Nancy D Berkman

Literacy and health outcomes

AbstractOBJECTIVE: To review the relationship between literacy and health outcomes. DATA SOURCES: We searched MEDLINE, Cumulative Index to Nursing and Allied Health (CINAHL), Educational Resources Information Center (ERIC), Public Affairs Information Service (PAIS), Industrial and Labor Relations Review (ILLR), PsychInfo, and Ageline from 1980 to 2003. STUDY SELECTION: We included observational studies that reported original data, measured literacy with any valid instrument, and measured one or more health outcomes. Two abstractors reviewed each study for inclusion and resolved disagreements by discussion. DATA EXTRACTION: One reviewer abstracted data from each article into an evidence table; the second reviewer checked each entry. The whole study team reconciled disagreements about information in evidence tables. Both data extractors independently completed an 11-item quality scale for each article; scores were averaged to give a final measure of article quality. DATA SYNTHESIS: We reviewed 3,015 titles and abstracts and pulled 684 articles for full review; 73 articles met inclusion criteria and, of those, 44 addressed the questions of this report. Patients with low literacy had poorer health outcomes, including knowledge, intermediate disease markers, measures of morbidity, general health status, and use of health resources. Patients with low literacy were generally 1.5 to 3 times more likely to experience a given poor outcome. The average quality of the articles was fair to good. Most studies were cross-sectional in design; many failed to address adequately confounding and the use of multiple comparisons. CONCLUSIONS: Low literacy is associated with several adverse health outcomes. Future research, using more rigorous methods, will better define these relationships and guide developers of new interventions.

Low health literacy and health outcomes: an updated systematic review.

BACKGROUND Approximately 80 million Americans have limited health literacy, which puts them at greater risk for poorer access to care and poorer health outcomes. PURPOSE To update a 2004 systematic review and determine whether low health literacy is related to poorer use of health care, outcomes, costs, and disparities in health outcomes among persons of all ages. DATA SOURCES English-language articles identified through MEDLINE, CINAHL, PsycINFO, ERIC, and Cochrane Library databases and hand-searching (search dates for articles on health literacy, 2003 to 22 February 2011; for articles on numeracy, 1966 to 22 February 2011). STUDY SELECTION Two reviewers independently selected studies that compared outcomes by differences in directly measured health literacy or numeracy levels. DATA EXTRACTION One reviewer abstracted article information into evidence tables; a second reviewer checked information for accuracy. Two reviewers independently rated study quality by using predefined criteria, and the investigative team jointly graded the overall strength of evidence. DATA SYNTHESIS 96 relevant good- or fair-quality studies in 111 articles were identified: 98 articles on health literacy, 22 on numeracy, and 9 on both. Low health literacy was consistently associated with more hospitalizations; greater use of emergency care; lower receipt of mammography screening and influenza vaccine; poorer ability to demonstrate taking medications appropriately; poorer ability to interpret labels and health messages; and, among elderly persons, poorer overall health status and higher mortality rates. Poor health literacy partially explains racial disparities in some outcomes. Reviewers could not reach firm conclusions about the relationship between numeracy and health outcomes because of few studies or inconsistent results among studies. LIMITATIONS Searches were limited to articles published in English. No Medical Subject Heading terms exist for identifying relevant studies. No evidence concerning oral health literacy (speaking and listening skills) and outcomes was found. CONCLUSION Low health literacy is associated with poorer health outcomes and poorer use of health care services. PRIMARY FUNDING SOURCE Agency for Healthcare Research and Quality.

ROBINS-I: a tool for assessing risk of bias in non-randomised studies of interventions

Non-randomised studies of the effects of interventions are critical to many areas of healthcare evaluation, but their results may be biased. It is therefore important to understand and appraise their strengths and weaknesses. We developed ROBINS-I (“Risk Of Bias In Non-randomised Studies - of Interventions”), a new tool for evaluating risk of bias in estimates of the comparative effectiveness (harm or benefit) of interventions from studies that did not use randomisation to allocate units (individuals or clusters of individuals) to comparison groups. The tool will be particularly useful to those undertaking systematic reviews that include non-randomised studies.

Health literacy: what is it?

The concept of health literacy evolved from a history of defining, redefining, and quantifying the functional literacy needs of the adult population. Along with these changes has come the recognition that sophisticated literacy skills are increasingly needed to function in society and that low literacy may have an effect on health and health care. We present a brief history of literacy in the United States, followed by a discussion of the origins and conceptualization of health literacy. Increased attention to this important issue suggests the need to review existing definitions of the term “health literacy,” because despite the growing interest in this field, one question that persists is, “What is health literacy?”

Interventions to Improve Health Outcomes for Patients with Low Literacy: A Systematic Review

AbstractOBJECTIVE: To perform a systematic review of interventions designed to improve health outcomes for persons with low literacy skills. DATA SOURCES: We searched MEDLINE, Cumulative Index to Nursing and Allied Health (CINAHL), Educational Resources Information Center (ERIC), Public Affairs Information Service (PAIS), Industrial and Labor Relations Review (ILLR), PsycInfo, and Ageline from 1980 to 2003. STUDY SELECTION: We included controlled and uncontrolled trials that measured literacy and examined the effect of interventions for people with low literacy on health outcomes, including health knowledge, health behaviors, use of health care resources, intermediate markers of disease status, and measures of morbidity or mortality. Two abstractors reviewed each study for inclusion. Disagreements were resolved by consensus among the research team. DATA EXTRACTION: One reviewer abstracted data from each article into an evidence table; the second reviewer checked each entry. Disagreements about information in evidence tables were resolved by team consensus. Both data extractors independently completed an 11-item quality scale for each article; scores were averaged to give a final measure of article quality. DATA SYNTHESIS: We identified 20 articles examining interventions designed to improve health among people with low literacy. The most common outcome studied was health knowledge; fewer studies examined health behaviors, intermediate markers, or measures of disease prevalence or severity. The effectiveness of interventions appeared mixed. Limitations in research quality and heterogeneity in outcome measures make drawing firm conclusions about effective strategies difficult. Only 5 articles examined the interaction between literacy level and the effect of the intervention; they also found mixed results. CONCLUSIONS: Several interventions have been developed to improve health for people with low literacy. Limitations in study design, interventions tested, and outcomes assessed make drawing conclusions about effectiveness difficult. Further research is required to understand better the types of interventions that are most effective and efficient for overcoming literacy-related barriers to good health.

Interventions for Individuals with Low Health Literacy: A Systematic Review

The U.S. Department of Health and Human Services recently called for action on health literacy. An important first step is defining the current state of the literature about interventions designed to mitigate the effects of low health literacy. We performed an updated systematic review examining the effects of interventions that authors reported were specifically designed to mitigate the effects of low health literacy. We searched MEDLINE®, The Cumulative Index to Nursing and Allied Health Literature (CINAHL), PsycINFO, Educational Resources Information Center (ERIC), and the Cochrane Library databases (2003 forward for health literacy; 1966 forward for numeracy). Two reviewers independently reviewed titles, abstracts, and full-text articles for inclusion and included studies that examined outcomes by health literacy level and met other pre-specified criteria. One reviewer abstracted article information into evidence tables; a second checked accuracy. Two reviewers independently rated study quality using predefined criteria. Among 38 included studies, we found multiple discrete design features that improved comprehension in one or a few studies (e.g., presenting essential information by itself or first, presenting information so that the higher number is better, adding icon arrays to numerical information, adding video to verbal narratives). In a few studies, we also found consistent, direct, fair or good-quality evidence that intensive self-management interventions reduced emergency department visits and hospitalizations; and intensive self- and disease-management interventions reduced disease severity. Evidence for the effects of interventions on other outcomes was either limited or mixed. Multiple interventions show promise for mitigating the effects of low health literacy and could be considered for use in clinical practice.

Measuring Health Literacy: A Pilot Study of a New Skills-Based Instrument

Although a number of instruments have been used to measure health literacy, a key limitation of the leading instruments is that they only measure reading ability or print literacy and, to a limited extent, numeracy. Consequently, the present study aimed to develop a new instrument to measure an individuals health literacy using a more comprehensive and skills-based approach. First, we identified a set of skills to demonstrate and tasks to perform. Next, we selected real-world health-related stimuli to enable measurement of these skills, and then we developed survey items. After a series of cognitive interviews, the survey items were revised, developed into a 38-item instrument, and pilot tested using a Web-based panel. Based on the psychometric properties, we removed items that did not perform as well, resulting in a 25-item instrument named the Health Literacy Skills Instrument. Based on confirmatory factor analysis, the items were grouped into five subscales representing prose, document, quantitative, oral, and Internet-based information seeking skills. Construct validity was supported by correlations with the short form of the Test of Functional Health Literacy in Adults and self-reported skills. The overall instrument demonstrated good internal consistency, with a Cronbachs alpha of 0.86. Additional analyses are planned, with the goal of creating a short form of the instrument.

Development quality criteria to evaluate nontherapeutic studies of incidence, prevalence, or risk factors of chronic diseases: Pilot study of new checklists

OBJECTIVE To develop two checklists for the quality of observational studies of incidence or risk factors of diseases. STUDY DESIGN AND SETTING Initial development of the checklists was based on a systematic literature review. The checklists were refined after pilot trials of validity and reliability were conducted by seven experts, who tested the checklists on 10 articles. RESULTS The checklist for studies of incidence or prevalence of chronic disease had six criteria for external validity and five for internal validity. The checklist for risk factor studies had six criteria for external validity, 13 criteria for internal validity, and two aspects of causality. A Microsoft Access database produced automated standardized reports about external and internal validities. Pilot testing demonstrated face and content validities and discrimination of reporting vs. methodological qualities. Interrater agreement was poor. The experts suggested future reliability testing of the checklists in systematic reviews with preplanned protocols, a priori consensus about research-specific quality criteria, and training of the reviewers. CONCLUSION We propose transparent and standardized quality assessment criteria of observational studies using the developed checklists. Future testing of the checklists in systematic reviews is necessary to develop reliable tools that can be used with confidence.

The Health Literacy Skills Framework

Although there are a variety of models and frameworks that describe factors that are associated with health literacy skills, few illustrate the full pathway from development and moderators of health literacy skills, their application, and the outcomes that result all in one framework or model. This article introduces the Health Literacy Skills conceptual framework that does encompass this full continuum. To develop the framework, the authors reviewed and built upon existing health literacy frameworks. The Health Literacy Skills framework hypothesizes the relations between health literacy and health-related outcomes and depicts how health literacy functions at the level of the individual. The framework also reflects how factors external to the individual (e.g., family, setting, community, culture, and media) influence the constructs and relations represented in the framework. The framework is organized into 4 primary components: (a) factors that influence the development and use of health literacy skills; (b) health-related stimuli; (c) health literacy skills needed to comprehend the stimulus and perform the task; and (d) mediators between health literacy and health outcomes. Previous theoretical frameworks lend support to the proposed causal pathways it illustrates. The authors hope this conceptual framework can serve as a springboard for further discussion and advancement in operationalizing this complex construct. The Health Literacy Skills framework could also be used to guide the development of interventions to improve health literacy. Future research should be conducted to fully test the relations in the framework.

Quality assessment of observational studies in a drug-safety systematic review, comparison of two tools: the Newcastle–Ottawa Scale and the RTI item bank

Background The study objective was to compare the Newcastle–Ottawa Scale (NOS) and the RTI item bank (RTI-IB) and estimate interrater agreement using the RTI-IB within a systematic review on the cardiovascular safety of glucose-lowering drugs. Methods We tailored both tools and added four questions to the RTI-IB. Two reviewers assessed the quality of the 44 included studies with both tools, (independently for the RTI-IB) and agreed on which responses conveyed low, unclear, or high risk of bias. For each question in the RTI-IB (n=31), the observed interrater agreement was calculated as the percentage of studies given the same bias assessment by both reviewers; chance-adjusted interrater agreement was estimated with the first-order agreement coefficient (AC1) statistic. Results The NOS required less tailoring and was easier to use than the RTI-IB, but the RTI-IB produced a more thorough assessment. The RTI-IB includes most of the domains measured in the NOS. Median observed interrater agreement for the RTI-IB was 75% (25th percentile [p25] =61%; p75 =89%); median AC1 statistic was 0.64 (p25 =0.51; p75 =0.86). Conclusion The RTI-IB facilitates a more complete quality assessment than the NOS but is more burdensome. The observed agreement and AC1 statistic in this study were higher than those reported by the RTI-IB’s developers.