Single-Item Literacy Screener (SILS) Questionnaire

Someone sitting across the table from doctor with clipboard

What is the Single-Item Literacy Screener (SILS) Questionnaire?

The Single-Item Literacy Screener (SILS) is a single question intended to identify adult patients in need of help with printed health material. It was developed as part of a larger project, the Vermont Diabetes Information System, a randomized trial of a diabetes decision support system. It is an abbreviated version of the Short Test of Functional Health Literacy Assessment (S-TOFHLA). The S-TOFHLA is a timed 36-item, 7-minute test of reading comprehension that was used as the reference measure for health literacy skills to compare and validate the results of the SILS questionnaire. Within the population screened, 17% had limited reading ability on S-TOFHLA scores, and 23% reported a SILS score >2 (needed help with health-related reading materials sometimes, often, or always).

The SILS was created to address the need for a more rapid estimate of adult literacy in medicine. Health literacy is known to be a factor in patient outcomes, and as the CDC says, “at some point in our lives, we all need to be able to find, understand, and use health information and services.” Providers can use SILS to quickly determine which patients are most likely to require additional help understanding their treatment. While it is not as robust as the S-TOFHLA in identifying the level of a patient’s health literacy, it can provide powerful insight when utilized correctly.

How is the SILS Questionnaire Scored?

There are 2 versions of the SILS tool. The SILS1 asks “How often do you need to have someone help you when you read instructions, pamphlets, or other written material from your doctor or pharmacy?” The SILS2 words the question differently, stating “How comfortable are you filling out medical forms by yourself?” Both versions use a Likert-style scale, but the wording and scoring of the answer options differ as shown below:

table explaining SILS point system

Strengths

The greatest strength of the Single-Item Literacy Screener Questionnaire is its brevity. While maintaining good validity compared to the well-accepted S-TOFHLA, the single item questionnaire is far easier and more quickly completed than other measures of health literacy, and captures patients that would otherwise be missed, due to being beneath the required literacy to take other assessments. In addition to being highly comparable to the S-TOFHLA, it also serves as a practical in-clinic way for providers to identify which patients will need the most help in order to access and understand their treatment and health information.

Considerations

While the SILS questionnaire shows good comparability to its longer health literacy screening counterparts, researchers did not expect or record an exact match between the SILS and the S-TOFHLA. This is because the S-TOFHLA more broadly measures reading ability, while the SILS specifically measures the need for help with reading health-related materials. The SILS and SILS2 are excellent tools to quickly identify patients who might require more help with understanding complex medical information, however use of this measure should depend on what the need is. More research is needed to investigate evidence of validity across patient populations, which may be affected by the fact that different scoring thresholds would likely be used across different studies.

It is also important to understand what version of the SILS survey is in use as the scoring system is different between the two versions. For example, a score of 2 on the SILS represents someone who rarely needs help when reading written materials. However a score of 2 on the SILS2 represents someone who is only somewhat comfortable filling out medical forms on their own. 

Licensing and Cost

The Single-Item Literacy Screener (SILS) Questionnaire is freely available for noncommercial use. More information can be found here: https://healthliteracy.bu.edu/sils

Resources

CDC – Understanding Health Literacy  |  Health Literacy Tool Shed – SILS  |  Researchgate – The Single Item Literacy Screener: Evaluation of a brief instrument to identify limited reading ability  |  Health Literacy Tool Shed – S-TOFHLA |  Pubmed – Development of a brief test to measure functional health literacy  | Validation of Screening Questions for Limited Health Literacy in a Large VA Outpatient Population  |  Patient-Reported Outcomes (PROs) Following Elective Primary Total Hip and/or Total Knee Arthroplasty: Hospital-Level Performance Measure

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