Present: Peter Callas, Emily Houston, Jennifer Oshita, Liliane Savard, Connie van Eeghen (5)
1. Warm Up: PhD degrees… always taking longer than expected, sort of like finalizing manuscripts with many co-authors!
2. Jen’s methods and survival analysis: Jen will explain the project and methods, then ask for feedback on the covariates used to build her model, on a secondary analysis, and how best to present the results
a. NHATS: National health trends survey of older adults set up as a cohort study from 2011, still ongoing
i. This study has nine years of data: 2011-2020
ii. What is the hazard of dying of someone with communication disabilities (CD) vs someone without?
iii. Including only community dwelling older adults: those living independently with no assistive services imbedded in an institutional setting
iv. Excluding persons who do not speak English or have a cognitive impairment (dx of dementia)
1. Used an orientation question to assess impairment, plus word recall exercises
v. 5K+ beneficiaries
1. No CD (about 3K)
2. Any CD: could have single subtype of CD
a. Hearing only (self-reported)
b. Expressive only (self-reported)
c. Cognitive only
d. Multiple of above CDs
b. Analysis
i. If you have a CD at baseline, what is your HR over a nine year period, adjusting for covariates that might change over time (excluding gender, race, ethnicity), such as self rating of health, comorbidities, other disabilities (number of ADLs), mobility disabilities,…
1. Not BMI or other biometric measures
2. Not employment status (all are 65+ years of age) – Jen will recheck this for an association
3. Not falls – Jen will recheck this too; check with Nancy Gell
4. Consider lag time of covariates over the 9 years for a future study (not this time)
ii. Secondary analysis
1. Planning to break down CDs by subtypes, but Expressive group is relatively small compared to Hearing and Cognitive groups; the outcomes vary among groups
a. Good to help assess which subtypes might be drivers of the outcomes
b. Sample sizes are not too small
iii. Assumptions: because Jen is using time as a covariate, and death removes data for that and subsequent years, Jen had to impute missing data to prevent Stata from removing those records
1. Checked against the UCSD check list of assumptions
2. Reviewed Kaplan Meier plots for logical outcomes
3. Goodness of fit analysis (Nelson-Aalen cumulative hazard compared to Cox-Snell residual): Jen will find out more about how to interpret these results
4. How does sudden death affect the outcome? Likely shows up similarly in both groups, so not a confounder.
5. Include the number (median months?) with the presentation of the graph, along with IQR
6. Table 2: represents the final model at a high level (none, any CDs) – looks good
c. Next steps after following up on additional mediators and more investigation on interpretation
i. Check on falls and employment
ii. Follow up with Peter on Cox-Snell interpretation
iii. Finish writing up
3. Next week: TBD
Recorded by: CvE
Posts
