Abstracts

Objective: At the end of this activity, the participants should be able to discuss the development and testing of a scale to measure stigma among adults with epilepsy.
The purpose of the present study, part of a larger study of self-management in people with epilepsy, was to examine the reliability and validity of a 10-item self-report instrument to measure perceived stigma among adults with epilepsy. The scale was originally designed for parents of children with epilepsy and revised to measure perceived stigma among adults with epilepsy.
METHODS: Participants for the study were recruited from two epilepsy centers[ndash]one in Atlanta and one in Boston, and a neurology clinic in Atlanta. Participants completed 3 assessments each 3 months apart. At each assessment, they completed the stigma scale along with psychosocial measures and measures of self-management and personal characteristics. A total of 321 adult men and women with epilepsy were enrolled in the study. The responses of the participants to the items on the stigma scale were first assessed for internal consistency and test-retest reliability. Construct validity was assessed using factor analysis and hypothesis testing. Item response theory (IRT) techniques were used to assess the adequacy of the items in measuring the full range of the construct of stigma.
RESULTS: Participants range in age from 19-75 years with a mean of 43 years; 50.5% are female and 80.4% are white. The mean age when seizures began was 22 years, and 76% of participants reported having a seizure within the past year. The results of these analyses demonstrated that the internal consistency was quite high as evidenced by a Cronbach[ssquote]s alpha coefficient of .91. The test-retest reliability coefficients for two three-month periods were .83 and .85. For a six-month period, the test-retest reliability coefficient was .77. These coefficients provide evidence for moderate to high stability. Principal component analysis yielded one factor with factor loadings ranging from .637 to .830. The stigma scale also demonstrated evidence of construct validity. As predicted, perceived stigma was negatively correlated with depression, patient satisfaction, attitudes toward treatment and seizures, medication management, social support, and self-efficacy. Participants who reported seizures within the past year, less control of their seizures, and more seizure severity expressed higher levels of stigma. And as expected, levels of perceived stigma were similar for men and women and across ethnic and age groups. A unidimensional IRT model was fit to the data. The item discrimination parameters ranged from .74 to 1.61. The threshold parameters ranged from [ndash]1.40 to -.206 for the lowest category and from 1.24 to 2.43 for the highest category.
CONCLUSIONS: The results of the study suggest that the Stigma Scale demonstrates acceptable reliability and validity for use among adults with epilepsy. The set of analyses, in particular the IRT analysis, provides useful information for the further development of the scale.
[Supported by: This research was supported by a grant from the National Institute of Nursing Research R01 NR04770]