Dataset Information

Use of item response theory to investigate disability-related questions in the National Health and Nutrition Examination Survey.

ABSTRACT:

Objectives

Accurately measuring disability is critical toward policy development, economic analyses, and determining individual-level effects of health interventions. Nationally representative population surveys such as the National Health and Nutrition Examination Survey provide key opportunities to measure disability constructs such as activity limitations. However, only very limited work has previously evaluated the item response properties of questions pertaining to limitations in National Health and Nutrition Examination Survey.

Methods

This was a cross-sectional study. We included participants ⩾20 years old for the 2013-2018 National Health and Nutrition Examination Survey cycles. Activity limitations, and a smaller number of body function impairments or participation restrictions, were determined from interview questions. We performed item response theory models (a two-parameter logistic and a graded response model) to characterize discriminating information along the latent continuum of activity limitation.

Results

We included 17,057 participants. Although each particular limitation was somewhat rare (maximally 13%), 7214 (38%) responded having at least one limitation. We found a high amount of discriminating information at 1-2 standard deviations above average limitation, though essentially zero discrimination below that range. Items had substantial overlap in the range at which they provided information distinguishing individuals. The ordinal graded response model including 20 limitations provided greater information than the dichotomous two-parameter logistic model, though further omitting items from the graded response model led to loss of information.

Conclusion

National Health and Nutrition Examination Survey disability-related questions, mostly specifically activity limitations, provided a high degree of information distinguishing individuals with higher than average limitations on the latent continuum, but essentially zero resolution to distinguish individuals with low or average limitations. Future work may focus on developing items which better distinguish individuals at the "lower" end of the limitation spectrum.

SUBMITTER: Terman SW

PROVIDER: S-EPMC8107668 | biostudies-literature |

REPOSITORIES: biostudies-literature

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Project description:BackgroundAssessment of cognitive competence is a major element of the internship qualification exam in undergraduate medical education in Ethiopia. Assessing the quality of exam items can help to improve the validity of assessments and assure stakeholders about the accuracy of the go/no decision to the internship. However, we know little about the quality of exam items utilized to ascertain fitness to join the medical internship. Therefore, this study aimed to analyze the quality of multiple-choice questions (MCQs) of the qualification exam administered to final-year medical students at Debre Tabor University (DTU), Ethiopia.MethodsA psychometric study was conducted to assess the qualities of 120 randomly selected MCQs and 407 distractors. Item characteristics were estimated using the item response theory (IRT) model. T-test, one-way ANOVA, and chi-square tests were run to analyze the univariate association between factors. Pearson's correlation test was done to determine the predictive validity of the qualification examination.ResultOverall, 16, 51, and 33% of the items had high, moderate, and low distractor efficiency, respectively. About two-thirds (65.8%) of the items had two or more functioning distractors and 42.5% exhibited a desirable difficulty index. However, 77.8% of items administered in the qualification examination had a negative or poor discrimination index. Four and five option items didn't show significant differences in psychometric qualities. The qualification exam showed a positive predictive value of success in the national licensing examination (Pearson's correlation coefficient = 0.5).ConclusionsThe psychometric properties of the medical qualification exam were inadequate for making valid decisions. Five option MCQs were not better than four options in terms of psychometric qualities. The qualification examination had a positive predictive validity of future performance. High-stakes examination items must be properly created and reviewed before being administered.