Patients’ experiences of delirium: A systematic review and meta‐summary of qualitative research

Abstract

Aims
The purpose of this systematic review and meta‐summary was the aggregation of the empirical qualitative literature on patients’ experiences of delirium in order to support the development and implementation of patient‐oriented delirium management and to guide future research.

Design
We conducted a systematic literature review of qualitative research published between January 1980 and June 2019.

Data sources
In June 2019, we searched in Medline, CINAHL, SSCI and PsycInfo to identify relevant reports. In addition, we conducted searches in three dissertation databases (BASE, DART and ProQuest) and Google Scholar.

Review methods
We used methods developed by Sandelowski and Barroso to construct a meta‐summary of the findings by extracting them from the reports, abstracting them into meta‐ findings and calculating their manifest interstudy frequency effect sizes.

Results
Out of the 742 identified records, 24 reports based on delirium experience accounts of 483 patients met our criteria and were included. One thousand ninety‐seven findings were extracted from these reports and abstracted into 92 meta‐findings. These were grouped to the five emerging themes ‘perception’, ‘emotions’, ‘interaction with others’, ‘dealing with delirium’ and ‘influence on further life’.

Conclusion
Delirium is commonly perceived as an overall distressing condition, which can accompany and influence patients even after hospital discharge.

Impact
This systematic review and meta‐summary is the most comprehensive aggregation of qualitative research of the patient delirium experience to date. It allows us to better understand, extract meaning from, and weigh the qualitative findings in their context by calculating their manifest frequency effect sizes. This can be used to support the development and implementation of delirium management concepts.

Full text

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J Adv Nurs. 2021;77:3692–3706.wileyonlinelibrary.com/journal/jan
Received: 21 November 2020
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Revised: 3 April 2021
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Accepted: 9 April 2021
DOI : 10.1111/jan.1486 5
REVIEW
Patients’ experiences of delirium: A systematic review and
meta- summary of qualitative research
Eero Kuusisto- Gussmann1 | Carolin Höckelmann1 | Verena von der Lühe1 |
Roman Schmädig1 | Marion Baltes1,2 | Astrid Stephan1,2
This is an open access article under the terms of the Creative Commons Attribution- NonCommercial- NoDerivs License, which permits use and distribution in
any medium, provided the original work is properly cited, the use is non- commercial and no modifications or adaptations are made.
© 2021 The Authors. Journal of Advanced Nursing published by John Wiley & Sons Ltd
Eero Kuusisto- Gussm ann, Carolin H öckelmann, Vere na von der Lühe, an d Roman
Schmädig contr ibuted equally to this work.
1Institute for Health and Nursing
Sciences, Martin Luther University Halle-
Wittenberg, Halle (Saale), Germany
2Uniklinik RWTH Aachen, Aachen,
Germany
Correspondence
Dr. Astrid Stephan, Institute for Health
and Nursing Sciences, Martin Luther
University Halle- Wittenberg, Halle (Saale),
Germany.
Email: asstephan@ukaachen.de
Abstract
Aims: The purpose of this systematic review and meta- summary was the aggregation
of the empirical qualitative literature on patients’ experiences of delirium in order to
support the development and implementation of patient- oriented delirium manage-
ment and to guide future research.
Design: We conducted a systematic literature review of qualitative research pub-
lished between January 1980 and June 2019.
Data sources: In June 2019, we searched in Medline, CINAHL, SSCI and PsycInfo to
identify relevant reports. In addition, we conducted searches in three dissertation
databases (BASE, DART and ProQuest) and Google Scholar.
Review methods: We used methods developed by Sandelowski and Barroso to con-
struct a meta- summary of the findings by extracting them from the reports, abstract-
ing them into meta- findings and calculating their manifest interstudy frequency
effect sizes.
Results: Out of the 742 identified records, 24 reports based on delirium experience
accounts of 483 patients met our criteria and were included. One thousand ninety-
seven findings were extracted from these reports and abstracted into 92 meta-
findings. These were grouped to the five emerging themes ‘perception’, ‘emotions’,
‘interaction with others’, ‘dealing with delirium’ and ‘influence on further life’.
Conclusion: Delirium is commonly perceived as an overall distressing condition, which
can accompany and influence patients even after hospital discharge.
Impact: This systematic review and meta- summary is the most comprehensive ag-
gregation of qualitative research of the patient delirium experience to date. It allows
us to better understand, extract meaning from, and weigh the qualitative findings in
their context by calculating their manifest frequency effect sizes. This can be used
to support the development and implementation of delirium management concepts.
KEYWORDS
delirium, nursing, qualitative research, systematic review

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1 | INTRODUC TION
Delirium is a state of acute mental confusion that is associated
wi th sev eral ad verse outcom e s (Mar tins & Ferna ndes , 2012; Sa lluh
et al., 2015). According to the American Psychiatric Association
(2013), delirium is defined by the following components: distur-
bance in attention and awareness which develops over a short pe-
riod of time and tends to fluctuate in severity during the course
of the day. It is accompanied by disturbance in cognition which
may manifest as a deficit of memory, language or visual percep-
tion. These disturbances cannot be explained by a pre- existing
neurocognitive disorder and represent an acute change from base-
line attention and awareness. A distinction is made between the
hypoactive, hyperactive and a hybrid form of delirium (American
Psychiatric Association, 2013).
2 | BAC KGROU ND
The prevalence of delirium varies in the literature and ranges from
17.6% to 28.4% in adult acute inpatient care (Krewulak et al., 2018;
Ryan et al., 2013; Schubert et al., 2018). Delirium is most likely to be
observed in intensive care unit (ICU) with a prevalence of 31.0%–
54.0% (Krewulak et al., 2018; Mehta et al., 2015; Rueden et al.,
2017). According to a recent meta- analysis, the most common sub-
type in adult ICU population is hypoactive delirium with a preva-
lence of 17.0% (Krewulak et al., 2018).
Risk fac to rs of delirium can be divided into predisposing and pre-
cipitating factors. Most common predisposing risk factors include
dementia, higher age and cognitive or functional impairment. Known
precipitating factors include polypharmacy, psychoactive medi-
cation use, surgery and use of physical restraints. The significance
of these factors may vary across patient populations (Inouye et al.,
2014; see also Oh et al., 2015; Ryan et al., 2013).
Delirium may have serious and permanent consequences.
Adverse events like increased mortality, prolonged hospitalisation,
increased readmission rates, decrease in cognitive functions and loss
of quality of life are, among others, associated with an ep isode of de -
lirium (Crocker et al., 2016; Martins & Fernandes, 2012; Salluh et al.,
2015; Schubert et al., 2018).
Delirium increases the cost of hospitalization and the need
for post- acute care, resulting in higher healthcare expenditure
and places a possible financial burden on informal caregivers.
Prevention of delirium not only reduces the cost of delirium but
also may decrease subsequent rates of dementia (Caplan et al.,
2020).
While quantitative indicators are important for evaluating de-
lirium outcomes, they cannot completely capture the complexity
of the phenomenon. Evidence from qualitative research is used to
address questions, which cannot be sufficiently answered from a
purely quantitative perspective (Lewin & Glenton, 2018; Lewin et al.,
2019; Williams et al., 2019). Literature reviews play an important
role since they aggregate the qualitative evidence and bundle it in an
accessible form for practitioners and decision makers. Thus, the ag-
gregation of findings from qualitative research is gaining importance
for evidence- based healthcare (Noyes et al., 2018).
In this context, the perspective of those affected by delirium
comes into focus. The ability to remember an episode of delirium
ranges from total amnesia to concrete reproduction of a detailed
description of the experience (Fuller, 2016; Partridge et al., 2013).
These insights into the subjective delirium experience help to better
understand the patient's perspective, hence enabling the develop-
ment of adequate concepts to better accompany and support them
as well as their relatives (Partridge et al., 2013).
Qualitative research on delirium experience has been aggre-
gated in reviews before. However, most of them are not system-
atic reviews; they do not solely focus patients’ experiences and
mostly exclude non- ICU settings (see, e.g., Bélanger & Ducharme,
2011; Fuller, 2016; O'Malley et al., 2008; Partridge et al., 2013).
Furthermore, new research has been published in recent years that
provide important contributions to the previous body of knowledge,
which until today has not been the subject of a literature review (e.g.,
Instenes et al., 2017; Weissenberger- Leduc et al., 2019).
3 | THE REVIEW
3.1 | Aim
This present work provides deeper insights into the subjec tive expe-
rience of delirium by aggregating the empirical qualitative literature
on patients’ experiences and memories of delirium. This meta-
summary can be used to support the development and implementa-
tion of patient- oriented delirium management and to guide future
research. The review question is: “How do patients experience and
recall delirium in acute care settings?”.
3.2 | Design
A qualitative meta- summary is a quantitatively oriented aggrega-
tion of qualitative findings. It reflects a quantitative logic by also
discerning the frequency of these findings across the target domain
of research (Sandelowski & Barroso, 2007). The used techniques in
a qualitative meta- summary include: (a) extracting and separating of
relevant findings from each primary research report, (b) editing of
findings to make them accessible, (c) grouping of findings in topi-
cally similar domains, (d) abstracting and formatting the findings and
(e) calculating manifest effect sizes (Sandelowski & Barroso, 2007;
Sandelowski et al., 2007). Frequency effect sizes are a unique fea-
ture of this method, as it adds numbers to the qualitative process.
Effect sizes assess the prevalence of findings within the literature,
which allow searching for patterns or hypotheses and offer a quick
overview (Ludvigsen et al., 2016). A qualitative meta- summary can
serve as an endpoint of research or be used as an empirical founda-
tion for a meta- synthesis (Sandelowski & Barroso, 2007).

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A review protocol was developed by all authors in March 2019
and guided the research process.
3.3 | Search methods
We searched Medline, Cumulative Index to Nursing and Allied
Health Literature (CINAHL), PsycInfo and Social Sciences Citation
Index (SSCI). We developed and tested the search strategies in each
of the databases against a sample set of articles (n = 16) that were
identified from the references of the previously published reviews.
Table 1 shows an example of our search string.
Our inclusion criteria for the literature were as follows:
• Qualitative research, published between 1980 and 2019, which
focuses on adult patients’ experiences of delirium in acute care
settings.
• Mixed- methods research provided that the qualitative findings
are reported separately.
• English or German language reports worldwide.
To limit the scope of the search to qualitative research, we used
the recommended filters from University of Washington Libraries
(2019). In case of SSCI, we could not find a validated filter and cre-
ated our own based on the available Medline (PubMed) filter by
translating its syntax. We also tuned all used filters more sensitive by
adding the search term ‘inter view’. Our filters and the exact search
string for each database can be found in the appendix. The searches
were restricted to English and German language and to references
published after January 1980. This restriction was due to the fact
that delirium was first included in the Diagnostic and Statistical
Manual of Mental Disorders (DSM) in that year (European Delirium
Association & American Delirium Society, 2014). All articles in the
sample set were found with our strategy— with the exception of
one older report, which did not include any description of the used
methods in its abstract and was therefore not caught by our filters.
The final searches were performed in June 2019 by two reviewers
independently from each other. The results were then compared to
make sure they were an exact match.
In addition, we conducted supplementary searches in three
dissertation databases (BASE, DART and ProQuest) and Google
Scholar. We also undertook a backward and forward citation track-
ing using the articles that we did include as well as all known previ-
ous reviews. The backward citations were collected manually. We
used the R package citecorp (Chamberlain, 2019) to download all
forward citations from OpenCitations Index of Crossref open DOI-
to- DOI references.
The abstracts and titles of the found records were then screened
independently by two reviewers using the online platform Rayyan
(Ouzzani et al., 2016). The same procedure was followed during the
assessment of the full- text articles. Conflicts were resolved by a
third reviewer. In the case of two articles, a fourth reviewer was also
consulted. If a full- text article was not available, we contacted the
authors to request a copy.
3.4 | Search outcome
Our searches in electronic databases yielded 1,156 results in total.
Nine further potentially relevant references were identified through
our supplementary searches (dissertation databases, backward and
forward citation tracking). After removing duplicates, we screened
the titles and abstracts of 742 references.
Fifty full- texts were assessed for eligibility and 24 of those are
included in the meta- summary (Table 2). Two reports of interest
were not available as full- text. However, they were both disserta-
tions that had also been published as journal articles— both of which
are included. Two further dissertations were also excluded because
the relevant results were already published in the form of a journal
article (see Figure 1 for a PRISMA Flow Diagram with a complete list
of exclusion reasons).
Three articles were excluded due to the type of their findings.
Two of them did not interpret their material in a way that would
qualify as qualitative research in the typology of Sandelowski and
Barroso (2007). On the other hand, in one article, the findings were
too abstract to be included in a meta- summary (‘interpretative ex-
planation’). Figure 2 shows a visualization of the types of findings
included in this meta- summary.
3.5 | Quality appraisal
All included articles were appraised independently by two review-
ers using the Critical Appraisal Skills Programme (CASP) check-
list for qualitative research. Conflicts were resolved by discussing
them after the comparison of the outcomes or by a third reviewer.
Following Sandelowski and Barroso's (2007) advice, no report was
excluded because of poor quality. The outcomes of the appraisal are
available as Supplementary Material.
3.6 | Data abstraction
We used a 25- item data extraction sheet, which was developed in
accordance to the recommendations of Sandelowski and Barroso
(2007). To allow a better comparison of the included reports, the
extracted information was then used to build a comprehensive char-
acteristics table, which included bibliographical and methodological
TABLE 1 Search string without filters in Medline (PubMed)
Delirium[MeSH Terms] OR deliri*[TIAB] OR acute confusion*[TIAB]
OR temporary confusion*[TIAB] OR "ICU syndrom*"[TIAB]
OR "ICU psychosis"[TIAB] OR "ICU- psychosis" OR "ICU-
Syndrome" AND Memory[MeSH Terms] OR experienc*[TIAB]
OR memor*[TIAB] OR recall*[TIAB] OR recollection*[TIAB] OR
perspectiv*[TIAB]

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TABLE 2 Included reports and their main characteristics
Report ID
Author (year),
country Aim n (f/m)
Mean
age Setting Stated method Type of finding s
1Andersson,
Hallberg, et al.
(2002), Sweden
To illuminate lived experience of having
been in an acute confusional state
50 (39/11) 84.7 Orthopaedic care Phenonemological
hermeneutic
Thematic survey
2Andersson,
Norberg, et al.
(2002), Sweden
To illuminate the pattern of confusional
episodes with regard to the content of
elderly patients’ actions and speech
51 (39/12) 84.6 Orthopaedic care Manifest and latent content
analysis
Thematic survey/conceptual
thematic description
3Claesson Lingehall
et al.
(2015), Sweden
To illuminate experiences of undergoing
cardiac surgery among older people
diagnosed with postoperative delirium
49 (17/32) 78 Cardiac surgery Qualitative content analysis
by Graneheim and
Lundman
Thematic survey
4Cohen et al., (2009),
USA
To develop a better understanding of
deliriumrelated distress among patients
with advanced cancer and their
caregivers
34 (18/16) 63 Palliative care Phenomenological
hermeneutic
Topical survey
5Darbyshire et al.,
(2016),
UK
To explore themes relating specifically to
sleep and delirium
40 (16/24) 52.2 ICU Secondary thematic analysis Topical survey/thematic survey
6Fagerberg and
Jönhagen
(2002), Sweden
To describe how older people experience
the phenomenon of temporary confusion
and their reasoning
5 (1/4) 73.8 Acute care
(mixed)
Phenomenological method by
Giorgi
Thematic survey
7Flynn et al., (2014),
UK
To explore the narratives of people who
have had a heart or lung transplant and
who report experiencing delirium in the
ICU
11 (4/7) n.a. ICU Narrative analysis Thematic survey
8Granberg et al.,
(1999),
Sweden
To describe and illuminate patients’
experiences of acute confusion,
disorientation, dreams and nightmares or
so- called’unreal’ experiences during and
after ICU stay
19 (6/13) 62 ICU Hermeneutic approach Thematic survey
9Hartwick (2003),
USA
To explore a patient's and his family's
perspectives related to ICU delirium
1 (0/1) 42 ICU Case study Topical survey
10 Instenes et al.,
(2018),
Norway
To explore and describe how octogenarian
patients with post- aortic valve
replacement delirium experience
interactions with healthcare
professionals and relatives
10 (5/5) 83 Cardiac surgery Qualitative content analysis Thematic survey
11 Instenes et al.,
(2017 ),
Norway
To explore how octogenarian patients
experience postoperative delirium
10 (5/5) 83 Cardiac surgery Phenomenological approach
by Giorgi
Thematic survey
(Continues)

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Report ID
Author (year),
country Aim n (f/m)
Mean
age Setting Stated method Type of finding s
12 Laitinen (1996),
Finland
To describe and reflect upon the patients’
real descriptions of their unique
experiences of confusion in the ICU
10 (n.a.) n.a. ICU Phenomemological
hermeneutic
Thematic survey
13 Magarey and
McCutcheon
(2005), Australia
To explore the memories of patients who
had a short- term admission to the ICU,
with a particular focus on dreams,
nightmares and confusion
8 (2/6) 54.2 ICU Thematic analysis by Morse
and Field
Topical survey/thematic survey
14 McCurren and
Nones Cronin
(2003),
USA
To describe the phenomenon of delirium
based on the lived experience of
hospitalized elders
14 (4/10) 75. 2 Medicalsurgical Phenomenological approach
by
Colaizzi
Thematic survey
15 Pollard et al.,
(2015),
Australia
To explore and recount the experience older
people had of being delirious following
orthopaedic surgery
11 (3/8) n.a. Orthopaedic care Qualitative description by
Sandelowski
Thematic survey
16 Schmitt et al.,
(2017), USA
To describe common delirium burdens
among older patients, family caregivers
and nurses
18 (10/8) 79 Acute care
(mixed)
Interpretive description by
Thorne
Thematic survey
24 Whitehorne et al.,
(2015),
Canada
To understand the lived experience of
intensive care for critically ill patients
who experienced delirium
10 (3/7) n.a. ICU Hermeneutic phenomenology
by van Manen
Thematic survey
TABLE 2 (Continued)

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information (e.g., author, year, country, aim, data collection method,
stated research method, delirium assessment method, sample size,
mean age and setting). Table 2 is an abridged version of that table.
3.7 | Synthesis
According to Sandelowski and Barroso (2007) qualitative research
can be classified based on the degree of abstraction— independent
from the stated method of the study. Two reviewers classified the
findings independently from each other. In case of conflicts, a third
reviewer was consulted.
The typology of qualitative findings can be presented as a contin-
uum (depicted in Figure 2). Reports which present ‘raw’ data without
interpretation (e.g., stories and quotations) are considered as ‘no-
finding’ reports and should be excluded. Topical surveys remain close
to raw data and typically use classification systems to organize topics
mentioned by par ticipants. They briefly define the topics and illustrate
FIGURE 1 PRISMA flow diagram
FIGURE 2 A heat map of the types of findings in the included reports projected onto the typology of qualitative research by Sandelowski
and Barroso (2007) [Colour figure can be viewed at wileyonlinelibrary.com]

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them with a few quotations. Thematic surveys show a discernible
step away from categorizing towards describing themes. It is done by
using everyday language of participants or by importing empirical or
theoretical concepts. They are followed by conceptual/thematic de-
scription, which go beyond the organisation and description of data
towards the interpretation of a phenomenon. While topical and the-
matic surveys are characterized by a more nominal use of classifying
data, conceptual- thematic descriptions use concepts to reframe and
integrate data. Rightmost on the continuum are the reports classified
as interpretative explanation. While topical surveys, thematic surveys
and conceptual/thematic descriptions represent one or more elements
of an experience, interpretive explanations offer an integrated, com-
prehensive penetration of the fundamental nature of events or experi-
ences (Sandelowski & Barroso, 2003, 2007).
The findings were extracted and separated from the section Results
of all report s independently by two reviewers using designated finding
extraction sheets. After a comparison of the extraction sheets, a third
reviewer was consulted if there were conflicts about the inclusion
of a finding in the meta- summary. In a next step, extracted findings
were edited to be accessible to any reader. Each separated finding was
coded sequentially and grouped into topical domains in an inductive
process. This was done following methods of qualitative content anal-
ysis by Kuckartz (2016) in MAXQDA (VERBI Software, 2018). First, all
findings were roughly coded into main categories. Then, subcategories
were shaped. In a repetitive process, after the differentiated category
system was formed, all findings were coded again. As this part is a re-
flexive process, the grouping of findings was done together, allowing a
dialogue between the reviewers.
Abstraction of findings into meta- findings was at first done together
by two reviewers in one category to reach a mutual understanding of
the process and subsequently done by two reviewers separately. To
ensure the validity of the separately abstracted meta- findings and cat-
egories, we compared and discussed the results with all authors during
the process. We then calculated the manifest interstudy frequency ef-
fect sizes for each meta- finding by dividing the number of reports con-
tributing to the meta- finding by the total number of included reports
with unique samples. If two reports using an identical or overlapping
sample contributed to the same meta- finding, it only counted once.
During the process the definition of ‘experiencing delirium’ was
discussed and ad apted . In ad ditio n to the lived experienc e during de-
lirium, patients’ reflections about their perceptions afterwards were
included into our definition of the phenomenon.
4 | RESULTS
All 24 included reports are journal articles published between 1996
and 2019. Ten of them focused on delirium experience in ICU, the
rest in various acute care settings, e.g., mixed wards (n = 4), ortho-
paedic care (n = 4) and cardiac surgery (n = 3). Almost half of the
studies (n = 11) were conducted in the Nordic countries: Sweden
(n = 7), Norway (n = 2), Finland (n = 1) and Denmark (n = 1). The
remaining studies were done in the United States (n = 4), the United
Kingdom (n = 2), Austral ia (n = 2), Canada (n = 1), New Zealand (n = 1),
Austria (n = 1), Belgium (n = 1) and Iran (n = 1).
The sample sizes varied between one and 114 patients (median:
11). Collectively, the reports were based on 483 individual patient
accounts (215 females, 249 males— two articles did not report the
gender of the participants). In all cases, these experiences were col-
lected with different forms of interviews. In one case, non- participant
observation was used in addition to interviews and published sepa-
rately (Andersson, Hallberg, et al., 2002, Andersson, Norberg, et al.,
2002). Two articles did not report the age of the participants at all,
whereas four reports lacked information about the mean age. The
pooled mean age of all reported participants was 68.7 years with a
range between 18 and 98 years.
See Table 2 for more information about the characteristics of the
reports. Each report was assigned a specific report ID to transpar-
ently link them with the respective meta- findings they contributed
to.
4.1 | Findings of the meta- summary
A total of 1,097 findings were extracted from 24 reports. These
findings could be abstracted into 92 meta- findings. Table 3 shows
68 meta- findings which yield a frequency effect size of ≥10%. The
meta- findings below this threshold are available as Supplementary
Material.
During the process of grouping, five main themes emerged:
Perception, Emotions, Interaction with others, Dealing with delirium and
Influence on further life. The meta- findings are categorized into these
main themes and sorted according to their frequency effect sizes
as shown in Table 3. The reports, which contributed to each meta-
finding, are indicated by showing the respective report IDs after the
meta- findings. Each meta- finding was assigned a meta- finding- ID as
displayed in Table 3. These IDs are used in the following text to refer
to meta- findings (e.g., E1 refers to the finding with the highest fre-
quency effect size in category Emotions: ‘Patients experience feel-
ings of fear and anxiety’).
Perception is the most common theme across all included articles
and encompasses as a category both the highest number of meta-
findings (n = 32) and the meta- findings with the greatest frequency
effects sizes (P1: 95%, P2: 87%). Emotions is the second biggest cat-
egory (n = 15), but the frequency effects sizes are not as high and
half of them are lower than 20%. The remaining categories, interac-
tion with others, dealing with delirium and influence on further life, each
contain less than ten meta- findings. With the exception of meta-
findings I1 and D1 all frequency effect sizes in those categories are
≤50%.
4.2 | Perception
Crucial to the delirium experience is the patients’ self- awareness and
the perception of their environment. This includes disorientation in

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TABLE 3 Meta- findings sorted according to their frequency effect sizes in the main categories
Meta- finding ID Meta- finding Report ID*
Frequency
effect size
P1 Perception
Patients recall having vivid unreal experiences, which they describe as hallucinations, visions,
fantasies, fuzziness or as unusual dreams and/or nightmares, which can occur even in an awake
state.1,2 ,3,4 ,5,6 ,7,8,9,10,11,13,14,15 ,16,17,18,19,20, 21,22 ,23, 24
95%
P2 Disorientation is generally described during delirium.1,2 ,3,4, 5,8 ,9,10,11,12,13,14,16 ,17,18,19,20,21 ,22 ,23, 24 86%
P3 Patients felt inable to control the situation or themselves while being delirious
1,2, 3,6, 7,11,13,14,15,16,18 ,19,21,22
59%
P4 The delirium experience was perceived as real and unreal at the same time, or as moving
on a continuum from reality to unreality, as a struggle to distinguish real from
unreal.1,5,6, 7,8,9,11,13,17,18,19,24
54%
P5 Patients differ in their ability to recall their experience of delirium; their descriptions vary from
having detailed recollections to not remembering anything at all.1,4,5,9,11,12 ,13,15,17,19,21, 24
54%
P6 Perceiving themselves during delirium, patients see themselves as being
confused.1,2,3, 4,5, 8,11,12,1 3,14,17,22
50%
P7 The types of visual hallucinations vary from living beings, concrete places and surroundings to
abstract forms, geometric shapes and colours.1,2 ,3,4 ,7,9,13,16,19,22,23
45%
P8 Negative hallucinations are perceived as life threatening experiences, such as being trapped,
imprisoned or killed. 3 ,5,7,8,13 ,15,16,17,19,21
45%
P9 Spatial disorientation manifests in patients not knowing where they are.1, 2,3 ,4,8 ,12,14,16, 21, 22 40%
P10 Patients describe positive hallucinations such as creatures or colours.1,3,7,8,1 3,15,17,21 36%
P11 Patients describe disorientation in space as thinking they are somewhere else than the hospital, or
they are at two places at the same time.4,8,10 ,11,14,17,19,24
31%
P12 Temporal disorientation manifests itself in patients not knowing what time it is.3, 8,9,11,12, 21,2 2 31%
P13 Situative disorientation manifests itself as a misinterpretation of events and an unability to place
them in context.5,10,12 ,14,16,17,21
31%
P14 Trying to cover the whole delirium experience in their description, patients referred to being in
another, strange world.1,3 ,8,11,14,1 5,21
31%
P15 Auditor y hallucinations include rain, voices and music.2,9,14,16, 22,2 3,24 31%
P16 Patients describe moving around in space and time during their unreal experiences.2 ,5,8 ,17,19,22,24 31%
P17 Patients feel unable to communicate and to express their needs.5,8,16 ,17,21,22 ,24 31%
P18 Patients felt unable to think clearly and retain information during delirium.6 ,8,16,18 ,22 ,24 27%
P19 Patients describe merging the current situation with events, memories or people from their
past.1,2,10 ,17,19,23
22%
P20 Death is a re- emerging theme in patients’ hallucinations (e.g., meeting the deceased, dying or being
killed).7,11,13,17,21
22%
P21 Patients perceice themselves as being lucid during delirium.3 ,8,14,17,23 22%
P22 A disturbed day– night rhythm evokes difficulties in distinguishing day from night and being awake
from being asleep.8,11,14, 21
18%
P23 Disorientation in time includes differences in the perception of passage of time, which can be
perceived as time standing still or that time is completely missing.8 ,13,14,18
18%
P24 Patients describe travel in time as altering between present and past, or multiple events taking place
simultaneously.2,14,17,19
18%
P25 By trying to give the delirium description a shape, patients struggle to capture it, as its boundaries
are blurred.1, 3, 7,1 7
18%
P26 Patients see themselves as an outsider, a stranger and feel separated from their surroundings.5 ,8,10,18 18%
P27 Patients’ behaviour during delirium differs from their behaviour in daily life.1, 3,15,16 18%
P28 In their delirious state, patients are unable to understand the situation.1,2,18,22 13%
P29 Ordinary things appear dangerous and unsafe without any reason.3, 5,17 13%
P30 Patients remember the beginning and ending of delirium differently (e.g., sudden or gradual).16,17,21 13%
(Continues)

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Meta- finding ID Meta- finding Report ID*
Frequency
effect size
P31 Delusional beliefs and hallucinations are intensed and/or triggered by isolation, paranoia, falling
asleep, day of time, unfamiliar activities due to hospital setting and impaired ability to
communicate.5,8,24
13%
P32 Patients question their personality during delirium.6 ,15,16 13%
Emotions
E1 Patients experience feelings of fear and anxiety.2,3 ,5,6 ,7,8,10,11,13 ,14,15,16,17,21, 22, 23,24 72%
E2 Patients experience feelings of threat, distress and insecurity that either persist and/or fluctuate for
brief periods or for days and weeks at a time.1,2 ,4,5 ,6,8 ,11,13,15,16 ,17,18
50%
E3 Perceived reasons for anxiety and fear were as follows: imminent death, hallucinations and
nightmares, incapacity to understand, to act or to locate situations correctly, feelings
of vulnerability, worries of permanent changes in behaviour or ‘going crazy’ again
.4,7,8,11,12 ,13,16,17,19,21,24
50%
E4 Loss of control and autonomy, hallucinations and nightmares are common causes for irritation,
anger, aggression, powerlessness, helplessness, dependency and frustration.2,3, 4,8,14,1 5,16,17,21, 22
45%
E5 Patients describe strong emotional feelings of loneliness, abandonment, hopelessness and isolation,
which are amplified if they feel alone, can't rely on family or friends, are inable to communicate
or if they are confined to bed.3,5, 6,8 ,12,15,18 ,21
36%
E6 Patients experience feelings of shame, embarrassment, remorse and
guilt towards staff, family and friends during delirium.1, 3,6,14 ,16,17,21,24
36%
E7 Patients can experience feelings of security and confidence when they recognize the actions as
routines, get used to the delirium state, realize they are not alone, possess familiar objects or
have a feeling of a higher power beyond their control.1,2,3,8,18,24
22%
E8 Patients’ experiences are connected with a variety of positive
(pleasant) and negative (unpleasant) emotions.17,20,22,23
18%
E9 Patients recognize delirium subjectively as a negative (unpleasant) experience, but the descriptions
differ in their intensity and scope.1,14,16, 23
18%
E10 Patients feel restless during delirium.3,9,11, 21 18%
E11 Patients experience a threat directed against themselves, their spouse or against values and
interests vital to them.6 ,7, 17, 24
18%
E12 Relief and liberation is experienced at the moment when patients become aware that their
experiences aren't true.3,15,17,21
18%
E13 Patients experience the episode of delirium as emotionally neutral or sometimes completely without
feelings of discomfort (e.g., because they expected that delirium might occur).2, 4,11
13%
E14 Patients think they are going mad and describe an emotional chaos because of delirium and
nightmares.3,8,15
13%
E15 Feelings of panic can be triggered by a sense of being alone or by the frightening discovery of
changes in their own personality.11,16,17
13%
Interaction with othe rs
I1 Barriers are created between patients and staff (e.g., when staff behaves disrespectfully and
insensitively, use a harsh tone of voice, show rejection, exclude patients from their care,
ridicule and not take them seriously, try to reorient the patients or when they sense a lack of
information, explanations, support or trained hospital staff).3,5 ,6,10,14 ,15,16,18,19,2 1,22 ,24
54%
I2 Patients feel supported by relatives if their presence creates a calm and positive atmosphere, if their
relatives are understanding, supporting, trusting, comforting and reassuring or if they can help
them putting things into perspective.1,2, 6,8 ,10,12,13,14 ,18,19,21
45%
I3 Patients feel supported by healthcare staff if they are positive, pleasant, adaptable, supportive, self-
confident, understanding, communicative and familiar or if they provide explanations to what is
happening.2,6 ,10,12,13 ,14,18, 21,24
40%
I4 Barriers are created between patients and their relatives if the relatives are ashamed of the
patients’ behaviour, try to control or reorient the patients or if patients perceive a lack of help or
disrespectful behaviour or a lack of willingness to communicate with them.3,6, 8,10,15 ,18,19,22
36%
TABLE 3 (Continued)
(Continues)

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the current situation (P2), which can be divided into the interpreta-
tion of time (P12, P23, P24), space (P9, P11) and current situation
(P13, P19, P29). In addition to disorientation as a misinterpretation
of the environment, patients report unreal experiences without di-
rect stimuli from their environment (P1, P16, P20, P31). Visual (P7)
and auditive (P15) hallucinations are reported, which can have nega-
tive (P8) or positive (P10) content. The theme ‘death’ reoccurs across
reports in patients’ descriptions of their hallucinations, which has
positive (e.g., meeting deceased loved ones) or negative connota-
tions (e.g., being killed) (P20).
Meta- finding ID Meta- finding Report ID*
Frequency
effect size
I5 Patients become suspicious and mistrustful towards other people (including staff, relatives and
fellow patients).2,6,7,14,15,18
27%
I6 Patients feel heard but not understood from staff and relatives; this provokes the feeling of being
alone in their struggle.5,6 ,15,17,18
22%
I7 Patients need constant interaction with healthcare staff and their relatives.8 ,10,12,1 5,24 22%
I8 Interaction with others is difficult and is experienced as unequal, especially when patients’
experiences are questioned or the interaction is linked to hallucinations.2,14,18 ,21
18%
I9 Patients use different strategies to hide their delirium during interactions (e.g., they show little
willingness to answer questions or to communicate, but also ask the nurses questions to ensure
that they give a correct answer).2,3,22,23
1%
Dealing with delirium
D1 Patients try to understand their experiences by communicating with others and by rationalizing
their experience and thoughts (e.g., by asking questions to get information about time, place
and situation, by incorporating delirium into a meaningful whole, by narrating their memories to
others or by withdrawing to find quietness).1, 2,5, 6,7,8,9,10,13 ,14,17,18,21, 22,24
63%
D2 Patients try to find reasons for delirium within themselves (e.g., in age, in illness or in their private
life), in factors related to their hospitalization or in medication.1, 4,5, 6,8,1 5,17,18,21
40%
D3 Factors that evoke feelings of control and security and that improve orientation before and during
delirium include: familiar everyday routines, an emotionally neutral or familiar voice, daylight,
characteristics of the environment, situation awareness, self- determination (decision- making
autonomy) and increased knowledge (informedness).2,4,8,11,18,20
27%
D4 Patients do not want to talk about their experiences because they tr y to escape and distance
themselves and to forget the memories.1,14,15 ,17
18%
Influence on further life
F1 Even after recovery, feelings of anxiety and fear still persist, which patients describe as a fear of
reoccuring delirium, fear of never forgetting the experience and as a constant occupation of
their mind with the experience.1, 3,6, 7,12,15,16,17,21, 24
45%
F2 Talking about their experience gives a feeling of taking control over delirium and is perceived as
helpful.1,12,15,17,21, 24
27%
F3 Patients vary in their ability to leave delirium behind and to look at it with detachment; for some
delirium still occupies their minds, or affects them emotionally— others remain indifferent
about their experiences.1,6,11 ,12,13, 21
27%
F4 Patients report a permanent loss of their dignity after recovering from delirium; they still
remember the awkwardness of the situation, see their loss of self- control in the situation as
painful, which results to long lasting feelings of shame. 3, 6,7,11,12,15
27%
F5 Even in the interview situation patients want to keep their delirium a secret and neglect or
suppress their experiences (e.g., the respondent blocks the conversation and changes the
topic).1,7, 17, 21
18%
F6 Patients avoid behaviour that could trigger another episode of delirium (e.g., avoid seeking
medical support, taking sleep medication or going back to the hospital where they
experienced delirium).7,15 , 24
13%
F7 The delirium experience can have positive influence on patients’ life (e.g., they can draw strength
from it, feel less stressed or worried in their daily life after the experience or see it as a
learning occasion).15 ,1 7,2 1
13%
F8 Patients describe how delirium affected their personality after their experiences as being
changed forever or having a disturbed sense of oneself.7,1 5 ,2 1
13%
*Report IDs are displayed in Table 2.
TABLE 3 (Continued)

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In contrast to the perception of their environment, patients
give detailed descriptions on how they are aware of themselves
in their delirious state (P26, P27, P32). The main focus is their in-
ability to act (P3, P17, P18, P28) and seeing themselves either as
confused (P6) or lucid (P21) while being delirious. From a retro-
spective position, patients try to capture the whole experience
with words and refer to more general aspects of delirium (e.g., re-
calling the beginning and ending of delirium) in the meta- findings
P4, P5, P14, P25 and P30.
4.3 | Emotions
The theme emotions incorporates all of the patients’ feelings
caused by delirium. These could arouse during their delirious epi-
sodes or while reflecting their experiences retrospectively. Most
articles describe patient s being emotionally affected, but there are
exceptions that report emotional neutrality (E13). A wide range of
positive and negative emotions are reported (E8). Most common
are fear and anxiety (E1, E3, E17, E18). Other negative emotions
reported are feeling threatened (E2, E11), insecurity (E2), panic
(E15), anger (E4), restlessness (E10), powerlessness (E4), helpless-
ness (E4), frustration (E4), loneliness and hopelessness (E5), vul-
nerability (E16), guilt, shame (E6), ‘going mad’ and emotional chaos
(E14). Feelings of threat, distress and insecurity can persist either
for brief periods or days or even weeks during the delirious phase
(E2). Delirium is recognized as a negative experience, but the indi-
vidua l expe rien ces differ in thei r int ensity and scope (E9). Alt hough
most reports describe negative emotions (E9), there are also some
positive emotions associated with the delirium experience, such as
feeling confident or secure (E7). Relief is also a common emotion
at the moment when patients realize that their experiences are not
true (E12).
4.4 | Interaction with others
The theme interaction with others descr ibe s soc ial int erac tio ns during
the delirious state and reflects how patients experience themselves
in these interactions. It shows that they are aware of and can re-
call their encounters with relatives, staff and fellow patients. On the
one hand, patients perceive interaction with others as unequal and
difficult (I8), feel heard but not understood (I6), develop feelings of
suspicion and mistrust (I5). On the other hand, patients can need
constant interac tion (I7 ) and descr ibe supportive (I2, I3) as well as in-
hibiting (I1, I4) aspects in their contact with relatives and staff during
delirium. A loving, understanding, trusting, respectful, participating,
reassuring and positive encounter seems to be the scaffolding for
supportive interaction (I1– I4). Patients use strategies to hide their
delirium because they feel a lack of trust and understanding during
the encounter, feel that they are not allowed to disclose their mental
state or are afraid and ashamed of their strange behaviour (I9).
4.5 | Dealing with delirium
During as well as after recovering from delirium, different strategies
of coping are reported, which build the theme dealing with delirium.
These mechanisms include coping strategies both to confront and to
ignore or avoid the experience. The confronting coping mechanisms
are based on patients trying to better understand the situation by
communicating with others and by rationalizing their experiences
and thoughts (D1). Beyond that, patients try to find a reason for
their delirium (D2). Coping mechanisms based on avoidance include
patients not wanting to talk about their experiences because they
try to distance themselves and forget the situation (D4).
But there are also external factors (facilitators) that can have a
positive influence on dealing with delirium. This includes, among
other aspects, familiar everyday routines, daylight, an emotionally
neutral or familiar voice, decision- making autonomy and being in-
formed about delirium symptoms and progress (D3).
4.6 | Influence on further life
The delirium experience does not end at discharge from the hospi-
tal. Patients take their memories with them into their everyday life,
which means that they continue to reflect these experiences even
afterward. The experience can either benefit (F7) or directly or indi-
rectly harm (F1, F4, F6) patients in their present and future situation.
Patients’ descriptions of being emotionally affected by their experi-
ence vary; some remain indifferent, and for others, it still occupies
their mind (F3). The most dominant emotions while being delirious—
anxiety and fear— are still present and can influence patients’ actions
(F1), as they avoid behaviour that could cause another episode of de-
lirium (F6). Patients continue using coping mechanisms to deal with
their experiences (F5, F2). Some influences might have a permanent
impact on patients’ life and personality (F8).
5 | DISCUSSION
The patient delirium experience has been gaining interest as a sub-
ject of qualitative research in recent years, with half of our included
articles published in the past 5 years. Several of them have not been
included in a review of the literature prior to this meta- summary.
In comparison to previous reviews, which all examined the topic
from slightly different points of view, this meta- summary offers a
broader perspective by aggregating experiences from different set-
tings, with a sole focus on patients’ experiences. Nevertheless, our
meta- findings are supported by the core results of these previous
reviews (Bélanger & Ducharme, 2011; Fuller, 2016; O'Malley et al.,
2008; Gaete Ortega et al., 2020; Partridge et al., 2013). We also did
not encounter any contradicting findings that would suggest the
need to conduct a separate analysis based on the setting or patient
population.

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KUUSIS TO- GUSSM ANN eT A l.
This current meta- summary further contributes to the body of
knowledge by calculating the frequency effect sizes, which allows us
to bet ter und ers tand, ex trac t meani ng from , and weigh the qualit ative
fin dings in their context. This kind of quantification of qualitative data
is a controversial topic (Maxwell, 2010) with no consensus on what
constitutes an ‘effect size’ or even what the unit of analysis is (van
Grootel et al., 2020). The manifest frequency effect sizes make the
implicit verbal counting of findings (‘in several cases’, ‘most articles’,
etc.) explicit (Onwuegbuzie, 2003) and therefore help avoid common
pitfalls such as overweighting vivid description or underweighting
aspects that do not conform to the expected patterns (Sandelowski,
2001). Thus, they offer a transparent method of indicating the sup-
port for each meta- finding in the literature. For example, delirium
is commonly perceived as an overall distressing condition, which is
supported by our findings with the largest effect sizes in each of the
categories. Most of the previous reviews report only these negative
aspects (e.g., Fuller, 2016; Gaete Ortega et al., 2020; Partridge et al.,
2013). There are however meta- f indin gs that sug ge st a more dif feren-
tiated view: despite a predominantly negative impact, some findings
imply that patients can also be neutral to the situation— or even have
positive associations with delirium. Similar findings have also been re-
ported in previous reviews (e.g., O'Malley et al., 20 08). The frequenc y
effect sizes reveal that neutral or positive perspectives on different
aspects of delirium experience exist but are in the minority and re-
ported only in 12%– 16% of the reports.
We chose a rather low effect size cut- off (≥10%) to illuminate
some of these infrequent aspects that otherwise would be over-
shadowed by the more prevalent findings. This also underlines that
frequency effect sizes should not be used to value or devalue the
findings (Herber et al., 2017). They can assist in making decisions but
are to be interpreted cautiously: an aspect with a low frequency in
the literature can be crucial on an individual level or a high effect size
meta- finding might be irrelevant for the development of a delirium
management concept.
The theme influence on further life arose during the process of
grouping and abstracting findings into meta- findings. Our original
working definition of ‘delirium experience’ was stricter and more
focused on the recalled experiences during delirium. In accordance
with Sandelowski and Barroso (2007), we allowed these findings to
change our definition during the process, hence enabling their inte-
gration into the meta- summary. They are presented as an indepen-
dent category that can be regarded separately from the experiences
during delirium but are still an essential part of the whole delirium
experience, which accompanies and influences patients even after
hospital discharge. Seeing these findings as a part of the delirium
experience is also supported by Gaete Ortega et al., (2020) and
O'Malley et al., (2008). Because these ‘post- delirium’ experiences
were not our – nor the primary reports’ - main focus, the calculated
frequency effect sizes are however relatively low. Most of the lit-
erature investigating lasting effects of delirium focuses on ICU
patients and adverse outcomes (e.g., PTSD) that can be measured
with validated assessments (see, e.g. Kiekkas et al., 2010; Nouwen
et al., 2012). Further research is needed to assess the more subtle
long- term psychological consequences like lingering feelings of anx-
iety and fear or avoidance behaviour.
5.1 | Limitations
Our database searches were restricted to English and German lan-
guage reports by use of filters. We did not apply filters in disser-
tation databases and Google Scholar, and no report was excluded
based on language during our screening process. There still may
exist more literature in other languages that was excluded from this
review by not specifically searching in these languages, as well as
grey literature, that we were not able to locate.
Looking at the countries the reports originate from, it is obvious
that the vast majority of the literature (n = 23) underlying this meta-
summary provides a rather western perspective on the subject, with
a disproportionate part of the articles coming from Northern Europe
(n = 15). The ethnicity of the participants was rarely reported, so we
can only assume that the participant s in these studies were predom-
inantly Caucasian. The only report presenting a different cultural
background (Vahedian Azimi et al., 2015) gave insights into a more
middle- eastern perspective on experiencing delirium in an Iranian
hospital. They reported religious aspects (e.g., Quran recitations as
part of the daily hospital routine) which had an influence on the de-
lirium experience. Their findings did, however, fit well to our other
findings; the aforementioned religious aspects were subsumed
under ‘familiar everyday routines’ (D3), and we could not extract any
findings that would contradict or expand the more western view of
all other included reports. Nevertheless, a more diverse scope of
publications could illuminate further aspects that would be relevant
for culturally sensitive nursing practice.
Another limitation of this review is that the findings were ex-
tracted only from the Results section of the repor ts (including tables
and figures). If new findings were presented in other parts of the
articles, they are not included in this meta- summary. We also did not
use a validated delirium assessment as an inclusion criterion, as we
wanted to enable the inclusion of older articles, some of them which
did not use— or report using— any validated assessments.
During the process, we found relationships between all cat-
egories and found most of the meta- findings being interwoven or
built upon each other. For example, patients perceive themselves as
behaving differently in delirium than they are used to (P27), which
can lead to feelings of shame (E6), which then might result in pa-
tients trying to hide their delirious state from family and staff (I9).
The experienced emotions are also strongly related to the catego-
ries Perception, Interaction with others and Dealing with delirium. For
example, a loss of control over the situation (P3) can evoke feelings
of helplessness and fright (E4); patients feeling heard but not un-
derstood (I6) can result in loneliness and hopelessness (E5). Due to
the nature of our methodology, we were not able to explore and
display these relationships in an adequate way. This would call for a
meta- synthesis of the literature, which could be used to develop a
theoretical model of the delirium experience.

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6 | CONCLUSION
Our findings support the notion that giving patients the possibility
to talk about their delirium experience both during (D1) and after
(F2) delirium can have therapeutic value and should be offered in a
sensible, empathic way because not everyone wants to talk about
the experience (D4). This is backed by the findings of Fuller (2016),
Bélanger and Ducharme (2011) and Gaete Ortega et al., (2020).
Our results do not support reorienting the patients forcefully (e.g.,
questioning their experiences or hallucinations), which has been
discussed in the literature previously (e.g., O'Malley et al., 2008),
as this can result in barriers between patients and people around
them (I1, I4). The focus should be on giving patients the possibil-
ity to orient themselves by familiar routines and voices, daylight,
decision- making autonomy and offering information (D3). Providing
information about delirium symptoms and progress— both before
and after occur rence— is also supported by the findings of Partridge
et al., (2013) and Bélanger and Ducharme (2011). This also applies
to family members who need guidance in contact with delirious
patients (O'Malley et al., 2008). Our findings underline that their
presence during delirium can have a supportive and soothing ef-
fect on patients’ emotional state, as also reported by Bélanger and
Ducharme (2011).
This present systematic review and meta- summary provides
the most comprehensive aggregation of qualitative research of the
patient delirium experience to date. It can also be seen as a ‘quan-
titative transformation of qualitative data’ (Sandelowski & Barroso,
2007), which can be used to extract more meaning from qualitative
findin gs and to ass ess their relevance to the developm ent and imp le-
mentation of complex interventions, such as delirium management
concepts.
This meta- summary represents the endpoint of our current
project. Further research is needed to explore the relationships
we encountered between the individual components of the delir-
ium experience. We encourage others to take on the challenge of
conducting a meta- synthesis of the literature and building the first
theoretical model of the patient delirium experience.
FUNDING STATEMENT
This research received no specific grant from any funding agency in
the public, commercial or not- for- profit sectors.
ACKNOWLEDGEMENTS
The authors would like to thank Prof. Dr. Gabriele Meyer (Martin
Luther University Halle- Wittenberg) for her support and feedback
during the project.
CONFLICT OF INTEREST
No conflict of interest has been declared by the authors.
AUTHOR CONTRIBUTIONS
The review protocol was written by EK, CH, RS and VL and approved
by the supervisors MB and AS. EK and RS developed the search
strategies, conducted the searches and screened the literature. CH
and VL performed the quality appraisal, classified the literature and
conducted the main analysis. RS and EK validated the results of their
analysis. EK calculated the effect sizes and created the tables for the
meta- summar y. MB and AS provided feedback during the process
and were consulted in all phases of the project. EK, CH, RS and VL
drafted the manuscript. The final version was written by EK based
on feedback from MB and AS and approved by all authors.
PEER REVIEW
The peer review history for this article is available at https://publo
ns.com/publo n/10.1111/jan.14865.
ORCID
Eero Kuusisto- Gussmann https://orcid.
org/0000-0002-9178-954X
Carolin Höckelmann https://orcid.org/0000-0003-3624-3621
Verena von der Lühe https://orcid.org/0000-0001-5385-522X
Roman Schmädig https://orcid.org/0000-0002-1564-7611
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Patients’ experiences of delirium: A systematic review and
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