@article {1338, title = {Surrogate screening models for the low physical activity criterion of frailty.}, journal = {Aging Clin Exp Res}, volume = {23}, year = {2011}, month = {2011 Jun}, pages = {209-16}, abstract = {

BACKGROUND AND AIMS: Low physical activity, one of five criteria in a validated clinical phenotype of frailty, is assessed by a standardized, semiquantitative questionnaire on up to 20 leisure time activities. Because of the time demanded to collect the interview data, it has been challenging to translate to studies other than the Cardiovascular Health Study (CHS), for which it was developed. Considering subsets of activities, we identified and evaluated streamlined surrogate assessment methods and compared them to one implemented in the Women{\textquoteright}s Health and Aging Study (WHAS).

METHODS: Using data on men and women ages 65 and older from the CHS, we applied logistic regression models to rank activities by "relative influence" in predicting low physical activity.We considered subsets of the most influential activities as inputs to potential surrogate models (logistic regressions). We evaluated predictive accuracy and predictive validity using the area under receiver operating characteristic curves and assessed criterion validity using proportional hazards models relating frailty status (defined using the surrogate) to mortality.

RESULTS: Walking for exercise and moderately strenuous household chores were highly influential for both genders. Women required fewer activities than men for accurate classification. The WHAS model (8 CHS activities) was an effective surrogate, but a surrogate using 6 activities (walking, chores, gardening, general exercise, mowing and golfing) was also highly predictive.

CONCLUSIONS: We recommend a 6 activity questionnaire to assess physical activity for men and women. If efficiency is essential and the study involves only women, fewer activities can be included.

}, keywords = {Activities of Daily Living, Aged, Cohort Studies, Exercise, Female, Follow-Up Studies, Frail Elderly, Geriatric Assessment, Humans, Leisure Activities, Logistic Models, Male, Motor Activity, Prospective Studies, Surveys and Questionnaires, Women{\textquoteright}s Health}, issn = {1594-0667}, author = {Eckel, Sandrah P and Bandeen-Roche, Karen and Chaves, Paulo H M and Fried, Linda P and Louis, Thomas A} } @article {6608, title = {Simple biologically informed inflammatory index of two serum cytokines predicts 10 year all-cause mortality in older adults.}, journal = {J Gerontol A Biol Sci Med Sci}, volume = {69}, year = {2014}, month = {2014 Feb}, pages = {165-73}, abstract = {

BACKGROUND: Individual measurements of inflammation have been utilized to assess adverse outcomes risk in older adults with varying degrees of success. This study was designed to identify biologically informed, aggregate measures of inflammation for optimal risk assessment and to inform further biological study of inflammatory pathways.

METHODS: In total, 15 nuclear factor-kappa B-mediated pathway markers of inflammation were first measured in baseline serum samples of 1,155 older participants in the InCHIANTI population. Of these, C-reactive protein, interleukin-1-receptor antagonist, interleukin-6, interleukin-18, and soluble tumor necrosis factor-α receptor-1 were independent predictors of 5-year mortality. These five inflammatory markers were measured in baseline serum samples of 5,600 Cardiovascular Health Study participants. A weighted summary score, the first principal component summary score, and an inflammation index score were developed from these five log-transformed inflammatory markers, and their prediction of 10-year all-cause mortality was evaluated in Cardiovascular Health Study and then validated in InCHIANTI.

RESULTS: The inflammation index score that included interleukin-6 and soluble tumor necrosis factor-α receptor-1 was the best predictor of 10-year all-cause mortality in Cardiovascular Health Study, after adjusting for age, sex, education, race, smoking, and body mass index (hazards ratio = 1.62; 95\% CI: 1.54, 1.70) compared with all other single and combined measures. The inflammation index score was also the best predictor of mortality in the InCHIANTI validation study (hazards ratio 1.33; 95\% CI: 1.17-1.52). Stratification by sex and CVD status further strengthened the association of inflammation index score with mortality.

CONCLUSION: A simple additive index of serum interleukin-6 and soluble tumor necrosis factor-α receptor-1 best captures the effect of chronic inflammation on mortality in older adults among the 15 biomarkers measured.

}, keywords = {Aged, Aged, 80 and over, Biomarkers, C-Reactive Protein, Cohort Studies, Female, Humans, Inflammation, Interleukin 1 Receptor Antagonist Protein, Interleukin-18, Interleukin-6, Longevity, Male, Receptors, Tumor Necrosis Factor, Type I, Risk Factors}, issn = {1758-535X}, doi = {10.1093/gerona/glt023}, author = {Varadhan, Ravi and Yao, Wenliang and Matteini, Amy and Beamer, Brock A and Xue, Qian-Li and Yang, Huanle and Manwani, Bhavish and Reiner, Alexander and Jenny, Nancy and Parekh, Neel and Fallin, M Daniele and Newman, Anne and Bandeen-Roche, Karen and Tracy, Russell and Ferrucci, Luigi and Walston, Jeremy} } @article {6545, title = {Association of mitochondrial DNA levels with frailty and all-cause mortality.}, journal = {J Mol Med (Berl)}, volume = {93}, year = {2015}, month = {2015 Feb}, pages = {177-186}, abstract = {

Mitochondrial function is altered with age and variants in mitochondrial DNA (mtDNA) modulate risk for several age-related disease states. However, the association of mtDNA copy number, a readily available marker which reflects mitochondrial depletion, energy reserves, and oxidative stress, on aging and mortality in the general population has not been addressed. To assess the association between mtDNA copy number and two primary outcomes--prevalent frailty and all-cause mortality--we utilize data from participants who were from two multicenter, multiethnic, community-based, prospective studies--the Cardiovascular Health Study (CHS) (1989-2006) and the Atherosclerosis Risk in Communities (ARIC) study (1987-2013). A total of 4892 participants (43.3\% men) from CHS and 11,509 participants (44.9\% men) from ARIC self-identifying as white or black were included in the analysis. mtDNA copy number, the trait of interest, was measured using a qPCR-based method in CHS and an array-based method in ARIC from DNA isolated from whole blood in participants from both cohorts. In race-stratified meta-analyses, we observe a significant inverse association of mtDNA copy number with age and higher mtDNA copy number in women relative to men. Lower mtDNA copy number was also significantly associated with prevalent frailty in white participants from CHS (OR 0.91, 95\% CI 0.85-0.97). Additionally, mtDNA copy number was a strong independent predictor of all-cause mortality in an age- and sex-adjusted, race-stratified analysis of 16,401 participants from both cohorts with a pooled hazard ratio of 1.47 (95\% CI 1.33-1.62) for the lowest quintile of mtDNA copy number relative to the highest quintile. Key messages: Mitochondrial DNA (mtDNA) copy number is associated with age and sex. Lower mtDNA copy number is also associated with prevalent frailty. mtDNA copy number is a significant predictor of all-cause mortality in a multiethnic population.

}, keywords = {African Americans, Aged, Aged, 80 and over, Aging, DNA, Mitochondrial, European Continental Ancestry Group, Female, Follow-Up Studies, Gene Dosage, Geriatric Assessment, Humans, Kaplan-Meier Estimate, Male, Mortality, Odds Ratio, Population Surveillance, Prospective Studies, Surveys and Questionnaires, United States}, issn = {1432-1440}, doi = {10.1007/s00109-014-1233-3}, author = {Ashar, Foram N and Moes, Anna and Moore, Ann Z and Grove, Megan L and Chaves, Paulo H M and Coresh, Josef and Newman, Anne B and Matteini, Amy M and Bandeen-Roche, Karen and Boerwinkle, Eric and Walston, Jeremy D and Arking, Dan E} } @article {7982, title = {Discrepancy in Frailty Identification: Move beyond Predictive Validity.}, journal = {J Gerontol A Biol Sci Med Sci}, year = {2019}, month = {2019 Feb 21}, abstract = {

BACKGROUND: To evaluate the discordance in frailty classification between the frailty index (FI) and the physical frailty phenotype (PFP) and identify factors discriminating those with discordant frailty classification from each other and from those for whom the assessments agree.

METHODS: A prospective observational study of older adults aged 65 and older selected from Medicare eligibility lists in four US communities (n=5,362). The PFP was measured by the Cardiovascular Health Study PFP. Subjects meeting >=3 of the 5 criteria were deemed frail. The FI was calculated as the proportion of deficits in an a priori selected set of 48 measures and subjects were classified as frail if FI>0.35.

RESULTS: The prevalence of frailty was 7.0\% by the PFP and 8.3\% by the FI. Of the 730 deemed frail by either instrument, only 12\% were in agreement; whereas 39\% were classified as frail by PFP but not FI; and 48\% were classified as frail by FI but not PFP. Participants aged 65-72 or greater disease burden were mostly likely to be characterized as being FI-frail but not PFP-frail. The associations of frailty with age and mortality was stronger when frailty was measured by the PFP rather than the FI.

CONCLUSIONS: Despite comparable frailty prevalence between the PFP and the FI, there was substantial discordance in individual-level classification, with highest agreement existing only in the most vulnerable subset. These findings suggest that there are clinically important contexts in which PFP and FI cannot be used interchangeably.

}, issn = {1758-535X}, doi = {10.1093/gerona/glz052}, author = {Xue, Qian-Li and Tian, Jing and Walston, Jeremy D and Chaves, Paulo H M and Newman, Anne B and Bandeen-Roche, Karen} } @article {9445, title = {Substitution of self-reported measures for objectively assessed grip strength and slow walk in the Physical Frailty Phenotype: ramifications for validity.}, journal = {BMC Geriatr}, volume = {23}, year = {2023}, month = {2023 Jul 22}, pages = {451}, abstract = {

BACKGROUND: Frailty assessment promises to identify older adults at risk for adverse consequences following stressors and target interventions to improve health outcomes. The Physical Frailty Phenotype (PFP) is a widely-studied, well validated assessment but incorporates performance-based slow walk and grip strength criteria that challenge its use in some clinical settings. Variants replacing performance-based elements with self-reported proxies have been proposed. Our study evaluated whether commonly available disability self-reports could be substituted for the performance-based criteria in the PFP while still identifying as "frail" the same subpopulations of individuals.

METHODS: Parallel analyses were conducted in 3393 female and 2495 male Cardiovascular Health Study, Round 2 participants assessed in 1989-90. Candidate self-reported proxies for the phenotype{\textquoteright}s "slowness" and "weakness" criteria were evaluated for comparable prevalence and agreement by mode of measurement. For best-performing candidates: Frailty status (3 + positive criteria out of 5) was compared for prevalence and agreement between the PFP and mostly self-reported versions. Personal characteristics were compared between those adjudicated as frail by (a) only a self-reported version; (b) only the PFP; (c) both, using bivariable analyses and multinomial logistic regression.

RESULTS: Self-reported difficulty walking {\textonehalf} mile was selected as a proxy for the phenotype{\textquoteright}s slowness criterion. Two self-reported weakness proxies were examined: difficulty transferring from a bed or chair or gripping with hands, and difficulty as just defined or in lifting a 10-pound bag. Prevalences matched to within 4\% between self-reported and performance-based criteria in the whole sample, but in all cases the self-reported prevalence for women exceeded that for men by 11\% or more. Cross-modal agreement was moderate, with by-criterion and frailty-wide Kappa statistics of 0.55-0.60 in all cases. Frail subgroups (a), (b), (c) were independently discriminated (p < 0.05) by race, BMI, and depression in women; by age in men; and by self-reported health for both.

CONCLUSIONS: Commonly used self-reported disability items cannot be assumed to stand in for performance-based criteria in the PFP. We found subpopulations identified as frail by resultant phenotypes versus the original phenotype to systematically differ. Work to develop self-reported proxies that more closely replicate their objective phenotypic counterparts than standard disability self-reports is needed.

}, keywords = {Advance Directives, Female, Frailty, Hand Strength, Humans, Male, Phenotype, Self Report}, issn = {1471-2318}, doi = {10.1186/s12877-023-04105-8}, author = {Bandeen-Roche, Karen and Tian, Jing and Buta, Brian and Walston, Jeremy and Xue, Qian-Li} }