Adaptation and preliminary psychometric properties of three self-stigma outcome measures for people living with dementia.

BACKGROUND

A diagnosis of dementia presents individuals with both social and psychological challenges but research on self-stigma in dementia has been largely confined to qualitative approaches due to a lack of robust outcome measures that assess change. The Stigma Impact Scale (SIS) is the most commonly used measure of self-stigma in dementia but its suitability as a tool to assess change in a UK population is unclear. Thus, the aim of this study was to identify, adapt and evaluate the acceptability and preliminary psychometric properties of self-stigma measures for people with dementia for use as measures of change.

METHOD

A 4-step sequential design of identifying, selecting, adapting and testing psychometric measures as follows: 1) identification of stigma outcome measures through reviewing anti-stigma intervention literature, 2) selection of candidate measures through quality assessment (Terwee criteria) and expert consultation, 3) adaptation for UK dementia population (Stewart and colleagues Modification Framework) 4) testing of adapted measures in people living with dementia (N=40) to establish acceptability and preliminary reproducibility (test retest), criterion (concurrent with SIS) and construct (negative convergence with Rosenberg self-esteem scale) validity.

RESULTS

Seven measures were identified from the review, but most were poor quality (Terwee range: 0-4). Three measures were selected for modification: Stigma Stress Scale; Secrecy subscale of the Stigma Coping Orientation Scale; Disclosure Related Distress Scale. Internal consistency and test-retest reliability were acceptable (.866≤α≤ .938; ICC .721-.774), except for the Stigma Stress Scale (α= .643) for which the component subscales (perceived harm, ability to cope) had stronger psychometric properties. Concurrent validity with the SIS was not established (r<.7) although there were significant correlations between total SIS and perceived harm (r=.587) and between internalized shame and secrecy (r=.488). Relationships with self-esteem were in the hypothesized direction for all scales and subscales indicating convergent validity.

CONCLUSION

Stigma scales from mental health are not readily adapted for use with people with dementia. However there is preliminary evidence for the acceptability, reliability and validity of measures of perceived harm, secrecy and stigma impact. Further conceptual and psychometric development is required.