Performance of health literacy tests among older adults with diabetes.

BACKGROUND

Knowing a patient's health literacy can help clinicians and researchers anticipate a patient's ability to understand complex health regimens and deliver better patient-centered instructions and information. Poor health literacy has been linked with lower ability to function adequately in health care systems.

OBJECTIVE

We evaluated and compared three measures of health literacy and performance among older patients with diabetes.

DESIGN

Cross-sectional study utilizing in-person interviews conducted in participants' homes.

PARTICIPANTS

A tri-ethnic sample (n = 563) of African American, American Indian, and white older adults with diabetes from eight counties in south-central North Carolina.

MAIN MEASURE

Participants completed interviews and health literacy assessments using the Short-Form Test of Functional Health Literacy in Adults (S-TOFHLA), the Rapid Estimates of Adult Literacy in Medicine Short-Form (REALM-SF), or the Newest Vital Signs (NVS). Scores for reading comprehension and numeracy were calculated.

RESULTS

Over 90% completed the S-TOFHLA numeracy and approximately 85% completed the S-TOFHLA reading and REALM-SF. Only 73% completed the NVS. The correlation of S-TOFHLA total scores with REALM-SF and NVS were 0.48 and 0.54, respectively. Age, gender, ethnic, educational and income differences in health literacy emerged for several instruments, but the pattern of results across the instruments was highly variable.

CONCLUSIONS

A large segment of older adults is unable to complete short-form assessments of health literacy. Among those who were able to complete assessments, the REALM-SF and NVS performed comparably, but their relatively low convergence with the S-TOFHLA raises questions about instrument selection when studying health literacy of older adults.