Development and validation of the General Health Numeracy Test (GHNT).
ABSTRACT: OBJECTIVE:Because existing numeracy measures may not optimally assess 'health numeracy', we developed and validated the General Health Numeracy Test (GHNT). METHODS:An iterative pilot testing process produced 21 GHNT items that were administered to 205 patients along with validated measures of health literacy, objective numeracy, subjective numeracy, and medication understanding and medication adherence. We assessed the GHNT's internal consistency reliability, construct validity, and explored its predictive validity. RESULTS:On average, participants were 55.0 ± 13.8 years old, 64.9% female, 29.8% non-White, and 51.7% had incomes ?$39K with 14.4 ± 2.9 years of education. Psychometric testing produced a 6-item version (GHNT-6). The GHNT-21 and GHNT-6 had acceptable-good internal consistency reliability (KR-20=0.87 vs. 0.77, respectively). Both versions were positively associated with income, education, health literacy, objective numeracy, and subjective numeracy (all p<.001). Furthermore, both versions were associated with participants' understanding of their medications and medication adherence in unadjusted analyses, but only the GHNT-21 was associated with medication understanding in adjusted analyses. CONCLUSIONS:The GHNT-21 and GHNT-6 are reliable and valid tools for assessing health numeracy. PRACTICE IMPLICATIONS:Brief, reliable, and valid assessments of health numeracy can assess a patient's numeracy status, and may ultimately help providers and educators tailor education to patients.
Project description:BACKGROUND:Health literacy and numeracy influence many health-related behaviors and outcomes. Health literacy and numeracy have been assessed objectively and subjectively, but interrelationships among the measures and the consistency of their association with health knowledge have not been examined. OBJECTIVE:To increase understanding of the structure and interrelations among objective and subjective health literacy and numeracy and how these constructs relate to knowledge of risk factors of two major diseases. DESIGN:Secondary analysis of cross-sectional survey data, weighted to be representative of the general US population of non-institutionalized adults. PARTICIPANTS:Participants (N = 1005, 55.2% response rate) were recruited from GfK KnowledgePanel. The unweighted sample included 52% women, 26% racial/ethnic minorities, and 37% with no college experience. MAIN MEASURES:Objective health literacy, subjective health literacy, objective numeracy, subjective numeracy. Objective and perceived knowledge of diabetes and colon cancer risk factors were also assessed. KEY RESULTS:Confirmatory factor analyses indicated that a model with correlated (r = 0.16-0.56) but separate factors for each of the four literacy/numeracy constructs best fit the data (RMSEA = 0.055 (95% CI 0.049-0.061), CFI = 0.94). Consistency between measures in classifying people as having adequate or limited health literacy or numeracy was 60.9-77.1%, depending on the combination of measures. All four literacy/numeracy constructs were independently associated with objective diabetes knowledge and objective colon cancer knowledge (all ps < .04). Subjective (but not objective) literacy and numeracy measures were associated with diabetes perceived knowledge (all ps < .02). No literacy/numeracy measures were associated with perceived colon cancer knowledge. CONCLUSIONS:We identified objective and subjective health literacy and numeracy as four distinct but related concepts. We also found that each construct accounts for unique variance in objective (but not subjective) disease knowledge. Until research uncovers what psychological processes drive subjective measures (e.g., motivation, self-efficacy), research investigating the relationship between health literacy and health outcomes should consider assessing all four measures.
Project description:Background:Non-steroidal anti-inflammatory drugs are widely used and have a potential for over-the-counter misuse. Limited health literacy is associated with poor health outcomes. Identification of new strategies to assess literacy and numeracy could be useful in targeting effective education initiatives. Objective:To characterize numeracy and literacy skills related to non-steroidal anti-inflammatory drug labels in primary care patients. Methods:Patients were recruited and consented over an 8-month period after their regular primary care visit. Demographic information was collected and two instruments were administered to assess literacy and numeracy skills: (1) a medication label literacy instrument focused on non-steroidal anti-inflammatory drugs (MedLit-NSAID) and (2) a general healthy literacy-screening tool, the Newest Vital Sign. Two questions on the MedLit-NSAID instrument evaluated understanding of the Food and Drug Administration medication guide for non-steroidal anti-inflammatory drugs and the Food and Drug Administration approved over-the-counter label. Results:A total of 145 patients were enrolled. Mean MedLit-NSAID and Newest Vital Sign scores were 6.8 (scale range 0-8) and 4.2 (scale range 0-6), respectively. Higher education level was associated with higher scores for both tools (p???0.05). Total MedLit-NSAID scores on average were higher in females compared with males (6.5 vs 6, p?=?0.05). Patients with decreased kidney function (n?=?18) had significantly lower MedLit-NSAID scores (p???0.05). Test-retest scores were not significantly different for MedLit-NSAID (p?=?0.32). The correlation between the tools was 0.54 and internal consistency MedLit-NSAID was 0.61. Conclusion:A medication information focused instrument provided specific information to assess health literacy related to non-steroidal anti-inflammatory drug labels. This information could be utilized to develop patient education initiatives for medication label comprehension.
Project description:Self-management of moderate-to-severe asthma depends on the patient's ability to (1) navigate (access health care to obtain diagnoses and treatment), (2) use inhaled corticosteroids (ICSs) properly, and (3) understand ICS function.We sought to test whether navigation skills (medication recall, knowledge of copay requirements, and ability to provide information needed for a medical visit about a persistent cough unresponsive to medication) are related to other self-management skills and health literacy.A 21-item Navigating Ability (NAV2) questionnaire was developed, validated, and then read to adults with moderate-to-severe asthma. ICS technique was evaluated by using scales derived from instructions in national guidelines; knowledge of ICS function was evaluated by using a validated 10-item questionnaire. Spearman correlation was computed between NAV2 score and these questionnaires and with numeracy (Asthma Numeracy Questionnaire) and print literacy (Short Test of Functional Health Literacy in Adults).Two hundred fifty adults participated: age, 51 ± 13 years; 72% female; 65% African American; 10% Latino; 50% with household income of less than $30,000/y; 47% with no more than a 12th-grade education; and 29% experienced hospitalizations for asthma in the prior year. A higher NAV2 score was associated with correct ICS technique (? = 0.24, P = .0002), knowledge of ICSs (? = 0.35, P < .001), better print literacy (? = 0.44, P < .001), and numeracy (? = 0.41, P < .001).Patients with poor navigational ability are likely to have poor inhaler technique and limited understanding of ICS function, as well as limited numeracy and print literacy. Clinicians should consider these elements of self-management for their effect on asthma care and as a marker of more general health literacy deficits.
Project description:BACKGROUND: Limited literacy skills are common in the United States (US) and are related to lower HIV knowledge and worse health behaviors and outcomes. The extent of these associations is unknown in countries like Mozambique, where no rigorously validated literacy and numeracy measures exist. METHODS: A validated measure of literacy and numeracy, the Wide Range Achievement Test, version 3 (WRAT-3) was translated into Portuguese, adapted for a Mozambican context, and administered to a cross-section of female heads-of-household during a provincially representative survey conducted from August 8 to September 25, 2010. Construct validity of each subscale was examined by testing associations with education, income, and possession of socioeconomic assets, stratified by Portuguese speaking ability. Multivariable regression models estimated the association among literacy/numeracy and HIV knowledge, self-reported HIV testing, and utilization of prenatal care. RESULTS: Data from 3,557 women were analyzed; 1,110 (37.9%) reported speaking Portuguese. Respondents' mean age was 31.2; 44.6% lacked formal education, and 34.3% reported no income. Illiteracy was common (50.4% of Portuguese speakers, 93.7% of non-Portuguese speakers) and the mean numeracy score (10.4) corresponded to US kindergarten-level skills. Literacy or numeracy was associated (p<0.01) with education, income, age, and other socioeconomic assets. Literacy and numeracy skills were associated with HIV knowledge in adjusted models, but not with HIV testing or receipt of clinic-based prenatal care. CONCLUSION: The adapted literacy and numeracy subscales are valid for use with rural Mozambican women. Limited literacy and numeracy skills were common and associated with lower HIV knowledge. Further study is needed to determine the extent to which addressing literacy/numeracy will lead to improved health outcomes.
Project description:Background:Health literacy is an essential predictor of health status, disease control and adherence to medications. Objectives:The study goals were to assess the health literacy level of the general population in Saudi Arabia using translated Gulf Arabic version of the short-version of the Test of Functional Health Literacy in Adults (S-TOFHLA) and Single Item Literacy Screener (SILS) tests and to measure the relationship between health literacy and education level. Methods:The study was a cross-sectional with a convenience sample of 123 participants from the general population in Riyadh. Data were collected using the modified (Gulf) Arabic versions of both S-TOFHLA and SILS. Fisher's Exact test was used to measure the difference of the health literacy scores according to the education degrees and Cronbach's alpha was used to measure the internal consistency of the S-TOFHLA items. Results:More than half (55.4%) of the participants were male, 50.4% had a middle school or less education level, and we found that 84.4% had adequate health literacy as measured by the S-TOFHLA, compared to 49.6% as measured by SILS. The Fisher's Exact test showed a significant difference (P<.05) in the S-TOFHLA and SILS scores according to education categories. Conclusions:The level of education has a significant positive association with S-TOFHLA and SILS results. The Gulf Arabic version of S-TOFHLA is a reliable test with a good internal consistency and a significant positive correlation between the two parts of S-TOFHLA. We recommend the use of S-TOFHLA or SILS at the first patient visit.
Project description:BACKGROUND:Health coaching is an effective behavior change strategy. Understanding if there is a differential impact of health coaching on patients with low health literacy has not been well investigated. OBJECTIVE:To determine whether a telephone coaching intervention would result in similar improvements in enrollment in prevention programs and patient activation among Veterans with low versus high health literacy (specifically, reading literacy and numeracy). DESIGN:Secondary analysis of a randomized controlled trial. PARTICIPANTS:Four hundred seventeen Veterans with at least one modifiable risk factor: current smoker, BMI???30, or <?150 min of moderate physical activity weekly. METHODS:A single-item assessment of health literacy and a subjective numeracy scale were assessed at baseline. A logistic regression and general linear longitudinal models were used to examine the differential impact of the intervention compared to control on enrollment in prevention programs and changes in patient activation measures (PAM) scores among patients with low versus high health literacy. RESULTS:The coaching intervention resulted in higher enrollment in prevention programs and improvements in PAM scores compared to usual care regardless of baseline health literacy. The coaching intervention had a greater effect on the probability of enrollment in prevention programs for patients with low numeracy (intervention vs control difference of 0.31, 95% CI 0.18, 0.45) as compared to those with high numeracy (0.13, 95% CI -?0.01, 0.27); the low compared to high differential effect was clinically, but not statistically significant (0.18, 95% CI -?0.01, 0.38; p?=?0.07). Among patients with high numeracy, the intervention group had greater increases in PAM as compared to the control group at 6 months (mean difference in improvement 4.8; 95% CI 1.7, 7.9; p?=?0.003). This led to a clinically and statistically significant differential intervention effect for low vs high numeracy (-?4.6; 95% CI -?9.1, -?0.15; p?=?0.04). CONCLUSIONS:We suggest that health coaching may be particularly beneficial in behavior change strategies in populations with low numeracy when interpretation of health risk information is part of the intervention. CLINICALTRIALS. GOV IDENTIFIER:NCT01828567.
Project description:Purpose. There is no gold-standard health literacy measure. The Single Item Literacy Screener (SILS) and Subjective Literacy Screener (SLS) ask people to self-report ability to understand health information. They were developed in older adults, before common use of electronic health information. This study explored whether the SILS and SLS related to objective literacy, numeracy, and comprehension among young adults, and whether specifying "online" or "paper-based" wording affected these relationships. Methods. Eligible individuals (18-35 years of age, English-speaking, US residents) from an online survey company were randomized to 1) original measures; 2) measures adding "paper-based" to describe health information/forms; or 3) measures adding "online" to describe health information/forms. We examined how each measure related to e-Health Literacy (eHEALS), subjective numeracy (SNS), objective numeracy (ONS), and comprehension of a short passage. Results. A total of 848/1342 respondents correctly answered attention-checks and were analyzed. The validated SILS related to comprehension (P = 0.003), eHEALS (P = 0.04), and ONS (P < 0.001) but not SNS (P = 0.44). When adding "paper-based," SILS related to eHEALS (P < 0.001) and ONS (P = 0.003) but did not relate to comprehension (P = 0.25) or SNS (P = 0.35). When adding "online," SILS related to comprehension (P < 0.001), eHEALS (P < 0.001), ONS (P = 0.005), and SNS (P = 0.03). The validated SLS related to comprehension (P < 0.001), eHEALS (P < 0.001), ONS (P < 0.001), and SNS (P < 0.001). When adding "paper-based," the SLS only related to eHEALS (P = <0.001) and comprehension (P = 0.03) but did not relate to ONS (P = 0.13) or SNS (P = 0.33). When adding "online," the SLS related to comprehension (P < 0.001), eHEALS (P < 0.001), and SNS (P = 0.03) but not ONS (P = 0.06). Conclusions. Young adults might interpret subjective health literacy measures differently when prompted to think about electronic or paper-based information. Researchers should consider clearer instructions or modified wording when using these measures in this population.
Project description:Introduction. Enhanced visual effects, like animation, have the potential to improve comprehension of probabilistic risk information, particularly for those with lower health literacy. We tested the effect of presentation format on comprehension of colorectal cancer (CRC) screening probabilities to identify optimal risk communication strategies. Methods. Participants from a community foodbank and a cancer prevention center were randomized to 1 of 3 CRC screening risk presentations. The presentations used identical content but varied in format: 1) video with animated pictographs, 2) video with static pictographs, and 3) audiobooklet with static pictographs. Participants completed pre- and postpresentation surveys. The primary outcome was knowledge of probability/risk information regarding CRC screening, calculated as total, verbatim, and gist scores. Results. In total, 187 participants completed the study and were included in this analysis. Median age was 58 years (interquartile range [IQR]: 14 years), most participants were women (63%), and almost half had a high school education or less (46%). Approximately one-quarter had inadequate health literacy (Short Test of Functional Health Literacy in Adults marginal/inadequate: 28%; Brief Health Literacy Screener low: 18%), and about half had low numeracy (Subjective Numeracy Scale low: 54%; Graphical Literacy Measure low: 50%). We found no significant differences in total, verbatim, or gist knowledge across presentation formats (all P > 0.05). Discussion. Use of an animated pictograph to communicate risk does not appear to augment or impede knowledge of risk information. Regardless of health literacy level, difficulty understanding pictographs presenting numerical information persists. There may be a benefit to teaching or priming individuals on how to interpret numerical information presented in pictographs before communicating risk using visual methods. Trial Registry: NCT02151032.
Project description:Greater numeracy has been correlated with better health and financial outcomes in past studies, but causal effects in adults are unknown. In a 9-week longitudinal study, undergraduate students, all taking a psychology statistics course, were randomly assigned to a control condition or a values-affirmation manipulation intended to improve numeracy. By the final week in the course, the numeracy intervention (statistics-course enrollment combined with values affirmation) enhanced objective numeracy, subjective numeracy, and two decision-related outcomes (financial literacy and health-related behaviors). It also showed positive indirect-only effects on financial outcomes and a series of STEM-related outcomes (course grades, intentions to take more math-intensive courses, later math-intensive courses taken based on academic transcripts). All decision and STEM-related outcome effects were mediated by the changes in objective and/or subjective numeracy and demonstrated similar and robust enhancements. Improvements to abstract numeric reasoning can improve everyday outcomes.
Project description:Background. Numeracy skills are important for medical decision making as lower numeracy is associated with misinterpreting statistical health risks. Math anxiety, characterized by negative emotions about numerical tasks, and lower subjective numeracy (i.e., self-assessments of numerical competence) are also associated with poor risk comprehension. Objective. To explore independent and mediated associations of math anxiety, numerical ability, and subjective numeracy with risk comprehension and to ascertain whether their associations are specific to the health domain. Methods. Objective numeracy was measured with a 14-item test. Math anxiety and subjective numeracy were assessed with self-report scales. Risk comprehension was measured with a 12-item test. In experiment 1, risk comprehension items were limited to scenarios in the health domain. In experiment 2, participants were randomly assigned to receive numerically equivalent risk comprehension items in either a health or nonhealth domain. Results. Linear regression analyses revealed that individuals with higher objective numeracy were more likely to respond correctly to the risk comprehension items, as were individuals with higher subjective numeracy. Higher math anxiety was associated with a lower likelihood of correct responding when controlling for objective numeracy but not when controlling for subjective numeracy. Mediation analyses indicated that math anxiety may undermine risk comprehension in 3 ways, including through 1) objective numeracy, 2) subjective numeracy, and 3) objective and subjective numeracy in serial, with subjective numeracy mediating the association between objective numeracy and risk comprehension. Findings did not differ by domain. Conclusions. Math anxiety, objective numeracy, and subjective numeracy are associated with risk comprehension through unique pathways. Education initiatives for improving health risk comprehension may be most effective if jointly aimed at tackling numerical ability as well as negative emotions and self-evaluations related to numeracy.