Purpose: To evaluate the performance of a standard decision aid (DA) in an underserved population with and without a scripted, low-literacy educational supplement.
Method: We assessed understanding of a standard DA on early stage prostate cancer treatment (Informed Medical Decisions Foundation) using scripted face to face interviews of African American men recruited from three low-income clinics. To avoid interfering in decision making with an untested intervention, men age ≥ 40 without a history of prostate cancer were included. Patients viewed the DA and then participated in a low-literacy educational supplement that did not rely on the patients’ reading or math skills. The low-literacy supplement allowed patients to choose between colloquial and medical terms for genitourinary (GU) function to augment explanation of DA content. Symbols were used to explain treatment side effects using the patient’s chosen language; chance wheels, poker chips, or cards served as tangible representations of the probabilities of treatment side effects. We measured decisional conflict, understanding of treatment side effects and prevalence of side effects, after patients viewed the DA, and after they received the low-literacy supplement.
Result: A total of 62 men were interviewed; 94% were African American. Average age was 50; median annual income $9,438. Most patients (53%) had a high school degree, 24% had less than a high school education, and 6% had a college degree. Median health literacy was 7th-8thgrade measured by the Rapid Estimate of Adult Literacy in Medicine. Only 34% could calculate a simple fraction and percents. Participants generally did not understand the DA: 54% could name the cancer treatments discussed without prompting and 44% understood the icon arrays used to illustrate probabilities of treatment side effects. Comprehension of medical terms used in the DA was poor (e.g. only 15% knew the word “incontinence” and 60% understood “impotent”). Most patients preferred colloquial terms for GU function and anatomy. After participating in the low-literacy educational supplement, comprehension of treatment side effects and prevalence were improved to ≈90% or more (p<0.05); and decisional conflict decreased statistically significantly (from mean total 21.2 to 11.7).
Conclusion: DA content, including icon arrays, was poorly understood by most study patients. Comprehension of prostate cancer treatment side effects and decisional conflict was significantly improved by explicitly addressing health literacy.