WU-NEAT: A clinically validated, open-source MATLAB toolbox for limited-channel neonatal EEG analysis.

BACKGROUND: Limited-channel EEG research in neonates is hindered by lack of open, accessible analytic tools. To overcome this limitation, we have created the Washington University-Neonatal EEG Analysis Toolbox (WU-NEAT), containing two of the most commonly used tools, provided in an open-source, clinically-validated package running within MATLAB. METHODS: The first algorithm is the amplitude-integrated EEG (aEEG), which is generated by filtering, rectifying and time-compressing the original EEG recording, with subsequent semi-logarithmic display. The second algorithm is the spectral edge frequency (SEF), calculated as the critical frequency below which a user-defined proportion of the EEG spectral power is located. The aEEG algorithm was validated by three experienced reviewers. Reviewers evaluated aEEG recordings of fourteen preterm/term infants, displayed twice in random order, once using a reference algorithm and again using the WU-NEAT aEEG algorithm. Using standard methodology, reviewers assigned a background pattern classification. Inter/intra-rater reliability was assessed. For the SEF, calculations were made using the same fourteen recordings, first with the reference and then with the WU-NEAT algorithm. Results were compared using Pearson's correlation coefficient. RESULTS: For the aEEG algorithm, intra- and inter-rater reliability was 100% and 98%, respectively. For the SEF, the mean±SD Pearson correlation coefficient between algorithms was 0.96±0.04. CONCLUSION: We have demonstrated a clinically-validated toolbox for generating the aEEG as well as calculating the SEF from EEG data. Open-source access will enable widespread use of common analytic algorithms which are device-independent and unlikely to become outdated as technology changes, thereby facilitating future collaborative research in neonatal EEG.

Population-based approaches to treatment and readmission after spinal cord injury.

BACKGROUND: Recent studies in surgical and non-surgical specialties have suggested that patients admitted on the weekend may have worse outcomes. In particular, patients with stroke and acute cardiovascular events have shown worse outcomes with weekend treatment. It is unclear whether this extends to patients with spinal cord injury (SCI). This study was designed to evaluate factors for readmission after index hospitalization for spinal cord injury. METHODS: This cohort was constructed from the State Inpatient Databases of California, New York, and Florida. For this study 14,396 patients with SCI were identified. The primary outcome measure evaluated was 30-day readmission. Secondary measures include in-hospital complications. Univariate and multivariate analysis were utilized to evaluate covariates. c2, Fisher's exact, and linear, logistic, and modified Poisson regression methods were utilized for statistical analysis. Propensity score methods were used with matched pairs analysis performed by the McNemar's Test. RESULTS: Weekend admission was not associated with increased 30- day readmission rates in multivariate analysis. Race and discharge to a facility (RR 1.60 [1.43-1.79]) or home with home care (RR 1.23 [1.07-1.42]), were statistically significant risk factors for readmission. Payor status did not affect rates of readmission. In propensity score matched pairs analysis, weekend admission was not associated with increased odds of 30-day readmission (OR 1.04 [0.89-1.21]). Patients admitted to high volume centers had significantly lower risk of readmission when compared with patients admitted to low volume centers. CONCLUSIONS: Our results suggest that the weekend effect, described previously in other patient populations, may not play as important a role in patients with SCI.

Readmission after spinal cord injury: analysis of an institutional cohort of 795 patients.

BACKGROUND: Recent studies in other fields have suggested that healthcare on the weekend may have worse outcomes. In particular, patients with stroke and acute cardiovascular events have shown worse outcomes with weekend treatment. It is unclear whether this extends to patients with spinal cord injury. This study was designed to evaluate factors for readmission after index hospitalization for spinal cord injury. METHODS: A total of 795 consecutive patients over an 11-year period were analyzed. After excluding patients with chronic spinal cord injury and surgical care at an outside hospital, 745 patients remained. The primary outcome measure evaluated was 30-day readmission. Secondary measures include perioperative complications, readmission rate when discharged on the weekend, and the effect of race and insurance status on readmission rate. Univariate and multivariate analysis were utilized to evaluate the covariates collected. The χ2 test, Fisher's exact test, and linear and logistic regression methods were utilized for statistical analysis. RESULTS: A total of 745 patients were analyzed after exclusions. Payer status did not affect length of stay, ICU length of stay, or perioperative complications. Neither weekend admission nor weekend operation affected length of stay, ICU length of stay, or readmission by 30 days. Patients undergoing weekend surgical treatment had lower perioperative complication rates (2.2% vs. 6.5% on weekday, P<0.01). Discharge on the weekend was associated with a significantly lower rate of readmission by 30 days (OR=0.07, 95% CI: 0.009-0.525, P<0.005). Payer status was associated with 30-day readmission (P<0.005). Patients with Medicare (20.8%) and Medicaid (20.1%) showed higher rates of readmission than patients with other payers. 21.1% of African-American patients were readmitted, versus 10.2% of other patients (Odds ratio: 2.2, 95% confidence interval 1.36-3.27, P<0.001). Correcting for payer status lessened but did not eliminate the effect of race on readmission. CONCLUSIONS: Weekend admission did not increase perioperative complications or hospital length of stay. After discharge, patients with Medicaid and Medicare show higher rates of 30-day readmission, as do African-American patients. The effect of race on readmission is multifactorial, and may partially explained by the increased rate of Medicaid coverage in African-Americans in our institutions catchment area.