| Author: | Zhao, Jinlong |
| Title: | Developing and validating a psychological frailty index for older individuals : a cross-sectional study based on the China health and retirement longitudinal study |
| Advisors: | Liu, Yat-wa Justina (SN) |
| Degree: | DHSc |
| Year: | 2025 |
| Subject: | Older people -- Psychology Older people -- China Older people -- Psychological testing Hong Kong Polytechnic University -- Dissertations |
| Department: | Faculty of Health and Social Sciences |
| Pages: | xiv, 173 pages : color illustrations |
| Language: | English |
| Abstract: | Background: Frailty is a multifaceted concept involving at least physical, cognitive, and psychological domains. However, psychological frailty has not attracted as much research attention as other domains of frailty. It can be operationally defined as the coexistence of physical vulnerability and various psychological problems. As an evolving concept, psychological frailty still lacks a standardized measure. Consequently, the development of a measure for psychological frailty is crucial in contemporary research. Aim and objectives: This thesis aimed to establish and validate a novel measure of psychological frailty following the cumulative deficit model. Accordingly, the thesis was divided into four stages, each with a specific objective: (a) Develop and initially validate a Psychological Frailty Index (PFI) (Stage 1); (b) Describe its score profile and associated factors (Stage 2); (c) Evaluate its associations with adverse health outcomes: lower life expectancy, outpatient treatments, and hospitalization (Stage 3); (d) Examine its associations with multimorbidity and 14 chronic diseases (Stage 4). Methods: The China Health and Retirement Longitudinal Study (CHARLS) follow-up wave 4 was used. Eligible participants (aged 65 years and older; responded without missing values on related variables; responded without "do not know," "refuse to answer," or "not assessed") extracted from Wave 4 (n=3,934 out of 19,817) were analyzed. Various socio-demographic, lifestyle, psychological, and other variables were utilized. The construction of the PFI in a random sample (n=1,290) followed standardized procedures of previous studies. The PFI's potential structure was determined by principal component analysis and validated by confirmatory factor analysis. Population tertiles determined cut-off values for identifying robust, pre-psychological frailty, and psychological frailty. A high cut-off value denotes a more severe degree of psychological frailty. In the full sample (n=3,934), the receiver operating characteristic (ROC) curve evaluated its discriminative abilities, and the quantile regression assessed its associated factors. Logistic regressions examined associations between the PFI, adverse health outcomes, multimorbidity, and diseases. Results: The factor analysis on 15-item PFI extracted four factors for psychological frailty (psychological distress, cognitive decline, physical vulnerability, and memory decline). The four-factor structure was validated by confirmatory factor analysis (χ²/df = 2.715, comparative fit index [CFI] = 0.989, root mean square error of approximation [RMSEA] = 0.021). The PFI had satisfactory internal consistency (Cronbach's alpha = 0.764) and criterion validity (rho = 0.806) with the Tilburg Frailty Indicator. Concerning its discriminative abilities, the area under the ROC curve (95% confidence intervals [CI]) was 0.846 (0.828–0.864) for self-rated depression. At distinct quantiles (0.10, 0.33, 0.50, 0.67, or 0.90), older age, female gender, physical disability, and multimorbidity were positively associated with psychological frailty. Better financial status, higher education, and frequent physical activities were inversely related to psychological frailty. Compared to robust participants, those with psychological frailty had a lower life expectancy (odds ratio: 3.16, 95% CI: 2.61–3.83), increased outpatient treatments (1.39, 1.09–1.78), higher likelihood of hospitalization (1.75, 1.38–2.22), higher odds of memory-related diseases (4.49, 2.89–7.17), increased odds of psychiatric problems (4.38, 2.17–9.67), and higher odds of asthma (3.31, 2.36–4.69). Conclusions: The PFI has demonstrated satisfactory reliability and validity as a tool for identifying psychological frailty. Its associations with adverse health outcomes and diseases have been validated, underscoring the PFI's applicability in exploring their relationships. |
| Rights: | All rights reserved |
| Access: | restricted access |
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| File | Description | Size | Format | |
|---|---|---|---|---|
| 8639.pdf | For All Users (off-campus access for PolyU Staff & Students only) | 10.22 MB | Adobe PDF | View/Open |
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