maximum) and ANs and elderly care workers (mean = 15.33; 72.9% of the maximum). These results are higher than those reported by Toye in Australia (66.7%) [16] and Piovezan in Brazil (70.5%) [19], and quite similar to those of Robinson in Australia (76.1%) [36], all using the DKAT2.

A few studies have measured the knowledge of dementia care in nursing students. The mean ADKS score for nursing students in Malta was 19.36 (64.5% of the maximum) [37]. Another study in Tasmanian undergraduate nursing students using the DKAT2 showed similar figures (mean = 14.51; 69% of the maximum) [38]. In our study, the mean DKAT2-Sp score in students was 12.85 (61.2% of the maximum), which was lower than that in the other studies listed here. It should be acknowledged, however, that more than 40% of the study sample were second year students, which may have influenced the overall scores because they had not yet taken any courses on geriatric care. Overall, the DKAT2-Sp shows a lower amount of knowledge about dementia in students versus nursing staff; since this is the expected finding, it is a fact that supports the correct functioning of the questionnaire when measuring knowledge.

Three items appear among the least known for both nursing staff and students: “Blood vessel disease can also cause dementia” (I4), “When a person who has dementia is distressed, it may help to talk to them about their feelings” (I17), and “It is impossible to tell if a person who is in the later stages of dementia is in pain” (I20). Nursing students also declared scarce knowledge about other items (I8, I12, I14, I16, I18). This poor knowledge about the management of pain or distress in patients with dementia is an important gap; as a result, there are important aspects in nursing care.

Our research has several limitations that should also be mentioned. The sampling was not random; therefore, it is not possible to generalize these results because the sample of nursing students was from a single school. The response rate in some nursing homes was low; therefore, there may be an overestimation of the results, because the most knowledgeable and motivated nurses were those who completed the questionnaire. This could be considered when interpreting the results. We have addressed this possible bias by sampling a high number of nursing homes (up to 24) with different locations, organizations, and sizes, in order to increase the representativeness of the results.

Additionally, the DKAT2-Sp should be tested in family caregivers, because people with dementia remaining at home, living with their family, is becoming more and more frequent. In this context, this questionnaire could be a useful way to detect areas of intervention with family caregivers.

In conclusion, the DKAT2-Sp is an adequate and useful questionnaire to measure the level of knowledge about dementia in nursing staff and nursing students in a Spanish-speaking context. The DKAT2-Sp could be used for clinical, educational, or research purposes, and the data obtained can be comparable with studies using the original DKAT2.

Footnotes

ACKNOWLEDGMENTS

The authors acknowledge all of the nurses and staff from nursing homes and all of the nursing students from the University of Jaén who have participated in this study. Special thanks to Dr. Christine Toye from Curtin University (Australia) for permission to use the questionnaire and for critical review of the manuscript.

Authors’ disclosures available online ().

The supplementary material is available in the electronic version of this article: .

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