Measuring self-efficacy in MS: A newly developed scale and shortforms.
|Title||Measuring self-efficacy in MS: A newly developed scale and shortforms.|
|Publication Type||Journal Article|
|Authors||Amtmann D, Bamer AM, Brockway J A, Noonan VK, Cook KF, Johnson KL|
|Journal||International Journal of MS Care|
|Management of activities of daily living in MS|
Background: Managing one’s health can be demanding for people with multiple sclerosis (MS) given the complexities of the disease and array of symptoms experienced. Those who develop confidence in disease management often have better health outcomes and quality of life. Few scales exist to measure self-efficacy (SE) in rehabilitation populations. Objectives: The objective of our study was to develop an SE scale to measure an individual’s confidence in his or her ability to manage MS and its impact on emotional well-being and quality of life. Methods: Items were developed to assess respondents’ confidence to meet commonly reported challenges in MS. Data were collected via surveys of communitydwelling individuals with MS (N = 473) enrolled in an ongoing longitudinal survey study. Items were administered three times within 12 months to the same sample. Statistical analyses were conducted and items were modified based on results after each administration. Dimensionality was examined using factor analyses. Item Response Theory (IRT) analyses were used to examine psychometric properties of the scale. Short forms were created by balancing item content and IRT parameters (difficulty and discrimination). Scoring tables were created for the full scale and short forms. Results: The final full scale consists of 18 scored items and 2 additional unscored items for clinical purposes only. Factor analytic results indicated that the scale is sufficiently unidimensional to meet the assumptions of IRT. All 18 final items fit the Graded Response Model. A six-item and a ten-item short form correlated >0.96 with the full 18-item scale. Individuals with greater SE had statistically significantly (all P < .001) greater SF8 physical and mental scores and less pain interference, fatigue, depression, anxiety, perceived stress, interference with participation in valued activities, and sleep problems. Conclusions: The new SE scale is psychometrically sound and includes items relevant for measuring SE of people with MS.