Publications

Frailty and delirium, although seemingly distinct syndromes, both result in significant negative health outcomes in older adults. Frailty and delirium may be different clinical expressions of a shared vulnerability to stress in older adults, and future research will determine whether this vulnerability is age related, pathological, genetic, environmental, or most likely, a combination of all of these factors. This article explores the clinical overlap of frailty and delirium, describes possible pathophysiological mechanisms linking the two, and proposes research opportunities to further knowledge of the interrelationships between these important geriatric syndromes. Frailty, a diminished ability to compensate for stressors, is generally viewed as a chronic condition, whereas delirium is an acute change in attention and cognition, but there is a developing literature on transitions in frailty status around acute events, as well as on delirium as a chronic, persistent condition. If frailty predisposes an individual to delirium, and delirium delays recovery from a stressor, then both syndromes may contribute to a downward spiral of declining function, increasing risk, and negative outcomes. In addition, frailty and delirium may have shared pathophysiology, such as inflammation, atherosclerosis, and chronic nutritional deficiencies, which will require further investigation. The fields of frailty and delirium are rapidly evolving, and future research may help to better define the interrelationship of these common and morbid geriatric syndromes. Because of the heterogeneous pathophysiology and presentation associated with frailty and delirium, typical of all geriatric syndromes, multicomponent prevention and treatment strategies are most likely to be effective and should be developed and tested.

Cognitive and brain reserve are well studied in the context of age-associated cognitive impairment and dementia. However, there is a paucity of research that examines the role of cognitive or brain reserve in delirium. Indicators (or proxy measures) of cognitive or brain reserve (such as brain size, education, and activities) pose challenges in the context of the long prodromal phase of Alzheimer disease but are diminished in the context of delirium, which is of acute onset. This article provides a review of original articles on cognitive and brain reserve across many conditions affecting the central nervous system, with a focus on delirium. The authors review current definitions of reserve. The authors identify indicators for reserve used in earlier studies and discuss these indicators in the context of delirium. The authors highlight future research directions to move the field ahead. Reserve may be a potentially modifiable characteristic. Studying the role of reserve in delirium can advance prevention strategies for delirium and may advance knowledge of reserve and its role in aging and neuropsychiatric disease generally.

PURPOSE Few data are available on breast cancer characteristics, treatment, and survival for women age 80 years or older. PATIENTS AND METHODS We used the linked Surveillance, Epidemiology and End Results-Medicare data set from 1992 to 2003 to examine tumor characteristics, treatments (mastectomy, breast-conserving surgery [BCS] with radiation therapy or alone, or no surgery), and outcomes of women age 80 years or older (80 to 84, 85 to 89, > or = 90 years) with stage I/II breast cancer compared with younger women (age 67 to 79 years). We used Cox proportional hazard models to examine the impact of age on breast cancer-related and other causes of death. Analyses were performed within stage, adjusted for tumor and sociodemographic characteristics, treatments received, and comorbidities. Results In total, 49,616 women age 67 years or older with stage I/II disease were included. Tumor characteristics (grade, hormone receptivity) were similar across age groups. Treatment with BCS alone increased with age, especially after age 80. The risk of dying from breast cancer increased with age, significantly after age 80. For stage I disease, the adjusted hazard ratio of dying from breast cancer for women age > or = 90 years compared with women age 67 to 69 years was 2.6 (range, 2.0 to 3.4). Types of treatments received were significantly associated with age and comorbidity, with age as the stronger predictor (26% of women age > or = 80 years without comorbidity received BCS alone or no surgery compared with 6% of women age 67 to 79 years). CONCLUSION Women age > or = 80 years have breast cancer characteristics similar to those of younger women yet receive less aggressive treatment and experience higher mortality from early-stage breast cancer. Future studies should focus on identifying tumor and patient characteristics to help target treatments to the oldest women most likely to benefit.

BACKGROUND: Preoperative B-type natriuretic peptide (BNP) is known to predict adverse outcomes after cardiac surgery. The value of postoperative BNP for predicting adverse outcomes is less well delineated. The authors hypothesized that peak postoperative plasma BNP (measured postoperative days 1-5) predicts hospital length of stay (HLOS) and mortality in patients undergoing primary coronary artery bypass grafting, even after adjusting for preoperative BNP and perioperative clinical risk factors.

METHODS: This study is a prospective longitudinal study of 1,183 patients undergoing primary coronary artery bypass grafting surgery. Mortality was defined as all-cause death within 5 yr after surgery. Cox proportional hazards analyses were conducted to separately evaluate the associations between peak postoperative BNP and HLOS and mortality. Multivariable adjustments were made for patient demographics, preoperative BNP concentration, and clinical risk factors. BNP measurements were log10 transformed before analysis.

RESULTS: One hundred fifteen deaths (9.7%) occurred in the cohort (mean follow-up = 4.3 yr, range = 2.38-5.0 yr). After multivariable adjustment for preoperative BNP and clinical covariates, peak postoperative BNP predicted HLOS (hazard ratio [HR] = 1.28, 95% CI = 1.002-1.64, P = 0.049) but not mortality (HR = 1.62, CI = 0.71-3.68, P = 0.25), whereas preoperative BNP independently predicted HLOS (HR = 1.09, CI = 1.01-1.18, P = 0.03) and approached being an independent predictor of mortality (HR = 1.36, CI = 0.96-1.94, P = 0.08). When preoperative and peak postoperative BNP were separately adjusted for within the clinical multivariable models, each independently predicted HLOS (preoperative BNP HR = 1.13, CI = 1.05-1.21, P = 0.0007; peak postoperative BNP HR = 1.44, CI = 1.15-1.81, P = 0.001) and mortality (preoperative BNP HR = 1.50, CI = 1.09-2.07, P = 0.01; peak postoperative BNP HR = 2.29, CI = 1.11-4.73, P = 0.02).

CONCLUSIONS: Preoperative BNP may be better than peak postoperative BNP for predicting HLOS and longer term mortality after primary coronary artery bypass grafting surgery.

OBJECTIVES: To determine whether patients who developed delirium after cardiac surgery were at risk of functional decline.

DESIGN: Prospective cohort study.

SETTING: Two academic hospitals and a Veterans Affairs Medical Center.

PARTICIPANTS: One hundred ninety patients aged 60 and older undergoing elective or urgent cardiac surgery.

MEASUREMENTS: Delirium was assessed daily and was diagnosed according to the Confusion Assessment Method. Before surgery and 1 and 12 months postoperatively, patients were assessed for function using the instrumental activities of daily living (IADL) scale. Functional decline was defined as a decrease in ability to perform one IADL at follow-up.

RESULTS: Delirium occurred in 43.1% (n=82) of the patients (mean age 73.7+/-6.7). Functional decline occurred in 36.3% (n=65/179) at 1 month and in 14.6% (n=26/178) at 12 months. Delirium was associated with greater risk of functional decline at 1 month (relative risk (RR)=1.9, 95% confidence interval (CI)=1.3-2.8) and tended toward greater risk at 12 months (RR=1.9, 95% CI=0.9-3.8). After adjustment for age, cognition, comorbidity, and baseline function, delirium remained significantly associated with functional decline at 1 month (adjusted RR=1.8, 95% CI=1.2-2.6) but not at 12 months (adjusted RR=1.5, 95% CI=0.6-3.3).

CONCLUSION: Delirium was independently associated with functional decline at 1 month and had a trend toward association at 12 months. These findings provide justification for intervention trials to evaluate whether delirium prevention or treatment strategies might improve postoperative functional recovery.

OBJECTIVE: To examine the association between the prevalence of delirium among patients admitted to postacute care and the quality of nursing home care as reflected in deficiency counts.

DESIGN: Analysis of screening data from a randomized controlled trial (RCT) of a delirium abatement program.

SETTING AND PARTICIPANTS: We screened 4744 of 6352 RCT-eligible persons admitted to 1 of 8 skilled nursing facilities in the Boston area over a 3-year period. Quality of care was operationalized with the count of deficiencies noted by state surveyors.

MEASUREMENTS: Prevalence of Confusion Assessment Method (CAM) diagnoses of delirium as completed by trained research interviewers at each facility.

RESULTS: About 1 in 7 persons admitted to postacute care met CAM criteria for delirium, but this varied from 1 in 15 to 1 in 4 across facilities. The correlation of deficiency count per 100 beds and the prevalence of CAM delirium was strong (r=0.45) and significant (95% Confidence interval =0.07, 0.71).

CONCLUSION: Although this study is limited by small sample size, limited geographic scope, and crude assessment of quality with deficiency counts, we have found that facilities with more deficiencies admit more persons that satisfy CAM criteria for delirium. It is possible that good facilities often choose to admit and/or are referred good candidates for rehabilitation, whereas facilities with more deficiencies are not able to be so selective. The end result may be that delirious patients are being preferentially admitted to poorer quality facilities, increasing their likelihood of poor postacute outcomes.

OBJECTIVES: To determine whether a delirium abatement program (DAP) can shorten duration of delirium in new admissions to postacute care (PAC).

DESIGN: Cluster randomized controlled trial.

SETTING: Eight skilled nursing facilities specializing in PAC within a single metropolitan region.

PARTICIPANTS: Four hundred fifty-seven participants with delirium at PAC admission.

INTERVENTION: The DAP consisted of four steps: assessment for delirium within 5 days of PAC admission, assessment and correction of common reversible causes of delirium, prevention of complications of delirium, and restoration of function.

MEASUREMENTS: Trained researchers screened eligible patients. Those with delirium defined according to the Confusion Assessment Method were eligible for participation using proxy consent. Regardless of location, researchers blind to intervention status re-assessed participants for delirium 2 weeks and 1 month after enrollment.

RESULTS: Nurses at DAP sites detected delirium in 41% of participants, versus 12% in usual care sites (P<.001), and completed DAP documentation in most participants in whom delirium was detected, but the DAP intervention had no effect on delirium persistence based on two measurements at 2 weeks (DAP 68% vs usual care 66%) and 1 month (DAP 60% vs usual care 51%) (adjusted P> or =.20). Adjusting for baseline differences between DAP and usual care participants and restricting analysis to DAP participants in whom delirium was detected did not alter the results.

CONCLUSION: Detection of delirium improved at the DAP sites, but the DAP had no effect on the persistence of delirium. This effectiveness trial demonstrated that a nurse-led DAP intervention was not effective in typical PAC facilities.

The objective of this analysis was to develop a measure of neuropsychological performance for cardiac surgery and to assess its psychometric properties. Older patients (n = 210) underwent a neuropsychological battery using nine assessments. The number of factors was identified with variable reduction methods. Factor analysis methods based on item response theory were used to evaluate the measure. Modified parallel analysis supported a single factor, and the battery formed an internally consistent set (coefficient alpha = .82). The developed measure provided a reliable, continuous measure (reliability > .90) across a broad range of performance (-1.5 SDs to +1.0 SDs) with minimal ceiling and floor effects.

OBJECTIVES: To examine the rates of and risk factors for acute hospitalization in a prospective cohort of older community-dwelling patients with Alzheimer's disease (AD).

DESIGN: Longitudinal patient registry.

SETTING: AD research center.

PARTICIPANTS: Eight hundred twenty-seven older persons with AD.

MEASUREMENTS: Acute hospitalization after AD research center visit was determined from a Medicare database. Risk factor variables included demographics, dementia-related, comorbidity and diagnoses and were measured in interviews and according to Medicare data.

RESULTS: Of the 827 eligible patients seen at the ADRC during 1991 to 2006 (median follow-up 3.0 years), 542 (66%) were hospitalized at least once, and 389 (47%) were hospitalized two or more times, with a median of 3 days spent in the hospital per person-year. Leading reasons for admission were syncope or falls (26%), ischemic heart disease (17%), gastrointestinal disease (9%), pneumonia (6%), and delirium (5%). Five significant independent risk factors for hospitalization were higher comorbidity (hazard ratio (HR)=1.87, 95% confidence interval (CI)=1.57-2.23), previous acute hospitalization (HR=1.65, 95% CI=1.37-1.99), older age (HR=1.51, 95% CI=1.26-1.81), male sex (HR=1.27, 95% CI=1.04-1.54), and shorter duration of dementia symptoms (HR=1.26, 95% CI=1.02-1.56). Cumulative risk of hospitalization increased with number of risk factors present at baseline: 38% with zero factors, 57% with one factor, 70% with two or three factors, and 85% with four or five factors (P(trend) <.001).

CONCLUSION: In a community-dwelling population with generally mild AD, hospitalization is frequent, occurring in two-thirds of participants over a median follow-up time of 3 years. With these results, clinicians may be able to identify dementia patients at high risk for hospitalization.