The Elderly Functional Index (ELFI), a patient-reported outcome measure of functional status in patients with cancer: a multicentre, prospective validation study
Bibliographic record
Abstract
BACKGROUND: Functional assessment of patients with cancer can be challenging and is often undertaken by the clinician with minimal direct input from the patient. We developed and aimed to validate the Elderly Functional Index (ELFI), a composite measure of self-reported functioning in older patients with cancer. METHODS: In this multicentre, prospective validation study, we validated ELFI in adult patients attending five oncology practices in Australia. ELFI is a 12-item composite measure of self-reported functioning derived from functional scales of the European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire (QLQ): physical, role, and social functioning, and mobility. For evaluation of validity and internal consistency, participants self-completed ELFI, cognitive functioning and emotional functioning scales of the EORTC QLQ Core-30, Eastern Cooperative Oncology Group Performance Status (ECOG-PS), instrumental activities of daily living (IADL), and Clinical Frailty Scale (CFS) at baseline. For evaluation of test-retest reliability, participants opted in to repeat ELFI, cognitive functioning scale, emotional functioning scale, and ECOG-PS 1 week later, as well as completing the Global Rating of Change. Internal consistency reliability was assessed using Cronbach's α and test-retest reliability was assessed using intraclass correlation (ICC). We assessed ELFI for convergent and discriminant validity (Spearman's r), known-groups validity (ANOVA), and structural validity (exploratory factor analysis). FINDINGS: Between May 6 and Dec 15, 2017, 877 participants with cancer returned a total of 869 baseline questionnaires and 482 retest questionnaires. 621 (71%) participants (192 [31%] aged ≥70 years) were included in evaluations of validity and internal consistency and 278 (32%) participants (106 [38%] aged ≥70 years) in evaluations of test-retest reliability. ELFI demonstrated excellent internal consistency reliability (Cronbach's α=0·93 for all participants; p<0·0001) and test-retest reliability (overall ICC 0·90, 95% CI 0·87-0·92; p<0·0001). Hypotheses regarding convergent and discriminant validity were confirmed, with all item-scale correlations exceeding 0·40 except for one on the physical functioning scale. ELFI was better than its component scales and other function measures at differentiating between groups with different function and frailty scores (known-groups validity). Exploratory factor analysis provided empirical support to the structural validity of ELFI. Strong correlation was observed between ELFI and its component scales (r ranging from 0·67 to 0·79), ECOG-PS (-0·79), IADL (0·69), and CFS (-0·73). INTERPRETATION: ELFI is a validated and simple person-reported multidimensional measure of functional status, which captures broad dimensions of functioning. ELFI has enhanced statistical efficiency relative to its components, reducing the sample size required to detect a given effect. ELFI could be used as a clinical trial endpoint to assess functional domains of health-related quality of life. FUNDING: National Health and Medical Research Council, Monash University, Eastern Health.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.008 | 0.010 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 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 source (direct Gemma or distilled Codex), 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".