Sustained effect on diet quality of a self-care intervention to reduce cardiovascular disease risk among informal rural caregivers of people with chronic illnesses: does health literacy matter?

Background/Introduction Rural caregivers of those with chronic illnesses have higher cardiovascular disease (CVD) risk than urban caregivers. Diet is a major lifestyle factor that contributes to CVD risk. However, interventions are often not constructed with health literacy in mind. We previously found a moderation effect of health literacy on short-term (4-month) diet quality from a self-care intervention to reduce cardiovascular disease risk (RICHH) among rural caregivers. The RICHH intervention was designed to be equally effective in caregivers with marginal or adequate health literacy. Purpose To compare the impact of RICHH intervention on 12-month diet quality in rural caregivers with marginal versus adequate health literacy. Methods A total of 296 rural caregivers (54.5±13.7 years old, 76% female) of individuals with chronic illnesses participated. The newest vital sign (NVS) and Healthy Eating Index-2015 (HEI-2015) were used to determine health literacy and diet quality, respectively. The NVS was dichotomized using a cutoff score of 4. The HEI-2015 was computed based on food frequency questionnaires at baseline, 4-month, and 12-month. The RICHH intervention was delivered using video conferencing technology by nurse interventionists once a week for 12 weeks followed by bi-weekly and monthly booster sessions. A piecewise linear mixed-effect model, controlling for age, education, smoking status, and perceived stress, was used to evaluate the impact of the intervention on diet quality between the two health literacy groups. Results There was a significant difference in improvement in the HEI-2015 total scores at 4 months between control and intervention in the marginal health literacy group (beta estimate = 1.56, SE=0.74, P=0.039) but not in the adequate health literacy group (beta estimate = 0.27, SE=0.38, P=0.475). The improvement in the marginal health literacy group was sustained at 12-months (beta estimate = 8.12, SE=3.57, P=0.022). Conclusions The results of our study indicate that an intervention designed to address health literacy is effective in producing a sustained improvement in diet quality to reduce CVD risk in rural caregivers with marginal health literacy. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): National Institutes of Health National Institute of Nursing Research