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Pua YH, Terluin B, Tay L, Clark RA, Thumboo J, Tay EL, Mah SM, Ng YS. Using item response theory to estimate interpretation threshold values for the Frailty Index in community dwelling older adults. Arch Gerontol Geriatr 2024; 117:105280. [PMID: 38000095 DOI: 10.1016/j.archger.2023.105280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Revised: 11/10/2023] [Accepted: 11/17/2023] [Indexed: 11/26/2023]
Abstract
BACKGROUND Although the frailty index (FI) is designed as a continuous measure of frailty, thresholds are often needed to guide its interpretation. This study aimed to introduce and demonstrate the utility of an item response theory (IRT) method in estimating FI interpretation thresholds in community-dwelling adults and to compare them with cutoffs estimated using the receiver operating characteristics (ROC) method. METHODS A sample of 1,149 community-dwelling adults (mean[SD], 68[7] years) participated in this cross-sectional study. Participants completed a multi-domain geriatric screen from which the 40-item FI and 3 clinical anchors were computed - namely, (i)self-reported mobility limitations (SRML), (ii)"fair" or "poor" self-rated health (SRH), and (iii) restricted life-space mobility (RLSM). Participants were classified as having SRML-1 if they responded "Yes" to either of the 2 questions regarding walking and stair climbing difficulty and SRML-2 if they reported having walking and stair climbing difficulty. Participants with a Life Space Assessment score <60 points were classified as having RLSM. Threshold values for all anchor questions were estimated using the IRT method and ROC analysis with Youden criterion. RESULTS The proportions of participants with SRML-1, SRML-2, Fair/Poor SRH, and RLSM were 21 %, 8 %, 22 %, and 9 %, respectively. The IRT-based thresholds for SRML-2 (0.26), fair/poor SRH (0.29), and RLSM (0.32) were significantly higher than those for SRML-1 (0.18). ROC-based FI cutoffs were significantly lower than IRT-based values for SRML-2, SRH, and RLSM (0.12 to 0.17), and they varied minimally and non-systematically across the anchors. CONCLUSIONS The IRT method identifies biologically plausible FI thresholds that could meaningfully complement and contextualize existing thresholds for defining frailty.
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Affiliation(s)
- Yong-Hao Pua
- Department of Physiotherapy, Singapore General Hospital, Singapore; Medicine Academic Programme, Duke-NUS Graduate Medical School, Singapore.
| | - Berend Terluin
- Amsterdam Public Health research institute, Amsterdam, the Netherlands; Amsterdam UMC location Vrije Universiteit Amsterdam, Department of General Practice, Amsterdam, the Netherlands
| | - Laura Tay
- Department of General Medicine (Geriatric Medicine), Sengkang General Hospital, Singapore
| | - Ross Allan Clark
- School of Health and Behavioural Science, University of the Sunshine Coast, Sunshine Coast, Australia
| | - Julian Thumboo
- Medicine Academic Programme, Duke-NUS Graduate Medical School, Singapore; Department of Rheumatology and Immunology, Singapore General Hospital, Singapore; Health Services Research & Evaluation, SingHealth Office of Regional Health, Singapore
| | - Ee-Ling Tay
- Department of Physiotherapy, Sengkang General Hospital, Singapore
| | - Shi-Min Mah
- Department of Physiotherapy, Sengkang General Hospital, Singapore
| | - Yee-Sien Ng
- Geriatric Education and Research Institute, Singapore; Duke-NUS Medical School, Singapore; Department of Rehabilitation Medicine, Singapore General Hospital and Sengkang General Hospital, Singapore
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Pua YH, Tay L, Terluin B, Clark RA, Thumboo J, Tay EL, Mah SM, Ng YS. Estimating cutpoints of gait speed and sit-to-stand test values for self-reported mobility limitations in a cohort of community-dwelling older adults from Singapore: comparing receiver operating characteristic (ROC) analysis with adjusted predictive modelling. Arch Gerontol Geriatr 2023; 112:105036. [PMID: 37075584 DOI: 10.1016/j.archger.2023.105036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 04/05/2023] [Accepted: 04/13/2023] [Indexed: 04/21/2023]
Abstract
OBJECTIVES Clinical interpretability of the gait speed and 5-times sit-to-stand (5-STS) tests is commonly established by comparing older adults with and without self-reported mobility limitations (SRML) on gait speed and 5-STS performance, and estimating clinical cutpoints for SRML using the receiver operating characteristics (ROC) method. Accumulating evidence, however, suggests that the adjusted predictive modeling (APM) method may be more appropriate to estimate these interpretational cutpoints. Thus, we aimed to compare, in community-dwelling older adults, gait speed and 5-STS cutpoints estimated using the ROC and APM methods. DESIGN Cross-sectional study. SETTING AND PARTICIPANTS This study analyzed data from 955 community-dwelling independently walking older adults (73%women) aged ≥60 years (mean, 68; range, 60-88). METHODS Participants completed the 10-metre gait speed and 5-STS tests. Participants were classified as having SRML if they responded "Yes" to either of the 2 questions regarding walking and stair climbing difficulty. Cutpoints for SRML and its component questions were estimated using ROC analysis with Youden criterion and the APM method. RESULTS The proportions of participants with self-reported walking difficulty, self-reported stair climbing difficulty, and SRML were 10%, 19%, and 22%, respectively. Gait speed and 5-STS time were moderately correlated with each other (r=-0.56) and with the self-reported measures (absolute r-values, 0.39-0.44). ROC-based gait speed cutpoints were 0.14 to 0.16 m/s greater than APM-based cutpoints (P < 0.05) whilst ROC-based 5-STS time cutpoints were 0.8 to 3.3 s lower than APM-based cutpoints (P < 0.05 for walking difficulty). Compared with ROC-based cutpoints, APM-based cutptoints were more precise and they varied monotonically with self-reported walking difficulty, self-reported stair climbing difficulty, and SRML. CONCLUSIONS AND IMPLICATIONS In a sample of 955 older adults, our findings of precise and biologically plausible gait speed and 5-STS cutpoints for SRML estimated using the APM method indicate that this promising method could potentially complement or even replace traditional ROC methods.
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Affiliation(s)
- Yong-Hao Pua
- Department of Physiotherapy, Singapore General Hospital, Singapore; Medicine Academic Programme, Duke-NUS Graduate Medical School, Singapore.
| | - Laura Tay
- Department of General Medicine (Geriatric Medicine), Sengkang General Hospital, Singapore
| | - Berend Terluin
- Department of General Practice, Amsterdam UMC location Vrije Universiteit Amsterdam, Amsterdam, the Netherlands; Amsterdam Public Health Research Institute, Amsterdam, the Netherlands
| | - Ross Allan Clark
- School of Health and Behavioural Science, University of the Sunshine Coast, Sunshine Coast, Australia
| | - Julian Thumboo
- Medicine Academic Programme, Duke-NUS Graduate Medical School, Singapore; Department of Rheumatology and Immunology, Singapore General Hospital, Singapore; Health Services Research & Evaluation, SingHealth Office of Regional Health, Singapore
| | - Ee-Ling Tay
- Department of Physiotherapy, Sengkang General Hospital, Singapore
| | - Shi-Min Mah
- Department of Physiotherapy, Sengkang General Hospital, Singapore
| | - Yee-Sien Ng
- Geriatric Education and Research Institute, Singapore; Duke-NUS Medical School, Singapore; Department of Rehabilitation Medicine, Singapore General Hospital and Sengkang General Hospital, Singapore
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Pua YH, Tay L, Clark RA, Thumboo J, Tay EL, Mah SM, Ng YS. Associations of height, weight, and body mass index with handgrip strength: A Bayesian comparison in older adults. Clin Nutr ESPEN 2023; 54:206-210. [PMID: 36963864 DOI: 10.1016/j.clnesp.2023.01.028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 01/06/2023] [Accepted: 01/22/2023] [Indexed: 02/05/2023]
Abstract
BACKGROUND & AIMS Handgrip strength is commonly normalized or stratified by body size to define subgroup-specific cut-points and reference limits values. However, it remains unclear which anthropometric variable is most strongly associated with handgrip strength. We aimed to, in older adults with no self-reported mobility limitations, determine whether height, weight, and body mass index (BMI) were meaningfully associated with handgrip strength. METHODS This cross-sectional study included community-dwelling ambulant participants, and we identified 775 older adults who reported no difficulty walking 100 m, climbing stairs, and rising from the chair. Handgrip strength was measured with a digital dynamometer. Bayesian linear regression was used to estimate the probabilities that the positive associations of height, weight, and BMI with handgrip strength exceeded 0 kg (the null value) and 2.5 kg (the clinically meaningful threshold value). RESULTS Mean handgrip strength was 22.1 kg (SD, 4) for women and 32.9 kg (SD, 6) for men. Body height, weight, and BMI had >99.9% probabilities of a positive association with handgrip strength; however, the associations of per interquartile increase in body weight and BMI with handgrip strength had low probabilities (<5%) of exceeding the clinically meaningful threshold of 2.5 kg. In contrast, body height had the highest probability (99.6%) of a clinically meaningful association with handgrip strength: adjusting for age and gender, handgrip strength was 3.2 kg (95% CrI, 2.7 to 3.8) greater in older adults 1.61 m tall than in older adults 1.51 m tall. CONCLUSIONS In a large sample of mobile-intact older adults, handgrip strength differed meaningfully by body height. Although requiring validation, our findings suggest that future efforts should be directed at normalizing handgrip strength by body height to better define subgroup-specific handgrip weakness. A web-based application (https://sghpt.shinyapps.io/ippts/) was created to allow interactive exploration of predicted values and reference limits of age-, gender-, and height-subgroups.
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Affiliation(s)
- Yong-Hao Pua
- Department of Physiotherapy, Singapore General Hospital, Singapore; Medicine Academic Programme, Duke-NUS Graduate Medical School, Singapore.
| | - Laura Tay
- Department of General Medicine (Geriatric Medicine), Sengkang General Hospital, Singapore
| | - Ross Allan Clark
- Research Health Institute, University of the Sunshine Coast, Sunshine Coast, Australia
| | - Julian Thumboo
- Medicine Academic Programme, Duke-NUS Graduate Medical School, Singapore; Department of Rheumatology and Immunology, Singapore General Hospital, Singapore; Health Services Research & Evaluation, Singhealth Office of Regional Health, Singapore
| | - Ee-Ling Tay
- Department of Physiotherapy, SengKang General Hospital, Singapore
| | - Shi-Min Mah
- Department of Physiotherapy, SengKang General Hospital, Singapore
| | - Yee-Sien Ng
- Department of Rehabilitation Medicine, Singapore General Hospital and Sengkang General Hospital, Singapore; Geriatric Education and Research Institute, Singapore; Duke-NUS Medical School, Singapore
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Pua YH, Tay L, Clark RA, Thumboo J, Tay EL, Mah SM, Lee PY, Ng YS. Development and validation of a physical frailty phenotype index-based model to estimate the frailty index. Diagn Progn Res 2023; 7:5. [PMID: 36941719 PMCID: PMC10029224 DOI: 10.1186/s41512-023-00143-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Accepted: 01/23/2023] [Indexed: 03/23/2023] Open
Abstract
BACKGROUND The conventional count-based physical frailty phenotype (PFP) dichotomizes its criterion predictors-an approach that creates information loss and depends on the availability of population-derived cut-points. This study proposes an alternative approach to computing the PFP by developing and validating a model that uses PFP components to predict the frailty index (FI) in community-dwelling older adults, without the need for predictor dichotomization. METHODS A sample of 998 community-dwelling older adults (mean [SD], 68 [7] years) participated in this prospective cohort study. Participants completed a multi-domain geriatric screen and a physical fitness assessment from which the count-based PFP and the 36-item FI were computed. One-year prospective falls and hospitalization rates were also measured. Bayesian beta regression analysis, allowing for nonlinear effects of the non-dichotomized PFP criterion predictors, was used to develop a model for FI ("model-based PFP"). Approximate leave-one-out (LOO) cross-validation was used to examine model overfitting. RESULTS The model-based PFP showed good calibration with the FI, and it had better out-of-sample predictive performance than the count-based PFP (LOO-R2, 0.35 vs 0.22). In clinical terms, the improvement in prediction (i) translated to improved classification agreement with the FI (Cohen's kw, 0.47 vs 0.36) and (ii) resulted primarily in a 23% (95%CI, 18-28%) net increase in FI-defined "prefrail/frail" participants correctly classified. The model-based PFP showed stronger prognostic performance for predicting falls and hospitalization than did the count-based PFP. CONCLUSION The developed model-based PFP predicted FI and clinical outcomes more strongly than did the count-based PFP in community-dwelling older adults. By not requiring predictor cut-points, the model-based PFP potentially facilitates usage and feasibility. Future validation studies should aim to obtain clear evidence on the benefits of this approach.
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Affiliation(s)
- Yong-Hao Pua
- Department of Physiotherapy, Singapore General Hospital, Outram Road, Singapore, 169608, Singapore.
- Medicine Academic Programme, Duke-NUS Graduate Medical School, Singapore, Singapore.
| | - Laura Tay
- Department of General Medicine (Geriatric Medicine), Sengkang General Hospital, Singapore, Singapore
| | - Ross Allan Clark
- School of Health and Behavioural Science, University of the Sunshine Coast, Sunshine Coast, Australia
| | - Julian Thumboo
- Medicine Academic Programme, Duke-NUS Graduate Medical School, Singapore, Singapore
- Department of Rheumatology and Immunology, Singapore General Hospital, Singapore, Singapore
- Health Services Research & Evaluation, SingHealth Office of Regional Health, Singapore, Singapore
| | - Ee-Ling Tay
- Department of Physiotherapy, Sengkang General Hospital, Singapore, Singapore
| | - Shi-Min Mah
- Department of Physiotherapy, Sengkang General Hospital, Singapore, Singapore
| | - Pei-Yueng Lee
- Organization Planning and Performance, Singapore General Hospital, Singapore, Singapore
| | - Yee-Sien Ng
- Geriatric Education and Research Institute, Singapore, Singapore
- Duke-NUS Medical School, Singapore, Singapore
- Department of Rehabilitation Medicine, Singapore General Hospital and Sengkang General Hospital, Singapore, Singapore
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Pua YH, Tay L, Clark RA, Thumboo J, Tay EL, Mah SM, Ng YS. Screening accuracy of percentage predicted gait speed for prefrailty/frailty in community-dwelling older adults. Geriatr Gerontol Int 2022; 22:575-580. [PMID: 35716008 DOI: 10.1111/ggi.14418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 05/11/2022] [Accepted: 05/21/2022] [Indexed: 11/29/2022]
Abstract
AIM In order to account for the variability in gait speed due to demographic factors, an observed gait speed value can be compared with its predicted value based on age, sex, and body height (observed gait speed divided by predicted gait speed, termed "GS%predicted" henceforth). This study aimed to examine the screening accuracy of an optimal GS%predicted threshold for prefrailty/frailty. METHODS This cross-sectional study included 998 community-dwelling ambulant participants aged >50 years (mean age = 68 years). Participants completed a multi-domain geriatric screen and a physical fitness assessment, from which the 10-m habitual gait speed, GS%predicted, Physical Frailty Phenotype (PFP) index, and 36-item Frailty Index (FI) were computed. RESULTS Based on the FI, ~49% of participants had pre-frailty or frailty. The optimal threshold of GS%predicted (0.93) had greater screening accuracy than the 1.0 m/s fixed threshold for gait speed (AUC, 0.65 vs. 0.60; DeLong's P < 0.001). Replacing gait speed with GS%predicted in the PFP improved its overall discrimination (AUC, 0.70 vs. 0.67 of original PFP; DeLong's P < 0.001). CONCLUSIONS Defining a "slow" gait speed by a GS%predicted value of <0.93 provided greater screening accuracy than the traditional 1.0 m/s threshold for gait speed. Our results also support the use of GS%predicted-derived PFP to identify older adults at risk of prefrailty/frailty. Geriatr Gerontol Int 2022; ••: ••-••.
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Affiliation(s)
- Yong-Hao Pua
- Department of Physiotherapy, Singapore General Hospital, Singapore.,Medicine Academic Programme, Duke-NUS Graduate Medical School, Singapore, Singapore
| | - Laura Tay
- Department of General Medicine (Geriatric Medicine), Sengkang General Hospital, Singapore.,Geriatric Education and Research Institute, Singapore
| | - Ross Allan Clark
- Research Health Institute, University of the Sunshine Coast, Maroochydore DC, Queensland, Australia
| | - Julian Thumboo
- Medicine Academic Programme, Duke-NUS Graduate Medical School, Singapore, Singapore.,Department of Rheumatology and Immunology, Singapore General Hospital, Singapore.,Health Services Research and Evaluation, Singhealth Office of Regional Health, Singapore
| | - Ee-Ling Tay
- Department of Physiotherapy, Sengkang General Hospital, Singapore
| | - Shi-Min Mah
- Department of Physiotherapy, Sengkang General Hospital, Singapore
| | - Yee-Sien Ng
- Medicine Academic Programme, Duke-NUS Graduate Medical School, Singapore, Singapore.,Geriatric Education and Research Institute, Singapore.,Department of Rehabilitation Medicine, Singapore General Hospital and Sengkang General Hospital, Singapore
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Low WL, Sultana R, Huda Mukhlis AB, Ho JCY, Latib A, Tay EL, Mah SM, Chan HN, Ng YS, Tay L. A Non-Controlled Study of a Multi-Factorial Exercise and Nutritional Intervention to Improve Functional Performance and Prevent Frailty Progression in Community-Dwelling Pre-Frail Older Adults. JAR Life 2021; 10:1-7. [PMID: 36923514 PMCID: PMC10002973 DOI: 10.14283/jarlife.2021.1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Accepted: 12/08/2019] [Indexed: 11/11/2022]
Abstract
Background Preventing frailty is important to avoid adverse health outcomes. Intervention studies have largely focused on frail elderly, although the intermediate pre-frail state may be more amenable to improvement. Objectives This study aims to assess how physical performance may change among pre-frail elderly enrolled in a pragmatic non-controlled exercise and nutritional intervention programme. Methods This is a non-controlled study involving a 4-month exercise and nutritional intervention for community dwelling pre-frail older adults. Pre-frailty was defined as the presence of 1 or 2 positive responses on the FRAIL questionnaire, or evidence of weak grip strength (<26kg for males; <18kg for females) or slow gait speed (<0.8m/s) amongst participants who were asymptomatic on FRAIL. Physical performance in flexibility, grip and lower limb strength, endurance, balance, and Short Physical Performance Battery were measured at 3 time-points: baseline, 3-month from recruitment (without intervention), and immediate post-intervention. Repeated measures mixed model analysis was performed to compare physical performance measures across the 3 time-points. Results 94 pre-frail participants were eligible for intervention, of whom 59 (mean age = 70.9±7.2 years) were ready for the post-intervention review. 21 (35.6%) transitioned to robust phenotype while 32 (54.2%) remained as pre-frail. Significant improvement post-intervention was observed in lower limb strength and power, evident on reduction in time taken for 5 sit-to-stand repetitions (0.46±0.20s, p=0.03). There was no significant change to the other physical performance measures examined. Conclusion We observed reversibility of pre-frailty, and the benefit of multi-component intervention in improving physical performance of pre-frail older adults. The findings in this non-controlled study will need to be corroborated with future controlled trials.
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Affiliation(s)
- W L Low
- Duke-NUS Medical School, Singapore
| | | | | | - J C Y Ho
- Research Office, Sengkang General Hospital, Singapore
| | - A Latib
- Health Services Research and Evaluation, SingHealth, Singapore
| | - E L Tay
- Physiotherapy Department, Sengkang General Hospital, Singapore
| | - S M Mah
- Physiotherapy Department, Sengkang General Hospital, Singapore
| | - H N Chan
- Department of Dietetics, Sengkang General Hospital, Singapore
| | - Y S Ng
- Department of General Medicine, Sengkang General Hospital, Singapore
| | - L Tay
- Department of General Medicine, Sengkang General Hospital, Singapore
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Lim YJ, Ng YS, Sultana R, Tay EL, Mah SM, Chan CHN, Latib AB, Abu-Bakar HM, Ho JCY, Kwek THH, Tay L. Frailty Assessment in Community-Dwelling Older Adults: A Comparison of 3 Diagnostic Instruments. J Nutr Health Aging 2020; 24:582-590. [PMID: 32510110 DOI: 10.1007/s12603-020-1396-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
OBJECTIVES Compare the diagnostic performance of FRAIL against Fried Phenotype and Frailty Index (FI), and identify clinical factors associated with pre-frailty/frailty. DESIGN Cross-sectional analysis. SETTING Community-based screenings in Senior Activity Centres, Residents' Corners and Community Centres in northeast Singapore. PARTICIPANTS 517 community dwelling participants aged >55 years and ambulant independently (with/ without walking aids) were included in this study. Residents of sheltered or nursing homes, and seniors unable to ambulate at least four meters independently were excluded. MEASUREMENTS The multidomain geriatric screen included assessments for social vulnerability, mood, cognition, sarcopenia and nutrition. Participants completed a battery of physical fitness tests for grip strength, gait speed, lower limb strength and power, flexibility, balance and endurance, with overall physical performance represented by Short Physical Performance Battery (SPPB). Frailty status was assigned on FRAIL, Fried and 35-item FI. RESULTS Prevalence of frailty was 1.3% (FRAIL) to 3.1% (FI). Pre-frailty prevalence ranged from 17.0% (FRAIL) to 51.2% (FI). FRAIL demonstrated poor agreement with FI (kappa=0.171, p<0.0001), and Fried (kappa=0.194, p<0.0001). A lower FRAIL cut-off ≥1 yielded significantly improved AUC of 0.70 (95%CI 0.55 to 0.86, p=0.009) against Fried, and 0.71 (95%CI 0.55 to 0.86, p=0.008) against FI. All 3 frailty measures were diagnostic of impaired physical performance on SPPB, with AUCs ranging from 0.69 on FRAIL to 0.77 on Fried (all p values <0.01). Prevalence of low socio-economic status, depression, malnutrition and sarcopenia increased significantly, while fitness measures of gait speed, balance, and endurance declined progressively across robust, pre-frail and frail on all 3 frailty instruments (p <0.05). CONCLUSIONS Our results suggest that different frailty instruments may capture over-lapping albeit distinct constructs, and thus may not be used interchangeably. FRAIL has utility for quick screening, and any positive response should trigger further assessment, including evaluation for depression, social vulnerability and malnutrition.
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Affiliation(s)
- Y J Lim
- Laura Tay, Sengkang General Hospital, Singapore,
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Abstract
Processing of the pre-microRNA (pre-miRNA) through Dicer1 generates a miRNA duplex, consisting of a miRNA and miRNA* strand (also termed guide strand and passenger strand, respectively). Despite the general consensus that miRNA*s have no regulatory activity, recent publications have provided evidence that the abundance, possible function, and physiological relevance of miRNA*s have been underestimated. This review provides an account of our current understanding of miRNA* origination and activity, mounting evidence for their unique functions and regulatory mechanisms, and examples of specific miRNA*s from the literature.
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Affiliation(s)
- S M Mah
- Terry Fox Laboratory, BC Cancer Agency, Vancouver, BC, Canada, V5Z 1L3
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Mah SM, Durham JS, Anderson DW, Irvine RA, Chow C, Fache JS, Weir I, Coupland DB. Functional results in oral cavity reconstruction using reinnervated versus nonreinnervated free fasciocutaneous grafts. J Otolaryngol 1996; 25:75-81. [PMID: 8683656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Recent advances in free-tissue transfer have given the otolaryngologist--head and neck surgeon a number of reliable options for reconstruction of the oral cavity following ablative procedures. One recent modification has been the transfer of free reinnervated fasciocutaneous grafts in the hope of enhancing oral rehabilitation following surgery. To assess the efficacy of this modification, a protocol was established to retrospectively evaluate patients that received either reinnervated or non-reinnervated free-tissue transfers. Factors including site, surgical resection, type of tissue transfer, and follow-up period were controlled. Evaluation of free-graft sensory return and quality of life was carried out through physical examination and patient interview. Speech assessment was carried out using standardized tests of intelligibility administered by a speech pathologist. Swallowing assessment was carried out with videocinefluoroscopic and scintigraphic techniques, and the oropharyngeal swallow efficiency was calculated. Sensory return in the reinnervate free grafts was superior; however, there was not statistical difference between groups in the speech and swallowing tests. Quality of life was judged to be good in both groups. Sensory return and functional outcome in intraoral reconstruction after tumour ablation was reviewed and discussed
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Affiliation(s)
- S M Mah
- Division of Otolaryngology, Vancouver Hospital and Health Sciences Centre, British Columbia
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