Readability of medicinal package leaflets: a systematic review

Pires, Carla; Vigário, Marina; Cavaco, Afonso

doi:10.1590/S0034-8910.2015049005559

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Sumário

Review • Rev. Saúde Pública 49 • 2015 • https://doi.org/10.1590/S0034-8910.2015049005559 copy

Readability of medicinal package leaflets: a systematic review

Authorship SCIMAGO INSTITUTIONS RANKINGS

OBJECTIVE

To review studies on the readability of package leaflets of medicinal products for human use.

METHODS

We conducted a systematic literature review between 2008 and 2013 using the keywords “Readability and Package Leaflet” and “Readability and Package Insert” in the academic search engine Biblioteca do Conhecimento Online, comprising different bibliographic resources/databases. The preferred reporting items for systematic reviews and meta-analyses criteria were applied to prepare the draft of the report. Quantitative and qualitative original studies were included. Opinion or review studies not written in English, Portuguese, Italian, French, or Spanish were excluded.

RESULTS

We identified 202 studies, of which 180 were excluded and 22 were enrolled [two enrolling healthcare professionals, 10 enrolling other type of participants (including patients), three focused on adverse reactions, and 7 descriptive studies]. The package leaflets presented various readability problems, such as complex and difficult to understand texts, small font size, or few illustrations. The main methods to assess the readability of the package leaflet were usability tests or legibility formulae. Limitations with these methods included reduced number of participants; lack of readability formulas specifically validated for specific languages (e.g., Portuguese); and absence of an assessment on patients literacy, health knowledge, cognitive skills, levels of satisfaction, and opinions.

CONCLUSIONS

Overall, the package leaflets presented various readability problems. In this review, some methodological limitations were identified, including the participation of a limited number of patients and healthcare professionals, the absence of prior assessments of participant literacy, humor or sense of satisfaction, or the predominance of studies not based on role-plays about the use of medicines. These limitations should be avoided in future studies and be considered when interpreting the results.

Medicine Package Inserts; Comprehension; Consumer Health Information; Review

Criteria
Inclusion	Exclusion

Studies or abstracts	Studies or abstracts
Original	Out of the research period
Quantitative	Repeated
Qualitative	Review or opinion
Exploratory	Not directly related with the research topica^a
Descriptive	Other languages^b

Search tool	Keywords	Total	Repeated	Excluded/Reasons	Selected^a
PubMed	“Readability and Package Insert”	17	1	14	2
				10 - out of the period
				1 - other language^b
				1 - opinion studies
				2 - other topics
	“Readability and Package Leaflet”	67	6	58	3
				34 - out of the period
				2 - other language
				1 - opinion studies
				5 - other topics
				16 - other products^c
B-on	“Readability and Package Insert”	59	20	32	7
				28 - out of period
				1 - other language
				3 - other products
	“Readability and Package Leaflet”	59	3	46	10
				29 - out of period
				4 - opinion studies
				3 - other topics
				10 - other products^c
Total		202	30	150	22

Reference	Objective(s)	Methods	Results	Conclusion
A. Exploratory studies with the participation of health professionals
Cavaco et al,⁵ 2012 (resume)	Optimization of package leaflets	2 groups: potential users and physicians An original and optimized package leaflet (diclofenac) was tested Questionnaires Opinion on technical terms (Likert scale)	42 potential users 42 physicians Satisfaction on the original package leaflet: 0.0% good; 10.0% satisfactory Satisfaction on the technical terms (optimized package leaflet): 20.0% good; 65.0% satisfactory	Lexical modifications produced favorable results
March J et al,²² 2009	Opinion study	Interviews Flesch formula (25 package leaflets)	Participants: (40) patients, (6) physicians, (11) pharmacists and (13) from associations of patients Health professionals attributed more importance to the package leaflets in comparison to patients More difficult issues: dosage, ADR and contra-indications Flesch index: high	The real needs of health professionals and patients should be considered during the development of package leaflets The patients preferred to receive the direct opinion of health professionals
B. 1. Exploratory studies with the participation of potential users of medicines: studies on patients’ comprehension of drug adverse reactions
Knapp et al,¹⁷ 2010 (brief communication)	Comprehension of ADR	ADR presented in different formats Opinion on the preferred format Imaginary scenario: opinion on the probability of ADR (if taking tamoxifen)	134 participants The absolute frequencies (e.g., 48 persons in each 100) were considered more precise/clear than the interval of frequencies (e.g., affect more than one person in each 10)	The use of absolute frequencies to present ADR demonstrated to be more appropriate
Knapp P et al,¹⁸ 2009	Presentation of ADR	Classification of ADR: using verbal (e.g., rare) or numerical (e.g., 1 in 10) descriptors, or both Imaginary scenario: estimate the risk of 4 ADR and satisfaction (if taking tamoxifen)	187 Participants Absolute frequencies were more favorable	Future studies are advisable
B. 2. Exploratory studies with the participation of users or potential users of medicines: comprehension studies
Symonds T et al,²⁶ 2010	Participant comprehension (sildenafil package leaflet)	Two groups of participants: consultationversus hypothetical auto-administration Questionnaire Blind study	Participants: 113 healthy men and 70 with health problems (e.g., prostatic hypertrophy) The results between both groups were concordant in more than 73.9%	It may be necessary to optimize the indications
Shiffman S et al,²⁵ 2011	Participant comprehension (antidepressant information)	Materials: medication guide and package leaflet Blind study 52 participants	A rare and dangerous ADR was identified by less than 20.0% of the participants	The information was not fully understood
Fuch et al,¹² 2010	Text length (evaluation)	Crossover study: 1,105 participants (first phase), and 1,057 participants (second phase) Tested materials: 5 original package leaflets + 5 optimized package leaflets Questionnaire	The location of information was more difficult in the longer package leaflets Average of words: 2,505 (original) and 2,002 (optimized) The optimized package leaflets contained: less technical words (14 versus 86), less abbreviations (4 versus 17), and shorter phrases (7 versus 29)	The length of the package leaflets was related with participant comprehension The shorter package leaflets (1,500 words) were more adequate
Lee et al,¹⁹ 2012 (abstract)	Legibility tests (comparison)	Two package leaflets: over the counter medicines (acetaminophen) Task: difficult words were underlined Questionnaire: the questions were based on imaginary scenarios and related with the topics of the package leaflets	51 students Better scores (73.0% to 80.0%) on: indications, dosage, pregnancy information, contra-indications, and formulation 118 difficult words	Simplification of the package leaflets (friendlier package leaflets)
Maat HP et al,²¹ 2010	Readability (evaluation)	3 original package leaflets + 3 optimized package leaflets (shorter phrases, simple text). Questionnaire	154/164 potential users (original/modified package leaflets) Optimized package leaflets: higher proportion of correct answers and topics located	The use of more narrow criteria to conceive the package leaflets is advisable
Brosnan S et al,¹ 2012	Readability (evaluation)	Patients with a prescription of clozapine A validated tool was used to evaluate patients’ literacy Optimized package leaflet: shorter phrases Questionnaire on comprehension	40 patients Literacy: 29 (72.5%) adequate, 11 low Score of questionnaire: 72.5% (original package leaflet), 95.0% (optimized package leaflet)	It is important to consider patients’ literacy during the optimization of package leaflets
Cavaco A et al,⁶ 2012 (Brief communication)	Literacy and readability	Clients of community pharmacies A validated tool was used to evaluate participant literacy Satisfaction with the readability of a diclofenac package leaflet (Likert scale)	53 participants (40.0% higher education, 80.0% adequate literacy) The average satisfaction was scored slightly below the neutrality Less favorable issues: letter size, medical technical terms, and abbreviations	The readability issues were not related with the literacy level
Calamusa A et al,² 2012	Quantifying knowledge	Questionnaire (drug store in large shopping areas) Topics: medicine use and specific terminology	1,206 adults 42.0% participants mistook contraindications for ADR Lack of information on the long-term use of: laxatives (14.0%) or nasal decongestants (20.0%)	Advice on the use of medicines is recommended
Dowse R et al,⁸ 2011	Participant comprehension	Low-literate participants Package leaflet containing pictograms (anti-retroviral) Interview: locate and explain the information, and give opinion on the use of pictograms	39 participants Average (comprehension): 60.0% The zones of text with pictograms were better understood All participants agreed with the use of pictograms	It is important to consider patient literacy in the development of package leaflets The use of pictograms is likely to increase the intelligibility of package leaflets
Franck J et al,¹¹ 2011	Participant comprehension	2 package leaflets (oxazepam and tetracycline) An informatics tool was used to optimize the package leaflets (brief explanation on medical terms) Legibility tests (in accordance to the guideline of European Medicine Agency)	Participants: 10/20 (original/ optimized package leaflets) Participant literacy: homogeneous Optimized package leaflets: more favorable results	The time and cost to optimize the package leaflets was reduced in consequence of using an informatics methodology
C. Descriptive studies: evaluation of the linguistic characteristics
Weiss SM et al,²⁸ 2010	Adequacy of texts	Informative materials: approved/not approved by Food and Drug Administration Formula of Simple Measure of Gobbledygook (SMOG)	Index of SMOG: above the recommended	Simplification of the package leaflets, especially for the low educated patients
Fuch J et al,¹³ 2010	Information (characterization)	271 package leaflets Quantification: number of words/difficult words Other topics identified: maximum daily dose, ADR, among other	Distribution of the information in the package leaflets: 29.5% maximum daily dosage; 54.6% ADR, and 24.2% frequency of ADR The more recent package leaflets were lengthier and comprised a higher proportion of difficult words	Simplification of the package leaflets, such as useful information to patients
Knapp P et al,³ 2008 (brief communication)	Presentation of ADR	50 Package leaflets Presentation of ADR: characterization and evaluation	20 (40.0%) of the package leaflets gave no indication of the likelihood of the ADR 26 (42.0%) package leaflets included verbal descriptors, such as the general designation “common” 4 (8.0%) included data of frequency	In the majority of the cases ADR were not adequately presented
Pinero-Lopez MA et al,²³ 2011 (abstract)	Evaluation of text-readability	Package leaflets of biopharmaceutical medicines Formulas: SMOG and Flesch	40 package leaflets Readability index: low (both formulas) Most difficult section: ADR	Simplification of the package leaflets
Roskos SE et al,²⁴ 2008	Evaluation of text-readability	7 package leaflets of nasal steroids Formula of Fry The size of letter and illustrations size were evaluated	On average, the package leaflets were classified as appropriate to people with seven years of schooling (instead of the five years recommended) Letter size: 9 instead of 11 (or the minimum recommended size) Only three pictures in the package leaflets	Readability problems were identified
Wallace et al,²⁷ 2007	Adequacy of texts	83 sample of tablets + package leaflets (hospital) Formula of Fry Letter size	Package leaflets: only in 19 samples The package leaflets were classified as appropriate to people with 10 years of schooling (formula values)	Ideally, samples should contain package leaflets Simplification of the package leaflets
Zite NB et al,³⁰ 2008	Characteristics of texts	8 package leaflets (contraceptive). Formula of Gobbledygook “User-Friendliness Toll” to evaluate: layout, graphical aspects and clarity of information	The package leaflets were classified as appropriate to people with 10 years of schooling (formula values) It was found dosage issues and different explanations on the ideal contraceptive effect	Simplification of the package leaflets (review of texts)
Cavaco A et al,⁴ 2010	Evaluation of text-readability	4 package leaflets Translation: Portuguese to English Formulas of SMOG and Flesch-kincaid (English translations)	The package leaflets were classified as appropriate to people with 10 years of schooling (formula values) Correlation of Spearman between the results: high	Simplification of the package leaflets for less-educated people (adjustment/adaptation)

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[1] Correspondence: Afonso Cavaco. Faculdade de Farmácia, Universidade de Lisboa. Av. Prof. Gama Pinto. 1649-003 Lisboa, Portugal. E-mail:acavaco@ff.ul.pt