Clinical associations of delirium in hospitalized adult patients and the role of on admission presentation.

OBJECTIVE: To describe clinical associations of delirium in hospitalized patients and relationships to on admission presentation. DESIGN: Retrospective analysis of an administrative hospitalization database 1998-2007. SETTING: Acute care hospitalizations in the New York State (NYS). MEASUREMENTS: Four categories of diagnosis related group (DRG) hospitalizations were extracted from a NYS administrative database: pneumonia, congestive heart failure, urinary tract/kidney infection (UTI), and lower extremity orthopedic surgery (LEOS) DRGs. These hospitalizations were examined for clinical associations with delirium coding both on and after admission. RESULTS: Delirium was coded in 0.8% of the cohort, of which an on admission diagnosis was present in 59%. On admission delirium was strongly associated with dementia (adjusted odds ratio 0, 95%CI 5.8-6.3) and with adverse drug effects (ADEs) (adjusted odds ratio 4.6, 95%CI 4.3, 5.0). After admission delirium was even more highly associated with ADEs (adjusted odds ratio 22.2, 95%CI 20.7-23.7). The UTI DRG category had the greatest proportion of on admission delirium. However after admission delirium was more common in the LEOS DRG category. Over time, there was a greater increase in delirium proportions in the UTI DRG category, and an overall increase in coding for encephalopathy states (potential alternative delirium descriptors). CONCLUSION: ADEs play an important role in delirium regardless of whether or not it is present on admission. While the finding that most delirium hospitalizations presented on admission suggests that delirium impacts more as a clinical admitting determinant, in-hospital prevention strategies may still have benefit in targeted settings where after admission delirium is more frequent, such as patients with LEOS.

Drug-induced, dementia-associated and non-dementia, non-drug delirium hospitalizations in the United States, 1998-2005: an analysis of the national inpatient sample.

BACKGROUND: The incidence and pattern of delirium recorded in a broad spectrum of American hospitalizations has not been well described. The National Inpatient Sample (NIS) of the Healthcare Cost and Utilization Project is an administrative database of hospitalizations in the US that affords an opportunity to examine for International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9) codes relating to delirium. OBJECTIVE: To examine the prevalence of delirium diagnoses and associated clinical factors, including adverse drug effects, in a broad spectrum of hospitalizations in the US. Delirium was grouped into three categories: drug-induced delirium, dementia-associated delirium, and non-dementia, non-drug (NDND). METHODS: Hospitalizations during the years 1998-2005 in the NIS databases were examined. These databases represent samples of hospitalizations that allow for national prevalence estimates. ICD-9 codes for drug-induced, dementia-associated and NDND delirium were identified in the hospitalizations for each year. Delirium tremens was not considered in this classification, and paediatric and psychiatric admissions were excluded. Yearly prevalence for drug-induced, dementia-associated and NDND delirium were tabulated, and time trends were analysed with negative binomial regression. A hospitalization subset cohort with urinary tract/kidney infection, pneumonia, heart failure and lower extremity orthopaedic surgery diagnosis-related group categories was also analysed for clinical associations with the presence of the three categories of delirium using multinomial logistic regression. ICD-9 E codes (external causes of injury) constituting adverse drug effects were identified and considered as clinical predictors. RESULTS: Delirium was recorded in 1 269 185 (0.54%) non-psychiatric adult hospitalizations during the study years. Whereas the overall prevalence of dementia-associated delirium and NDND delirium decreased over time, drug-induced delirium prevalence increased (p < 0.0001). As expected, the presence of dementia and adverse drug effects had the strongest associations with dementia-associated and drug-induced delirium, respectively, in the cohort hospitalizations. CONCLUSIONS: Drug-induced delirium and NDND delirium had the strongest associations with lower extremity orthopaedic surgery hospitalizations and urinary tract/kidney infection hospitalizations, respectively. Among the NDND co-morbid conditions, volume depletion and sodium imbalance had the strongest, albeit modest, associations with delirium. The association between decade of age and delirium was strongest for NDND delirium (adjusted odds ratio 1.53; 95% CI 1.52, 1.53), but age had significant associations with drug-induced and dementia-associated delirium as well. In the cohort, the most frequent adverse effects codes were for opioids and for benzodiazepines or other sedatives, which were noted in 21.3% and 15.2% of drug-induced delirium hospitalizations, respectively. Drug-induced delirium is being increasingly identified in hospitalized patients. Administrative hospitalization databases constitute a resource to explore factors and trends associated with delirium. The findings suggest that interventions focusing on adverse drug effects have the greatest potential for preventing delirium.

Efficient and accurate measurement of physical restraint use in acute care.

OBJECTIVES: Describe and evaluate a method for assessing whether physical restraint prevalence differs by timing and frequency of data collection and to determine the minimum period of observation necessary to provide accurate prevalence estimates on both Intensive Care Unit (ICU) and medical-surgical units. DESIGN: Two-period, cross-sectional design with repeated observations in year 1 for 18 consecutive days and in year 2 for 21 consecutive days with method modifications. SETTING: 400-bed urban teaching hospital. PARTICIPANTS: All beds on general medical, surgical, and intensive care units. MEASUREMENT: Direct observation of patients, nurse interview, and medical record review conducted by trained observers. RESULTS: There were no significant differences in mean restraint use prevalence rates comparing: (a) morning and evening periods; (b) weekdays and weekend days; and (c) observation periods of 7, 14, or 21 consecutive days or for 7 days using every 3rd day on either medical-surgical units or ICUs. Analyses using data from an increasing number of days of observation indicates that the mean prevalence rate stabilizes after 16 days. There were larger mean differences for comparisons on ICU-ventilator units and lack of significant differences may be due to low statistical power. CONCLUSION: Direct observation by trained observers, supplemented by nurse report and medical record documentation over brief monitoring periods, results in accurate, nonintrusive, cost-efficient estimates of physical restraint prevalence. As few as seven consecutive or nonconsecutive days in measuring restraint prevalence is sufficient to obtain accurate estimates, although the number of days may vary depending on patient mix and unit type.