Dong, Xinxin
(2009)
ANALYSIS OF IMPACT OF MISSING DATA IN THE STUDY OF RACIAL DIFFERENCES IN ENDOMETRIAL CANCER SURVIVAL.
Master's Thesis, University of Pittsburgh.
(Unpublished)
Abstract
Endometrial cancer is the third most common cause of gynecologic cancer death and shows the largest overall survival difference (34%) between the races. The National Cancer Institute (NCI) Black/White Cancer Survival Study was a population-based study of racial differences in cancer survival. Endometrial cancer cases consisted of 149 black women, ages 20-79 years, residing in three selected metropolitan areas, who were diagnosed with endometrial cancer between 1985 and 1987. Cases were frequency matched in a ratio of approximately 1:2 to a sample of 341 white women with endometrial cancer. Information was derived from abstracts of hospital and physicians' records, centralized pathology review, and interviews. Potential explanatory factors for black-white survival differences have been previously investigated using Cox regression. However, there was a high proportion of missing values since 24 percent of patients were never interviewed. Some values were also missing for three other variables derived from medical records. Missing values may introduced bias in previous findings based only on the information available.The primary objective of this thesis is to evaluate the effect of missing data on the estimated black/white mortality ratios adjusted for various explanatory factors. A second objective is to obtain more precise confidence intervals for the estimated mortality ratios. Nearest neighbor hot deck imputation has been used to generate fifty "complete" datasets. Adjusting for age and geographic location, the black/white mortality ratio for the imputed datasets was 3.3. When adjusted for all covariates, the mortality ratio was only 1.2. Overall, 87% of the excess mortality could be attributed to racial differences in disease stage, tumor characteristics, treatment, sociodemographic characteristics, hormonal and reproductive factors, the number of comorbidities and health behavior. The results based on multiple imputation indicate that missing data did not introduce major bias in the earlier analyses. However, multiple imputation provided narrower confidence intervals than those obtained previously. Multiple imputation was worthwhile since it gave more precise estimates for the relative mortality ratios. These findings have public health importance: they have implications for development of health policies and planning interventions to reduce the excess risk of death among black women with endometrial cancer.
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Details
| Item Type: |
University of Pittsburgh ETD
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| Status: |
Unpublished |
| Creators/Authors: |
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| ETD Committee: |
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| Date: |
29 June 2009 |
| Date Type: |
Completion |
| Defense Date: |
20 April 2009 |
| Approval Date: |
29 June 2009 |
| Submission Date: |
8 April 2009 |
| Access Restriction: |
5 year -- Restrict access to University of Pittsburgh for a period of 5 years. |
| Institution: |
University of Pittsburgh |
| Schools and Programs: |
School of Public Health > Biostatistics |
| Degree: |
MS - Master of Science |
| Thesis Type: |
Master's Thesis |
| Refereed: |
Yes |
| Uncontrolled Keywords: |
black/white study; endometrial cancer; missing data; survival |
| Other ID: |
http://etd.library.pitt.edu/ETD/available/etd-04082009-151224/, etd-04082009-151224 |
| Date Deposited: |
10 Nov 2011 19:35 |
| Last Modified: |
15 Nov 2016 13:39 |
| URI: |
http://d-scholarship.pitt.edu/id/eprint/6905 |
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