Dataset Information

The impact of stratification by implausible energy reporting status on estimates of diet-health relationships.

ABSTRACT: The food frequency questionnaire (FFQ) is known to be prone to measurement error. Researchers have suggested excluding implausible energy reporters (IERs) of FFQ total energy when examining the relationship between a health outcome and FFQ-reported intake to obtain less biased estimates of the effect of the error-prone measure of exposure; however, the statistical properties of stratifying by IER status have not been studied. Under certain assumptions, including nondifferential error, we show that when stratifying by IER status, the attenuation of the estimated relative risk in the stratified models will be either greater or less in both strata (implausible and plausible reporters) than for the nonstratified model, contrary to the common belief that the attenuation will be less among plausible reporters and greater among IERs. Whether there is more or less attenuation depends on the pairwise correlations between true exposure, observed exposure, and the stratification variable. Thus exclusion of IERs is inadvisable but stratification by IER status can sometimes help. We also address the case of differential error. Examples from the Observing Protein and Energy Nutrition Study and simulations illustrate these results.

SUBMITTER: Tooze JA

PROVIDER: S-EPMC5093067 | biostudies-literature | 2016 Nov

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

The impact of stratification by implausible energy reporting status on estimates of diet-health relationships.

Tooze Janet A JA Freedman Laurence S LS Carroll Raymond J RJ Midthune Douglas D Kipnis Victor V

Biometrical journal. Biometrische Zeitschrift 20160823 6

The food frequency questionnaire (FFQ) is known to be prone to measurement error. Researchers have suggested excluding implausible energy reporters (IERs) of FFQ total energy when examining the relationship between a health outcome and FFQ-reported intake to obtain less biased estimates of the effect of the error-prone measure of exposure; however, the statistical properties of stratifying by IER status have not been studied. Under certain assumptions, including nondifferential error, we show th ...[more]

PMID: 27550787

Similar Datasets

Project description:ObjectivePrevious studies have demonstrated that weight loss has been shown to improve pain in weight-bearing joints, and more recent studies suggest that weight loss may be accompanied by improvements in pain in non-weight-bearing regions. In previous work, we demonstrated that these symptoms improve substantially in patients with obesity undergoing 12 weeks of a very low-energy diet (VLED) restricted to 800 kcal as part of a weight-loss program. Preclinical models also have shown analgesic effects of calorie restriction. The purpose of the current observational study was to determine the time course and trajectory of improvement in pain and other symptoms, especially during the early phase of a VLED intervention, prior to major weight loss.MethodsParticipants were 195 individuals with obesity who had elevated levels of pain and associated symptoms at baseline (score of ≥4 on Fibromyalgia Survey Criteria) and completed a minimum of 3 weeks of a VLED intervention. The primary outcome was improvement in Fibromyalgia Survey Criteria at week 3. In secondary analyses, we created groups of those showing little/no improvement, moderate improvement, and high improvement (little/no improvement mean, 2.21; SD, 1.02; moderate improvement mean, 2.25; SD, 0.81; high improvement mean, 2.42; SD, 0.95; F2,189 = 1.01, P = 0.37), then compared baseline characteristics.ResultsA large proportion of study participants (72%) experienced symptom reductions of 30% or greater by week 3, but there were no differences in the amount of weight lost at this time point. Those who showed little or no improvement (less than 30%) had a higher body mass index at baseline and were more likely to report a diagnosis of depression (both P < 0.05).ConclusionThis degree of improvement after 3 weeks of a VLED is encouraging. These findings help establish the temporal pattern of symptom improvement associated with caloric restriction and suggest that the palliative effects of this diet are at least partly due to the diet itself, rather than the weight loss that ensues.

Project description:ImportanceA primary objective in managing atrial fibrillation (AF) is to optimize patients' health status, which can be done only if physicians accurately quantify the outcomes associated with AF in patients' lives.ObjectiveTo explore physicians' estimation of the health status of patients with AF and its association with subsequent care and outcomes.Design, setting, and participantsA multicenter, prospective cohort study was conducted in 2 outpatient practices in Tokyo, Japan. Participants included patients with newly diagnosed AF or those referred for initial treatment of AF at outpatient practices and treating physicians from November 8, 2018, to April 1, 2020. Data analysis was performed from December 22, 2022, to July 7, 2023.ExposuresParticipating patients completed the Atrial Fibrillation Effect on Quality-of-Life (AFEQT) questionnaire, a 20-item tool covering 4 domains with a 7-point Likert scale; 3 domains (symptoms, daily activities, and treatment concerns) were used in this study. Blinded to patients' responses, treating physicians answered a 3-item questionnaire quantifying each patient's AFEQT domain with a single item. Patients' mean Likert scale responses within each AFEQT domain were subtracted from the physicians' assessments so that higher scores (≥0.5 points) indicate physician underestimation, while lower scores (≤0.5 points) indicate physician overestimation of the health status of patients with AF.Main outcomes and measuresThe independent association of physician-patient concordance with treatment escalation (alteration or initiation of antiarrhythmic drugs, cardioversion, or catheter ablation) and 1-year adjusted changes in AFEQT scores.ResultsAmong 330 patients (238 [72.1%] men; mean [SD] age, 67.9 [11.9] years; 163 [49.4%] with paroxysmal AF), physicians correctly estimated health status in 112 patients (33.9%), underestimated it in 42 patients (12.7%), and overestimated it in 176 patients (53.3%). Treatment escalation occurred in 63.6% of patients whose health status was correctly estimated, 47.6% of those whose health status was underestimated, and 66.3% of patients whose health status was overestimated. After multivariable adjustment, underestimation of health status was independently associated with less treatment escalation (adjusted odds ratio, 0.43; 95% CI, 0.20-0.90) and less frequent AFEQT overall summary score improvement at 1 year (underestimated, 2.5 [95% CI, -1.6 to 6.7] vs correctly and overestimated health status, 8.4 [95% CI, 7.0-9.9] points; P = .01).Conclusions and relevanceIn this cohort study, physician underestimation of the health status of patients with AF was common and associated with less aggressive treatment and less health status improvement at 1 year.

Dataset Information

The impact of stratification by implausible energy reporting status on estimates of diet-health relationships.

Publications

The impact of stratification by implausible energy reporting status on estimates of diet-health relationships.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets