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Test of Functional Health Literacy in Adults (TOFHLA)
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Practical Information
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Instrument Name:
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Test of Functional Health Literacy in Adults (TOFHLA)
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Instrument Description:
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The TOFHLA measures the functional literacy level of patients, using real-to-life health care materials. These materials include patient education information, prescription bottle labels, registration forms, and instructions for diagnostic tests. The TOFHLA assesses two main constructs, numeracy and reading comprehension; it has a total of 67 items. The numeracy scale, used to measure the ability to read and understand numbers, includes 17 items; the reading comprehension scale, used to measure the patient’s ability to read and understand health care-related passages, contains 50 items. The reading comprehension scale utilizes the Cloze procedure, a technique that presents the patient with reading passages that are missing every fifth to seventh word; the patient must then select the appropriate missing word from a list of four possible answers. Only one choice is correct with regard to grammar or the context of the sentence. (Ref: 1)
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Price:
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$50; Available from Peppercorn Books (see Research Contacts section below)
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Administration Time:
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Numeracy scale -- 10 minutes maximum; Reading comprehension scale -- 12 minutes maximum.
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Publication Year:
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1995
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Item Readability:
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According to the Gunning Fog Index, the reading levels for the reading comprehension section, reported as grade levels, are 4.3 (Passage A), 10.4 (Passage B), and 19.5 (Passage C). The median difficulty of the reading comprehension section was, by design, 72%, and the numeracy scale median difficulty was 64%. (Ref: 1) The overall reading level of the numeracy section, by Gunning Fog Index, is 9.4.
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Scale Format:
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The numeracy scale uses a dichotomous response scale; the reading comprehension scale uses a multiple-choice presentation. All answers are scored as either correct or incorrect.
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Administration Technique:
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The reading comprehension scale is self-administered, and the numeracy scale is interviewer administered.
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Scoring and Interpretation:
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In the reading comprehension section, patients are asked to select the correct response from a list of four possible choices. Responses are reviewed for accuracy, and each item answered correctly is assigned a score of one. Incorrect items are given a score of zero. The numeracy section is scored with the same dichotomous scale process of one (for correct responses) and zero (for incorrect responses). (Ref: 1) Raw scores are converted to scaled scores, which range from 0-100. The numeracy items are summed, and their total multiplied by 2.941 so as to create scores that range from 0-50; reading comprehension items are summed (range: 0-50) and are then added to the scaled numeracy score. To interpret the total score, participants receiving a score of 59 or below are considered to have inadequate functional health literacy; those scoring 60-74 have marginal functional health literacy, and subjects scoring 75 and above have adequate functional health literacy. (Ref: 2)
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Forms:
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There are two additional versions of the TOFHLA: TOFHLA-S, a validated Spanish translation, and the S-TOFHLA, a short form that requires up to 12 minutes to administer. The short form is composed of 4 numeracy items and 36 reading comprehension items.
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Research Contacts
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Instrument Developers:
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Ruth Parker, David Baker, Mark Williams & Joanne Nurss
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Instrument Development Location:
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The TOFHLA is available for purchase from http://www.peppercornbooks.com/. From the Pepper Corn homepage, select the TOFHLA link at the top. The full version includes the TOFHLA, TOFHLA-S, and the Spanish version, as well as the technical manual and license for use.
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Instrument Developer Email:
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No information found.
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Instrument Developer Website:
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No information found.
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Annotated Bibliography
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1. Parker RM, Baker DW, Williams MV, & Nurss JR. The Test of Functional Health Literacy in Adults: a new instrument for measuring patients' literacy skills. J Gen Intern Med 1995;10:537-41. [PMID:8576769]
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Purpose:
To develop a reliable and valid measure that assesses the functional health literacy of patients.
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Sample:
This study validated the English and Spanish versions of the TOFHLA; therefore, two groups of participants were recruited. The English version test group was comprised of 200 patients with a mean age of 40 years, 51% female, 91% African-American, 7% Caucasian, and 1% Hispanic. The educational levels of the sample included 8% below the 6th grade, 33% between the 7th and 11th grade, 40% graduated high school or obtained a GED, and 21% attended some college. The Spanish-speaking group totaled 203 patients with a mean age of 42 years, 68% female, and 99% Hispanic. The educational levels were 63% below the 6th grade, 13% between the 7th and 11th grade, 15% completed high school or obtained a GED, and 9% attended some college.
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Methods:
A reading expert reviewed hospital texts commonly read by patients, paying specific attention to sections involving patient-directed instruction and information. This literature served as the basis for developing a functional health literacy instrument—the TOFHLA. Researchers then conducted a pilot study to validate both the English and Spanish versions of the TOFHLA. Next, they recruited participants from Grady Memorial hospital, a 1000-bed public hospital in Atlanta, GA and Harbor-UCLA Medical Center, a 500-bed public hospital in Torrance, CA. Researchers excluded those who were under 18 years of age, had alcohol on the breath, spoke unintelligibly, were in police custody, had a mental illness, spoke English as a second language (for the TOFHLA test), or had an extreme physical illness. Patients with visual acuities of >20/50 were also excluded. |
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Implications:
Researchers reported that functional literacy is situation-specific and that it may vary according to context and setting. The study indicated that the TOFHLA can provide reliable and valid measures, as evidence of its concurrent validity (i.e., statistically significant correlations) with several other literacy measures suggests. The study reported low literacy levels (i.e., TOFHLA scores of <50%) present in fluent English- and Spanish-speaking individuals (27% and 37%, respectively) in an outpatient public hospital setting, demonstrating that not all patients might be able to perform what is required of them to initiate and maintain health care treatment regimens.
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2. Parikh NS, Parker RM, Nurss JR, Baker DW, & Williams MV. Shame and health literacy: the unspoken connection. Patient Education and Counseling 1996;27:33-9. [PMID:8788747]
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Purpose:
To assess the functional literacy levels of patients and the relationship of shame with low literacy levels in a health care setting.
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Sample:
There were 202 participants with a mean age of 41.4 years, 92.1% were African American, 51.5% were female, and 49.5% had less than a high school education.
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Methods:
Research assistants with extensive training (i.e., 15 hours) focused on interviewing and administering the TOFHLA to patients. Participants were recruited from Grady Memorial Hospital (Atlanta, GA) and were excluded from the study if they were younger than 18 years, had psychiatric illnesses, spoke English as a second language, had unintelligible speech, had a visual acuity >20/100, or were too physically ill to participate. Research assistants collected consent forms from eligible individuals, gathered demographic information, and administered the TOFHLA.
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Implications:
Researchers reported that harboring shame due to an inability to read might make it difficult for patients to interact with healthcare providers. Many low literacy patients in this study had not informed spouses of their difficulty reading (67.2%), had not informed important others (>50%), and had never brought anyone with them to the hospital to help them with reading (75.9%).
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3. Williams MV, Parker RM, Baker DW, Parikh NS, Pitkin K, Coates WC, & Nurss JR. Inadequate functional health literacy among patients at two public hospitals. JAMA 1995 Dec 6; 274(21):1677-82.[PMID:7474271]
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Purpose:
To determine the level of functional health literacy in patients seeking care at two public hospitals.
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Sample:
In Atlanta, GA 979 individuals were recruited; all participated using the English TOFHLA. In Los Angeles County, CA 1680 were recruited, 767 of whom participated using the Spanish version TOFHLA. Demographic characteristics of the Atlanta group: median age of 40 years (ranging from 18 to 88), 58.8% female, 91.8% African-American, and 7.8% White. The Los Angeles County English TOFHLA group had a median age of 36 years, 49.5% female, 47.4% African American, 29.4% White, 20.7% Latino, and 2.5% other. The Los Angeles County Spanish TOFHLA group had a median age of 35 years, 64.5% female, and was primarily Latino (99.5%).
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Methods:
Trained research assistants recruited subjects from Grady Memorial Hospital in Atlanta, GA and Harbor-UCLA Medical Center in Torrance, CA (operated by Los Angeles County). Exclusion criteria were the same as in references 1 and 2 above, with the addition of excluding patients who were presenting for follow-up visits. The study was introduced to subjects by indicating that its focus was to determine what health literature patients understood and what information was confusing to patients. Demographic information and consent forms were collected from eligible patients. The English version TOFHLA was administered to all patients in Atlanta and to those in Los Angeles County for whom English was the primary language. The TOFHLA-S was administered to Los Angeles County patients whose primary language was Spanish.
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Implications:
Identifying individuals with inadequate reading levels is important: health care providers must use other methods of communication than writing or the provision of reading materials when working with low literacy patients in order to successfully offer the best quality care. The authors reported that it was difficult to identify individuals with inadequate literacy skills via self-report methods because these individuals may harbor shame about their reading deficiencies and thus may not volunteer this information readily. Screening tools are likely required. Unfortunately, due to its length, the TOFHLA may not be the functional health literacy measure of choice. Other reading measures such as the WRAT-R and the REALM may be used, but have their own disadvantages. For example, the WRAT_R and the REALM may overestimate an individual’s reading level. Overall, the authors suggest that the REALM may be the best rapid screening test for English speaking individuals regarding health literacy. However, a test such as the TOFHLA that assesses both numeracy skills and reading comprehension may provide more valid measures of functional health literacy than tests that only assess word recognition skills.
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Factors and Norms
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Factor Analysis Work:
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No information found.
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Normative Information Availability:
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No information found.
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Reliability Evidence
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Test-retest:
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No information found.
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Inter-rater:
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No information found.
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Internal Consistency:
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The Spearman-Brown split-half coefficient was used to determine the internal consistency of both the English and Spanish versions of the TOFHLA. Results were 0.92 and 0.84, respectively. However, no information was provided as to how the TOFHLA items were divided into two equivalent halves. Cronbach’s alpha was also used to examine the internal consistency of the TOFHLA. The English and Spanish versions of the measure both had alpha coefficients of 0.98. (Ref: 1)
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Alternate Forms:
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No information found.
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Validity Evidence
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Construct/ Convergent/ Discriminant:
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The English version of the TOFHLA was compared to other literacy measures, specifically, the WRAT-R and the REALM. The study computed Spearman’s rank correlations and reported results of 0.74 (TOFHLA and WRAT-R) and 0.84 (TOFHLA and REALM). (Ref: 1) Similar validation evidence for the Spanish version of the TOFHLA was not gathered because neither the REALM nor the WRAT-R were available in Spanish versions. (Ref: 1)
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Criterion-related/ Concurrent/ Predictive:
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One study compared race, gender, educational level, and age with functional reading level and found significant group differences. For example, participants with low literacy were more likely to have less than a high school education (p <0.01), be male (p <0.05), and be over the age of 60 (p <0.01). (Ref: 2) Another study found many variables correlated with TOFHLA scores, but only two variables, age and education, were independent predictors of TOFHLA scores (p <0.001). (Ref: 3)
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Content:
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The TOFHLA was developed using actual hospital medical texts as the sources for its numeracy and reading comprehension items.
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Responsiveness Evidence:
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No information found.
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Scale Application in VA Populations:
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No information found. (Two studies included elderly patients, though not specifically VA patients, in their samples. (Ref: 2, 3))
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Scale Application in non-VA Populations:
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Yes. (Ref: 1-3)
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Comments
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For a measure of functional health literacy to be of much use in medical settings, it must be brief, yet accurate. By the authors’ own admissions, the TOFHLA may be too long (22 minutes) for this purpose. However, the fact that it exists in both English and Spanish versions and covers both literacy and numeracy are important considerations. Perhaps the short form (12 minutes) may be more manageable, however, the minimum amount of psychometric information available on the short form leaves many doubts about the efficacy of this measure. Obviously, more focused studies using the short form are in order. Does this measure provide more predictive information for outcomes of health studies than, say, more easily obtained stand-ins, such as educational level? The kind of study that might further the recommendation of the scale could be, for example, an examination of whether the TOFHLA predicts adherence to a prescriptive regimen over and above educational level. Until such studies are completed, the utility of the measure is mainly descriptive.
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