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Eric Fombonne


In Review
Autism Spectrum Disorders: Early Detection, Intervention, Education, and Psychopharmacological Management

Susan E Bryson, Sally J Rogers, Eric Fombonne


Diagnosis and Epidemiology of Autism Spectrum Disorders
Lee Tidmarsh, Fred R Volkmar


Genetic and Neurodevelopmental Influences in Autistic Disorder
Rob Nicolson, Peter Szatmari


Original Research
Attitudes of Senior Psychiatry Residents Toward Persons with Intellectual Disabilities

Hélène Ouellette-Kuntz, Philip Burge, David B Henry, Elspeth A Bradley, Pierre Leichner


The Efficacy of 2 Different Dosages of Methylphenidate in Treating Adults With Attention-Deficit Hyperactivity Disorder

Rachelle Bouffard, Lily Hechtman,, Klaus Minde, Fiorella Iaboni-Kassab


Delirium in Hospital: an Underreported Event at Discharge

Louis T van Zyl, Paul R Davidson


Brief Communication
Removing Barriers to Treatment of First-Episode Psychotic Disorders

Derek J Scholten, Ashok K Malla, Ross MG Norman, Terry S McLean, Elizabeth M McIntosh, Chris L McDonald,, Michael Eliasziw, Kathy N Speechley


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Couple Therapy with Gay Men.
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What Forever Means After The Death of a Child.
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Fighting for Mental Health: A Personal View.
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Paul Grof, MD, FRCPC

Understanding the Mind: The Nature and Power of the Mind. 2nd ed.
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Response of Catatonic Schizophrenia to Amisulpride: A Case Report

Medication Noncompliance Among Psychiatric Outpatients In Iran

Diogenes Syndrome in a Pair of Siblings

Treatment Option for Seasonal Affective Disorder

Factitious Anemia and Magnetic Resonance Imaging Abnormalities

Pregnancy and Respiratory Nocturnal Panic Attacks

Original Research

Delirium in Hospital: an Underreported Event at Discharge

Louis T van Zyl, MB, ChB, MMed (Psych), FRCPC1, Paul R Davidson, PhD, CPsych2


Objective: Delirium, an important event in hospital, is associated with significant mortality and morbidity. Most patients with delirium recover fully; however, when left untreated, delirium may progress to stupor, coma, or death. Delirium is less likely to resolve completely in elderly patients in whom persistent cognitive deficits commonly occur. The extent to which this information is available to family doctors after discharge was investigated.

Methods: A total of 31 patients with delirium who were referred to consultation-liaison psychiatry were assessed using standardized measures. Medical services completed discharge summaries on these patients; a chart review captured the extent to which the diagnosis of delirium and the involvement of psychiatry was recorded in the discharge summaries.

Results: In structured discharge summaries, a reference to delirium occurrence was found in 55% of cases. In unstructured discharge summaries, the reporting was much lower (16% of cases). Delirium was more likely to be reported in women than in men, when it was more severe, or when it was the principal reason for admission, rather than when it occurred during an admission for some other reason.

Conclusions: Delirium episodes that occur during a period of hospitalization for treatment of any medical disorder are underreported, even when specifically diagnosed. Structured discharge summaries tend to increase the rate of reporting.

(Can J Psychiatry 2003:48: 555–560)

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Clinical Implications

  • Hospital discharge summaries form the main communication link between hospitalists and primary practitioners and may provide vital information for continuing and future patient care.

  • Prior episodes of delirium predict vulnerability to future episodes.

  • Discharge from hospital of a patient with residual symptoms of delirium requires ongoing management, monitoring, and follow-up in the community.

  • The fact that many episodes of delirium are not recorded in the discharge summary has implications for ongoing patient care after discharge.

  • Consulting psychiatrists need to teach medical and surgical residents the long-term importance of delirium.

  • Hospital clinical teaching units need to improve teaching of the value of clinical notes and discharge summaries to other health professionals.


  • A small sample size was used.

Key Words
: delirium, discharge summaries, underreporting

Résumé : Le délire à l’hôpital : un événement sous-déclaré au moment du congé

Delirium, a syndrome defined as a disturbance of consciousness, attention, cognition, and perception, has associated symptoms that may include disturbances in emotions, sleep, and psychomotor behaviour (1). The prevalence of delirium ranges from 10% to 30% in hospitalized patients who are medically ill, to as high as 51% in postoperative patients, and up to 80% in patients with terminal illness (2–5). Prodromal or subclinical symptoms may precede full-blown delirium by 1 to 3 days. Delirium symptoms may last from a few days to as long as 2 months but typically resolve in 10 to 12 days. Most patients with delirium recover fully; however, when untreated, delirium may progress to stupor, coma, or death. Delirium is less likely to resolve completely in elderly patients, with persistent cognitive deficits occurring frequently (2,3,5–9).

Delirium in the medically ill is associated with significant morbidity and mortality. Patients with delirium are at increased risk for various complications, such as pneumonia, decubitus ulcers, and postoperative complications, as well as longer hospital stays and poor hospital outcomes (10). Delirium results in increased risk for death in hospital and during the months following discharge (11). Studies suggest that up to 25% of patients with delirium die within 6 months of discharge (12).

Despite its morbidity and mortality, delirium is often misdiagnosed or is unrecognized by treating physicians. Armstrong and colleagues found that house staff misdiagnosed as many as 46% of delirium cases over a 5-year period (13).

Hospital discharge summaries serve as the main communication link between hospitalists and primary practitioners. Physician surveys yielding information on what a quality discharge summary should include report that a good discharge summary comprises the following: admission diagnosis, pertinent physical examination findings, laboratory results, procedures, complications in hospital, discharge diagnosis, discharge medications, active medical problems at discharge, and follow-up information (14,15). Delirium symptoms often persist following discharge and represent a risk factor for subsequent delirium episodes. Thus, delirium is an important event to record on discharge. Unfortunately, even when delirium is diagnosed and treated, it fails to be reported on the discharge summary (16).

This study examined potential factors that may influence the reporting of delirium as a diagnosis in general hospital discharge summaries.


Participants were drawn from all referrals to a consultation- liaison psychiatry service in a university teaching general hospital between July 2000 and September 2001.

All patients were seen in an inpatient setting. Referrals were received mainly from internal medicine and its subspecialties, and a small number of consultations were seen from the surgical specialties. Although consultation-liaison psychiatry diagnosed 80 patients with delirium, only 37 of these patients had been assessed using standardized delirium assessment and severity scales. Of these 37 cases, discharge summaries could be obtained for only 31. This paper focuses on the latter group, which comprised 11 men and 20 women, with a mean (SD) age of 73.34 (13.75) years.

Delirium was assessed clinically and was rated using the Delirium Rating Scale (DRS) and DRS-Revised-98 (DRS-R-98) (17–19). The DRS, a 10-item scale, is completed by the clinician. The DRS-R-98 is a 16-item, clinician-rated scale with 13 severity items and 3 diagnostic items. The DRS assesses 10 aspects of delirium: temporal onset of symptoms, the presence of perceptual disturbances, the presence of hallucinations or of delusions, psychomotor retardation and agitation, cognitive status, physical disorder, sleep–wake cycle disturbances, lability of mood, and variability of symptoms. The DRS-R-98 includes all these, along with language impairment, abnormal thought processes, and fluctuation of symptom severity. For the DRS-R-98, the psychomotor retardation and agitation item of the DRS was subdivided into 2 items, and cognitive status was divided into orientation, attention, short-term memory, long-term memory, and visiospatial ability.

The DRS and the DRS-R-98 rate each item on a 3-, 4-, or 5-point scale, with higher scores representing more intense delirium symptoms. In some cases, physical problems interfered with administering the DRS and the DRS-R-98 to the extent that some items could not be evaluated (for example, visiospatial ability). In these instances, prorated DRS and DRS-R-98 scores were derived using the mean response to the items completed as an estimate of the score for the items not completed. Cut-off scores for the DRS-R-98 were 15.25 (severity) and 17.75 (total) (19). The cut-off score for the DRS (severity) was 12.

Another measure used in assessing delirium severity in this study was the Clinical Global Impression (CGI) scale. This scale is a widely used single-item, 7-point rating of the severity of the patient’s illness, relative to others in the same population.

Psychiatric Diagnoses
All patients met DSM-IV criteria for delirium. A psychiatrist who was experienced in the area of consultation-liaison psychiatry and in the evaluation of delirium provided the clinical assessment and the diagnosis in every instance.

Discharge Summaries
Discharge summaries were reviewed to assess the extent to which they included information about the delirium episode that had taken place during the admission. These summaries were completed after patients were discharged from inpatient hospital care. The styles of discharge summary vary from service to service; for this reason, we looked for specific items of reference. In each discharge summary’s review, 5 specific questions were addressed: Was delirium specifically included as a diagnosis arrived at during hospitalization? Was delirium or a synonym (20) included as a diagnosis arrived at during hospitalization? Was the word delirium mentioned in the body of the discharge summary? Was the word delirium or a synonym (20) mentioned in the body of the discharge summary? Was the consultation with psychiatry mentioned in the discharge summary?


In the process of discharge summary review, 2 broad categories of discharge summaries were identified (that is, unstructured and structured). Most discharge summaries were in a narrative format without specific headings or a clear template. These were regarded as unstructured. A smaller number of discharge summaries, to varying degrees, contained headings or followed a template for describing aspects that related to the inpatient hospital stay. If headings included a preferred diagnosis or if a section of the discharge summary was specifically dedicated to discussion of diagnosis and comorbidities, these were regarded as structured discharge summaries. In this context, 22 discharge summaries were unstructured, and 9 were structured. Accordingly, in Table 1, results were reported according to this concept.

Table 1  Proportions of discharge summaries (DS) containing various indications of delirium and involving psychiatry services 


Unstructured DS 

Structured DS 

Total DS sample 


n = 22 

n = 9 

n = 31 


Number of cases 

Number of cases 

Number of cases 

DS mentions the word “delirium” 





DS mentions the word “delirium” and (or) synonym of delirium 






Specific discharge diagnosis of delirium 




Discharge diagnosis of delirium and (or) synonym of delirium 




DS mentions psychiatric involvement 







Table 1 sets out the proportion of discharge summaries containing the various indications of delirium. We examined the reporting of the diagnosis of delirium. For structured discharge summaries (n = 9), reporting delirium as a primary diagnosis or as a comorbidity ranged from 55% (using the word delirium) to 66% (using delirium or a synonym). None of the unstructured discharge summaries (n = 22) contained a specific delirium diagnosis or a synonym. Placing this in the context of the total sample (n = 31), only 16% contained a specific discharge diagnosis of delirium, and 19.4% made the discharge diagnosis of delirium or used a synonym.

Some unstructured discharge summaries referred to delirium or one of its synonyms without reporting it as an actual diagnosis. It was found that 32% referred to delirium, and 59% referred to delirium or a synonym. In these instances, delirium was not specifically identified as a discharge diagnosis but referred to as an event that occurred during hospitalization.

If any reference to delirium or to one of its synonyms is regarded as equivalent to making a discharge diagnosis of the condition, then unstructured discharge summaries (n = 22) reported the diagnosis in 59% of cases, and structured discharge summaries (n = 9) in 66% of cases, with the total sample (n = 31) of discharge summaries reporting the event in 61% of cases.

Of the discharge summaries, 48% reported that psychiatry had been consulted.

We examined the variables that correlated with whether or not delirium was referred to in the discharge summary. Of the 9 discharge summaries identified as structured, when the reason for admission was delirium (n = 5), the discharge diagnosis always included delirium. Conversely, in structured discharge summaries for which the admission was not delirium (n = 4), the discharge summary was unlikely to include delirium (1 summary in 4 included delirium).

When we examined whether delirium or a synonym was mentioned as a problem or event during the admission, 3 variables that were significantly correlated with this emerged (Table 2). These were the DRS-R-98 total score, the DRS-R-98 severity score, and the sex of the patient. Higher scores on the DRS-R-98 predicted a higher likelihood of including delirium in the discharge summary. Female sex was found to have a significant positive relation to the inclusion of delirium (or synonym) in the discharge summary. For 10 of 11 women, discharge summaries included delirium (or a synonym), whereas in men it was less likely to be included (only 9 of 20).

Table 2  Variables predicting the mention of the word delirium or a synonym in the discharge summary 





c2 = 6.34 


DRS-R-98 severity 

r = 0.46 


DRS-R-98 total 

r = 0.43 



r = 0.24 

0.20 (ns) 

DRS = Delirium Rating Scale; ns = not significant 

Table 3 presents the range of scores that were obtained from our patient sample using the various rating instruments. This table also includes the means and standard deviations of these scores and refers to maximum scores that might be obtained for each of these instruments, as well as their cut-off scores. The mean DRS score is 17.61, with quite a wide distribution. This score is comparable with the mean of 17.0 (SD 4.0) reported by Rockwood (8). The mean DRS-R-98 severity score is 16.10, also with a wide distribution. The DRS-R-98 total score of 21.24 includes an assessment of language impairment and thought processes, as well as a fluctuation of symptom severity. The mean CGI score is 4.20.

Table 3   Mean rating: instrument scores 


Mean (SD) 

Maximum possible score and cut-off scores for delirium for measuring instruments 


Range in our study 

DRS-R-98 total 

21.24 (6.19) 

46 (17) 



DRS-R-98 severity 

16.10 (6.16) 

39 (15) 



DRS severity 

17.61 (4.82) 

32 (12) 




4.20 (0.94) 

7 (3) 



CGI = Clinical Global Impression; DRS = Delirium Rating Scale 


In this study, underreporting of an important medical event in the discharge summary coincides with the published literature. Such underreporting is also described for intracranial injuries, thoracic injuries, and spinal fractures (16). Generally, community physicians expect to be informed of complications that occur during treatment of their patient while in hospital (15). In the instance of delirium, prior episodes of delirium predict vulnerability to future episodes, not only making this a complication occurring during hospitalization but also identifying a risk factor that is important to convey to the treating physician. In addition, delirium does not resolve completely by the time of discharge in many patients (21). Residual symptoms and persistent cognitive impairment may require ongoing management following hospital discharge.

Our study found that most of the discharge summaries lacked much structure. Reporting the event of delirium was less likely to occur in the unstructured discharge summaries than in those with a more structured format. The unstructured format of most discharge summaries in our sample may be one factor that contributes to the low reporting.

In patients with delirium at the time of admission, discharge summary reporting was higher, compared with patients whose delirium developed during the inpatient stay (22). This finding indicates that greater emphasis is placed on delirium when the primary reason for admission is to investigate and to identify the etiology of the acute confusional state. This differs from cases in which delirium develops during the course of managing a primary physical problem, wherein a transient period of delirium may be sometimes expected (for example, in elderly patients hospitalized for treatment of community- acquired pneumonia) (4). In these instances, the occurrence of a mild, rapidly transient episode of delirium may be regarded as part and parcel of the pneumonia, not as a separate entity requiring specific reporting in a discharge summary.

The distribution of scores on all the rating instruments used contains low figures (reflecting less severe delirium) because, in many instances, the delirium that was diagnosed was resolving or being managed by the medical service prior to consulting us. The low scores most likely reflect that many patients’ delirium had improved and was no longer as severe at the time of rating.

Although the consultation-liaison psychiatry service had been asked to see all the patients in our study, the discharge summary mentions psychiatric involvement in only 48% of cases. We did not compare this with the level of reporting for other disciplines that may have been consulted during the course of the hospitalization.

The DRS is the most widely used instrument for rating delirium severity (23). As a result of research on the original instrument, however, the DRS-R-98 was developed and validated (19). The original DRS did not emerge as a significant predictor of discharge summary reporting of delirium, but this was the case with the DRS-R-98. This suggests that the improvements in the revised scale (for example, more weight for cognitive impairments) make it more sensitive to the variables that affect whether a clinician sees the delirium as significant enough to report at discharge.

Our data suggest that the severity of the delirium is a factor affecting delirium reporting in the discharge summary, with more severe deliria more likely to be reported. In addition, the sex of the patient appears to be related to reporting a delirium diagnosis in the discharge summary, with a higher rate of reporting in women with delirium, compared with reporting in men. We examined the relation between sex and delirium severity and found that DRS-R-98 scores did not differ significantly between men and women: mean (SD) for men 22.8 (6.56); mean (SD) for women 20.41 (5.97) (differences not significant, P > 0.25). The 2 groups were also equivalent in age: mean (SD) for men 77.5 years (15.27), mean (SD) for women 71.0 years (12.63), (difference no significant, t [29] = 0.97, P > 20). This suggests that the sex of the patient is in itself an important factor in reporting delirium, but the reason for the relation is unclear from the present data. The small sample size was a limitation.


Episodes of delirium that occur during a period of hospitalization for treatment of any medical disorder are underreported, even when specifically diagnosed. In this study, the exception to underreporting was for those cases in which delirium was diagnosed at the time of admission: reporting occurred in every instance.

The likelihood of reporting delirium in the discharge summary increases with the severity of the delirium, and in this regard, the DRS-R-98 seems a more useful assessment tool for evaluating delirium than the older DRS version.


The authors thank Dr Michael J Robinson, Assistant Professor, Division of Consultation-Liaison Psychiatry, Queen’s University, for manuscript review and helpful comments and suggestions.


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4. Riquelme R, Torres A, El Ebiary M, Mensa J, Estruch R, Ruiz M, and others. Community-acquired pneumonia in the elderly. Clinical and nutritional aspects. Am J Respir Crit Care Med 1997;156:1908–14.

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14. Solomon JK, Maxwell RB, Hopkins AP. Content of a discharge summary from a medical ward: views of general practitioners and hospital doctors. J R Coll Physicians Lond 1995;29:307–10.

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16. Glick RE, Sanders KM, Stern TA. Failure to record delirium as a complication of intra-aortic balloon pump treatment: a retrospective study. J Geriatr Psychiatry Neurol 1996;9:97–9.

17. Trzepacz PT, Baker RW, Greenhouse J. A symptom rating scale for delirium. Psychiatry Res 1988;23:89–97.

18. Trzepacz PT. The Delirium Rating Scale. Its use in consultation-liaison research. Psychosomatics 1999;40:193–204.

19. Trzepacz PT, Mittal D, Torres R, Kanary K, Norton J, Jimerson N. Validation of the Delirium Rating Scale-Revised-98: comparison with the delirium rating scale and the cognitive test for delirium. J Neuropsychiatry Clin Neurosci 2001;13:229–42.

20. Wise MG, Brandt MG. Delirium. In: Yudofsky SC, Hales RE, editors. The American Psychiatric Press textbook of neuropsychiatry. Washington (DC): American Psychiatric Press; 1992.

21. Hill CD, Risby E, Morgan N. Cognitive deficits in delirium: assessment over time. Psychopharmacol Bull 1992;28:401–7.

22. Patten SB, Williams JV, Petcu R, Oldfield R. Delirium in psychiatric inpatients: a case-control study. Can J Psychiatry 2001;46:162–6.

23. Trzepacz PT. A review of delirium assessment instruments. Gen Hosp Psychiatry 1994;16:397–405.


Manuscript received January 2003, revised, and accepted March 2003.

Previously presented at the 51st Annual Meeting of the Canadian Psychiatric Association; November 2, 2001; Montreal (QC).

Two posters were presented at the 16th World Congress on Psychosomatic Medicine; August 24, 2001; Gothenburg, Sweden; and at the 48th Annual Meeting of the Academy of Psychosomatic Medicine; November 15, 2001; San Antonio (TX).

1. Assistant Professor and Chair, Division of Consultation-Liaison Psychiatry, Department of Psychiatry, Queen’s University, Kingston, Ontario.

2. Assistant Professor, Division of Consultation-Liaison Psychiatry, Department of Psychiatry, Queen’s University, Kingston, Ontario.

Address for correspondence: Dr L van Zyl, Division of Consultation-Liaison Psychiatry, Connell-4, Suite 2-486, Kingston General Hospital, 76 Stuart Street, Kingston, ON K7L 2V7


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