In very old and/or frail older people living in long-term care facilities, physical inactivity negatively affects activities of daily living. The main reason to assess older adults' perceived fitness is to establish the relation with their beliefs about their ability to perform physical activity adjusted …

QUESTION: Do negative expectations in patients after the onset of acute low back pain increase the odds of absence from usual work due to progression to chronic low back pain? DESIGN: Systematic review with meta-analysis of prospective inception cohort studies. PARTICIPANTS: Adults with acute or subacute …

BACKGROUND: This paper reports a study about the effect of knowledge sources, such as handbooks, an assessment format and a predefined record structure for diagnostic documentation, as well as the influence of knowledge, disposition toward critical thinking and reasoning skills, on the accuracy of nursing …

Patients with chronic obstructive pulmonary disease (COPD) are often limited in their daily physical activity. However, the level, type and intensity of daily physical activity are not known, nor there is a clear insight in the contributing factors. The aim of this review is to describe daily physical …

From the literature three types of predictors for factor scores are available. These are characterized by the constraints: linear, linear conditionally unbiased, and linear correlation preserving. Each of these constraints generates a class of predictors. Best predictors are defined in terms of L?wner's …

The CANDECOMP/PARAFAC (CP) model decomposes a three-way array into a prespecified number of R factors and a residual array by minimizing the sum of squares of the latter. It is well known that an optimal solution for CP need not exist. We show that if an optimal CP solution does not exist, then any sequence …

Several models in data analysis are estimated by minimizing the objective function defined as the residual sum of squares between the model and the data. A necessary and sufficient condition for the existence of a least squares estimator is that the objective function attains its infimum at a unique …

The assumptions of the model for factor analysis do not exclude a class of indeterminate covariances between factors and error variables (Grayson, 2003). The construction of all factors of the model for factor analysis is generalized to incorporate indeterminate factor-error covariances. A necessary …

If the ratio m/p tends to zero, where m is the number of factors m and p the number of observable variables, then the inverse diagonal element of the inverted observable covariance matrix (σ pjj) -1 tends to the corresponding unique variance ψ jj for almost all of these (Guttman, 1956). If the smallest …

Sufficient conditions for mean square convergence of factor predictors in common factor analysis are given by Guttman, by Williams, and by Schneeweiss and Mathes. These conditions do not hold for confirmatory factor analysis or when an error variance equals zero (Heywood cases). Two sufficient conditions …