Estimating the Cost of Care for Emergency Department Syncope Patients: Comparison of Three Models.

INTRODUCTION: We sought to compare three hospital cost-estimation models for patients undergoing evaluation for unexplained syncope using hospital cost data. Developing such a model would allow researchers to assess the value of novel clinical algorithms for syncope management. METHODS: We collected complete health services data, including disposition, testing, and length of stay (LOS), on 67 adult patients (age 60 years and older) who presented to the emergency department (ED) with syncope at a single hospital. Patients were excluded if a serious medical condition was identified. We created three hospital cost-estimation models to estimate facility costs: V1, unadjusted Medicare payments for observation and/or hospital admission; V2: modified Medicare payment, prorated by LOS in calendar days; and V3: modified Medicare payment, prorated by LOS in hours. Total hospital costs included unadjusted Medicare payments for diagnostic testing and estimated facility costs. We plotted these estimates against actual cost data from the hospital finance department, and performed correlation and regression analyses. RESULTS: Of the three models, V3 consistently outperformed the others with regard to correlation and goodness of fit. The Pearson correlation coefficient for V3 was 0.88 (95% confidence interval [CI] 0.81, 0.92) with an R-square value of 0.77 and a linear regression coefficient of 0.87 (95% CI 0.76, 0.99). CONCLUSION: Using basic health services data, it is possible to accurately estimate hospital costs for older adults undergoing a hospital-based evaluation for unexplained syncope. This methodology could help assess the potential economic impact of implementing novel clinical algorithms for ED syncope.

Early Fever As a Predictor of Paroxysmal Sympathetic Hyperactivity in Traumatic Brain Injury.

OBJECTIVE: Paroxysmal sympathetic hyperactivity (PSH) is characterized by episodic, hyperadrenergic alterations in vital signs after traumatic brain injury (TBI). We sought to apply an objective scale to the vital sign alterations of PSH in order to determine whether 1 element might be predictive of developing PSH. SETTING/PARTICIPANTS/DESIGN: We conducted an observational study of consecutive TBI patients (Glasgow Coma Scale score ≤12) and monitored the cohort for clinical evidence of PSH. PSH was defined as a paroxysm of 3 or more of the following characteristics: (1) tachycardia, (2) tachypnea, (3) hypertension, (4) fever, (5) dystonia (rigidity or decerebrate posturing), and (6) diaphoresis, with no other obvious causation (ie, alcohol withdrawal, sepsis). MAIN MEASURES: The Modified Clinical Feature Severity Scale (mCFSS) was applied to each participant once daily for the first 5 days of hospitalization. RESULTS: Nineteen (11%) of the 167 patients met criteria for PSH. Patients with PSH had a higher 5-day cumulative mCFSS score than those without PSH (median [interquartile range] = 36 [29-42] vs 29 [22-35], P = .01). Of the 4 components of the mCFSS, elevated temperature appeared to be most predictive of the development of PSH, especially during the first 24 hours (odds ratio = 1.95; 95% confidence interval, 1.12-3.40). CONCLUSION: Early fever after TBI may signal impending autonomic dysfunction.

Meta-analysis of the Impact of Patient Characteristics on Estimates of Effectiveness and Harms of Recombinant Human Bone Morphogenetic Protein-2 in Lumbar Spinal Fusion.

STUDY DESIGN: Meta-analysis of individual patient data from randomized controlled trials of recombinant human bone morphogenetic protein-2 (rhBMP-2) in lumbar spinal fusion. OBJECTIVE: To determine how patient characteristics impact estimates of effectiveness and harms of rhBMP-2 versus iliac crest bone graft (ICBG) in lumbar spinal fusion. SUMMARY OF BACKGROUND DATA: Patient characteristics are thought to impact rates of fusion in spinal fusion surgery, but no analyses examining the effect of patient characteristics on efficacy and safety of rhBMP-2 as compared with ICBG have been conducted. METHODS: Using individual patient data obtained from the Yale Open Data Access Project, the impact of patient characteristics on the effects of rhBMP-2 on fusion, overall success, and harms were assessed using linear and generalized linear mixed effects models. RESULTS: Ten industry-sponsored randomized controlled trials of rhBMP-2 were included in the analysis. There is preliminary support for an association between rhBMP-2 and improved outcomes for smokers (P = 0.01), individuals under the age of 60 years (P < 0.01), and patients of normal weight (P = 0.03), but not in patients who are nonsmokers, over the age of 60 years, obese or severely obese. RhBMP-2 usage was associated with decreased harms in individuals with no previous back surgeries but this was not seen in individuals with a previous back surgery (P < 0.01). CONCLUSION: Effects of rhBMP-2 may vary according to patient characteristics. Future studies of rhBMP-2 should include planned subgroup analysis in patients over 60 years, smokers, patients that are obese and severely obese, and individuals with previous back surgeries to better identify those most likely to benefit. LEVEL OF EVIDENCE: 1.

Reliability of Clinical Assessments in Older Adults With Syncope or Near Syncope.

OBJECTIVES: Clinical prediction models for risk stratification of older adults with syncope or near syncope may improve resource utilization and management. Predictors considered for inclusion into such models must be reliable. Our primary objective was to evaluate the inter-rater agreement of historical, physical examination, and electrocardiogram (ECG) findings in older adults undergoing emergency department (ED) evaluation for syncope or near syncope. Our secondary objective was to assess the level of agreement between clinicians on the patient's overall risk for death or serious cardiac outcomes. METHODS: We conducted a cross-sectional study at 11 EDs in adults 60 years of age or older who presented with unexplained syncope or near syncope. We excluded patients with a presumptive cause of syncope (e.g., seizure) or if they were unable or unwilling to follow-up. Evaluations of the patient's past medical history and current medication use were completed by treating provider and trained research associate pairs. Evaluations of the patient's physical examination and ECG interpretation were completed by attending/resident, attending/advanced practice provider, or attending/attending pairs. All evaluations were blinded to the responses from the other rater. We calculated the percent agreement and kappa statistic for binary variables. Inter-rater agreement was considered acceptable if the kappa statistic was 0.6 or higher. RESULTS: We obtained paired observations from 255 patients; mean (±SD) age was 73 (±9) years, 137 (54%) were male, and 204 (80%) were admitted to the hospital. Acceptable agreement was achieved in 18 of the 21 (86%) past medical history and current medication findings, none of the 10 physical examination variables, and three of the 13 (23%) ECG interpretation variables. There was moderate agreement (Spearman correlation coefficient, r = 0.40) between clinicians on the patient's probability of 30-day death or serious cardiac outcome, although as the probability increased, there was less agreement. CONCLUSIONS: Acceptable agreement between raters was more commonly achieved with historical rather than physical examination or ECG interpretation variables. Clinicians had moderate agreement in assessing the patient's overall risk for a serious outcome at 30 days. Future development of clinical prediction models in older adults with syncope should account for variability of assessments between raters and consider the use of objective clinical variables.

Non-24-Hour Disorder in Blind Individuals Revisited: Variability and the Influence of Environmental Time Cues.

STUDY OBJECTIVES: To assess the interindividual and intraindividual variability in the circadian rhythms of blind individuals with non-24-h disorder and to quantify the influence of environmental time cues in blind subjects lacking entrainment (non-24-h individuals or N-24s). DESIGN: An observational study of 21 N-24s (11 females and 10 males, age 9-78 years) who kept a sleep/wake schedule of their choosing. Circadian phase was determined using the melatonin onset (MO) from plasma or saliva samples that were collected every 2 weeks. Melatonin concentrations were measured by radioimmunoassay. A total of 469 MO assessments were conducted over 5,536 days of study. The rate of drift of circadian phase was calculated using a series of MOs (total number of hours the MO drifted divided by the total number of days studied). Stability of the rest/activity rhythm was calculated using chi-squared periodogram analysis of wrist actigraphy data in 19 subjects. SETTING: Academic medical center. PARTICIPANTS: Paid volunteers. INTERVENTIONS: N/A. MEASUREMENTS AND RESULTS: Subjects lacked entrainment such that circadian phase drifted an average (± standard deviation) of 0.39 ± 0.29 h later per day; however, there was notable intersubject and intrasubject variability in the rate of drift including relative coordination and periods of transient entrainment during which there was little to no drift in the circadian phase. A regular, reproducible, and significant oscillation in the rate of drift was detected in 14 of the 21 subjects. A significant non-24-h rest/activity rhythm was detected in 18 of 19 subjects. There was a strong correlation (r = 0.793, P = 0.0001) between the non-24-h rest/activity rhythm and the rate of drift of the circadian phase. CONCLUSIONS: Most N-24s are influenced by unidentified environmental time cues and the non-entrained biological clock in such N-24s is reflected in their rest/activity rhythms. These findings may have diagnostic and treatment implications: this disorder might be diagnosed with actigraphy alone, relative coordination and transient entrainment may result in misdiagnosis and responsiveness to environmental time cues may influence treatment success with oral melatonin. CITATION: Emens JS; Laurie AL; Songer JB; Lewy AJ. Non-24-hour disorder in blind individuals revisited: variability and the influence of environmental time cues. SLEEP 2013;36(7):1091-1100.

Rest-activity cycle and melatonin rhythm in blind free-runners have similar periods.

In the absence of the entraining light-dark cycle, most totally blind humans free-run, albeit with relative coordination to nonphotic zeitgebers. Such blind free-runners (BFRs) often attempt to maintain a 24-h sleep-wake schedule and consequently suffer from recurrent sleep disruption and daytime somnolence. This study was conducted to determine the periods of the free-running melatonin rhythm and of the rest-activity cycle in 16 BFRs. It was found that the non-24-h component of the rest-activity rhythm correlated with the observed period of the circadian pacemaker.

Winter Depression: Integrating mood, circadian rhythms, and the sleep/wake and light/dark cycles into a bio-psycho-social-environmental model.

The phase shift hypothesis (PSH) states that most patients with SAD become depressed in the winter because of a delay in circadian rhythms with respect to the sleep/wake cycle: According to the PSH, these patients should preferentially respond to the antidepressant effects of bright light exposure when it is scheduled in the morning so as to provide a corrective phase advance and restore optimum alignment between the circadian rhythms tightly coupled to the endogenous circadian pacemaker and those rhythms that are related to the sleep/wake cycle. Recent support for the PSH has come from studies in which symptom severity was shown to correlate with the degree of circadian misalignment: it appears that a subgroup of patients are phase advanced, not phase delayed; however, the phase-delayed type is predominant in SAD and perhaps in other disorders as well, such as non-seasonal unipolar depression. It is expected that during the next few years the PSH will be tested in these and other conditions, particularly since healthy subjects appear to have more severe symptoms of sub-clinical dysphoria correlating with phase-delayed circadian misalignment; critically important will be the undertaking of treatment trials to investigate the therapeutic efficacy of morning bright light or afternoon/evening low-dose melatonin in these disorders in which symptoms are more severe as the dim light melatonin onset (DLMO) is delayed with respect to the sleep/wake cycle (non-restorative sleep should also be evaluated, as well as bipolar disorder). The possibility that some individuals (and disorders) will be of the phase-advanced type should be considered, taking into account that the correct timing of phase-resetting agents for them will be bright light scheduled in the evening and/or low-dose melatonin taken in the morning. While sleep researchers and clinicians are accustomed to phase-typing patients with circadian-rhythm sleep disorders according to the timing of sleep, phase typing based on the DLMO with respect to the sleep/wake cycle may lead to quite different recommendations for the optimal scheduling of phase-resetting agents, particularly for the above disorders and conditions.