ISSN:0277-6715    

DOI:10.1002/sim.4780070103

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1988

数据来源: WILEY

ISSN:0277-6715    

DOI:10.1002/sim.4780070104

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1988

数据来源: WILEY

ISSN:0277-6715    

DOI:10.1002/sim.4780070105

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1988

数据来源: WILEY

摘要:

AbstractLung function tests are used both clinically, in assessing disease, and epidemiologically, in identifying those factors which influence the growth and aging process of the lungs. The user must beware of several common pitfalls in the use of these tests. however. First, the commonly used tests of lung function can only identify patterns of dysfunction, not specific pathologic processes. Second, these tests are subject to many sources of intra‐ and inter‐subject variability, making it difficult to dissect out the signal (for example, the rate of lung aging in adults) from the noise which may greatly exceed the signal. Finally, the analysis of longitudinal pulmonary function data is complicated by the alinearity of the growth and aging process, missing data, variable follow‐up times, information censoring mechanisms and covariate processes, and problems in defining abnorm

ISSN:0277-6715    

DOI:10.1002/sim.4780070106

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1988

数据来源: WILEY

摘要:

AbstractWe compare three methods of longitudinal analysis of pulmonary function data. Our data set is taken from a study of exposure to toluene diisocyanate (TDI) vapours in a new manufacturing plant. The first two methods are a two‐stage weighted regression method and maximum likelihood estimation via the EM algorithm, and these give very similar results. The third method, regression with an autoregressive error structure, was not successfully implemented, and in our view needs better documentatio

ISSN:0277-6715    

DOI:10.1002/sim.4780070107

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1988

数据来源: WILEY

摘要:

AbstractWe present an overview of issues and methods for analysing repeated measures of a continuous random variable. We discuss modelling the mean vector and covariance structure, statistical efficiency, regression diagnostics, and discrepancies between longitudinal and cross‐sectional methods. We illustrate key points with examples and discuss areas requiring further developmen

ISSN:0277-6715    

DOI:10.1002/sim.4780070108

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1988

数据来源: WILEY

摘要:

AbstractFour thousand three hundred and thirteen children beginning at five to fourteen years of age have been examined on three to six occasions in Muscatine, Iowa, on alternate years. To compare blood pressures throughout the period of observation each value was expressed as a percentile rank. For each subject the average percentile rank (level), the trend in rank and the variability over time were calculated. Values for height, weight, relative weight and triceps skinfold thickness measurements were expressed in the same fashion. There is a relationship between average rank of blood pressure and average rank of body size as well as between trend of blood pressure and trend of body size percentiles. These observations indicate the importance of relative rate of growth in the establishment of the rank order of blood pressure during childhood.

ISSN:0277-6715    

DOI:10.1002/sim.4780070109

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1988

数据来源: WILEY

摘要:

AbstractMissing and/or unequally spaced examinations are often present in longitudinal studies. An autoregressive model is presented for the analysis of such data for continuous outcome variables. The fitting of the model can be accomplished by weighted non‐linear regression methods available in standard statistical packages. Some features of the model include consideration of both time‐dependent and fixed covariates, assessment of the relationships between changes in outcome and exposure over short periods of time, and use of all available person‐time for an individual. An illustration looking at the role of personal cigarette smoking on changes in pulmonary function in children is inc

ISSN:0277-6715    

DOI:10.1002/sim.4780070110

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1988

数据来源: WILEY

摘要:

AbstractThe first part of this paper describes how a Kalman filter can be used to construct maximum likelihood (ML) estimates of autoregressive (AR) and polynomial parameters in polynomial growth curves with AR‐1 errors and irregularly‐spaced data. The second part introduces a disturbed highest derivative polynomial (DHDP) as a model for growth curves. This model does not depend on regression coefficients. Variances of the highest derivative disturbance and the observation error are estimated (by ML) using a Kalman filter. The estimated DHDP growth curve is obtained by optimally smoothing the output of the filter. Equally spaced data is not required. The DHDP model and analysis are developed for an individual and extended to a population growth curve using data from many individuals with covaria

ISSN:0277-6715    

DOI:10.1002/sim.4780070111

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1988

数据来源: WILEY

ISSN:0277-6715    

DOI:10.1002/sim.4780070112

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1988

数据来源: WILEY