October, 2016 - SUPPORT Summary of a systematic review | print this article | download PDF
People with low health literacy are more likely to use health services incorrectly and to have poorer health outcomes than people with high health literacy. Single strategies to improve health literacy (e.g. alternative presentations of numerical data) might improve health service utilisation and health outcomes by improving health literacy. Other mixed strategies, such as self-management, disease management, and adherence interventions, might improve healthcare utilization and health outcomes in people with low health literacy by facilitating patient/provider communication, circumventing barriers to healthcare, or improving health-related skills.
Key messages
Health literacy is ‘the extent to which individulas can obtain, process, and understand the basic health information and services they need, to make appropriate health decisions’. However, health literacy is not defined and measured consistently. Most health literacy interventions (including most of the studies of “single strategies” included in this review) primarily focus on functional skills such as reading, writing and numeracy; and do not include critical or social skills. “Mixed strategies” that aim to improve the use of healthcare and health outcomes in people with low health literacy, may not aim to improve health literacy at all (including most of the studies of mixed strategies in this review).
Review objectives: To assess the effects of health literacy interventions on health services utilisation and health outcomes | ||
Type of | What the review authors searched for | What the review authors found |
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Study designs & interventions | Randomised trials, cluster-randomised trials, quasi-experimental studies, cohort studies,before-after studies,cross-sectional studies All interventions specifically designed to mitigate the effects of low health literacy by improving the use of healthcare services or health outcomes in low health literacy or low numeracy individuals |
42 intervention studies, including randomised trials (27),cluster-randomised trials (2), quasi-experimental pre-post studies (10),and quasi experimental post only studies (3).The interventions included: alternative document design (2 studies), alternative numerical presentations (3), additive or alternative pictorial representations (8), alternative media (4), combinations of alternative readability and document design (7),physician notification on patients’ literacy status (1), intensive self-management (3), educational interventions (1), and intensive disease management programs (2). |
Participants |
People of all ages, including different ethnicities and cultural groups |
People of all ages, whites, blacks, Hispanics, different ethnicities and cultural groups |
Settings | All settings |
Inpatient or outpatient settings in healthcare systems and institutions, various community based settings or homes. Only one of the studies was conducted in a low-income country. |
Outcomes | Use of healthcare services such as emergency room visits, office visits, hospitalizations and preven-tion Health outcomes such as disease, disease severity, quality of life and death. |
For single strategies (21 studies): physician use of effective communication (1), comprehension (14), knowledge (3), accuracy (3), self-efficacy (1), intent (1),use of healthcare (6), and health outcomes (10) |
Date of most recent search: May 2010. | ||
Limitations: This is a well-conducted systematic review with only minor limitations. |
Berkman ND, Sheridan SL, Donahue KE, et al. Health literacy interventions and outcomes: an updated systematic review. Evid Rep Technol Assess 2011; (199):1941.
The review included 81 studies (91 articles) that reported on the relationship of health literacy and various outcomes (including disparities in the use of healthcare services) and 42 studies (45 articles) that assessed the impact of various health literacy interventions. Of the 42 intervention studies, 21 studies focused on single design features (e.g. alternative document design) while the other 21 studies focused on combining multiple strategies (e.g. preventive service education to both providers and patients to mitigate the effects of low health literacy). The majority of the studies were from high-income countries. Only the results of the impact of health literacy interventions is summarised here.
Effects of health literacy interventions using single strategies |
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People: Individuals and caregivers of all races and ethnicities. Settings: All settings. Intervention: All single strategies specifically designed to mitigate the effects of low health literacy. Comparison: Any comparator designated by investigators. |
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Outcomes | Impact | Number of studies | Certainty of the evidence (GRADE) |
|
Comprehension, accuracy and choice of higher quality options |
Overall the certainty of the evidence for single strategies was very low. Some single strategies showed improvements in comprehension for low health literacy populations in one or a few studies,including: presenting essential information by itself, presenting essential information first,presenting information so that the higher numbers indicate better quality, using the same denominators to present baseline risk and treatment benefit information,adding icon arrays to numerical presentations of treatment benefit information and adding video to verbal narratives. |
25 |
Very low |
|
On the other hand using coloured traffic symbols to denote hospital quality seemed to worsenhealth choices among the people with low literacy. Likewise, adding symbols to non-essential quality informationseemed to draw attention away from the essential information and worsened health choices among those with low health literacy. |
Low |
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GRADE: GRADE Working Group grades of evidence (see above and last page) |
Effects of health literacy interventions using mixed strategies |
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People: Individuals and caregivers of all races and ethnicities. Settings: All settings. Intervention: All mixed strategies specifically designed to mitigate the effects of low health literacy. Comparison: Any comparator designated by investigators. |
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Outcomes | Impact | Number of studies | Certainty of the evidence (GRADE) |
|
Use of healthcare services |
Interventions such as intensive self-management and adherence interventions probably reduce emergency room visits and hospitalizations across health literacy levels. The effects of other mixed strategies on the use of healthcare services are mixed or uncertain. |
6 studies |
Moderate Very Low |
|
Health outcomes |
Intensive disease management programs probably reduce disease prevalence across health literacy levels. The effects of other mixed strategies on health outcomes are mixed or uncertain. |
39 studies |
Moderate Very low
|
|
Resource use |
There was insufficient evidence to assess the effects of mixed interventions on resource use. |
2 studies |
Very low |
|
Disparities in healthcare use |
No studies were found that examined the effects of mixed interventions on disparities in the utilisation of healthcare services. |
No studies | --- | |
GRADE: GRADE Working Group grades of evidence (see above and last page) |
Findings | Interpretation* |
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APPLICABILITY | |
Only one included study was conducted in a low-income country. |
There is insufficient evidence of the effectiveness of health literacy interventions in low-income countries. The effects observed in these studies were limited to clinical environments and narrow geographical areas. Impacts in low-income countries may be different because of differences in literacy levels and other contextual factors. |
EQUITY | |
The effects of single and mixed strategies on disparities in the use of healthcare services are uncertain.
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To the extent that improvements in comprehension led to improvements in the use of healthcare and health outcomes, single strategies could be expected to reduce inequities.
|
ECONOMIC CONSIDERATIONS | |
The impacts of single and mixed strategies on resource use are uncertain. |
Interventions such as intensive self management and intensive disease management programs may have considerable cost implications. Local costing studies are needed for these interventions. |
MONITORING & EVALUATION | |
The certainy of most of the evidence was very low, and only one of the included studies was conducted in a low-income country. |
Interventions to improve the use of healthcare and health outcomes in people with low health literacy should be rigorously evaluated before scaling up their use in low-income countries. |
*Judgements made by the authors of this summary, not necessarily those of the review authors, based on the findings of the review and consultation with researchers and policymakers in low-income countries. For additional details about how these judgements were made see:www.supportsummaries.org/methods |
Stacey LS, David JH, Anthony JV, et al. Interventions for individuals with low health literacy: a systematic review, J Health Commun 2011; 16:sup3, 30-54.
Car J, Lang B, Colledge A, et al. Interventions for enhancing consumers' online health literacy. Cochrane Database of Systematic Reviews 2011, No 6, CD007092.pub2.
Jacobs RJ , Lou JQ , Ownby RL , Caballero J. A systematic review of eHealth interventions to improve health litera-cy. Health Informatics J 2016; 22(2):81-98.
Mercy N Mulaku, School Of Pharmacy, University of Nairobi, Kenya
Conflict of interest
None declared. For details, see: www.supportsummaries.org/coi
Acknowledgements
This summary has been peer reviewed by: Nancy Berkman, Astrid Austvoll Dahlgren, and Daniel Semakula.
This review should be cited as
Berkman ND, Sheridan SL, Donahue KE, et al. Health literacy interventions and outcomes: an updated systematic review. Evid Rep Technol Assess 2011; (199):1-941.
The summary should be cited as
Mulaku N.M. What are the effects of interventions to improve healthcare utilization and health outcomes in people with low health literacy? A SUPPORT Summary of a systematic review. October 2016. www.supportsummaries.org.
Keywords
evidence-informed health policy, evidence based, systematic review, health systems research, health care, low and middle income countries, developing countries, primary health care, health literacy, literacy, numeracy.