Measuring Sensitivity to Nonignorability

Tracking Information
First Submitted Date	May 16, 2002
First Posted Date	May 17, 2002
Last Update Posted Date	July 29, 2016
Study Start Date	September 2001
Actual Primary Completion Date	August 2005 (Final data collection date for primary outcome measure)
Current Primary Outcome Measures	Not Provided
Original Primary Outcome Measures	Not Provided
Change History	Complete list of historical versions of study NCT00037362 on ClinicalTrials.gov Archive Site
Current Secondary Outcome Measures	Not Provided
Original Secondary Outcome Measures	Not Provided
Current Other Outcome Measures	Not Provided
Original Other Outcome Measures	Not Provided
Descriptive Information
Brief Title	Measuring Sensitivity to Nonignorability
Official Title	Not Provided
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.
Detailed Description	BACKGROUND: 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. DESIGN NARRATIVE: 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 Design	Not Provided
Target Follow-Up Duration	Not Provided
Biospecimen	Not Provided
Sampling Method	Not Provided
Study Population	Not Provided
Condition	Cardiovascular Diseases; Heart Diseases
Intervention	Not Provided
Study Groups/Cohorts	Not Provided
Publications *	Ma G, Troxel AB, Heitjan DF. An index of local sensitivity to nonignorable drop-out in longitudinal modelling. Stat Med. 2005 Jul 30;24(14):2129-50.
* Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline.
Recruitment Information
Recruitment Status	Completed
Enrollment	Not Provided
Original Enrollment	Not Provided
Actual Study Completion Date	August 2005
Actual Primary Completion Date	August 2005 (Final data collection date for primary outcome measure)
Eligibility Criteria	No eligibility criteria
Sex/Gender	Sexes Eligible for Study: Male
Ages	up to 100 Years (Child, Adult, Older Adult)
Accepts Healthy Volunteers	No
Contacts	Contact information is only displayed when the study is recruiting subjects
Listed Location Countries	Not Provided
Removed Location Countries
Administrative Information
NCT Number	NCT00037362
Other Study ID Numbers	1165; R01HL068074 ( U.S. NIH Grant/Contract )
Has Data Monitoring Committee	Not Provided
U.S. FDA-regulated Product	Not Provided
IPD Sharing Statement	Not Provided
Responsible Party	Not Provided
Study Sponsor	National Heart, Lung, and Blood Institute (NHLBI)
Collaborators	Not Provided
Investigators	Investigator: Daniel Heitjan Columbia University Health Sciences
PRS Account	National Heart, Lung, and Blood Institute (NHLBI)
Verification Date	January 2008