Breast augmentation with implants is one of the most performed aesthetic surgical procedures worldwide. According to the 2024 International Survey on Aesthetic/Cosmetic Procedures published by the International Society of Aesthetic Plastic Surgery (ISAPS), breast augmentation accounted for approximately 1,658,615 procedures globally, confirming its sustained popularity across continents [1]. The highest national procedure volumes were reported in Brazil (n=232,593, 14.0%) and the United States (n=227,470, 13.7%), followed by Italy (n=74,392, 4.5%), Germany (n=70,128, 4.2%), Mexico (n=67,893, 4.1%), France (n=58,520, 3.5%), Turkey (n=48,179, 2.9%), India (n=47,600, 2.9%), Spain (n=42,129, 2.5%), and Colombia (n=33,984, 2.0%) [1]. Collectively, these 10 countries account for a substantial proportion of all breast augmentation procedures performed worldwide, underscoring the global relevance of patient communication and informed consent across diverse linguistic and cultural settings.

Breast augmentation is pursued for a variety of patient-centered reasons, including restoration of breast volume following pregnancy or weight loss, correction of congenital or acquired asymmetry, enhancement of body proportion, and improvement of self-image and psychosocial well-being. Previous studies have demonstrated that motivation for breast augmentation was typically multifactorial and primarily internally driven rather than resulting from external pressure, with many patients reporting long-standing dissatisfaction with breast appearance and expectations of improved self-confidence and quality of life [2-4]. Patient-reported outcome research showed significant postoperative improvements in satisfaction with breasts and psychosocial and sexual well-being following breast augmentation [5]. Nevertheless, these benefits should be weighed against potential risks.

Implant-based breast augmentation has been associated with both short- and long-term complications, including infection, hematoma, seroma, implant malposition, rupture, and capsular contracture, the latter remaining one of the most frequent indications for revision surgery [6,7]. Moreover, breast implants are not lifetime devices, and patients should be aware of the potential need for additional operations over time [6]. The presence of such device-related and time-dependent risks highlights the critical importance of comprehensive patient counseling.

In this context, informed consent plays a central ethical and clinical role. Valid informed consent requires that patients clearly understand the expected benefits of surgery, the available alternatives, and the full range of possible complications and long-term consequences [8]. However, multiple studies across medical and surgical specialties have shown that informed consent documents often exceed recommended reading levels, thereby limiting patient comprehension and undermining shared decision-making [9,10]. Similar concerns have been raised within plastic surgery, including analyses of online patient education materials related to breast augmentation [11].

Accordingly, the aim of the present study was to evaluate the readability of publicly available online informed consent documents, which represent one of the information resources that prospective patients could access before a surgical consultation. This study was not intended to evaluate institution-specific consent forms routinely used during the formal clinical informed consent process. Publicly available online consent documents for implant-based breast augmentation in the languages of the 10 countries with the highest procedural volumes worldwide according to the 2024 ISAPS survey (Brazil, United States, Italy, Germany, Mexico, France, Turkey, India, Spain, and Colombia) were included [1]. To our knowledge, no previous study has systematically evaluated and compared the readability of breast augmentation informed consent documents across multiple high-volume countries and languages despite the worldwide popularity of this procedure and the increasing reliance on online health information.

The analysis showed that the mean LIX score for preoperative informed consent forms exceeded 50 points. According to the classic interpretation of the LIX score proposed by Anderson [15] and used in contemporary analyses of medical materials [20], the following thresholds were assumed: less than 30 indicates an easy text, 30 to 39 a moderately difficult text, 40 to 49 a difficult text, 50 to 60 a very difficult text, and greater than 60 a text with very high linguistic complexity. An important consideration is that the analyzed documents were publicly available online consent forms rather than institution-specific forms collected directly from clinical practice. Consequently, the present findings should be interpreted as reflecting the readability of consent materials accessible to patients before consultation rather than the readability of documents routinely used during the formal consent process. Nevertheless, publicly available consent forms could influence patient expectations and understanding before meeting with a surgeon and therefore remain clinically relevant.

A score of 50 or greater obtained in this study suggests that the analyzed form should be classified as a very difficult text, significantly exceeding the level considered accessible to the average reader. In our previous study, it was demonstrated that values above 40 could already make consent too difficult to understand for people without specialized training [21].

Although the LIX index enables comparisons across different languages without requiring syllable counting, its interpretation should be considered in light of language-specific linguistic characteristics [15,16]. Moreover, LIX captures only 1 dimension of readability, primarily reflecting sentence length and the proportion of long words. It does not assess other important determinants of text comprehensibility, such as lexical familiarity, semantic complexity, discourse organization, or the use of domain-specific medical terminology. For example, Turkish is characterized by productive agglutinative morphology, whereby multiple grammatical morphemes are attached to a single lexical stem, naturally resulting in longer word forms than those typically observed in more analytic languages such as English [22]. Consequently, higher LIX scores could partly reflect typological differences in language structure rather than greater conceptual complexity for native speakers [22]. Therefore, the original LIX interpretation thresholds should be applied cautiously in multilingual studies, and future research should investigate language-specific calibration and validation of readability cut-off values.

The high linguistic complexity of informed consent documents could limit their actual comprehensibility, with significant ethical and legal consequences. Informed consent, as the foundation of patient autonomy, requires not only the formal provision of information but also the actual understanding of it. Overly complex language could make fully informed decisions about treatment very difficult.

The results of this study indicate a need to simplify the content of forms by shortening sentences, limiting specialized terminology, and adapting the language level to the standards recommended for the general population. Improving the readability of documents could enhance doctor-patient communication and more effectively implement the concept of informed consent.

In this study, English-language materials had lower LIX scores than those in other languages, indicating greater linguistic accessibility of the analyzed texts. The literature emphasized that the English-language digital space is one of the most developed areas of online health communication, and English speakers were among the most active consumers of medical information on the internet [23]. The large scale of internet use for health purposes promotes the development of audience-oriented communication standards. Although ANOVA demonstrated significant differences in mean LIX scores, language groups represented by only a few documents yielded less precise estimates, as reflected by wider CIs. Consequently, comparisons involving these languages should be interpreted with caution, and future studies including larger numbers of consent forms would improve the precision of language-specific estimates.

In addition, the development of social media as a channel for health communication introduced formats characterized by brevity and multimedia content. Microblogging platforms are structurally limited to short messages, which could influence how health information is presented [24]. A systematic review indicated that social media facilitates rapid information exchange and user interaction while also raising concerns about content quality and reliability [25]. Differences in readability between languages could therefore result from a combination of systemic, cultural, and communication factors rather than solely from the ownership model or market structure.

This analysis did not reveal any significant differences in readability between documents prepared by private entities and those prepared by implant manufacturers, scientific societies, or university hospitals. Regardless of their source, informed consent forms had similarly high LIX scores, indicating that they were difficult or very difficult to understand. This means that the problem of excessive linguistic complexity is systemic rather than sector-specific.

No correlation was found between the number of forms analyzed and their average readability level. This indicates that the problem was not the excessive diversity of the consent forms but rather their linguistic structure. In other words, increasing the number of consent forms does not improve the accessibility of the content. Instead, simplifying the document’s structure and language is key. This result suggests that it would be appropriate to develop a single, standardized, and linguistically simplified template for informed consent forms.

This study had several limitations. First, only publicly available online consent forms were analyzed. We did not verify whether these documents were identical to the consent forms routinely used in clinical practice, and therefore, they may not fully represent the documents signed by patients before surgery. Second, Google search results could vary over time and according to geographic location and search engine algorithms despite the use of private browsing mode [26]. In addition, the translated search terms were not formally validated by native speakers or professional translators, which could have influenced document retrieval in some languages. Third, readability was assessed using the LIX index, which evaluates linguistic complexity but does not directly measure patient comprehension or assess the completeness, accuracy, or clinical adequacy of informed consent content. Furthermore, although the LIX index has been successfully applied in multilingual readability research [15-17,19], its interpretation could be influenced by language-specific morphological and syntactic characteristics. Finally, the number of eligible consent forms differed substantially across languages, which could reduce the precision of language-specific estimates, particularly for languages represented by only a few documents. Only 1 eligible German-language form and 1 Hindi-language form were identified. Therefore, these languages were excluded from the comparative statistical analysis. This limited availability could reflect a genuine scarcity of publicly accessible documents or methodological factors, including search term selection, regional indexing, and local publication practices. Consequently, the findings should not be generalized to Germany or India, particularly given Germany’s high procedural volume for breast augmentation.

Although readability indices such as LIX provide an objective and reproducible measure of linguistic complexity, readability alone does not ensure that patients understand informed consent documents. Patient comprehension is also influenced by the patient’s health literacy, educational level, prior knowledge, cultural background, and anxiety and the quality of physician-patient communication [27-29]. Therefore, readability should be regarded as one component of informed consent quality rather than a direct measure of its effectiveness. Future studies should combine readability assessment with qualitative evaluation of content completeness and direct measures of patient comprehension, such as teach-back methods or validated comprehension questionnaires, to determine whether improved readability translates into better patient understanding and more informed decision-making [27-29].

To conclude, the publicly available online breast augmentation consent forms analyzed in this study exhibited high linguistic complexity, indicating that information resources accessible to prospective patients before consultation could be difficult to understand. Although these findings cannot be directly extrapolated to institution-specific consent forms used in routine clinical practice, they highlight the need to simplify the language and structure of online informed consent materials and to evaluate whether similar patterns exist in clinical consent documents.