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Main Title Explaining Discrepancies between Longitudinal and Cross-Sectional Models.
Author Louis, T. A. ; Robins, J. ; Dockery, D. W. ; Spiro, A. ; Ware, J. H. ;
CORP Author Harvard School of Public Health, Boston, MA.;Health Effects Research Lab., Research Triangle Park, NC.
Year Published 1986
Report Number EPA-R-811650; EPA/600/J-86/459;
Stock Number PB88-204052
Additional Subjects Biometrics ; Epidemiology ; Biostatistics ; Reprints ; Longitudinal models ; Cross sectional models
Library Call Number Additional Info Location Last
NTIS  PB88-204052 Some EPA libraries have a fiche copy filed under the call number shown. 07/26/2022
Collation 11p
Abstract Data from longitudinal studies may be analyzed both cross-sectionally and longitudinally. Discrepancies between estimates obtained from these analyses pose questions about the validity of cross-sectional estimates of change. The report, shows that when the true relation between a dependent variable and age is non-linear (e.g. quadratic), but is modeled as linear, the estimated age effect will be a function of the age distribution. In a continuous-time idealization, if the age distribution is Gaussian, the estimated age effects agree. If the age distribution is symmetric and the non-linearity is quadratic, cross-sectional and longitudinal results agree. Otherwise they do not. The paper illustrates these points by analysis of the relation between aging and pulmonary function in middle and old age using data from a large, prospective, longitudinal study.
Supplementary Notes Pub. in Jnl. of Chronic Diseases, v39 n10 p831-839 1986. Sponsored by Health Effects Research Lab., Research Triangle Park, NC.
NTIS Title Notes Journal article.
Title Annotations Reprint: Explaining Discrepancies between Longitudinal and Cross-Sectional Models.
PUB Date Free Form c1986
Category Codes 57U; 44C
NTIS Prices PC A03/MF A01
Primary Description 600/11
Document Type NT
Cataloging Source NTIS/MT
Control Number 821125562
Origin NTIS
Type CAT