The likelihood of participation in clinical trials can be measured: the Clinical Research Involvement Scales

Abstract

Objective: We developed the Clinical Research Involvement Scales (CRIS) to assess the willingness to participate in a clinical trial.

Study design and setting: Diverse populations (N=919) aged 18 years or older from Atlanta, Georgia, were included in comprehensive testing of the 41-item CRIS instrument. The formative phase focused on item content for the new measures (n=54). Questionnaires from potential vaccine trial participants (n=865), collected at multiple time points, resulted in the evaluation of scale reliability and validity (i.e., attitudes, behavioral and normative beliefs, perceived social support for clinical research participation, social norm compliance, perceptions of the clinical research organization, and perceived relevance of the research endeavor).

Results: Qualitative testing revealed adequate comprehension and content validity of the initial item set. The subjective norms domain (n=3) initially exhibited poor internal consistency in pilot testing (Cronbach's alpha=0.525); yet, rewording of the items resulted in consistently stable measurement improvement (Cronbach's alpha=0.850). Each of the CRIS subscales demonstrated extremely high reliability, ranging from 0.734 to 0.918. Confirmatory factor analysis verified item-factor relationships and determined construct and convergent validity (root mean square error of approximation=0.068; comparative fit index=0.835).

Conclusions: CRIS is a reliable instrument for measuring community attitudes toward participation in biomedical research studies. Results of this study support the use of these scales to recruit diverse populations to clinical trials.