These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Methodology for generating continuous prediction equations for pulmonary function measures.
    Author: Sherrill DL, Lebowitz MD, Knudson RJ, Burrows B.
    Journal: Comput Biomed Res; 1991 Jun; 24(3):249-60. PubMed ID: 1868694.
    Abstract:
    A mathematical procedure is described for fitting piecewise linear equations constrained to join at estimable multiple junctions or breakpoints. The model parameters, a combination of both linear and nonlinear, are estimated using a "Separable Least Squares" algorithm. In this algorithm the linear parameters, estimated using the General Linear Model, are nested within the iterations of a nonlinear optimization routine. This formulation allows additional covariates to be included in the model and can be easily expanded to include any number of line segments, both linear and nonlinear. The procedure is demonstrated by estimating continuous lung function reference equations for healthy normal subjects. Comparison of these reference equations with previously published equations derived for the same subjects, illustrates the advantages of having continuous equations throughout the age range of the data.
    [Abstract] [Full Text] [Related] [New Search]