Dataset Information

Modeling individual and relative accuracy of screening tools in geriatric oncology.

ABSTRACT: Background:Classification probabilities reflect to what degree a screening test represents the true disease state and include true positive (TPF) and false positive fractions (FPF). With two tests, one can compare TPF and FPF using relative probabilities which offer advantages in terms of interpretation and statistical modeling. Our objective was to highlight how individual and relative TPF and FPF can be easily estimated and compared within a regression modeling framework. This allows the modeling of tests' accuracy while adjusting for multiple covariates, and thus provides valuable information in addition to the crude TPF and FPF. We illustrate our purpose with the G8 and VES-13 screening tests aimed at identifying elderly cancer patients in need for a comprehensive geriatric assessment (CGA). Methods:Prospective cohort with a paired design. TPF and FPF of each test, as well as relative TPF and FPF were modeled using log-linear models. Results:G8 detected patients in need for CGA better than VES-13 at the expense of misclassifying a large number of normal patients. Both tests had better TPF with older age and poorer performance status (PS), and for all cancer subtypes compared with prostate cancer. Effect of age and PS on TPF was more pronounced with VES-13. Age affected FPF, but not differentially. Conclusions:Regression modeling helps provide a thorough assessment of the accuracy of diagnostic tests and should be used more frequently. In the context of screening, we encourage the use of G8 as failing to identify patients in need of a CGA might be more problematic than over-detection. Moreover, although we identified variables associated with the sensitivity of these tests, this association was less pronounced for the G8.

SUBMITTER: Bellera CA

PROVIDER: S-EPMC5834042 | biostudies-literature | 2017 May

REPOSITORIES: biostudies-literature

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Modeling individual and relative accuracy of screening tools in geriatric oncology.

Bellera C A CA Artaud F F Rainfray M M Soubeyran P L PL Mathoulin-Pélissier S S

Annals of oncology : official journal of the European Society for Medical Oncology 20170501 5

<h4>Background</h4>Classification probabilities reflect to what degree a screening test represents the true disease state and include true positive (TPF) and false positive fractions (FPF). With two tests, one can compare TPF and FPF using relative probabilities which offer advantages in terms of interpretation and statistical modeling. Our objective was to highlight how individual and relative TPF and FPF can be easily estimated and compared within a regression modeling framework. This allows t ...[more]

PMID: 28327973

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Project description:In the study of numeracy, some hypotheses have been based on response time (RT) as a dependent variable and some on accuracy, and considerable controversy has arisen about the presence or absence of correlations between RT and accuracy, between RT or accuracy and individual differences like IQ and math ability, and between various numeracy tasks. In this article, we show that an integration of the two dependent variables is required, which we accomplish with a theory-based model of decision making. We report data from four tasks: numerosity discrimination, number discrimination, memory for two-digit numbers, and memory for three-digit numbers. Accuracy correlated across tasks, as did RTs. However, the negative correlations that might be expected between RT and accuracy were not obtained; if a subject was accurate, it did not mean that they were fast (and vice versa). When the diffusion decision-making model was applied to the data (Ratcliff, 1978), we found significant correlations across the tasks between the quality of the numeracy information (drift rate) driving the decision process and between the speed/accuracy criterion settings, suggesting that similar numeracy skills and similar speed-accuracy settings are involved in the four tasks. In the model, accuracy is related to drift rate and RT is related to speed-accuracy criteria, but drift rate and criteria are not related to each other across subjects. This provides a theoretical basis for understanding why negative correlations were not obtained between accuracy and RT. We also manipulated criteria by instructing subjects to maximize either speed or accuracy, but still found correlations between the criteria settings between and within tasks, suggesting that the settings may represent an individual trait that can be modulated but not equated across subjects. Our results demonstrate that a decision-making model may provide a way to reconcile inconsistent and sometimes contradictory results in numeracy research.

Project description:BackgroundFrailty is associated with multiple adverse outcomes in stage-5 chronic kidney disease (CKD-5) and upwards of one third of people receiving haemodialysis (HD) are frail. While many frailty screening methods are available in both uremic and non-uremic populations, their implementation in clinical settings is often challenged by time and resource constraints. In this study, we explored the diagnostic accuracy of time-efficient screening tools in people receiving HD.MethodsA convenience sample of 76 people receiving HD [mean age = 61.1 years (SD = 14), 53.9% male] from three Renal Units were recruited for this cross-sectional study. Frailty was diagnosed by means of the Fried phenotype. Physical performance-based screening tools encompassed handgrip strength, 15-ft gait speed, timed up and go (TUG), and five-repetition sit to stand (STS-5) tests. In addition, participants completed the SF-36 Health Survey, the short-form international physical activity questionnaire and the Tinetti falls efficacy scale (FES) as further frailty-related measures. Outcome measures included the area under the curve (AUC), sensitivity, specificity, positive (PPV) and negative predictive values (NPV). The diagnostic performance of screening tools in assessing fall-risk was also investigated.ResultsOverall, 36.8% of participants were classified as frail. All the examined instruments could significantly discriminate frailty status in the study population. Gait speed [AUC = 0.89 (95%CI: 0.81-0.98), sensitivity = 75%, specificity = 93%] and TUG [AUC = 0.90 (95%CI: 0.80-0.99), sensitivity = 89%, specificity = 85%] exhibited the highest diagnostic accuracy. There was a significant difference in gait speed AUC (20%, p = 0.013) between participants aged 65 years or older (n = 36) and those under 65 years of age (n = 40), with better discriminating performance in the younger sub-group. The Tinetti FES was the only instrument showing good diagnostic accuracy (AUCs≥0.80) for both frailty (sensitivity = 82%, specificity = 79%) and fall-risk (sensitivity = 82%, specificity = 71%) screening.ConclusionsThis cross-sectional study revealed that time- and cost-efficient walking performance measures can accurately be used for frailty-screening purposes in people receiving HD. While self-selected gait speed had an excellent performance in people under 65 years of age, TUG may be a more suitable screening method for elderly patients (≥65 years). The Tinetti FES may be a clinically useful test when physical testing is not achievable.

Dataset Information

Modeling individual and relative accuracy of screening tools in geriatric oncology.

Publications

Modeling individual and relative accuracy of screening tools in geriatric oncology.

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