Table 3 Patient comprehension and safety

Chan 2013 [21]

Comprehension

Guess ability; comprehension

- Mean and standard deviation of scores for all pharmaceutical pictograms were 64.8 and 17.1. The sign with the highest guess ability score was P5 (do not take if pregnant) (87.5), while the sign M3 (take 3 times a day with meals) had the lowest score (34.4) (p < 0.0001)

- Prospective-user factors of the drug purchase experience, attention to drug labels, etc. had no significant effects on guessing performance (p > 0.05). The factors of “occupation,” “age,” and “education level” were found to significantly affect the guessing performance of participants (p < 0.0001)

- The mean ratings for the sign feature evaluations for all the pharmaceutical pictograms were 53.5. (familiarity, SD = 9.7), 66.6 (concreteness, SD = 8.8), 66.3 (simplicity, SD = 8.2), 67.9 (meaningfulness, SD = 8.8), and 72.0 (semantic closeness, SD = 10.1), respectively

- User characteristics and sign features are critical for pharmaceutical pictograms if they are to effectively communicate messages to a user

- Decisions about sign design that involve assumptions about familiarity should be considered together with prospective user factors

- Pharmaceutical graphic designers need to emphasize the design of pharmaceutical pictograms, which have an obvious and direct connection with things encountered in daily life

- To facilitate understanding of the meaning of a sign, the sign should provide a direct visualization aid so that there are links between what is illustrated in the sign and the function it is intended to represent

Safety

Bhansali 2016 [18]

Comprehension

14 item, 5-point Likert scale

Standard label: 4.1 ± 0.5

Label design 1: 3.9 ± 0.5

Label design 2: 4.1 ± 0.6

Place warning information at the end of the Drug Facts panel to improve patient information processing and understanding to enhance patient safety

Safety

You 2011 [22]

Comprehension

Comprehension

Standard label: 76%

Design 1: 79%

Design 2: 94%

- Comprehension of the enhanced text + icon label was significantly higher than the standard and enhanced text-only labels

- After adjusting for age, race/ethnicity, education, literacy, number of medications currently taken, and study site, comprehension of the enhanced text + icon label remained significantly higher than standard and enhanced text-only labels

Teratogen warning labels with easy-to-read messages and icons can significantly improve comprehension

Safety

McCarthy 2013 [23]

Comprehension

Safety

Dosing errors

- The Take-Wait-Stop label worked best on untangling one common aspect of instructions: the maximum daily dose message but did not significantly improve problems with errors related to the spacing of doses

- Errors:

Exceed max dose: (31.8% vs 14%)

 > 2 pills per dose: (2.3% vs 0%)

Interval < 4 h: (20.5% vs 23.3%)

Future directions should improve how a Take-Wait-Stop approach can better communicate all aspects of proper dosing

Sahm 2012 [24]

Comprehension

Generalized estimating equation (GEE) model for correct interpretation of Rx label instructions

- PCL >  >  > standard for the more complex regimen, drug 3 (97% correct interpretation vs 79%; p = 0.02)

In multivariate analyses

- PCL > standard (not significant)

- PCL > PCL + pictogram

- Low literacy: PCL > standard (p = 0.06)

The PCL approach may improve patients’ understanding and use of their medication regimen

Safety

Tong 2018 [19]

Comprehension

User testing

Overall, all 4 alternative label formats supported consumers’ ability to find and understand key points

The existing standard label was poorer concerning participants’ ability to find and understand key points. Factors such as perceived usability, color, design, content, and content ordering impacted consumer preferences

Consumers often preferred the “Consumer Desires” or “Drug Facts” label over the TGA proposed format as the standardized OTC label

User testing of OTC labels and consumer feedback received as part of the testing process can assist in the refinement of OTC labeling to ensure that implemented policies are evidence-based

Safety

Tai 2016 [25]

Comprehension

MLT and STOFHLA score; analysis of covariance

- Participants using redesigned Rx labels showed significantly higher MLT scores than with current Rx labels both before (23.0 ± 2.3 vs 21.0 ± 2.4; p < 0.001) and after educational intervention (23.8 ± 1.7 vs 22.1 ± 3.1; p < 0.001)

- With the use of analysis of covariance, intervention participants using redesigned label showed significant improvement in both MLT (23.1 ± 2.0 to 24.3 ± 1.0; p < 0.001) and STOFHLA (29.8 ± 7.5 to 31.5 ± 5.7; p = 0.011) scores, whereas intervention participants using current Rx label did not show significant improvement in either MLT (p = 0.530) or STOFHLA (p = 0.215) scores

- Use of a redesigned patient-centered Rx label and a label-focused educational intervention should be encouraged to improve Rx label comprehension and FHL

- Simplifying communication with and confirming comprehension for all patients is one of the ways to improve primary care for people with limited health literacy

Safety

Freidman 1997 [20]

Comprehension

Open-ended answers were coded; statistical analysis was performed on close-ended questions

- Comprehension of the version of the symbol among high school non-graduates was significantly lower than the other versions

- No meaningful differences were noted between the graphic-text version and the text-only version

- There was a high rate of accuracy in participants (97%) selecting “see your doctor” on the label, (70%) selecting “read the package insert.”

- Respondents clearly understood the label communication objectives for drug interactions. 80% indicated that one should speak to a doctor before stopping/starting prescription drugs

- There was a high percentage of correct responses in the total population to close-ended questions: types of cholesterol, appropriate use of cholestyramine, preparation, and dosage

- Clear and comprehensible labeling of an OTC product is essential for establishing appropriate use among consumers and thereby maintaining safety and optimizing efficacy and compliance

- Following a systematic approach to developing, revalidation, and testing drug labeling, key messages can be written so that consumers will understand the proper use of a new category of OTC medication for a complex chronic condition

- Labeling must be able to convey the intended use of the product, provide adequate directions for its use, warn against potentially harmful effects, and provide instructions for an appropriate length of treatment and when to seek professional medical advice

Safety

Law 2010 [26]

Comprehension

Predominantly descriptive and also included correlational analysis

- The majority of patients, 366 (82.8%), preferred new labels over existing ones

- About 40% of respondents reported the table of times for administration and indication (27.9%) as advantages of the new labels

- Bigger font size and easiness of reading were other most preferred features, with 27.2 and 19.8% of responses

- Specific areas that could be changed include adding indications to the label, creating a timetable of medication administration, and creating a box for warnings

- Change in the design of labels in addition to content may be welcomed by patients. These include font size increase and changes in placement and white space

Safety

Dowse 2005 [27]

Comprehension

Chi-squared tests were used to test for differences in the understanding of medicine instructions

- The average score for understanding was significantly better in the experimental group (E) (95.2%) than in the control group (C) (69.5%)

- In the experimental group, the majority (72%) displayed a high level of understanding (> 90%)

- Significant correlation was found between literacy and understanding in the control group but not in the experimental group

 < 50% understanding = C 22% vs E 0%

51–70% understanding = C 31.7% vs E 2.2%

71–90% understanding = C 31.7% vs E 26.1%

91–100% understanding = C 14.6% = E 71.7%

p < 0.01

Policymakers and regulatory bodies in countries with a high incidence of inadequate literacy skills should pay particular attention to improving labeling practices and considering the inclusion of pictograms on selected medicine labels

Safety

Adherence (pill count/volume + self-report schedule/instructions)

- A high adherence of greater than 90% was found for 54% of the experimental group, compared with only 2% of the control group

- The presence of pictograms was found to contribute positively to both understanding of instructions and adherence

Desired levels of adherence should be specified for each disease and treatment

Davis 2009 [9]

Comprehension

Generalized estimating equation (GEE)

- 71% of adequate literacy, 84% of marginal literacy, and 93% of low literacy incorrectly interpreted one or more label instructions

- Rates of correct interpretation were lowest for instructions that depicted frequency in hourly intervals or the number of times per day (53% and 61%, respectively)

- Prescription instructions that gave periods or specific times were significantly less likely to be misinterpreted compared to those using the number of times per day

- 23% of responses were coded as incorrect. 78% misunderstood instructions, with 37% misunderstanding a minimum of three labels

- The interaction term for literacy and type of language used to depict drug frequency of use approached but did not reach statistical significance (ARR 0.91, 95% CI 0.85–1.01; p = 0.079)

- Use of precise wording on prescription drug label instructions can improve patient comprehension. Patient’s motivation, concentration, and comprehension might have been greater if they were reporting on their own medicine given by their physician for conditions they or their children had

- It is likely that patient counseling will also be needed to address health literacy deficits

Safety

Yin 2017 [28]

Comprehension

Safety

Dosing accuracy

- 83.5% of parents made ≥ 1 dosing error (overdosing was present in 12.1% of errors), and 29.3% of parents made ≥ 1 large error (> 2 × dose)

- Milliliter/teaspoon was associated with more errors than milliliter-only

- Parents who received text-only (versus text and pictogram) instructions or milliliter/teaspoon (versus milliliter-only) labels and tools made more large errors

Including pictographic diagrams and milliliter-only units on labels and tools may be especially helpful in preventing large dosing errors

Wolf 2016 [29]

Comprehension

Chi-square tests; generalized linear models (GLM); generalized estimating equation (GEE)

- Patients receiving the PCL demonstrated slightly better proper use of their drug regimens at first exposure (76.9% vs 70.1%) and at 9 months (85.9% vs 77.4%)

- The effect of the PCL was significant for English-speaking patients but not for Spanish speakers

- Overall, the PCL label did not improve medication adherence; however, significant benefits from the PCL were found among patients with limited literacy and those with medications to be taken ≥ 2 times a day

- A simple modification to pharmacy-generated labeling, with minimal investment required, can offer modest improvements to regimen use and adherence, mostly among patients with limited literacy and more complex regimens

- Even small increases in the proper use and adherence among subgroups of consumers might yield a cost–benefit

Safety

Malhotra 2019 [30]

Comprehension

Analysis of variance, chi-square tests, univariate and multivariate logistic regression models, univariate and multivariate negative binomial regression models

- The bilingual text label with pictograms (BLTP) had the highest proportions with complete and any understanding (40.1% and 76.5%) and the lowest median number of incorrect answers. Among those who could read English, we observed the highest proportion with complete understanding among those assigned to the BLTP label (59.5%), but the proportion with any understanding and the median number of incorrect answers among those with any understanding was largely similar across the four prototype PMLs

- Those who are unable to read English, the median number of incorrect answers had lower median values in the BLT and BLTP labels than in the ET and ETP labels

Adding bilingual text with or without pictograms on prescription medication labels considerably improved elderly Singaporeans’ understanding of the labels, strongly suggesting its application in practice

Safety