Table 1 Health Literacy Measures and Cut-points
From: Limitations of the S-TOFHLA in measuring poor numeracy: a cross-sectional study
Measure | Scores | Cut-points | Rationale for chosen cut-point* |
|---|---|---|---|
Short Test of Functional Health Literacy in Adults (S-TOFHLA) | |||
S-TOFHLA Total Score | 0–36 Range | ≤16 Low 17–22 Marginal ≥23 Adequate | The S-TOFHLA has a 7 min time limit and scores range from 0 to 36 with items worth 1 point each [10]. Based on their scores, participants are classified as having “inadequate” (0–16), “marginal” [17,18,19,20,21,22], or “adequate” [23,24,25,26,27,28,29,30,31,32,33,34,35,36] HL [10, 32]. The S-TOFHLA has good validity when compared to the full Test of Functional Health Literacy (TOFHLA) and internal consistency (Cronbach’s alpha = 0.97), yet its correlation with the Rapid Estimate of Adult Literacy in Medicine (REALM) is unclear [10, 54] |
Subjective Numeracy Scale (SNS) | |||
SNS Total Score | 1–6 Mean | ≤4 Low > 4 High | SNS cores range from 1 to 6 and we used the average SNS total score for analysis [17, 21, 33]. There is no established optimal cut-point for the SNS. Various methods have been used [27, 34,35,36]. We selected to use the median split score of 4 (median score on total and subscales) to be the cut-point for this investigation. This cut-point was chosen to compare those who are scoring above the median score to those who score below. The SNS is a reliable (Cronbach’s alpha = 0.82) and valid numeracy measure when compared to Objective Numeracy Scale items (r = 0.63–0.68) [17, 21]. |
SNS Ability Subscale | 1–6 Mean | ≤4 Low > 4 High | |
SNS Preference Subscale | 1–6 Mean | ≤4 Low > 4 High | |
Graphical Literacy Measure (GL) | |||
GL Total Score | 0–13 Range | ≤6 Low > 6 High | Each item is worth 1 point and scores range from 0 to 13, with higher scores suggesting higher graphical literacy [37]. There is no established optimal cut-point for the GL. The median cut-point for the total score and for the subscales (levels) was chosen to compare those who have some difficulty with graphical literacy (low) to those who do not have less difficulty with graphical literacy (high) [37, 43,44,45,46]. The GL is an adequately reliable (Cronbach’s alpha = 0.79) and valid (Construct validity = 0.54; Convergent validity = 0.50) measure of graphical literacy [37]. |
GL 1, Reading | 0–4 Range | ≤3 Low > 3 High | |
GL 2, Between | 0–4 Range | ≤1 Low > 1 High | |
GL 3, Beyond | 0–5 Range | ≤2 Low > 2 High | |