Development and validation of a frailty index in the Longitudinal Aging Study Amsterdam
Bibliographic record
Abstract
BACKGROUND: Frailty is a state of increased vulnerability to adverse outcomes. The frailty index (FI), defined by the deficit accumulation approach, is a sensitive instrument to measure levels of frailty, and therefore important for longitudinal studies of aging. AIMS: To develop an FI in the Longitudinal Aging Study Amsterdam (LASA), and to examine the predictive validity of this FI for 19-year mortality. METHODS: LASA is an ongoing study among Dutch older adults, based on a nationally representative sample. A 32-item FI (LASA-FI) was developed at the second LASA measurement wave (1995-1996) among 2218 people aged 57-88 years. An FI score between 0 and 1 was calculated for each individual. The LASA-FI included health deficits from the physical, mental and cognitive domain and can be constructed for most LASA measurement waves. Associations with 19-year mortality were assessed using Kaplan-Meier curves and Cox proportional hazards models. RESULTS: The mean LASA-FI score was 0.19 (SD = 0.12), with a 99% upper limit of 0.53. Scores were higher in women than men (women = 0.20, SD = 0.13 vs. men = 0.17, SD = 0.11, p < 0.001). The average age-related increase in the log-transformed LASA-FI score was 3.5% per year. In a model adjusted for age and sex, the FI score was significantly associated with 19-year all-cause mortality (HR per 0.01 = 1.03, 95% CI 1.03-1.04, p < 0.001). DISCUSSION/CONCLUSIONS: The key characteristics of the LASA-FI were in line with findings from previous FI studies in population-based samples of older people. The LASA-FI score was associated with mortality and may serve as an internal and external reference value.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.003 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".