Study Finds Lack of Health Literacy Does Not Increase Mortality Risk in COPD

A recent study looking at the association between low health literacy and mortality found that, compared with the general population and people with other chronic conditions, low health literacy did not increase mortality risks in individuals with chronic obstructive pulmonary disease (COPD).

The Danish investigators said it may be possible the nature of COPD outweighs the potential impact of health literacy on mortality in patients.

“Our study serves as a reminder to healthcare organizations to consider the health literacy responsiveness of their services in relation to diverse health literacy challenges and needs,” wrote the investigators in their report published in the International Journal of Environmental Research and Public Health.

Health literacy was defined by the investigators as the individual competences and situational resources needed for people to easily understand and use the information and services provided by health care providers to help them make decisions on their health.

In previous research, low health literacy has been shown to be associated with adverse health outcomes, including premature death. Older research has limitations in that most are conducted with US patients or solely focused on health-related reading and numeracy ability rather than other elements of health literacy, such as ease of access and comprehension of information.

Because of the differences in health care systems between the United States and Europe, studies conducted in the United States can’t be generalized to a Western European setting.

Investigators evaluated 2 aspects of health literacy, the ability to understand health-related information and the ability to actively engage with providers, by distributing a questionnaire to population-based sample of Danish participants. Some participants did not have any chronic illnesses and represented the general population. Others had chronic conditions, such as COPD, cardiovascular disease (CVD), diabetes, or a mental illness. Participants were given a follow-up after 6 years to assess mortality risks.

Out of the 46,354 people over age 24 that were invited to participate in the study, 29,473 (63%) individuals answered the questionnaire. A total of 1214 (3.9%) participants had COPD, 2389 (7.5%) had a diagnosis for CVD, 1685 (5.5%) had diabetes, and 1577 (6.4%) reported having a mental illness.

The mean age of the participants was 52.1[16.3] years, with the lowest mean age being among people with mental health illness (48.1 years) and ranging from 63.6 years to 66.1 years in people with the other 3 chronic conditions.

Compared with the general population, difficulties in understanding health-related information or trouble engaging with health care providers had a higher association with participants with all 4 chronic conditions studied.

Overall, investigators detected a higher risk of mortality among participants with low health literacy compared to those who did not have this difficulty (hazard ratio [HR], 1.38; 95% CI, 1.11–1.73).

The mortality risk for individuals with low health literacy and COPD (HR, 0.71; 95% CI, 0.41–1.21) was lower than the CVD group (HR, 1.47; 95% CI 1.01–2.14) , the diabetes group (HR 1.91; 95% CI, 1.13–3.22), the mental illness group (HR 2.18; 95% CI, 1.25–3.81), and the general population (HR, 1.35; 95% CI; 1.10–1.67) after adjusting for sociodemographic factors, multimorbidity, and health behavior.

By the time of the 6-year follow-up, the percentage was higher among the other 3 conditions, with 21.3% of participants with CVD, 26.3% of participants with COPD, and 18.7% of participants with diabetes having died. In contrast, death among the general population and participants with mental illness did not significantly differ, occurring in 6.7% of the general population and 7.2% of those with mental illness.

Investigators proposed that although patients with COPD in Denmark may be likely to have difficult relationships with health care providers because of the guilt and stigma associated with COPD caused by smoking, the nature of the disease means that engagement with health systems is frequent and thus, allows for patients to receive a lot of information and support.

“It is likely that the pathological process and physical deterioration are the strongest determinants of prognosis of COPD regardless of the health literacy level,” wrote the investigators.

Reference

Friis K, Aaby A, Lasgaard M, Pedersen MH, Osborne RH, Maindal HT. Low health literacy and mortality in individuals with cardiovascular disease, chronic obstructive pulmonary disease, diabetes, and mental illness: A 6-year population-based follow-up study. Int. J. Environ. Res. Public Health. Published online December 15, 2020. doi: 10.3390/ijerph17249399