USABILITY AND EFFICACY TESTING OF A SPANISH LANGUAGE COLORECTAL CANCER SCREENING DECISION AID IN LATINOS WITH LIMITED ENGLISH PROFICIENCY

Purpose:   Limited English proficient (LEP) Latino populations have low rates of knowledge of and adherence to colorectal cancer (CRC) screening guidelines.  Few interventions have attempted to provide LEP Latinos decision support for screening. This study evaluated a new Spanish-language CRC screening decision aid (DA) for usability and efficacy.

Method:    The DA is a 14-minute, computer-based video developed based on prior studies and formative research among LEP Latinos. For usability testing, we assessed how participants cognitively processed and perceived the DA content using the Think-aloud method and Likert scales. We revised the DA based on usability testing and then conducted a separate one-group, pre/post efficacy trial in which the primary outcomes were changes in screening-related knowledge and intent. We also assessed screening self-efficacy, screening preferences, and scores on the Control Preferences (CPS) and Decisional Conflict (DCS) Scales. 

Result:    Participants (n=47 usability testing and efficacy trial combined): average age 56; female 51%; Mexican-born 57%; low-income (<$20,000/year) 75%; recruited from community (vs. clinic) population 47%.    Usability testing (n=16): Most (94%) participants required assistance to navigate the DA prototype. However, they found the DA highly acceptable: nearly all completely understood (87%), trusted (100%), and agreed with (100%) it, and found it personally important (100%) and relevant (94%).    Efficacy trial (n=31): Compared to baseline, the revised DA significantly increased participants’ knowledge regarding: the availability of multiple screening tests (3% vs. 55%, p<.001); availability of an in-home test (16% vs. 84%, p<0.001); fecal occult blood test (FOBT) frequency (3% vs. 71%, p<.001); risk of complications for colonoscopy (3% vs. 68%, p<.001); need for driver after colonoscopy (29% vs. 74%, p<.001);  and recommended screening age (55% vs. 84%, p=.01). Viewing the DA increased the proportion of participants with intent to obtain screening (65% vs. 90%, p=.02) and to discuss screening with a doctor (52% vs. 90%, p<.001).  Screening preferences were: colonoscopy 52%, FOBT 45%, unsure 3%, and no screening 0%. We did not observe important increases in proportions with self-efficacy for obtaining screening (84% vs. 98%, p=.13) or preferences (CPS) for an active decision making role (65% vs. 77%, p=0.27). Post-DA decisional conflict was low [mean DCS=13.6/100; (SD 17)]. 

Conclusion: A Spanish-language CRC screening DA was highly acceptable to LEP Latinos. The revised version was efficacious in increasing screening-related knowledge and intent.