Distinguishing characteristics of delirium in a skilled nursing facility in Spain: Influence of baseline cognitive status.

OBJECTIVE: Mild cognitive impairment (MCI) and dementia (DEM) are prevalent in skilled nursing facilities (SNFs), confounding delirium detection. We report characteristics of delirium in an SNF to ascertain distinguishing features for delirium diagnosis, despite challenges of comorbidity with MCI and DEM. METHODS: Cross-sectional study of 200 consecutive patients from an SNF in Catalunya, Spain, assessed within the first 24 to 48 admission hours by independent experts with Spanish-Informant Questionnaire on Cognitive Decline in the Elderly (for MCI-DEM), Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) delirium criteria, and Delirium Rating Scale Revised-98 (DRS-R98) for delirium phenomenology. Delirium characteristics were modeled in successive steps, according to the presence of delirium and MCI-DEM, with analysis of variance (ANOVA), receiver operator characteristic analyses, and conditional logistic regression. RESULTS: The final model produced symptoms that represented each of the three delirium core domains (ie, cognitive, higher order thinking, and circadian). The DRS-R98 items rated these symptoms as moderate-severe attention/vigilance, mild-severe language, and moderate-severe sleep-wake cycle alterations. The delirium discriminant accuracy of the three symptoms together was high: 84.6% in the MCI-DEM group to 92.8% in the No MCI-DEM group. CONCLUSIONS: Impairments of attention, language, and sleep-wake cycle indicate delirium in SNF patients regardless of the underlying MCI-DEM status. Because delirium is underdetected in SNFs, where nursing staff/patient ratios are low, brief simple tools that measure these symptoms could potentially enhance delirium detection.

Delirium diagnosis defined by cluster analysis of symptoms versus diagnosis by DSM and ICD criteria: diagnostic accuracy study.

BACKGROUND: Information on validity and reliability of delirium criteria is necessary for clinicians, researchers, and further developments of DSM or ICD. We compare four DSM and ICD delirium diagnostic criteria versions, which were developed by consensus of experts, with a phenomenology-based natural diagnosis delineated using cluster analysis of delirium features in a sample with a high prevalence of dementia. We also measured inter-rater reliability of each system when applied by two evaluators from distinct disciplines. METHODS: Cross-sectional analysis of 200 consecutive patients admitted to a skilled nursing facility, independently assessed within 24-48 h after admission with the Delirium Rating Scale-Revised-98 (DRS-R98) and for DSM-III-R, DSM-IV, DSM-5, and ICD-10 criteria for delirium. Cluster analysis (CA) delineated natural delirium and nondelirium reference groups using DRS-R98 items and then diagnostic systems' performance were evaluated against the CA-defined groups using logistic regression and crosstabs for discriminant analysis (sensitivity, specificity, percentage of subjects correctly classified by each diagnostic system and their individual criteria, and performance for each system when excluding each individual criterion are reported). Kappa Index (K) was used to report inter-rater reliability for delirium diagnostic systems and their individual criteria. RESULTS: 117 (58.5 %) patients had preexisting dementia according to the Informant Questionnaire on Cognitive Decline in the Elderly. CA delineated 49 delirium subjects and 151 nondelirium. Against these CA groups, delirium diagnosis accuracy was highest using DSM-III-R (87.5 %) followed closely by DSM-IV (86.0 %), ICD-10 (85.5 %) and DSM-5 (84.5 %). ICD-10 had the highest specificity (96.0 %) but lowest sensitivity (53.1 %). DSM-III-R had the best sensitivity (81.6 %) and the best sensitivity-specificity balance. DSM-5 had the highest inter-rater reliability (K =0.73) while DSM-III-R criteria were the least reliable. CONCLUSIONS: Using our CA-defined, phenomenologically-based delirium designations as the reference standard, we found performance discordance among four diagnostic systems when tested in subjects where comorbid dementia was prevalent. The most complex diagnostic systems have higher accuracy and the newer DSM-5 have higher reliability. Our novel phenomenological approach to designing a delirium reference standard may be preferred to guide revisions of diagnostic systems in the future.

Performance of the Delirium Rating Scale-Revised-98 Against Different Delirium Diagnostic Criteria in a Population With a High Prevalence of Dementia.

BACKGROUND: Delirium diagnosis in elderly is often complicated by underlying dementia. OBJECTIVE: We evaluated performance of the Delirium Rating Scale-Revised-98 (DRS-R98) in patients with high dementia prevalence and also assessed concordance among past and current diagnostic criteria for delirium. METHODS: Cross-sectional analysis of newly admitted patients to a skilled nursing facility over 6 months, who were rated within 24-48 hours after admission. Interview for Diagnostic and Statistical Manual of Mental Disorders, 3rd edition-R (DSM)-III-R, DSM-IV, DSM-5, and International Classification of Diseases 10th edition delirium ratings, administration of the DRS-R98, and assessment of dementia using the Informant Questionnaire on Cognitive Decline in the Elderly were independently performed by 3 researchers. Discriminant analyses (receiver operating characteristics curves) were used to study DRS-R98 accuracy against different diagnostic criteria. Hanley and McNeil test compared the area under the curve for DRS-R98's discriminant performance for all diagnostic criteria. RESULTS: Dementia was present in 85/125 (68.0%) subjects, and 36/125 (28.8%) met criteria for delirium by at least 1 classification system, whereas only 19/36 (52.8%) did by all. DSM-III-R diagnosed the most as delirious (27.2%), followed by DSM-5 (24.8%), DSM-IV-TR (22.4%), and International Classification of Diseases 10th edition (16%). DRS-R98 had the highest AUC when discriminating DSM-III-R delirium (92.9%), followed by DSM-IV (92.4%), DSM-5 (91%), and International Classification of Diseases 10th edition (90.5%), without statistical differences among them. The best DRS-R98 cutoff score was ≥14.5 for all diagnostic systems except International Classification of Diseases 10th edition (≥15.5). CONCLUSIONS: There is a low concordance across diagnostic systems for identification of delirium. The DRS-R98 performs well despite differences across classification systems perhaps because it broadly assesses phenomenology, even in this population with a high prevalence of dementia.

Validation of the Delirium Diagnostic Tool-Provisional (DDT-Pro) in a skilled nursing facility and comparison to the 4 'A's test (4AT).

OBJECTIVE: To validate the Delirium Diagnostic Tool (DDT-Pro) in a SNF and compare its performance to the 4 A's Test (4AT) in real life conditions. METHODS: Prospective cross-sectional study of 262 consecutively admitted adults to a SNF, independently assessed by psychiatrists using DSM-5 delirium criteria and by geriatricians using the DDT-Pro (0-9 points) and 4AT (0-12 points). RESULTS: 141 (53.8%) participants had dementia and 79 (30.1%) had delirium. DDT-Pro and 4AT were moderately correlated (-0.59). Accuracies against DSM-5 diagnosis ranged from 80 to 85% and were comparable between tools regardless of dementia. Recommended delirium cutoff for the DDT-Pro (≤6) had 77.2% sensitivity, 84% specificity, and NPV = 89.5% and 4AT (≥4) had 54.4% sensitivity and 92.9% specificity, with lower specificity in the dementia subsample. DDT-Pro sensitivity increased (84.8%) at ≤7cutoff. Sensitivity and specificity of all DDT-Pro and 2/4 4AT items displayed gradients along severity levels, but two dichotomously rated 4AT items had low positivity. The tools had low concordance (p < 0.05) for delirium positivity. CONCLUSIONS: DDT-Pro is valid to detect delirium in SNF population where simple, structured tools with high sensitivity are needed. DDT-Pro items assess the three core domains of delirium as a continuous measure and may have advantages over the 4AT.