The content and quality of information supplied with drug products are among the most specifically defined areas associated with the products for sale. For patient or drug user, the information is presented in patient information leaflets (PILs) placed in the package. The readability testing of PILs is an important stage in the process of making the texts contained in the summary of product characteristics comprehensible to users, as this article discusses.
Summary of product characteristics The SPC is a drug description designed on the basis of research results and aimed at medical prescribers and other health care professionals. The purpose is to give adequate and up-to-date information regarding the drug and, thereby, ensure successful treatment. The SPC, approved in association with the marketing authorization approval process, is an essential part of the marketing authorization and should form the basis of all the information given concerning the drug and its marketing. After approval, the SPC may not be changed without the consent of the authorities.Patient information leaflet The marketing authorization holder draws up a legible and comprehensible PIL based on the SPC and intended for the drug user. Naturally, the text of the SPC intended for drug prescribers is not the same, and is not appropriate, as that directed at patients. The PIL follows the normative headings given by the authorities and an established order of presentation. The PIL contains headings taken from questions frequently asked by patients and the replies are presented in clear language. Typical questions are, for example:
As an aid in the design of the PIL, a legibility study can be used from which it is possible to assess the clarity of the information given in the PIL, the sequence of the details offered and the actual presentation.
A good PIL has a clear, simple and short structure that is comprehensible to the user. The user is generally only interested in the type of information that will give a clear answer to questions regarding what he/she should do and what results/side-effects are to be expected. Clear instructions for use and dealing with possible emergencies are essential. The text of the PIL should avoid unnecessary general information that may obscure any message essential for the use of the drug. Positive instructions and active language targeted directly at the patient are preferred.
The presentation is of great importance from the point of view of readability and comprehensibility. The text should be of sufficiently large type and easily readable. Different colours and text sizes may be used for distinguishing purposes. Clear listings of adverse effects, for example, improve the ease of understanding of the message. The following is a list of some general observations associated with readability:
Test of readability of the PIL The European Union (EU) drug legislation requires that the PILs should be clear and comprehensible. The current guidelines also mention a readability test, which is to be conducted among the PIL users, and which will allow the comprehensibility and clarity of the PILs to be studied. The Guideline on the Readability of the Label and Package Leaflet of Medicinal Product for Human Use (published in Rules governing medicinal products in the European Community; Notice to Applicants, Vol. 2C) was approved in 1998. The guideline recommends the use of a readability test developed in Australia to be used in the assessment of clarity and comprehensibility of PILs. If other methods than the EU model are used in the design of the PIL, the testing of readability is entirely the responsibility of the marketing authorization holder.
For several years, there has been particular attention paid to associating the readability test with the centralized procedure of marketing authorization approval processes. The PILs of a number of drug products have been put through the readability test in accordance with the EU guideline. These tests have permitted better understanding of the problems associated with PILs.
The readability is tested with a series of questions, some of which directly concern the factual content of the PIL. A typical question could be, for example: Imagine that you are allergic to penicillin; could you, in that case, use this medicine? Some of the questions are aimed at testing the general structure of the PIL (for example, the ease or difficulty of finding required information) and could typically be: What are the disadvantages of the PIL, and how could the PIL be improved? The time allowed for the test is naturally limited. The readability test can be done in two stages, which will provide an opportunity to find out whether the improvements made on the PIL have had any effect on its readability.
There are complexities involved in the readability test. The test methods are not yet quite established and the testing of the reliability of the various methods is inadequate. The question is, are we testing the readability of the PIL or the comprehensibility of the list of questions?
In accordance with the EU guideline, the various languages are divided into three groups, and one language of each group is required for the testing of readability:
Some of the languages, particularly those in group C, are not related to each other, which makes it doubtful whether any conclusions can be drawn from the results. A review of the analysed tests shows that there have seldom been any important differences between the results from different countries, which is why the testing of various language versions should be expanded.
Conclusion The content and quality of information supplied with the drug products are among the more specifically defined areas associated with the products for sale. The size of drug packaging is rather small; inserting adequate labelling that would satisfy everybody on the outer package is consequently impossible. Including all information essential for the choice of over-the-counter (OTC) drugs in the PIL is, of course, difficult. In the selection of services they offer, pharmacies should focus on whether it is possible for patients to familiarize themselves with the information leaflet.
Patient information leaflets are sources of information that complement the package labelling. The readability testing of PILs is an important stage in the process of refining the texts contained in the SPCs to make them comprehensible to the users. Readability testing of PILs is not legally required by the authorities, but such tests may improve PILs. The responsibility of PILs lies distinctly with the marketing authorization holder, whereas the correctness of the factual contents is checked by the authorities. From the patient's viewpoint, the implementation of readability testing could be a step towards improved drug information.
The European Council of Ministers has adopted the new EU pharmaceutical directive. As part of the proper use of medicinal products, the rules on packaging have been updated to take into account the experience acquired. Based on the new directive: "The package leaflet shall reflect the results of consultations with target patient groups to ensure that it is legible, clear and easy to use." Additionally, more requirements are set for the applicants of the marketing authorization as it is stated that concerning packages and PILs: "The results of assessments carried out in co-operation with target patient groups shall also be provided to the competent authority."