In studies with repeated measures of blood pressure (BP), particularly in trials of hypertension prevention, BP measurements often become censored once a participant commences antihypertensive medication. When prescribed by non-study physicians under uncontrolled conditions, the missing data mechani
A Simple Imputation Method for Longitudinal Studies with Non-ignorable Non-responses
โ Scribed by Molin Wang; Garrett M. Fitzmaurice
- Book ID
- 101715367
- Publisher
- John Wiley and Sons
- Year
- 2006
- Tongue
- English
- Weight
- 150 KB
- Volume
- 48
- Category
- Article
- ISSN
- 0323-3847
No coin nor oath required. For personal study only.
โฆ Synopsis
Abstract
Missing data are a common problem in longitudinal studies in the health sciences. Motivated by data from the Muscatine Coronary Risk Factor (MCRF) study, a longitudinal study of obesity, we propose a simple imputation method for handling nonโignorable nonโresponses (i.e., when nonโresponse is related to the specific values that should have been obtained) in longitudinal studies with either discrete or continuous outcomes. In the proposed approach, two regression models are specified; one for the marginal mean of the response, the other for the conditional mean of the response given nonโresponse patterns. Statistical inference for the model parameters is based on the generalized estimating equations (GEE) approach. An appealing feature of the proposed method is that it can be readily implemented using existing, widelyโavailable statistical software. The method is illustrated using longitudinal data on obesity from the MCRF study. (ยฉ 2006 WILEYโVCH Verlag GmbH & Co. KGaA, Weinheim)
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