Measuring Sensitivity to Nonignorability
| Tracking Information | |||||
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| First Received Date ICMJE | May 16, 2002 | ||||
| Last Updated Date | January 18, 2008 | ||||
| Start Date ICMJE | September 2001 | ||||
| Primary Completion Date | August 2005 (final data collection date for primary outcome measure) | ||||
| Current Primary Outcome Measures ICMJE | Not Provided | ||||
| Original Primary Outcome Measures ICMJE | Not Provided | ||||
| Change History | Complete list of historical versions of study NCT00037362 on ClinicalTrials.gov Archive Site | ||||
| Current Secondary Outcome Measures ICMJE | Not Provided | ||||
| Original Secondary Outcome Measures ICMJE | Not Provided | ||||
| Current Other Outcome Measures ICMJE | Not Provided | ||||
| Original Other Outcome Measures ICMJE | Not Provided | ||||
| Descriptive Information | |||||
| Brief Title ICMJE | Measuring Sensitivity to Nonignorability | ||||
| Official Title ICMJE | 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. |
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| 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. |
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| Study Type ICMJE | Observational | ||||
| Study Design ICMJE | Not Provided | ||||
| Target Follow-Up Duration | Not Provided | ||||
| Biospecimen | Not Provided | ||||
| Sampling Method | Not Provided | ||||
| Study Population | Not Provided | ||||
| Condition ICMJE |
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| Intervention ICMJE | Not Provided | ||||
| Study Group/Cohort (s) | 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. | ||||
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* Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline. |
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| Recruitment Information | |||||
| Recruitment Status ICMJE | Completed | ||||
| Enrollment ICMJE | Not Provided | ||||
| Completion Date | August 2005 | ||||
| Primary Completion Date | August 2005 (final data collection date for primary outcome measure) | ||||
| Eligibility Criteria ICMJE | No eligibility criteria |
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| Gender | Male | ||||
| Ages | Not Provided | ||||
| Accepts Healthy Volunteers | No | ||||
| Contacts ICMJE | Contact information is only displayed when the study is recruiting subjects | ||||
| Location Countries ICMJE | Not Provided | ||||
| Administrative Information | |||||
| NCT Number ICMJE | NCT00037362 | ||||
| Other Study ID Numbers ICMJE | 1165 | ||||
| Has Data Monitoring Committee | Not Provided | ||||
| Responsible Party | Not Provided | ||||
| Study Sponsor ICMJE | National Heart, Lung, and Blood Institute (NHLBI) | ||||
| Collaborators ICMJE | Not Provided | ||||
| Investigators ICMJE |
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| Information Provided By | National Heart, Lung, and Blood Institute (NHLBI) | ||||
| Verification Date | January 2008 | ||||
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ICMJE Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP |
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