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EMJ Online First, published on March 24, 2015 as 10.1136/emermed-2014-204379 Original article
The prevalence, risk factors and short-term outcomes of delirium in Thai elderly emergency department patients Jiraporn Sri-on,1,2 Gregory Philip Tirrell,1 Alissala Vanichkulbodee,2 Supa Niruntarai,2 Shan W Liu1 ▸ Additional material is published online only. To view please visit the journal online (http://dx.doi.org/10.1136/ emermed-2014-204379). 1
Emergency Department, Massachusetts General Hospital, Boston, Massachusetts, USA 2 Emergency Department, Vajira Hospital, Navamindradhiraj University, Dusit, Bangkok, Thailand Correspondence to Dr Jiraporn Sri-on, Emergency department, Vajira Hospital, Navamindradhiraj University, Khao street, Dusit, Bangkok 10300, Thailand; [email protected] Received 6 October 2014 Revised 26 January 2015 Accepted 22 February 2015
ABSTRACT Background We sought to determine the prevalence of delirium in a Thai emergency department (ED). The secondary objective was to identify risk factors and short-term outcomes in delirious elderly ED patients. Methods This was a prospective cross-sectional study in the ED of an urban tertiary care hospital. Patients aged ≥65 years who presented to the ED were included. We excluded patients who had severe dementia, were not responsive to verbal stimuli, had severe trauma and were blind, deaf, aphasic or unable to speak Thai. Delirium was determined using the Confusion Assessment Method for the Intensive Care Unit. We collected 30-day mortality rate, hospital length of stay and revisit rate as short-term outcomes. Results We had a final sample size of 232 patients; 27 (12%) were delirious in the ED, of which 16 (59%) were not recognised to be delirious by the emergency physician. Multivariable logistic regression analysis showed dementia (adjusted OR (AOR) 13.1; 95% CI 2.9 to 59.6), auditory impairment (AOR 4.8; 95% CI 1.6 to 13.8) and ED diagnosis of metabolic derangement (AOR 6.5; 95% CI 1.6 to 26.8) were associated with delirium in the ED. Delirium was associated with a higher mortality rate than those without delirium (15% vs 2%, p=0.004). Conclusions In one middle-income country, elderly ED patients were delirious >10% of the time. Delirium was underdiagnosed and was associated with an increased 30-day mortality rate. Delirium screening needs to be improved, potentially focusing on high-risk patients.
INTRODUCTION
To cite: Sri-on J, Tirrell GP, Vanichkulbodee A, et al. Emerg Med J Published Online First: [ please include Day Month Year] doi:10.1136/emermed-2014204379
The ageing population is growing worldwide.1 Mental status impairment, for example, delirium and cognitive impairment, is common in older emergency department (ED) patients.2–5 The prevalence of delirium in the ED ranges from 8.3% to 17.2%.4–6 Furthermore, delirium is associated with an increased risk of death, prolonged length of hospital stay and dementia in the elderly.7–9 Most delirium prevalence and outcome studies have been conducted in inpatient settings and in developed countries.4–9 The ED is often the first place during a hospital visit where delirium can be detected.10 Several studies have shown that the detection of delirium by emergency physicians (EPs) is low (16–35.5%).4–6 Furthermore, most ED delirium studies have been conducted in developed countries, limiting the generalisability of those studies to middle-income or lower-income countries where the culture and environment are different.
Key messages What is already known on this subject? Several studies have shown that the detection of delirium by emergency physicians (EPs) is low. Hence, most emergency department (ED) delirium studies have been conducted in developed countries in a in-hospital setting. This limits the generalisability of those studies to middle-income or lower-income countries where the culture and environment are different. What might this study add? The prevalence of delirium in elderly ED patients in one middle-income country is consistent with other developed countries. Still, delirium was undiagnosed by EPs in >50% of cases and was associated with an increased 30-day mortality rate. There needs to be improved delirium screening which focuses on high-risk patients, dementia, auditory impairment and ED diagnosis metabolic derangement may improve ED delirium screening efficiency.
Thailand is a middle-income country with an ageing society. The elderly population in Thailand increased from 13.2% in 2010 to 26.6% in 2013.11 This is an increasing number of elderly patients for hospitalisation.11 The prevalence of delirium in inpatients was 40.0% in a single-centre Thai study.12 The specific objectives of this study were to determine the prevalence of delirium and how often it is not recognised in a Thai ED. The secondary objective was to identify risk factors and short-term outcomes in delirious elderly ED patients in a middle-income country.
METHODS Study design and setting This was a prospective cohort study in the ED of an urban university hospital in Bangkok, Thailand, with an annual census of 70 000 patients, of which approximately 10% were aged ≥65.
Selection of participants We collected data from a convenience sample of patients between 08:00 and midnight, 7 days a week from 1 June 2013 to 15 July 2013. We included all patients aged ≥65 years who presented to the ED and excluded patients who refused to
Sri-on J, et al. Emerg Med J 2015;0:1–6. doi:10.1136/emermed-2014-204379
Copyright Article author (or their employer) 2015. Produced by BMJ Publishing Group Ltd under licence.
1
Downloaded from http://emj.bmj.com/ on May 24, 2015 - Published by group.bmj.com
Original article consent, had severe dementia, were not responsive to verbal stimuli, had severe trauma, were critically ill (ie, were intubated, severe sepsis or required emergency intervention), and who were blind, deaf, aphasic or unable to speak Thai. Our study followed the methods of Ely et al13 for informed consent. We used the Short Portable Mental Status Questionnaire (SPMSQ)14 for screening patients’ capacity to give informed consent. The SPMSQ is a 10-item questionnaire that evaluates orientation, memory and concentration. A patient with ≤4 errors was directly asked to sign a consent form. An authorised surrogate was asked to sign a consent form if the patient committed ≥5 errors on the SPMSQ. The SPMSQ is a brief screening test for organic brain dysfunction. It has proved to be a sensitive and specific screening test for moderate to severe dementia in the community and hospital. A patient with ≥8 errors was considered to have severe dementia and hence ineligible for our study. Also, we used the SPMSQ to exclude patients who had severe dementia or severe organic brain syndrome in an attempt to reduce the rate of misinterpretation of the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) for delirium detection.
Data collection and processing Three research assistants (RAs) enrolled patients and performed screenings. The RAs were trained prior the study by the principal investigator ((PI); JS). All RAs were experienced nurses who had worked in an ED for at least three years. Training lasted 3 days, and the RAs studied a delirium assessment manual for 1 day. The PI gave a didactic lecture about delirium and assessment for 2 h. The RAs practised using an adapted delirium flow sheet (Thai version) with the PI for 4 h. The RAs also practised the assessment using simulated patient scenarios for 1 day. The PI observed the RAs when performing these assessments with ED patients to check inter-rater reliability. The screening processes were conducted after the EPs determined patients’ dispositions and care plans but before the patients were discharged from the ED.
Outcome measure Delirium, the primary outcome, was determined using the CAM-ICU, following the same methodology reported by Han et al.4 The CAM-ICU has been validated in ICU and ED patients.13 15 This screening tool has an excellent sensitivity of
Figure 1 Enrolment of subjects. 2
72.0% (95% CI 58.3% to 72.5%) and specificity of 98.6% (95% CI 96.8% to 99.4%), as well as an excellent inter-rater reliability of 0.92 (95% CI 0.85 to 0.98) between physicians and RAs.15 The secondary outcome was to identify risk factors and shortterm outcomes in delirious elderly ED patients. Short-term outcomes include hospital length of stay, ED length of stay, 30-day mortality rate and ED revisit rates. We obtained 30-day outcome information by reviewing the medical records of all admitted patients and by attempting to contact all enrolled subjects by telephone up to five times.
Methods of measurement To determine EP recognition of delirium, two EPs reviewed ED medical records. These EPs were blinded to the patient’s CAM-ICU evaluation results, but were not blinded to the study hypothesis. We accepted synonyms for delirium, such as acute confusional state (or disorder), acute mental status change, encephalopathy, toxic metabolic state and acute organic brain syndrome if recorded in the physician’s diagnosis or impression, similar to the Ely et al study.13 Demographic data, triage level, residence, visual impairment, auditory impairment, medication used, recent history of trauma, Charlson comorbidity score, fall history, vital signs, diagnosis and results of laboratory tests conducted in the ED were collected from subjects, their surrogates and their medical records. Visual and auditory impairment were obtained from medical history and presence of corrective lenses or use of hearing aids.4 Dementia screening was performed in patients who had ≥4 SPMSQ errors by using the Thai Mental State Examination (TMSE).16 TMSE was adapted from the Mini-Mental State Examination for the Thai population. It is a screening tool for cognitive impairment and requires only 5–10 min to complete. Demented patients were defined as those who had a TMSE score 90 bpm RR >20 breaths/min Temperature 38°C SIRS criteria Biochemical profile, n (%) Hyponatraemia (Na20 Anaemia* ED disposition Discharged from ED Admitted to hospital
Total (n=232)
Delirium (n=27)
Non-delirium (n=205)
p Value
76 (6) 98 (42) 4.0 (1.3) 3 (0–8)
76 (7) 10 (37) 4.5 (1.3) 2 (0–7)
75 (6) 88 (43) 3.9 (1.3) 3 (0–8)
0.703 0.560 0.045 0.079
129 (56) 153 (66) 119 (51) 83 (36) 47 (20)
25 (93) 22 (82) 22 (82) 6 (22) 5 (19)
104 (51) 131 (64) 97 (47) 77 (38) 42 (21)
0.99 0.126 >0.99 >0.99 0.104 0.011 0.040
0.261 0.685 >0.99 >0.99 0.131 0.120 0.211 0.712 0.661 0.625
*Women: haemoglobin (Hb)90 bpm RR >20 breaths/min Temperature 38°C
Clinical outcome
Delirium diagnosed (n=16)
Delirium not diagnosed (n=11)
p Value
77 (8) 7 (44) 5 (1)
75 (4) 3 (27) 4 (2)
0.514 0.448 0.128
4 (6)
1.5 (2.5)
0.351
11 (100) 7 (64) 6 (55) 3 (27) 3 (27)
0.499 0.125 0.006 0.662 0.370 1
14 (88) 15 (94) 16 (100.0) 3 (19) 2 (13) 15 (94) 1 (6) n (%) 3 (19) 4 (25) 4 (25.0) 4 (25.0) 0
10 (91) 1 (9)
15 (94) 4 (37)
1 (6) 7 (64)
4 (25.0) 2 (12.5) 1 (6.3)
1 (9) 1 (9) 2 (18) 2 (18) 5 (46)
3 (27.3) 5 (45.5) 0
0.624 0.618 1 1 0.006 0.002
1 0.084 1
were admitted to the hospital, of which 4 (44%) were recognised as delirious by the EP. Delirious patients were associated with a history of dementia, impaired hearing, lower level of education, higher Charlson comorbidity index score, higher triage level and a metabolic derangement aetiology diagnosed in the ED more frequently than non-delirious patients. Delirious and non-delirious patients were similar in terms of age, residence, gender, history of falls, history of alcohol use, systemic inflammatory response criteria, number of medications and ED-diagnosed infection. When we compared biochemical profiles, there was no statistically significant difference between the delirium and non-delirium groups in the proportion of patients who had hyponatraemia, hypoglycaemia, hyperglycaemia, blood urea nitrogen/creatinine ratio
Table 3 Regression modelling, risk factors of delirium in the emergency department (ED) ODD (95% CI)
Auditory impairment Dementia ED diagnosis metabolic derangement
4
Table 4 Clinical outcomes of individuals with and without delirium
Unadjusted
Adjusted
4.8 (1.8 to 13.4) 12.1 (2.8 to 52.6) 4.0 (1.3 to 4.6)
4.7 (1.6 to 13.8) 13.0 (2.5 to 59.6) 6.5 (1.6 to 26.8)
Emergency department length of stay, median hours (IQR) Hospital admission, n (%) Hospital length of stay, median days (IQR) 30-day mortality, n (%) 30-day revisit, n (%)
Delirium (n=27) 4 (0–16)
Non-delirium (n=205) 4 (0–10)
p Value 0.611
9 (33) 5 (1–12)
57 (28) 1 (1–4)
0.625 0.938
4 (15) 6 (22)
3 (2) 49 (24)
0.004 0.847
>20 or anaemia (women: haemoglobin (Hb)
EMJ Online First, published on March 24, 2015 as 10.1136/emermed-2014-204379 Original article
The prevalence, risk factors and short-term outcomes of delirium in Thai elderly emergency department patients Jiraporn Sri-on,1,2 Gregory Philip Tirrell,1 Alissala Vanichkulbodee,2 Supa Niruntarai,2 Shan W Liu1 ▸ Additional material is published online only. To view please visit the journal online (http://dx.doi.org/10.1136/ emermed-2014-204379). 1
Emergency Department, Massachusetts General Hospital, Boston, Massachusetts, USA 2 Emergency Department, Vajira Hospital, Navamindradhiraj University, Dusit, Bangkok, Thailand Correspondence to Dr Jiraporn Sri-on, Emergency department, Vajira Hospital, Navamindradhiraj University, Khao street, Dusit, Bangkok 10300, Thailand; [email protected] Received 6 October 2014 Revised 26 January 2015 Accepted 22 February 2015
ABSTRACT Background We sought to determine the prevalence of delirium in a Thai emergency department (ED). The secondary objective was to identify risk factors and short-term outcomes in delirious elderly ED patients. Methods This was a prospective cross-sectional study in the ED of an urban tertiary care hospital. Patients aged ≥65 years who presented to the ED were included. We excluded patients who had severe dementia, were not responsive to verbal stimuli, had severe trauma and were blind, deaf, aphasic or unable to speak Thai. Delirium was determined using the Confusion Assessment Method for the Intensive Care Unit. We collected 30-day mortality rate, hospital length of stay and revisit rate as short-term outcomes. Results We had a final sample size of 232 patients; 27 (12%) were delirious in the ED, of which 16 (59%) were not recognised to be delirious by the emergency physician. Multivariable logistic regression analysis showed dementia (adjusted OR (AOR) 13.1; 95% CI 2.9 to 59.6), auditory impairment (AOR 4.8; 95% CI 1.6 to 13.8) and ED diagnosis of metabolic derangement (AOR 6.5; 95% CI 1.6 to 26.8) were associated with delirium in the ED. Delirium was associated with a higher mortality rate than those without delirium (15% vs 2%, p=0.004). Conclusions In one middle-income country, elderly ED patients were delirious >10% of the time. Delirium was underdiagnosed and was associated with an increased 30-day mortality rate. Delirium screening needs to be improved, potentially focusing on high-risk patients.
INTRODUCTION
To cite: Sri-on J, Tirrell GP, Vanichkulbodee A, et al. Emerg Med J Published Online First: [ please include Day Month Year] doi:10.1136/emermed-2014204379
The ageing population is growing worldwide.1 Mental status impairment, for example, delirium and cognitive impairment, is common in older emergency department (ED) patients.2–5 The prevalence of delirium in the ED ranges from 8.3% to 17.2%.4–6 Furthermore, delirium is associated with an increased risk of death, prolonged length of hospital stay and dementia in the elderly.7–9 Most delirium prevalence and outcome studies have been conducted in inpatient settings and in developed countries.4–9 The ED is often the first place during a hospital visit where delirium can be detected.10 Several studies have shown that the detection of delirium by emergency physicians (EPs) is low (16–35.5%).4–6 Furthermore, most ED delirium studies have been conducted in developed countries, limiting the generalisability of those studies to middle-income or lower-income countries where the culture and environment are different.
Key messages What is already known on this subject? Several studies have shown that the detection of delirium by emergency physicians (EPs) is low. Hence, most emergency department (ED) delirium studies have been conducted in developed countries in a in-hospital setting. This limits the generalisability of those studies to middle-income or lower-income countries where the culture and environment are different. What might this study add? The prevalence of delirium in elderly ED patients in one middle-income country is consistent with other developed countries. Still, delirium was undiagnosed by EPs in >50% of cases and was associated with an increased 30-day mortality rate. There needs to be improved delirium screening which focuses on high-risk patients, dementia, auditory impairment and ED diagnosis metabolic derangement may improve ED delirium screening efficiency.
Thailand is a middle-income country with an ageing society. The elderly population in Thailand increased from 13.2% in 2010 to 26.6% in 2013.11 This is an increasing number of elderly patients for hospitalisation.11 The prevalence of delirium in inpatients was 40.0% in a single-centre Thai study.12 The specific objectives of this study were to determine the prevalence of delirium and how often it is not recognised in a Thai ED. The secondary objective was to identify risk factors and short-term outcomes in delirious elderly ED patients in a middle-income country.
METHODS Study design and setting This was a prospective cohort study in the ED of an urban university hospital in Bangkok, Thailand, with an annual census of 70 000 patients, of which approximately 10% were aged ≥65.
Selection of participants We collected data from a convenience sample of patients between 08:00 and midnight, 7 days a week from 1 June 2013 to 15 July 2013. We included all patients aged ≥65 years who presented to the ED and excluded patients who refused to
Sri-on J, et al. Emerg Med J 2015;0:1–6. doi:10.1136/emermed-2014-204379
Copyright Article author (or their employer) 2015. Produced by BMJ Publishing Group Ltd under licence.
1
Downloaded from http://emj.bmj.com/ on May 24, 2015 - Published by group.bmj.com
Original article consent, had severe dementia, were not responsive to verbal stimuli, had severe trauma, were critically ill (ie, were intubated, severe sepsis or required emergency intervention), and who were blind, deaf, aphasic or unable to speak Thai. Our study followed the methods of Ely et al13 for informed consent. We used the Short Portable Mental Status Questionnaire (SPMSQ)14 for screening patients’ capacity to give informed consent. The SPMSQ is a 10-item questionnaire that evaluates orientation, memory and concentration. A patient with ≤4 errors was directly asked to sign a consent form. An authorised surrogate was asked to sign a consent form if the patient committed ≥5 errors on the SPMSQ. The SPMSQ is a brief screening test for organic brain dysfunction. It has proved to be a sensitive and specific screening test for moderate to severe dementia in the community and hospital. A patient with ≥8 errors was considered to have severe dementia and hence ineligible for our study. Also, we used the SPMSQ to exclude patients who had severe dementia or severe organic brain syndrome in an attempt to reduce the rate of misinterpretation of the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) for delirium detection.
Data collection and processing Three research assistants (RAs) enrolled patients and performed screenings. The RAs were trained prior the study by the principal investigator ((PI); JS). All RAs were experienced nurses who had worked in an ED for at least three years. Training lasted 3 days, and the RAs studied a delirium assessment manual for 1 day. The PI gave a didactic lecture about delirium and assessment for 2 h. The RAs practised using an adapted delirium flow sheet (Thai version) with the PI for 4 h. The RAs also practised the assessment using simulated patient scenarios for 1 day. The PI observed the RAs when performing these assessments with ED patients to check inter-rater reliability. The screening processes were conducted after the EPs determined patients’ dispositions and care plans but before the patients were discharged from the ED.
Outcome measure Delirium, the primary outcome, was determined using the CAM-ICU, following the same methodology reported by Han et al.4 The CAM-ICU has been validated in ICU and ED patients.13 15 This screening tool has an excellent sensitivity of
Figure 1 Enrolment of subjects. 2
72.0% (95% CI 58.3% to 72.5%) and specificity of 98.6% (95% CI 96.8% to 99.4%), as well as an excellent inter-rater reliability of 0.92 (95% CI 0.85 to 0.98) between physicians and RAs.15 The secondary outcome was to identify risk factors and shortterm outcomes in delirious elderly ED patients. Short-term outcomes include hospital length of stay, ED length of stay, 30-day mortality rate and ED revisit rates. We obtained 30-day outcome information by reviewing the medical records of all admitted patients and by attempting to contact all enrolled subjects by telephone up to five times.
Methods of measurement To determine EP recognition of delirium, two EPs reviewed ED medical records. These EPs were blinded to the patient’s CAM-ICU evaluation results, but were not blinded to the study hypothesis. We accepted synonyms for delirium, such as acute confusional state (or disorder), acute mental status change, encephalopathy, toxic metabolic state and acute organic brain syndrome if recorded in the physician’s diagnosis or impression, similar to the Ely et al study.13 Demographic data, triage level, residence, visual impairment, auditory impairment, medication used, recent history of trauma, Charlson comorbidity score, fall history, vital signs, diagnosis and results of laboratory tests conducted in the ED were collected from subjects, their surrogates and their medical records. Visual and auditory impairment were obtained from medical history and presence of corrective lenses or use of hearing aids.4 Dementia screening was performed in patients who had ≥4 SPMSQ errors by using the Thai Mental State Examination (TMSE).16 TMSE was adapted from the Mini-Mental State Examination for the Thai population. It is a screening tool for cognitive impairment and requires only 5–10 min to complete. Demented patients were defined as those who had a TMSE score 90 bpm RR >20 breaths/min Temperature 38°C SIRS criteria Biochemical profile, n (%) Hyponatraemia (Na20 Anaemia* ED disposition Discharged from ED Admitted to hospital
Total (n=232)
Delirium (n=27)
Non-delirium (n=205)
p Value
76 (6) 98 (42) 4.0 (1.3) 3 (0–8)
76 (7) 10 (37) 4.5 (1.3) 2 (0–7)
75 (6) 88 (43) 3.9 (1.3) 3 (0–8)
0.703 0.560 0.045 0.079
129 (56) 153 (66) 119 (51) 83 (36) 47 (20)
25 (93) 22 (82) 22 (82) 6 (22) 5 (19)
104 (51) 131 (64) 97 (47) 77 (38) 42 (21)
0.99 0.126 >0.99 >0.99 0.104 0.011 0.040
0.261 0.685 >0.99 >0.99 0.131 0.120 0.211 0.712 0.661 0.625
*Women: haemoglobin (Hb)90 bpm RR >20 breaths/min Temperature 38°C
Clinical outcome
Delirium diagnosed (n=16)
Delirium not diagnosed (n=11)
p Value
77 (8) 7 (44) 5 (1)
75 (4) 3 (27) 4 (2)
0.514 0.448 0.128
4 (6)
1.5 (2.5)
0.351
11 (100) 7 (64) 6 (55) 3 (27) 3 (27)
0.499 0.125 0.006 0.662 0.370 1
14 (88) 15 (94) 16 (100.0) 3 (19) 2 (13) 15 (94) 1 (6) n (%) 3 (19) 4 (25) 4 (25.0) 4 (25.0) 0
10 (91) 1 (9)
15 (94) 4 (37)
1 (6) 7 (64)
4 (25.0) 2 (12.5) 1 (6.3)
1 (9) 1 (9) 2 (18) 2 (18) 5 (46)
3 (27.3) 5 (45.5) 0
0.624 0.618 1 1 0.006 0.002
1 0.084 1
were admitted to the hospital, of which 4 (44%) were recognised as delirious by the EP. Delirious patients were associated with a history of dementia, impaired hearing, lower level of education, higher Charlson comorbidity index score, higher triage level and a metabolic derangement aetiology diagnosed in the ED more frequently than non-delirious patients. Delirious and non-delirious patients were similar in terms of age, residence, gender, history of falls, history of alcohol use, systemic inflammatory response criteria, number of medications and ED-diagnosed infection. When we compared biochemical profiles, there was no statistically significant difference between the delirium and non-delirium groups in the proportion of patients who had hyponatraemia, hypoglycaemia, hyperglycaemia, blood urea nitrogen/creatinine ratio
Table 3 Regression modelling, risk factors of delirium in the emergency department (ED) ODD (95% CI)
Auditory impairment Dementia ED diagnosis metabolic derangement
4
Table 4 Clinical outcomes of individuals with and without delirium
Unadjusted
Adjusted
4.8 (1.8 to 13.4) 12.1 (2.8 to 52.6) 4.0 (1.3 to 4.6)
4.7 (1.6 to 13.8) 13.0 (2.5 to 59.6) 6.5 (1.6 to 26.8)
Emergency department length of stay, median hours (IQR) Hospital admission, n (%) Hospital length of stay, median days (IQR) 30-day mortality, n (%) 30-day revisit, n (%)
Delirium (n=27) 4 (0–16)
Non-delirium (n=205) 4 (0–10)
p Value 0.611
9 (33) 5 (1–12)
57 (28) 1 (1–4)
0.625 0.938
4 (15) 6 (22)
3 (2) 49 (24)
0.004 0.847
>20 or anaemia (women: haemoglobin (Hb)
