Review of Nurses’ Knowledge of Delirium, Dementia and Depressions (3Ds): Systematic Literature Review

This paper aims at reviewing literature on nurses’ knowledge of delirium, dementia and depression (3Ds) which are rapidly increasing worldwide as the population ages, and to identify interventions that have shown effectiveness in improving nurses’ knowledge level of these diseases. Nurses’ knowledge of delirium, dementia and depression is essential to providing quality patient care. To access the literature, online databases including Medline (OVID), CINAHL (EBSCO), Nursing and Allied Health Source (ProQuest), and Health and Medicine (ProQuest), in addition to Google scholar search engine, were searched using key words “delirium”, “dementia”, “depres-sion”, “nurse * ”, “knowledge” and their alternative words. Overall, 20 articles were found to meet the criteria for inclusion in the review. The study found that nurses’ knowledge of the 3Ds was generally low, and they were not particularly able to differentiate between the three diseases. It is important that health care systems are adequately resourced to meet this growing challenge. Nurses should receive appropriate training about the 3Ds, and their knowledge be reinforced through continuing education.


Methodology
For this research study previously selected search keywords and phrases was utilised in combination with Boolean operators OR, as well as, AND. The previously selected keywords include "nurse * " AND "knowledge" or "information" or "awareness" or "education" or "understanding". These keywords were combined separately with "depression", "delirium" and "dementia". The search strategy has been designed on the basis of the Boolean search method and was run on relevant electronic databases, including MEDLINE (OVID), CINAHL (EBSCO), Nursing and Allied Health Source (ProQuest), and Health and Medicine (ProQuest) were searched for studies that addressed nurses' knowledge of the 3Ds and interventional studies that aimed at testing the effectiveness of educational programmes to enhance such knowledge. A further search, for the relevant literature, was carried out using Google Scholar. Articles published in peer-reviewed journals, in English, and during the last 10 years, were included. Studies that targeted patients, families, and health care providers other than nurses were excluded from this review. The database searches resulted in 248 articles after removing duplicates. The titles, abstracts, and full texts of these articles were reviewed for relevance, and finally, 20 articles were found to meet the eligibility criteria for this review. Among the 20 articles eight articles focused on knowledge assessment while the remaining 12 articles had looked at the effectiveness of interventions in improving nurses' knowledge. Moreover, among the articles, 11 were on delirium, 4 were on dementia and 5 were on depression. The following Figure 1 demonstrates the process of identifying the relevant articles.

Result
Findings of this review on knowledge of nurses of delirium, dementia and depression and the effective educational interventions are presented separately below.

Nurses Knowledge of Delirium and the Relevant Knowledge
Development Interventions (Table 1) As identified in the methodology, 11 articles on delirium were reviewed. Among the 11 articles, seven were on knowledge of delirium and the remaining four articles were on knowledge development interventions. The studies by Baker [17]- [20]. The study by Fick et al. (2007), on the other hand, used 5 validated case vignettes and the Mary Starke Harper Aging Knowledge Exam (MSHAKE), which are already validated [21]. The studies by Agar et al. (2011) used validated interview questions as the assessment tool and validated semi-structured interview questions and the study by Hosie et al. (2014) used a validated case vignette as the assessment tool [5] [22]. Interestingly, three of the studies were undertaken in USA, two were undertaken in Australia, one was undertaken in south-east Asia and one was undertaken in Jordan. The studies used various research designs/methods with five of the 7 studies being quantitative, one being qualitative and one being both qualitative and quantitative. A study undertaken using non-experimental descriptive study on a sample of 60 nurses from acute care setting to explore nurses' knowledge regarding delirium and their opinion on their knowledge level found that only 64% of the nurses had adequate knowledge on delirium and this was dependent on education level, years of experience and area of practice [17]. Similarly, a study undertaken using a cross-sectional survey and two administered measures on a sample of 29 registered nurses from two medical units of an Academic Medical Centre to investigate nurses' knowledge of delirium superimposed on dementia found that the nurses had a high level of general geriatric nursing knowledge, but low knowledge on hypoactive delirium [21]. Interestingly, a study undertaken on a convenience sample of 61 registered nurses that included 31 medical-surgical nurses and 30 intensive care nurses using a descriptive cross-sectional study to assess the power of registered nurses to recognize delirium on medical-surgical and intensive care units differed slightly with the above findings by indicating that at least 90% of the nurses can identify hyperactive symptoms of delirium and at least 77% can identify the hypoactive symptoms of delirium [19]. To evaluate medical intensive care unit nurses' knowledge in identifying and managing delirium using a descriptive self-administered survey undertaken on a sample of 53 registered nurses from 13-bedded intensive care unit interestingly agreed with the above studies by indicating that the knowledge level was about 67.3% [18]. Remarkably, the same study indicated that knowledge level for the signs and symptoms was 63.5%, knowledge level for risk factors was 63.5% and knowledge level for negative outcomes was 75% [18]. Interestingly, a study undertaken to explore nurses' knowledge and management skills of delirium in critical care units using a descriptive correlational study undertaken on a sample of 232 registered nurses in a critical care unit with a minimum of 6-months experience found that nurses' knowledge about deli- Weaknesses The use of interviews exposed it to respondent bias rium was significantly correlated to nursing practices [20]. A study using a qualitative design with critical incident technique on a sample of 30 registered or enrolled nurses working in palliative care inpatient setting to investigate palliative care nurses' understandings, opinions and practice in delirium identification and assessment found that knowledge in systematic and structured delirium screening and assessment procedures and application of the delirium diagnosis criteria was largely missing [22]. Moreover, a study undertaken using qualitative semi-structured interviews on a sample of 40 nurses working for 6-months in different shifts to investigate the nurses' understanding of delirium assessment and management found that nurses understand cognitive or behavioral manifestations of delirium, but do not recognize the diagnostic criteria and these depended largely on the area of practice of the nurse [5]. Interestingly, the studies differed in terms of the methodology used but the results obtained in each of the studies agreed or supported the results obtained in the other studies. For the four articles on knowledge development interventions, the study by Hare et al. (2008) and the study by Meako et al (2011) used survey questionnaire that were not valid because they had not been validated [23] [24]. The study Steeg et al. (2015) used validated 24 experimental questions as the assessment tool while the study by Rice et al. (2014) used validated Mini-Cog and CAM tools [25] [26]. A study undertaken using quantitative descriptive study on a sample of 338 nurses in one hospital to assess delirium knowledge and risk factors interestingly agree with the above findings by indicating that nurses have a low level of delirium knowledge, but indicates that this differs with the specific word where the nurse is attached with nurses in the orthopedic ward having the highest level of knowledge [23]. Interestingly, a study undertaken on a sample of 21 registered nurses from orthopedic unit using a quasi-experiment to examine the orthopedic nurses' basic knowledge about delirium disagreed with the findings in the above study by indicating that orthopedic registered nurses have a lack in understanding in delirium and therefore need educational sessions [24]. Interestingly, a study undertaken on a sample of 907 participants from internal medicine and surgical wards of 17 Dutch hospitals using a pre-test-andpost-test experimental study to test the effectiveness of an e-learning course on nurses' delirium knowledge established that nursing staffs have limited knowledge on delirium but this could be improved significantly through implementing an e-learning course [25]. Interestingly, the findings obtained from a study undertaken to investigate increase recognizing delirium clinical reasoning for older adults among nurses to validate the interventions using qualitative prospective mixed methods approach and semi-structured interviews on a sample of 31 nurses from five medical-surgical units agreed with the findings in the other studies by indicating that nurses find it difficult distinguish acute versus chronic mental status, the knowledge used by nurses to assess delirium patients was not rational and analytical and nurses where confused when assessing delirium patients [26]. Inte-restingly, the studies differed in terms of the methodology used but the results obtained in each of the studies agreed or supported the results obtained in the other studies.

Nurses Knowledge of Dementia and the Relevant Knowledge
Development Interventions (Table 2) As identified in the methodology, four articles on dementia were reviewed. Among the four articles, two were on knowledge of dementia and the remaining two articles were on knowledge development interventions. For the studies on knowledge of dementia, the study by Fessey (2007) undertaken in the UK used a validated questionnaire as the assessment tool while the study by Robinsone et al. (2014) used the 21 Dementia Knowledge Assessment Tool Version 2 (DKAT2), which is a highly valid and reliable dementia knowledge assessment tool [27] [28]. One of the studies was quantitative while the other one was both qualitative and quantitative. Interestingly, the research undertaken by Fessey (2007) using a mixed methods research on a sample of 49 registered nurses in adult care unit indicated that nurses have some knowledge and ability to deliver person-centered care, but there is a lack of consistency in the choices of approach [27]. Interestingly, another study undertaken using quantitative non-experimental study undertaken on a sample of 375 individuals that included nurses and health care workers and family members of dementia patients in Australia indicated that nurses and health care workers have significantly higher dementia knowledge when compared to family members and this was dependent on the years of experience of the nurses and healthcare workers [28]. Interestingly, the studies differed in terms of the methodology used but the results obtained in each of the studies agreed or supported the results obtained in the other studies. For the two articles on knowledge development interventions, the study by Broughton et al. (2011) in Australia used a validated Positive Aspects of Care-giving Questionnaire and knowledge of support strategy test, which was not validated as the assessment tool while the study by Gandesha et al. (2012), undertaken in Eng- Assess dementia knowledge among healthcare workers and family carers -Significant high score of DKAT2 for nurses and healthcare workers than family members -Significant correlation between high score and year of experience for nurses and healthcare workers

Used reliable and validated tools (DKAT2)
Weaknesses Non-experimental design reduces accuracy of results. Gandesha et al. 2012, England and Wales [29] Observe and assess the sufficiency of dementia training program among healthcare workers, and assess nurses' adequacy of their training among different hospital wards in particular -65% Doctors sufficiency rate overall mean for the 13 items, as higher than qualified nurses at 51%, or HCAs at 46% -Nurses rated the adequacy of their training as particularly weak in the field of mental health

Strengths
Experimental study encouraged more accurate results

Weaknesses
The study was open to respondent attrition.
land and Wales used the validated regular training sessions questionnaire and both studies were quantitative [12] [29]. Interestingly, a study used an intervention study with post-test only and a sample of 2211 staffs of all general hospitals in England and Wales providing acute services to observe and assess the sufficiency of dementia training program among healthcare workers and how this differed across different hospital wards found that the programs had the greatest impact on doctors when compared to other health care workers, but the impacts were generally low among all the healthcare workers [29]. Another study undertaken using controlled pre-and post-test trials undertaken on a sample of 52 staffs from four nursing homes to estimate the effectiveness of RECAPS and MESSAGE training on knowledge of nursing home staff in dementia found that the training increase knowledge significantly and that the training was both useful and applicable [12]. Interestingly, the studies differed in terms of the methodology used but the results obtained in each of the studies agreed or supported the results obtained in the other studies.

Nurses Knowledge of Depression and the Relevant Knowledge Development Interventions (Table 3)
As identified in the methodology, five articles on depression were reviewed. Among the five articles, three were on both the knowledge of depression and the knowledge development interventions and the remaining two articles were on knowledge development interventions. Among the studies, a study by Butler & Quayle (2007) undertaken in Ireland used already validated Late-Life Depression Quiz, Depression Attitude Questionnaire and Identify nurses' knowledge and practice regarding depression screening and referral for cardiac patients following the implementation of education workshops and a validated screening tool with referral actions -80% reported a "good" understanding of depression, post-program compared to 30% at baseline -60% reported routinely using the depression screening and referral tool -The interviews identified three main themes: knowledge improvement; perceived self-efficacy and new knowledge into practice

Use of validated tools
Weaknesses Pre-and post-test design is open to respondent attrition.

Sanders 2006,
USA [32] Explore the depression screening practices of certified nurse-midwives and certified midwives and examine its associated factors -Attitude, perceived ability, knowledge, and education accounted for 20% of the variance in depression screening conducted by certified nurse-midwives and certified midwives Strengths Participants distribution, enhanced more varied results with less sample bias effects Weaknesses Use individualized tool reduced results quality Choi et al. 2009, USA [33] Examine nursing home staff their opinions and experience of residents' risk factors of depression and explore current intervention programs and staff training -Participants indicate that the most common sign of depression in residents is social withdrawal as a result of grief, loss of control, independence, anxiety, and changing of their past lifestyle -75% of their residents' families were not involved with their relative

Strengths
Criteria of sample selection reduced issues of bias in sample selection Weaknesses Interviews used were open to interviewer bias Impact on Clinical Practice Questionnaire as the assessment tools while the study by Daele et al. (2014) undertaken in Belgium used Depression Attitude Questionnaire and an already validated Morris Confidence Scale as the assessment tool [13] [30]. The study undertaken by Worrall-Carter et al. (2012) in the UK used an already validated and reliable Cardiac Depression Scale as the assessment tool and a study by Sanders (2006) undertaken in the USA used un-validated 33-item survey questionnaire developed by the author as the assessment tool, while a study by Choi et al. (2009) undertaken in the USA used semi-structured interviews as the assessment tools [31]- [33]. Interestingly, four of the studies were quantitative while only one study was qualitative.
A study undertaken qualitatively on a sample of 25 participants that included administrators, nurses and social workers from 8 nursing homes in central Texas to examine nursing home staffs' opinions and experience of residents' risk factors of depression and explore current intervention programs and staff training indicated that the staffs lack adequate knowledge on residents' risk factors of depression but this could be improved significantly through intervention programs and staff training [33]. A study undertaken quantitatively on a sample of 378 attending the American College of Nurse-Midwives annual meeting to explore the depression screening practices of certified nurse-midwives and certified midwives and examine its associated factors found that attitude, perceived ability, knowledge and education accounted for 20% of the variance in depression screening conducted by the nurse-midwives and certified midwives [32]. Interestingly, a study undertaken using a quasi-experiment on a sample of 92 nurses, 63 in the intervention group and 29 in the control group to explore the confidence and attitude of home nurses in professional competence concerning depression and evaluate the capacity of minimal intervention for nurses to detect depression in patients and caregiver found that the intervention group did not differ significantly from the control group in terms of nurses' attitude/confidence in professional competences but the role attitude was significantly lower in the experimental group [13]. Moreover, the same study found that participants in the intervention group differed significantly from those in the control group in terms of identifying depressed patients [13]. Intriguingly, the study undertaken using pre-and post-test design on a sample of 84 nurses to identify nurses knowledge and practice regarding depression screening and referral for cardiac patients following the implementation of education workshops and a validated screening tool with referral actions found that implemented education workshops and validated screening tool with referrals improved understanding of depression by about 50% and the interventions are popularly used resulting to knowledge improvement and perceived self-efficacy [31]. The study undertaken by Butler & Quayle (2007) using uncontrolled pre-and post-test design on a sample of 67 nurses to evaluate to evaluate late-life depression education knowledge and assess the educational impact of nurses' attitude towards depressed elderly people found that training was significant in the improvement of nurses' depression knowledge and attitude towards depression [30]. Interestingly, the studies differed in terms of the methodology used but the results obtained in each of the studies agreed or supported the results obtained in the other studies.

Discussion
Managing patients with 3Ds is considered a professional challenge among nurses. Studies have shown low levels of relevant knowledge among nurses working with such patients, and some nurses faced difficulty to describe symptoms of delirium and dementia [17] [34]. This could be attributed to lack of adequate education, where to appropriately diagnose and treat 3Ds, nurses would most likely rely on their relevant knowledge. Apart from that, there are many methods, included in the nursing curricula, for assessing such mental disorders, and for nurses to screen patients with the 3Ds. For best practices, psychogeriatric nurses should learn skills and knowledge of solving the associated problems, and to know how to successfully face the challenges, and critically analyze the professional practice situations [35].
It is evident that nurses are the bases of the healthcare system that provides care and support to the patients. Therefore, it is important for any nurse to know about every medical illness's symptoms and treatment approaches within her/his field of specialty. Generally, patients with mental disorders are difficult to take care of because of the challenges associated with their illnesses such as distinguishing between dementia and delirium. Geriatric patients, with mental health challenges, usually have difficulty in managing their daily life activities, in addition to the fact that their behavior makes them aloof from others. Under such circumstances, they feel loneliness because of their age and mental disorders [3]. Hence, the only thing that may help them get back to normal living is the support they receive from their families, and understanding and professional care from the surrounding nursing and other hospital staff. Therefore, nurses should learn and gain more understanding about 3Ds, and develop their psychogeriatric nursing practices. Moreover, knowledge of these conditions has been found to be influenced by the level of professional experience [4] [12].
It is evident that negative attitudes of nurses towards 3Ds, are a challenge for most of them, and training of nurses caused that their attitudes became more positive towards patients with 3Ds [3] [30] [32]. There is an urgent need to provide quality care to cater for the rising number of 3Ds' cases, especially among the elderly [35]. This is because of their vulnerability and high chances of inadequate care that they are likely to receive from nurses as compared with other healthcare professionals. In this regard, Gandesha et al. (2012) confirmed that provision of quality care was found to be significantly correlated with improved knowledge and more training among healthcare workers, and that training among nurses has been postulated to be effective, especially in increasing nurses' awareness of 3Ds' management techniques [29]. This was a confirmation of another study's finding that one hour training session was able to create awareness of 3Ds among nurses [30]. This indicates that training would be effective as a capacity building strategy among nurses. Furthermore, training as an intervention to improve knowledge of 3Ds, was recognized by nurses following an interview on the benefits of such training, and their higher scores after the training [25]. Accordingly, nurses can greatly benefit from a solid foundation of knowledge about the identification, classification and management of the three overlapping health conditions, i.e. the 3Ds.
To improve patients' health outcome, there is a need to improve nurses' knowledge of the 3Ds, through training on direct communication, structured assessments, observations, pharmacological approaches, assistance with daily life activities, as well as non-pharmacological approaches, such as physiotherapy, aromatherapy, music therapy and cognitive behavioral therapy [4] [15]. The nurses also need capacity building, so they can play a vital role in offering psychosocial interventions to help relieve their clients psychological distress such as feelings of grief, depression and loneliness [16]. Moreover, nurses need to be updated with the best available clinical evidence so they can improve their professional practices for the elderly.
Despite all the challenges facing geriatric people and their caregivers, the 3D's are still commonly considered part of the normal aging process, while it should not. For instance, dementia is not an inevitable process even though it is commonly believed that memory loss and declining functional abilities are normal occurrences associated with aging [20] [21]. In this regard, it is important that psychogeriatric nurses develop a clear understanding of psychiatric symptomatology to be able to differentiate normal aged-related changes from psychological disorders. Furthermore, improved nursing knowledge and understanding of psychogeriatric disorders have been suggested as predictors of success among 3Ds patients, and improved quality of healthcare [8] [18] [23]. Therefore, there is a need to improve understanding among psychogeriatric nurses by increasing their knowledge of the symptoms, and be able to identify access to, and use of, appropriate screening tools as part of developing their professional practice.

Conclusion
The 3Ds comprise a challenge not only for the elderly, but for the whole population as well. Nurses face a challenge to differentiate between the 3Ds, especially their diagnosis and Treatment. This is because their considerable overlap and the simultaneous existence of the three conditions in the individual patients. Older patients are more vulnerable than other age groups; hence, nurses need more specific knowledge of 3Ds management strategies within the older age group. The primary care providers can undoubtedly benefit from a solid foundation of knowledge in the identification, classification, and treatment of these common health problems among the elderly. Therefore, 3Ds specific education courses, or workshops, need to be an integral part of any professional development programs for psychogeriatric nurses.