Evaluation of written medicine information: validation of the Consumer Information Rating Form

The Consumer Information Rating Form (CIRF) was developed as a direct method for measuring consumers' perceptions of the comprehensibility, utility, and design quality of written medicine information. The validity and reliability of the CIRF were evaluated in a small convenience consumer sample in the US. Its validity and reliability have yet to be established in a larger sample of consumers who are on chronic therapy in different settings.

To determine the validity and reliability of the CIRF in Australian consumers on chronic therapy.

Consumers read and subsequently evaluated a Consumer Medicine Information (CMI) leaflet for one of their own medications, using an adapted version of the CIRF. The construct validity and internal reliability of the adapted version of the CIRF were tested using principal components analysis (PCA) and Cronbach's alpha, respectively.

The adapted CIRF was completed by 282 consumers (aged 19-90 y; median 66; interquartile range 53-75 y; 60.3% females). Most respondents spoke primarily English at home (85.5%), had attained at least secondary education (84%), and had adequate health literacy levels (88.2%). Consumers rated CMI easy to read, understand, and navigate, but less easy to remember and keep. Most also found it to be useful and to contain the right amount of information. The design aspects also scored favorably, although CMI did score relatively poorly in terms of its attractiveness and tone (whether alarming or not). PCA yielded 3 factors (explaining 59.3% of the total variance) identical to those in the original CIRF: comprehensibility, utility, and design quality. All factors demonstrated good reliability (Cronbach's alpha 0.74, 0.92, and 0.75, respectively).

The CIRF appears to be a robust instrument for assessing consumers' perceptions of written medicine information. However, validity always needs to be reestablished when using a previously validated measure in a different population.