@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} }