Superior skin care is a nurse-sensitive outcome measure (Young, T., & Clark, M. (2009). Re-positioning for pressure ulcer prevention (protocol). The Cochrane Database of Systematic Review (2009) 3). This study sought to decrease incidence and risk of skin breakdown in the pediatric cardiac intensive care unit (PCICU). The study was conducted in a large hospital in upstate New York. A practice guideline was created and guided PCICU nurses on the interventions for potential skin-breakdown issues in their patients. The patients had a significant change in skin breakdown with a one-sided Fisher's Exact Test (p=.0422). A logistic regression model showed intervention as a significant factor in reducing incidence of pressure ulcers and length of stay (p=.0389).

Estimation of a nonparametric regression spectrum based on the periodogram is considered. Neither trend estimation nor smoothing of the periodogram are required. Alternatively, for cases where spectral estimation of phase shifts fails and the shift does not depend on frequency, a time domain estimator of the lag-shift is defined. Asymptotic properties of the frequency and time domain estimators are derived. Simulations and a data example illustrate the methods.

We consider dependence structures in multivariate time series that are characterized by deterministic trends. Results from spectral analysis for stationary processes are extended to deterministic trend functions. A regression cross covariance and spectrum are defined. Estimation of these quantities is based on wavelet thresholding. The method is illustrated by a simulated example and a three-dimensional time series consisting of ECG, blood pressure and cardiac stroke volume measurements.