The numeracy understanding in medicine instrument: a measure of health numeracy developed using item response theory.
The numeracy understanding in medicine instrument: a measure of health numeracy developed using item response theory.
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DOI：
10.1177/0272989x12447239
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发表时间：
2012-11
期刊：
影响因子：
--
通讯作者：
Jacobs EA
中科院分区：
文献类型：
--
作者：
Schapira MM;Walker CM;Cappaert KJ;Ganschow PS;Fletcher KE;McGinley EL;Del Pozo S;Schauer C;Tarima S;Jacobs EA
Health numeracy can be defined as the ability to understand medical information presented with numbers, tables and graphs, probability, and statistics and to use that information to communicate with one’s health care provider, take care of one’s health, and participate in medical decisions. To develop the Numeracy Understanding in Medicine Instrument (NUMi) using Item Response Theory scaling methods. A 20 item test was formed drawing from an item bank of numeracy questions. Items were calibrated using responses from 1000 participants and a 2 parameter Item Response Theory (IRT) model. Construct validity was assessed by comparing scores on the NUMi to established measures of print and numeric health literacy, mathematic achievement, and cognitive aptitude. Community and clinical populations in the Milwaukee and Chicago metropolitan areas. Twenty-nine percent of the 1000 respondents were Hispanic, 24% Non-Hispanic white, and 42% Non-Hispanic black. Forty-one percent (41%) had no more than a high school education. The mean score on the NUMi was 13.2 (SD 4.6) with a Cronbach’s alpha of 0.86. Difficulty and discrimination IRT parameters of the 20 items ranged from −1.70 to 1.45 and 0.39 to 1.98, respectively. Performance on the NUMi was strongly correlated with the WRAT-arithmetic test (0.73, p<0.001), the Lipkus expanded numeracy scale (0.69, p<0.001), the Medical Data Interpretation Test (0.75, p<0.001), and the Wonderlic Cognitive Ability Test (0.82, p<0.001). Performance was moderately correlated to the Short Test of Functional Health Literacy (0.43, p<0.001). The NUMi was found to be most discriminating among respondents with a lower than average level of health numeracy. The NUMi can be applied in research and clinical settings as a robust measure of the health numeracy construct.
