Measuring Sensitivity to Nonignorability

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00037362
Recruitment Status : Completed
First Posted : May 17, 2002
Last Update Posted : July 29, 2016
Information provided by:
National Heart, Lung, and Blood Institute (NHLBI)

Brief Summary:
To develop a new statistical index that measures sensitivity to non-ignorability (index of sensitivity to nonignorability, or ISNI) for model-based inferences.

Condition or disease
Cardiovascular Diseases Heart Diseases

Detailed Description:


Despite a considerable number of recent developments, missing data and associated methodology continues to be an important topic of research in biostatistics, medicine and public health. As investigators begin to understand the limitations of model-based inferences under the assumption of non-ignorable missingness, recent attention has turned to the formulation and implementation of sensitivity analyses. Having a general-purpose index to assess sensitivity to departures from ignorability would be extremely useful to researchers in a variety of fields in the health sciences. This is especially true if the index is relatively easy to compute and interpret.


It would be useful to have a general, easily computed diagnostic that characterizes data sets with respect to their potential for sensitivity to nonignorability. The investigators have developed a diagnostic that measures the effect of small perturbations from ignorability on coefficient estimates in the univariate linear model with missing observations.They will extend their analysis in a number of directions: i) They will develop a general class of diagnostics for Bayes and direct- likelihood inferences, and demonstrate its application to a number of important special cases. ii) They will develop an analogous theory for sensitivity to nonignorability in frequentist estimation and testing. iii) They will develop a general form of the diagnostic for the coarse-date model, a generalization of missing data that includes censoring and rounding as special cases. iv) They will analyze a number of real- world data sets that represent important cases where nonignorability is of interest, including dropout in longitudinal data, censored survival data, and cross-over in clinical trials.

Study Type : Observational
Study Start Date : September 2001
Actual Primary Completion Date : August 2005
Actual Study Completion Date : August 2005

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

Ages Eligible for Study:   up to 100 Years   (Child, Adult, Senior)
Sexes Eligible for Study:   Male
Accepts Healthy Volunteers:   No
No eligibility criteria

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00037362

Sponsors and Collaborators
National Heart, Lung, and Blood Institute (NHLBI)
OverallOfficial: Daniel Heitjan Columbia University Health Sciences

Publications: Identifier: NCT00037362     History of Changes
Other Study ID Numbers: 1165
R01HL068074 ( U.S. NIH Grant/Contract )
First Posted: May 17, 2002    Key Record Dates
Last Update Posted: July 29, 2016
Last Verified: January 2008

Additional relevant MeSH terms:
Cardiovascular Diseases
Heart Diseases