Geriatric Research Algorithms & Statistical Programs (GRASP)
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- Absolute risk
- Anticholinergic Medications Risk Assessment
- Assessing Probabilities of Harms and Benefits of Multiple Medication Use
- Calculation of Intraclass Correlation: continuous
- Calculation of Intracluster Correlation: binary
- Calculation of Probabilistic Index
- Covariance Structure Between Ligand-Specific TLR Cytokine Production
- CRCoder
- Exploratory Meta Analysis on Uniform Assessment Battery across Aging Studies
- Multiple Imputation Simulation
- Multiple Testing for Correlated Outcomes in Clinical Trials
- NLMIXED SAS Macro
- SAS Macro for Bivariate Analyses
- SAS MIXCORR Macro for data with repeated measures and clumping at zero
- Simple Bootstrap with Proc Surveyselect
- SpatioTemporal Modeling in Longitudinal Analyses of Areal Units
- Statistical Power Calculator
- Temporal Configuration Analysis
- Temporally Successive Multiple Imputation of Longitudinal Data
Absolute risk:
Summary
This submission of SAS code demonstrates a macro for finding the absolute risk assuming there is only one competing risk. This method uses odds ratios from logistic regression to estimate hazards in order to find absolute risk. This macro uses the simple exponential model, which assumes that every hazard has a constant value in the time interval of interest.
Author(s)
Murphy, TE
Yale University
Code Language(s)
SAS
Keywords
absolute risk ,aging ,death ,disability ,
FILE NAME (click to view/download) | DESCRIPTION |
---|---|
simple_exponential_model.txt | Excel File with Outputs From Sample |
state0model.txt | Data Structure |
GRASPAbsoluteRisk[1].doc | Summary of Submission |
GRASPAbsoluteRisk[1].pdf | Summary of Submission |
state0modelsmall.txt | Sample Data |
Murphy,TEAbsRiskSAScode.txt | Program |
simple_exponential_model_excel.xls | Excel File with Outputs From Sample |
BenichouGail90biometrics.pdf | References |
Anticholinergic Medications Risk Assessment:
Summary
The purposes of the submission are two fold: 1) To provide a free-access tool of more than 300 medications with assigned anticholinergic scores for use by interested clinical, epidemiological and pharmacological researchers. 2) To describe the novel methodology and instruments that can be readily applied/adapted to new medications that are not rated for CR- ACHS by us, but are of interest to outside researchers.
Author(s)
Han, L
Yale University
Keywords
anticholinergic risk score ,risk assessment method ,
FILE NAME (click to view/download) | DESCRIPTION |
---|---|
GRASP_CRACH_HAN.pdf | Summary |
GRASP_CRACH_Instrmnt.pdf | Instructions |
GRASP_CRACH_SAS.pdf | SAS code |
GRASP_ACH_list.pdf | List of drugs and scores |
Assessing Probabilities of Harms and Benefits of Multiple Medication Use:
Summary
We describe a simple technique to assist patients and doctors in how to systematically add candidate medications to their existing regimen. It is based on a simple multiplicative combination of utility values for each medication. These medication-specific utility values are in turn based on a simple average of the probabilities of benefits and adverse effects as recorded in the clinical literature. This GRASP submission consists simply of this summary document which cites the related clinical reference article.
Author(s)
Murphy, TE
Yale University
Collaborator(s)
Agostini JV,
Van Ness PH,
Tinetti ME,
Peduzzi PN,
Allore HG
Keywords
adverse effects ,geometric mean ,multiple medications ,tradeoffs ,utility value ,weighting ,
Link
http://jah.sagepub.com/cgi/reprint/20/6/694
Acknowledgement
This study was supported by the Yale Claude D. Pepper Older Americans
Independence Center (P30AG021342) from the National Institute on Aging. Dr. Agostini was supported by a Veterans Affairs Health Services Research Career Development Award. The views expressed in this article are those of the authors and do not necessarily reflect the position or policy of the Department of Veterans Affairs.
Citations
Murphy TE, Agostini JV, Van Ness PH, Peduzzi P, Tinetti ME, Allore HG (2008). Assessing the probabilities of harms and benefits of multiple medication use. Journal of Aging and Health, 20(6); 694 - 709.
Calculation of Intraclass Correlation: continuous:
Summary
This submission provides SAS code for calculating intraclass correlation coefficients (ICC) and corresponding confidence intervals. The data, program, and output serve for demonstrational purposes only.
Author(s)
Van Ness, PH
Yale University
Code Language(s)
SAS
Keywords
Clustered Data ,Instrument Selection ,Intraclass Correlation Coefficient Confidence Intervals ,mixed models ,Reliability Testing ,SAS ,
Link
http://jah.sagepub.com/cgi/reprint/20/2/183
FILE NAME (click to view/download) | DESCRIPTION |
---|---|
MCARSummaryNing.pdf | |
IccVanNess.zip | Zipped folder of all submission files. |
ICCsummaryVanNess.pdf | Summary of Submission |
ICCdataVanNess.txt | Data Structure |
ICCprogramVanNess.txt | Program |
ICCoutputVanNess.pdf | Output |
Acknowledgement
This study was supported by the Yale Claude D. Pepper Older Americans
Independence Center (P30AG021342) from the National Institute on Aging.
Citations
Van Ness PH, Towle VR, Juthani-Mehta M (2008). Testing measurement reliability in older populations: Methods for informed discrimination in instrument selection and application. Journal of Aging and Health; 20:183-197.
Calculation of Intracluster Correlation: binary:
Summary
This submission provides SAS code for creating an intraclass (or intracluster) correlation coefficient (ICC) for a binary outcome.
Author(s)
Van Ness, PH
Yale University
Code Language(s)
SAS 9.2
Keywords
Clustered Data ,Dependent Observations ,Recruiting ,SAS 9.2 ,
FILE NAME (click to view/download) | DESCRIPTION |
---|---|
BinaryICCProgramVanNess.txt.doc | Program |
BinaryICCSummaryVanNess.pdf | Summary of Submission |
BinaryICCDataVanNess.txt | Data Structure |
BinaryICCProgram[1].txt | Program |
BinaryICCOoutputVanNess.txt | Output |
Acknowledgement
This work was supported in part by the Claude D. Pepper Older Americans Independence Center at Yale University School of Medicine
Calculation of Probabilistic Index:
Summary
This project provides SAS code to calculate the probabilistic index as proposed by Laura Acion et al. It consists of a SAS program that provides code for calculating the probabilistic index from the Wilcoxon Rank Sum Statistic or from the Somers' D measure of association.
Author(s)
Van Ness, PH
Yale University
Code Language(s)
SAS
Keywords
C statistic ,clinically significant effect size ,nonparametric ,SAS 9.2 ,Somers' D ,Wilcoxon Rank Sum ,
Link
http://www3.interscience.wiley.com/cgi-bin/fulltext/111089436/PDFSTART
FILE NAME (click to view/download) | DESCRIPTION |
---|---|
ProbIndexOutputVanNess.txt | Output |
ProbIndexSummaryVanNess.doc | Summary of Submission |
ProbIndexDataVanNess.txt | Data Structure |
ProbIndexProgramVanNess.txt | Program |
PIndexVanNess.zip | Zipped folder with four files |
PIndexSummaryVanNess.pdf | Summary of Submission |
PIndexDataVanNess.txt | Data Structure |
PIndexProgramVanNess.txt | Program |
PIndexOutputVanNess.txt | Output |
Acknowledgement
This study was supported by the Yale Claude D. Pepper Older Americans
Independence Center (P30AG021342) from the National Institute on Aging.
Citations
Acion L, Peterson JJ, Temple S, and Arndt S (2006). Probabilistic index: an intuitive, non-parametric approach to measuring the size of treatment effects. Statistics in Medicine; 25:591-602.
Covariance Structure Between Ligand-Specific TLR Cytokine Production:
Summary
This document ties together the five different files that makeup the GRASP example drawn from analysis of TLR-production of cytokines that is stimulated specifically from each of six different ligands per participant at one point in time, i.e., cross-sectional. Because the six ligands are clustered within participants, their associated outcome measurements are correlated. Specifically, we use an unstructured covariance structure that allows each participant to have his or her own specific correlation structure for their set of six ligands, thus accounting for the inherent variation of each participant. Data has been sanitized by removing identifying information and adding random noise.
Author(s)
Allore, HG
Yale University
Code Language(s)
SAS
Keywords
aging ,correlation structure ,cross-sectional ,cytokines ,immunology ,ligands ,mixed models ,multivariable ,SAS ,toll-like receptor (TLR) ,
Link
http://www.jimmunol.org/cgi/reprint/178/2/970
FILE NAME (click to view/download) | DESCRIPTION |
---|---|
LigandCytokCorrProgramAllore.sas | Program |
LigandCytokCorrSummaryAlloreA.pdf | Summary of Submission |
LigandCytokCorrDataAllore.txt | Data Structure |
LigandCytokCorrProgramAllore.txt | Program |
LigandCytokCorrOutputAllore.pdf | Output |
Acknowledgement
This work was supported by the Center of Excellence in Aging at Yale University,
funded by the John A. Hartford Foundation, the Claude D. Pepper Older Americans
Independence Center at Yale University (P30 AG021342) (to A.C.S. and D.V.D.),
Yale School of Medicine Dean’s Pilot Project Grant in Translational Research (to
A.C.S.), National Institute of Allergy and Infectious Diseases Grants NO1 AI 50031
(to E.F., R.R.M., and A.C.S.) and AI 053279 (to E.F.). D.V.D. is a Clinical Research
Scholar in the Investigative Medicine Program, Yale University School of Medicine,
supported by the Yale Mentored Clinical Research Scholars Program (National Institutes of Health Grant NCRR K12RR17594). R.M. is an Investigator of the Howard Hughes Medical Institute.
Citations
van Duin D, Mohanty S, Thomas V, Ginter S, Montgomery RR, Fikrig E, Allore HG, Medzhitov R, Shaw AC, (2007). Age-Associated Defect in Human TLR-1/2 Function. J Immunol, 178(2):970-5. PMID: 17202359
van Duin, Allore HG, Mohanty S, Ginter S, Newman FK, Belshe RB, Medzhitov R, Shaw AC Prevaccine determination of the expression of costimulatory b7 molecules in activated monocytes predicts influenza vaccine responses in young and older adults. J. Infectious Disease. 2007. 195(11):1590-7. PMID: 17471428
Panda A, Qian F, Mohanty S, van Duin D, Newman FK, Zhang L, Chen S, Towle V, Belshe RB, Fikrig E, Allore HG, Montgomery RR, Shaw AC. Age-associated Decrease in Toll-like Receptor Function in Primary Human Dendritic Cells Predicts Influenza Vaccine Response. J Immunology 2010. 184(5):2518-27. PMID: 20100933
Dunne, DW, Shaw AC, Bockenstedt LK, Allore H, Chen S, Malawista SE, Leng LL, Mizue Y, Piecychna M, Zhang L, Towle V, Bucala R, Montgomery RR, Fikrig E. Increased TLR4 expression and Downstream Cytokine Production in Immunosuppressed Adults compared to Non-immunosuppressed Adults. 2010. PLoS ONE. 5(6):e11343 PMID: 20596538. PMCID: PMC2893205
CRCoder:
Summary
The SAS™ code helper for marginal and personalized concurrent risk modeling
Author(s)
Allore H, Charpentier P
Yale University
Collaborator(s)
Allore H, Charpentier P, McAvay G, Murphy T and Agogo G
Code Language(s)
SAS, PHP, MySQL
Keywords
Joint model, risk, longitudinal
Link
http://crcoder.phs.wakehealth.edu/
Acknowledgement
This work was supported by grants from the U.S. National Institute on Aging at the National Institutes of Health (R01 AG047891, P30AG021342-16S1, R33AG045050, U24AG059624).
Citations
McAvay GM, Murphy TE, Agogo GO, Allore HG. CRcoder: An Interactive Web Application and SAS Macro for Decision Support: Generation of Typical and Personalized Concurrent Risk. Permanente Journal Perm J. 2020;24. doi: 10.7812/TPP/19.078. Epub 2019 Dec 18.
https://doi.org/10.7812/TPP/19.078
Murphy TE, McAvay GJ, Agogo GO, Allore HG. Personalized and Typical Concurrent Risk of Limitations in Social Activity and Mobility in Older Persons with Multiple Chronic Conditions and Polypharmacy. Ann Epidemiol. 2019;S1047-2797(19)30222-4. doi: 10.1016/j.annepidem.2019.08.001. PMID: 31473124
Agogo GO, Murphy TE, McAvay GM, Allore HG. Joint modeling of concurrent binary outcomes for longitudinal observational studies using inverse probability of treatment weighting improved treatment effect estimation. Annals of Epidemiology 2019; pii: S1047-2797(18)30939-6. doi: 10.1016/j.annepidem.2019.04.008. PMID:31085069
Exploratory Meta Analysis on Uniform Assessment Battery across Aging Studies:
Summary
This summary file provides an overview of the exploratory meta analysis across different aging studies. Five components files plus this summary will be needed to run the SAS MACRO and the MATLAB function properly. The programs were originally written to analyze a set of "common assessment battery" of physical performance and biomarkers within Wake Forest University Health Sciences Pepper Center. The sample data used in this package is simulated data and for demonstration only. The relevant published work is referred if applicable.
Using the SAS output, bubble plots with bubble size proportional to sample size can be produced in MATLAB (unfortunately with SAS 9.1 we could not figure out an efficient way to plot the same). Therefore MATLAB were used. You may also use any other favorite graphic software to make the plots.
Author(s)
Leng, X
Wake Forest University
Code Language(s)
SAS and Matlab
Keywords
aging ,bubble plot ,covariate adjustment ,cross-sectional ,functional disability ,MATLAB ,meta-analysis ,multiple linear regression ,physical performance ,report table ,SAS ,
Link
http://biomedgerontology.oxfordjournals.org/cgi/content/full/gln038
FILE NAME (click to view/download) | DESCRIPTION |
---|---|
commonbattery.zip | package |
Copyright Notice and Disclaimer.pdf | Copyright Notice and Disclaimer |
Summary of Submission.pdf | Summary of Submission |
Document.pdf | Document |
Sample Program.sas | Sample Program |
slope_SD_adjbygender race10OCT08.rtf | Sample Output |
study.sas7bdat | Sample Data |
BubblePlot.m | Bubble plot function (MATLAB) |
Multiple Imputation Simulation:
Summary
This is a GRASP example for simulating missing data. In this simulation study, we made up pseudo ‘missing’ values by removing observed values from original datasets. The pseudo missing data were then imputed by two multiple imputation methods: sequential method vs. simultaneous method. We compared results between sequential and simultaneous methods using four criteria.
Author(s)
Ning, Y
Yale University
Keywords
Cardiovascular Health Study ,Longitudinal study ,missing data ,multiple imputation ,SAS ,simulation study ,
FILE NAME (click to view/download) | DESCRIPTION |
---|---|
MultipleImputationSimulation.txt | Program |
simple_exponential_model_excel.xls | |
SASProgramYuNing.txt | Program |
missing_simulation_code.txt | Programming Code |
missing_simulation_summary.pdf | Summary of Submission |
missing_simulation_data.txt | Sample Data |
missing_simulation_code1.txt | SAS Code |
missing_simulation_out.txt | Sample Output |
Multiple Testing for Correlated Outcomes in Clinical Trials:
Summary
When multiple outcomes are obtained from clinical trials, the most common approach in the medical literature is to analyze each outcome separately, presenting multiple p-values and an overall subject conclusion. However, it is well known that the excessive use of multiple significance tests can substantially increase the chance of false positive findings (type I error). On possible solution is to control a predefined error rate such as Family Error Rate (FER) in the strong sense, i.e., the probability of rejecting falsely at least one true individual null hypothesis, irrespective of which and how many of the individual null hypotheses are in fact true. Bonferroni method controls FER in the strong sense and is easy to apply. However when outcomes are correlated, Bonferroni method appears to be too conservative. We consider k normally distributed outcomes, each with known variance, for which all possible pairs have known correlation Ï쳌ij within each of two treatment groups. Then for given α , k, and Ï쳌ij we can derive numerically that the “nominalâ€쳌 value α* for individual tests which controls for FER at α under the null hypothesis. The MATLAB function multicompare calculates α* and the corresponding critical values as outputs. These can easily be extended to g (g >2) treatment groups and analysis of covariance for g (g ≥ 2) groups.
Author(s)
Leng, X
Wake Forest University
Code Language(s)
MATLAB
Keywords
aging ,Bonferroni ,correlated outcomes ,cross-sectional ,functional diability ,MATLAB ,multiple testing ,physical performance ,type I error ,
FILE NAME (click to view/download) | DESCRIPTION |
---|---|
Summary Multiple Testings for Correlated Outcomes in Clinical Trials.pdf | Summary of the package |
Document Multiple Testings for Correlated Outcomes in Clinical Trials.pdf | Documentation of the package |
multicomparison.zip | Package |
Copyright Notice and Disclaimer.pdf | Copyright Notice and Disclaimer |
Summary.pdf | Summary |
Document.pdf | Document |
multicomp.m | MATLAB program |
NLMIXED SAS Macro:
Summary
This submission provides SAS code for fitting a longitudinal logistic regression model in which a random intercept is included to induce a compound symmetry covariance structure for repeated measures on individual subjects.
Author(s)
Van Ness, PH
Yale University
Collaborator(s)
O'Leary JA
Fried T
Towle VR
et al
Code Language(s)
SAS
Keywords
longitudinal models ,mixed models ,repeated measures ,SAS ,
FILE NAME (click to view/download) | DESCRIPTION |
---|---|
NLmixedPackageVanNess.zip | Zipped folder of entire submission. |
NLMIXEDSummaryVanNess.pdf | Summary of Submission |
NLMIXEDDataVanNess.txt | Data Structure |
NLMIXEDProgramVanNess.txt | Program |
NLMIXEDOutputVanNess.txt | Output |
NLMIXEDarticle.pdf | Related Methodological Publication |
Acknowledgement
This work was supported in part by grants from the Biostatistics Core of the Claude D. Pepper Older Americans Independence Center at Yale University School of Medicine (#2P30AG021342-06).
Citations
Van Ness, PH, J. O'Leary, et al. (2004). "Fitting longitudinal mixed effect logistic regression models with the NLMIXED procedure." Proceedings of the 29th Annual SAS® Users Group International Conference (SUGI 29) 29: 1-6 (www2.sas.com/proceedings/sugi29/190-29.pdf).
Fried T, Byers, AL, Gallo, WT, Van Ness, PH, Towle, VR, O'Leary, JR, Dubin, JA. Prospective study of health status preferences and changes in preferences over time in older adults. Archives of Internal Medicine. 2006;166:890-895.
SAS Macro for Bivariate Analyses:
Summary
This submission consists of the four component files that makeup the GRASP example demonstrating a SAS-based macro that automatically calculates and tabulates the bivariate associations between continuous or categorical covariates and a dichotomous outcome. This example provides de-identified and sanitized data consisting of outcomes and 6 covariates from 50 pseudo subjects and serves for demonstrational purposes only.
Author(s)
Murphy, TE
Yale University
Code Language(s)
SAS
Keywords
admission characteristics ,bivariate analyses ,Confusion Assessment Method (CAM) ,delirium ,ICU ,logistic regression ,SAS ,
Link
http://archinte.ama-assn.org/cgi/content/full/167/15/1629
FILE NAME (click to view/download) | DESCRIPTION |
---|---|
MacroBivMurphy.zip | Zipped folder with four files comprising submission. |
MacroBivSummaryMurphy.pdf | Summary of Submission |
MacroBivDataSanMurphy.txt | Data Structure |
MacroBivProgramMurphy.txt | Program |
MacroBivOutputMurphy.pdf | Output |
Acknowledgement
This work was supported in part by the American Lung Association and Connecticut Thoracic Society (ID CG-002-N), Claude D. Pepper Older Americans Independence Center at Yale University School of Medicine (P30AG21342), and the Franklin T. Williams Geriatric Development Initiative through The CHEST Foundation, Association of Subspecialty Professors, Hartford Foundation. Dr Pisani is a recipient of a National Institutes of Health K23 Mentored Career Development Award (K23 AG 23023-01A1). Dr Inouye is supported in part by grants R21AG025193 and K24AG000949 from the National Institute on Aging. Dr Inouye holds the Milton and Shirley F. Levy Family Chair at Harvard University.
Citations
Pisani MA, Murphy TE, Van Ness PH, Araujo KLB, Inouye SK (2007). Admission characteristics associated with delirium in older patients in a medical intensive care unit. Archives of Internal Medicine; 167(15); 1629-1634.
SAS MIXCORR Macro for data with repeated measures and clumping at zero:
Summary
A mixed-effects, mixed-distribution model for data with repeated
measures and clumping at zero.
Author(s)
Tooze, JA
Wake Forest University
Collaborator(s)
Light, LS
Code Language(s)
SAS
Keywords
clumping at zero ,excess zero ,food intake ,mixed distribution ,physical activity ,repeated measures ,SAS ,walking speed ,
FILE NAME (click to view/download) | DESCRIPTION |
---|---|
tooze_mixcorr.zip | .zip file containing all documentation |
tooze 2002 accepted.pdf | Reference manuscript |
mixcorr.sas | SAS macro |
example.sas7bdat | example data |
Simple Bootstrap with Proc Surveyselect:
Summary
This submission ties together the four component files that demonstrate a simple SAS-based method of generating bootstrap datasets using Proc Surveyselect. In the past we would write a page or two of code to generate these datasets which is done here in a few lines by Proc Surveyselect. This example provides de-identified and sanitized data consisting of gender and a single outcome from 100 pseudo subjects and serves for demonstrational purposes only.
Author(s)
Murphy, TE
Yale University
Code Language(s)
SAS
Keywords
bootstrap ,confidence interval ,median ,
FILE NAME (click to view/download) | DESCRIPTION |
---|---|
SimpBootMurphy.zip | Zipped folder with four files comprising submission. |
SimpBootSummaryMurphy.pdf | Summary of Submission |
SimpBootDataSanMurphy.txt | Data Structure |
SimpBootProgramMurphy.txt | Program |
SimpBootOutputMurphy.pdf | Output |
Acknowledgement
This work was supported in part by the Claude D. Pepper Older Americans Independence Center at Yale University School of Medicine (P30AG021342), Dr. Pisani is a recipient of a NIH K23 Mentored Career Development Award (K23 AG 23023-01A1) and the Chest Foundation and Boehringer Ingelheim Pharmaceuticals, Inc. Clinical Research Award in Women’s Pulmonary Health.
Citations
Akgun K, Murphy TE, Araujo KLB, Van Ness PH, Pisani MA. Equivalent treatment of older medical intensive care unit patients based on gender. ''Under Review''.
SpatioTemporal Modeling in Longitudinal Analyses of Areal Units:
Summary
This document ties together six different files that demonstrate spatiotemporal modeling in the longitudinal analyses of areal units. Clinically, this is the statistical analysis underlying the Connecticut Collaboration for Fall Prevention (CCFP) at the Yale Pepper Center. This example takes a sample of 40 zip code tabulation areas (ZCTAs) from the total of 111 used in the formal, published analysis and serves for demonstrational purposes only. Data has been sanitized by removing identifying information and adding random noise.
Author(s)
Murphy, TE
Yale University
Collaborator(s)
Tinetti ME,
Allore HG
Code Language(s)
WinBUGS
Keywords
Bayesian methods ,CMS data ,ecological ,falls ,hierarchical models ,longitudinal models ,non-randomized design ,spatio-temporal correlation ,T2 ,translational research ,WinBUGS ,
Link
http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B7P72-4R0CKRG-2&_user=4...
FILE NAME (click to view/download) | DESCRIPTION |
---|---|
SpatioTempSummaryMurphy.pdf | Summary document |
SpatioTempDataMurphy.txt | Data Structure |
SpatioTempInitsMurphy.txt | Initial Values for Markov Chains |
SpatioTempProgramMurphy.txt | Program |
SpatioTempOutputMurphy.pdf | Output |
Acknowledgement
The Connecticut Collaboration for Fall Prevention is supported by the Donoghue Medical Research Foundation (DF#00-206) and the Claude D. Pepper OAIC at Yale University School of Medicine (#P30AG21342).
Citations
1) Murphy TE, Tinetti ME, and Allore HG (2008). Hierarchical models to evaluate translational research: Connecticut collaboration for fall prevention. Contemporary Clinical Trials, 29:343-350.
2) Tinetti, M. E., Baker, D. I., King, M., Gottschalk, M., Murphy, T. E., Acampora, D., et al (2008). Effect of dissemination of evidence in reducing injuries from falls. New England Journal of Medicine, 359(3), 252-261.
Statistical Power Calculator:
Summary
This submission provides a link to statistical power calculator (SPC) provided by Department of Biostatistics and Data Science within the Division of Public Health Sciences at Wake Forest University School of Medicine. The SPC is based on SAS PROC POWER. Currently available calculators include: correlation, one sample proportion, one sample mean, paired proportion, paired means, two sample proportion and two sample means. There is also a guide for choosing which calculator to use.
Author(s)
Hepler J, Lovato J
Wake Forest University
Collaborator(s)
Chen H, Lang W, Babcock D, Robertson J, Leng X
Code Language(s)
SAS, ColdFusion, SQL
Keywords
Correlation, Cross-Sectional, Mean, Power, Proportion, Sample Size, Paired, Calculation, Computational, Alpha, Variance
Link
http://power.phs.wakehealth.edu/
Acknowledgement
This calculator application is a labor of love supported by Department of Biostatistics and Data Science within the Division of Public Health Sciences at Wake Forest School of Medicine. Special thanks to everyone who has helped over the years.
Temporal Configuration Analysis:
Summary
Temporal Configuration Analysis (TCA) is a stand-alone application that analyzes the multivariate discrete longitudinal data in gerontology studies, such as ADL, physical activities (FAST23) and other social science studies. The method is based on the Hidden Markov Model (HMM) backbone to separate subjects into hidden classes whose interpretations depend on the estimated conditional probabilities. TCA expands the HMM into a more general Bayesian Network (BN) framework and also incorporates the generalize linear regression models into the BN framework to study covariates' impact on the BN parameters. For example, in an aging study, we like to see how BMI affects subjects' physical performance in transitioning from worse to better states.
Author(s)
Zhang, Q and Ip, E
Wake Forest University
Code Language(s)
MATLAB
Keywords
activities of daily living (ADLs) ,Bayesian methods ,generalized linear models ,intervention studies ,longitudinal models ,MATLAB ,mixed models ,physical activity ,physical performance ,repeated measures ,walking speed ,
FILE NAME (click to view/download) | DESCRIPTION |
---|---|
TCA.zip |
Temporally Successive Multiple Imputation of Longitudinal Data:
Summary
This document ties together the five component files that makeup the GRASP example demonstrating the technique of temporally successive multiple imputation as applied to data from the Precipitating Events Project (PEP) at the Yale Pepper Center. This example takes a sample of 100 pseudo subjects with 8 covariates measured over six waves of follow-up. The procedure was used to impute missing observations for risk factors measured at face-to-face interviews performed at 18-month intervals. This example serves for demonstrational purposes only.
Author(s)
Han, L
Yale University
Code Language(s)
SAS
Keywords
activities of daily living ,longitudinal models ,missing at random (MAR) ,missing data ,multiple imputation ,
Link
http://www3.interscience.wiley.com/cgi-bin/fulltext/117995771/PDFSTART
FILE NAME (click to view/download) | DESCRIPTION |
---|---|
SeqMIHan.zip | |
GRASP submission1.zip | zip file |
SeqMISummaryHANr.pdf | Summary |
SeqMI_InputData.pdf | Data structure |
SeqMI_dataset.txt | Dataset |
SeqMImacro.pdf | Sas code |
SeqMIOutputLH.pdf | SAS output/summary of imputation |
SeqMI_outputds.pdf | Output/imputed data structure |
Acknowledgement
The
work for this report was funded by grants from the National
Institute on Aging (R01AG022993, R37AG17560).
The study was conducted at the Yale Claude D. Pepper
Older Americans Independence Center (P30AG21342). Dr.
Gill is the recipient of a Midcareer Investigator Award
in Patient-Oriented Research (K24AG021507) from the
National Institute on Aging.
Citations
Gill TM, Han L, Allore HG. Predisposing factors and precipitants for bathing disability in older persons. Journal of the American Geriatrics Society. 2007;55:534-40.