Knowledge of Indonesian cancer patients regarding the management of chemotherapy side effects: a pharmacoepidemiological cross-sectional study

¹Department of Pharmacy, Faculty of Pharmacy, Hasanuddin University, Makassar 90245, South Sulawesi, Indonesia, ²Department of Pulmonology, Faculty of Medicine, Hasanuddin University, Makassar 90245, South Sulawesi, Indonesia

^&Corresponding author
Muh Akbar Bahar, Department of Pharmacy, Faculty of Pharmacy, Hasanuddin University, Makassar 90245, South Sulawesi, Indonesia

Introduction    

Cancer remains a leading cause of mortality and a major barrier to increasing life expectancy worldwide. According to the World Health Organization, cancer was the first or second leading cause of death before the age of 70 years in 112 countries in 2019 [1]. Globally, an estimated 19.3 million new cancer cases and nearly 10 million deaths were reported in 2020, with incidence rates higher among men than women, although substantial regional variations exist [2].

In Indonesia, cancer represents a significant public health burden. Data from the Institute for Health Metrics and Evaluation indicate that cancer is the second leading cause of death in Indonesia (2018), accounting for 13.4% of total mortality, following cardiovascular disease [2]. In 2020, approximately 396,914 new cancer cases and 234,511 deaths were reported nationwide, with breast cancer being the most common malignancy (16.6%) [2]. At the regional level, data from the South Sulawesi Provincial Health Office reported 33,693 cancer cases in 2018, highlighting the substantial local burden of disease in Makassar [3].

Chemotherapy remains a cornerstone in the management of many cancer types [4]. However, its non-selective mechanism of action leads to damage to both malignant and healthy cells, resulting in a wide range of adverse effects [5]. These include fatigue, nausea, vomiting, loss of appetite, fever, and gastrointestinal disturbances, all of which can significantly impair patients' physical condition, emotional well-being, and overall quality of life [6,7]. Importantly, inadequate management of these side effects may lead to dose reductions, treatment delays, or discontinuation, thereby compromising therapeutic outcomes. Effective management of chemotherapy-related side effects requires not only appropriate clinical interventions but also adequate patient knowledge and self-management capacity. A previous study has demonstrated that higher levels of patient knowledge are associated with improved self-care practices and coping strategies in managing chemotherapy-related toxicities [8]. Conversely, insufficient knowledge may contribute to delayed recognition of serious symptoms, inappropriate self-management, reduced treatment adherence, and an increased risk of complications [9]. From a pharmacoepidemiological perspective, understanding patients' knowledge and behavior regarding chemotherapy and its adverse effects is essential to identify gaps in real-world clinical practice and to inform targeted interventions. This approach allows evaluation of population-level patterns of knowledge, treatment experience, and self-management practices, as well as identification of factors influencing patient outcomes.

In this context, oncology pharmacists play a critical role in optimizing patient outcomes [8]. Their involvement in patient education, medication counseling, and safety monitoring has been shown to improve adherence, enhance the safe use of supportive therapies, and reduce the risk of severe adverse effects [10,11]. As integral members of the multidisciplinary cancer care team, pharmacists are well positioned to address knowledge gaps and support patients in managing chemotherapy-related toxicities [11]. Despite the growing recognition of the importance of patient knowledge in chemotherapy management, evidence from Indonesia remains limited, particularly at the patient level. Pharmacoepidemiological data evaluating patients' understanding of chemotherapy side effects and their management practices are lacking. This gap may contribute to suboptimal treatment outcomes and highlights the need for context-specific evidence. Therefore, this study aimed to assess the level of knowledge among cancer patients in Makassar City regarding the management of chemotherapy side effects. The findings are expected to provide a basis for developing targeted educational interventions and strengthening multidisciplinary approaches in oncology care, particularly through the optimization of pharmacist involvement.

Methods     

Study design and setting: a multicenter cross-sectional study was conducted using a structured questionnaire administered through face-to-face interviews with cancer patients over six months. This study was designed from a pharmacoepidemiological perspective to evaluate patients' knowledge of chemotherapy side effects, their understanding of side-effect management, preventive practices, and associated factors. The study was conducted at three hospitals in Makassar City, South Sulawesi, Indonesia, namely Hasanuddin University Hospital, Pelamonia Hospital, and Ibnu Sina Hospital. Data collection was carried out between October 2025 and March 2026.

Study population and eligibility criteria: the study population comprised adult cancer patients undergoing chemotherapy at the participating hospitals. Patients were eligible for inclusion if they met the following criteria: (1) aged ≥18 years; (2) diagnosed with cancer and currently receiving or having previously received chemotherapy; and (3) able to provide informed consent and participate in the interview process. Patients were excluded if they had cognitive impairment that interfered with questionnaire completion or were in a poor clinical condition that prevented participation.

Sample size and sampling technique: the minimum required sample size was calculated using the Slovin formula based on the estimated cancer population in Indonesia (N = 396,914) with a margin of error of 5%. The calculated minimum sample size was 400 participants. A total of 401 patients were ultimately included in the study. Participants were recruited using a convenience sampling approach during their chemotherapy visits at the participating hospitals. All eligible patients who were willing to participate during the study period were consecutively approached and enrolled.

Data collection and study instrument: data were collected using a structured questionnaire adapted from previously published studies [12,13]. The questionnaire was designed to assess multiple domains, including: sociodemographic characteristics, knowledge of chemotherapy regimens, knowledge of chemotherapy side effects, understanding of side-effect management, satisfaction with chemotherapy-related education, health-related behaviors and self-management practices. The questionnaire was administered through face-to-face interviews conducted by a trained researcher to ensure consistency and completeness of responses.

Translation, adaptation, and pre-testing: the questionnaire was translated from English into Indonesian using a forward translation process conducted by two independent professional translators to ensure conceptual equivalence. The translated version was then reviewed by experts in pharmacology and clinical oncology to ensure content validity and contextual relevance. A pilot test was conducted among 10 cancer patients undergoing chemotherapy to assess clarity, comprehensibility, and feasibility. Feedback from participants was used to refine wording and improve the usability of the instrument.

Validity and reliability: construct validity was assessed using Pearson's product-moment correlation to evaluate item-total correlations. Items demonstrating statistically significant correlations with the total score were considered valid. Internal consistency reliability was assessed using Cronbach's alpha coefficient, with a threshold of ≥0.70 indicating acceptable reliability [14,15].

Variables definition and data processing: knowledge of chemotherapy side effects was assessed using multiple items measured on a four-point Likert scale: "do not know," "little knowledge," "know," and "very knowledgeable." These responses were analyzed as ordinal variables and summarized as frequency distributions. Preventive practices were assessed using a four-level behavioral frequency scale: "do not perform," "perform to a limited extent," "perform," and "always perform," corresponding to responses ranging from "never" to "always". Understanding of chemotherapy side-effect management was assessed using dichotomous responses ("know" and "do not know"). Open-ended responses, such as listing premedication drugs or side effects, were coded into binary variables based on whether participants were able to provide at least one correct response. Patient satisfaction and information sources were assessed using multiple-response items. For analysis, responses were summarized based on the most frequently reported sources and preferences. Several sociodemographic and clinical characteristics were included as potential factors associated with patients' knowledge. These variables included age (categorized as 18-40 years and 41-65 years), sex (male or female), educational attainment (high school or below, and diploma/bachelor/postgraduate), presence of comorbidities (yes or no), duration of cancer (<12 months or ≥12 months), and type of cancer, which was categorized into major cancer types such as breast, cervical, lung, colorectal, and hematological malignancies.

Ethical considerations: ethical approval for this study was obtained from the Research Ethics Committee of the Faculty of Pharmacy, Hasanuddin University (approval number: 3783/UN4.1.23/KP.06.05/2025). The study was conducted in accordance with the principles outlined in the Declaration of Helsinki and its subsequent amendments. All participants were informed about the purpose and procedures of the study prior to data collection. Written informed consent was obtained from all participants before their inclusion in the study. Participation was entirely voluntary, and participants were assured of their right to withdraw at any time without any consequences. To ensure confidentiality and data protection, all collected data were anonymized and stored securely in a password-protected database accessible only to the research team. No personally identifiable information was recorded or disclosed at any stage of the study.

Statistical analysis: descriptive statistics were used to summarize participants' demographic and clinical characteristics, as well as knowledge levels. Data were presented as frequencies, percentages, means, and standard deviations, as appropriate. Bivariate analysis using the chi-square test was performed to assess the association between independent variables and patients' knowledge and understanding of chemotherapy side-effect management. A p-value of <0.05 was considered statistically significant. All statistical analyses were performed using IBM SPSS Statistics version 29.0.

Results     

Participant characteristics: a total of 401 cancer patients undergoing chemotherapy were included in this study (Table 1). The majority of participants were female (95%), while males accounted for only 5% of the sample. Most patients were aged 41-65 years (83.8%), with a smaller proportion aged 18-40 years (16.2%). Educational attainment was relatively evenly distributed, with 51.1% of patients having completed a diploma or higher education and 48.9% having a high school education or below. Regarding clinical characteristics, most patients had no comorbidities (78.6%), while 21.4% reported the presence of chronic diseases. More than half of the participants had been diagnosed with cancer for more than 12 months (55.4%). Breast cancer was the most common malignancy (84%), followed by colon cancer (4.7%), ovarian cancer (3.2%), and thyroid cancer (3.0%), while other cancer types were reported in smaller proportions (each <2%).

Knowledge of chemotherapy side effects: overall, patients demonstrated relatively good awareness of common and visible chemotherapy side effects (Table 2). Hair loss was the most recognized side effect, with 58.1% of patients reporting being very knowledgeable and 33.9% having adequate knowledge. Similarly, knowledge of nausea and vomiting was high, with 56.1% of patients being very knowledgeable and 35.2% knowledgeable. A comparable pattern was observed for diarrhea and constipation, with 52.6% of patients reporting high knowledge and 34.4% moderate knowledge. In contrast, knowledge gaps were evident for less visible or more clinically complex side effects. A substantial proportion of patients reported no knowledge of infection-related complications (40.9%), fatigue and pain (36.7%), and wounds or canker sores (30.9%). Psychological side effects were the least recognized, with nearly half of the patients (47.6%) reporting no knowledge. In addition, knowledge related to chemotherapy regimens was markedly limited. Approximately 91% of patients did not understand the frequency and duration of chemotherapy, and 93.8% were unable to identify the names of the chemotherapy drugs they received. These findings indicate that while patients may recognize common symptoms, their understanding of treatment-related aspects remains inadequate.

Association between patient characteristics and knowledge of chemotherapy side effects: the association between patient characteristics and knowledge of chemotherapy side effects is presented in Table 3. Among the variables analyzed, only cancer duration showed a statistically significant association with knowledge level (p < 0.001). Patients with a longer duration of cancer (≥13 months) demonstrated higher levels of knowledge compared with those diagnosed for less than 12 months. In this group, the majority of patients were categorized as having adequate knowledge (26.2%) and very good knowledge (12.2%), whereas only a small proportion (0.7%) remained in the "do not know" category. In contrast, patients with a shorter duration of cancer (<12 months) showed lower knowledge levels, with a higher proportion of patients categorized as having limited or no knowledge.

No statistically significant associations were observed for other variables, including sex (p = 0.956), age (p = 0.111), education level (p = 0.513), comorbidities (p = 0.278), and cancer type (p = 0.437). Female patients predominated across all knowledge categories, particularly in the "know" category (47.4%), reflecting the distribution of the study population. Similarly, patients aged 41-65 years showed higher proportions of adequate knowledge (42.4%) compared with younger patients. Educational level did not demonstrate a significant association with knowledge, although patients with higher education tended to have slightly better knowledge distribution. A similar pattern was observed for comorbidity status, with no meaningful differences between patients with and without chronic conditions. Overall, these findings suggest that longer exposure to cancer and its treatment is associated with improved patient knowledge, while sociodemographic characteristics alone may not be sufficient predictors of knowledge levels.

Preventive practices during chemotherapy: preventive practices during chemotherapy varied substantially across domains (Annex 1). Overall, adherence to essential preventive behaviors was low. The majority of patients did not perform routine body temperature monitoring (86.8%) and did not regularly engage in basic hygiene practices, including maintaining personal cleanliness (97.0%) and regular handwashing (97.0%). Avoidance of crowded places was reported by most patients at a limited level (83.8%), although consistent adherence was minimal. Similarly, dietary modifications were suboptimal, with 64.3% of patients avoiding spicy and fatty foods only to a limited extent, while 35.7% did not adopt this practice at all. Regarding oral care, 92.0% of patients reported using mouthwash only to a limited extent, indicating partial but inconsistent adherence. In contrast, nearly all patients (99.5%) reported avoiding vaccination without prior consultation with a physician at least to some extent, suggesting relatively better adherence compared to other preventive behaviors. These findings indicate that while some preventive behaviors are partially adopted, consistent and optimal implementation remains limited, particularly for fundamental practices such as hygiene and symptom monitoring.

Understanding of chemotherapy side-effect management: patients demonstrated a low level of understanding regarding chemotherapy side-effect management (Annex 1). Understanding related to premedication was particularly limited, with 99.3% of patients reporting no understanding of premedication drugs and 96.5% unable to list them. Similarly, understanding of chemotherapy side effects was inadequate. A majority of patients were unable to list chemotherapy side effects (76.8%) or recognize them (66.1%). In addition, 83.5% of patients did not understand appropriate home-based strategies or medications for managing side effects. In terms of health-related actions, most patients reported that they would seek hospital care when experiencing side effects (83%), whereas only 14.2% managed symptoms independently at home using medications. A small proportion of patients (1.7%) reported taking no action. These findings indicate that patients have limited capacity for independent management of chemotherapy-related side effects, with a strong reliance on healthcare facilities for symptom control.

Patient satisfaction with chemotherapy-related information: all patients (100%) reported that oncologists were their primary source of information regarding chemotherapy and its side effects (Annex 1). No patients identified pharmacists, nurses, family members, or the internet as their primary source of information. Most patients expressed a high level of comfort with information provided by oncologists, both for chemotherapy treatment (94.0%) and side-effect management (94.3%). In contrast, only a small proportion of patients reported comfort with information provided by nurses (4.5-4.7%) and pharmacists (1.2%). All participants perceived that their understanding of chemotherapy and its side effects would improve if more time were spent with oncologists. In terms of information delivery, face-to-face communication was overwhelmingly preferred (98.5%), while other methods were rarely selected. These findings indicate a strong dependence on oncologists for information and highlight the minimal involvement of other healthcare professionals, particularly pharmacists, in patient education.

Association between knowledge and understanding of side-effect management: a statistically significant association was observed between patients' knowledge of chemotherapy side effects and their understanding of side-effect management (p = 0.017) (Annex 1). Despite this association, most patients who lacked understanding of side-effect management were distributed across all levels of knowledge, including those categorized as "know" (48.6%) and "very knowledgeable" (18.5%). Only a small proportion of patients demonstrated both adequate knowledge and understanding of side-effect management (3.2%). These findings indicate that although knowledge and understanding are statistically associated, knowledge alone does not necessarily translate into effective self-management capacity. A substantial proportion of patients with higher levels of knowledge could not still appropriately manage chemotherapy-related side effects.

Discussion     

This study provides a comprehensive pharmacoepidemiological overview of cancer patients' knowledge, preventive practices, and self-management capacity related to chemotherapy side effects in Indonesia. The findings reveal a complex pattern in which patients demonstrate relatively good knowledge of common and visible adverse effects, yet show substantial deficiencies in clinically important areas, including treatment literacy, infection-related risks, and appropriate management of side effects. A key finding of this study is the clear disparity between recognition of common symptoms and deeper therapeutic understanding. Most patients were aware of visible side effects such as hair loss and gastrointestinal disturbances, whereas knowledge of less apparent but clinically significant complications, particularly infection and psychological effects, remained limited. This suggests that patient knowledge is largely shaped by personal experience and observable symptoms rather than structured and comprehensive education [12]. From a clinical perspective, this is concerning because failure to recognize serious complications may delay appropriate care and increase the risk of adverse outcomes.

In addition to these knowledge gaps, this study highlights a critical limitation in treatment-related understanding. Most patients were unable to identify their chemotherapy regimen or understand the frequency and duration of treatment. This reflects a broader issue of limited medication literacy in oncology care. Health literacy plays a key role in cancer care, with important implications for patient experience and outcomes. Those with lower health literacy face greater difficulties processing information, report poorer psychological outcomes and experience a poorer quality of life [16]. From a pharmacoepidemiological standpoint, inadequate understanding of treatment regimens may contribute to unsafe medication use, delayed recognition of adverse drug reactions, and suboptimal adherence to supportive therapies [6]. These findings indicate that current educational approaches may not sufficiently address the complexity of chemotherapy management. Certainly, those subjects with lower educational level and low health literacy are the ones who can benefit mostly from interventions aimed at improving health literacy, but this requires the use of specific strategies [17]. Another important observation is the discrepancy between knowledge and behavior. Although some patients demonstrated awareness of chemotherapy side effects, the implementation of essential preventive practices such as hand hygiene and temperature monitoring was notably low. This indicates that knowledge alone does not necessarily translate into appropriate health behavior [18]. Effective patient education should therefore extend beyond information provision and include strategies that support behavior change, such as reinforcement, practical training, and continuous engagement [17].

The findings related to side-effect management further reinforce this gap. Most patients were unable to identify appropriate medications to manage side effects at home and relied predominantly on hospital visits when symptoms occurred [12]. While this may reflect a cautious approach, it also indicates limited patient empowerment and preparedness for self-management. In settings with constrained healthcare resources, such dependence on facility-based care may contribute to delays in symptom control and increased burden on healthcare services. The role of healthcare professionals in patient education also emerges as a critical issue. This study found that patients relied almost exclusively on oncologists as their primary source of information, with minimal involvement of pharmacists and nurses. This pattern suggests that multidisciplinary care, particularly the role of pharmacists in patient education, has not been fully optimized [19]. Given the established contribution of oncology pharmacists in medication counseling, safety monitoring, and patient support, their limited involvement represents a missed opportunity to improve patient outcomes and enhance the quality of care [20].

The significant association observed between knowledge of chemotherapy side effects and understanding of their management suggests that these domains are related. However, the persistence of inadequate management capacity among patients with higher levels of knowledge indicates that knowledge alone is insufficient to ensure effective self-management [18]. Educational interventions should therefore be designed to bridge the gap between knowledge and practice by incorporating structured, repeated, and behavior-oriented approaches [17]. Importantly, this study also found that cancer duration was significantly associated with patients' knowledge levels, with those having a longer duration of disease demonstrating higher levels of knowledge. This finding suggests that knowledge may be gradually acquired through repeated exposure to treatment and interaction with healthcare providers [18]. However, relying on passive accumulation of knowledge over time may delay optimal patient preparedness, highlighting the need for early and structured educational interventions [17].

These findings should be interpreted in light of several limitations. The cross-sectional design limits the ability to establish causal relationships between knowledge and self-management capacity. The use of convenience sampling from selected hospitals may restrict the generalizability of the findings to other populations and healthcare settings. In addition, the use of interviewer-administered questionnaires may introduce social desirability bias, potentially leading to overestimation of knowledge levels. The measurement of knowledge was based on a study-specific instrument which, although tested for validity and reliability, may not fully capture the multidimensional nature of chemotherapy-related knowledge. Furthermore, important factors such as health literacy, psychological status, and access to information were not assessed and may have influenced the findings.

Despite these limitations, this study provides important insights into real-world gaps in patient knowledge and behavior in the context of chemotherapy. The findings have important implications for clinical practice. There is a need to strengthen patient education through structured and patient-centered approaches that emphasize both knowledge and practical skills [17]. Education should focus on early recognition of side effects, appropriate use of supportive medications, and clear guidance on when to seek medical attention. In addition, the role of pharmacists should be expanded within oncology care to support medication counseling, improve patient understanding, and enhance treatment safety [10]. From a policy perspective, these findings highlight the importance of developing standardized guidelines for patient education in chemotherapy care. Healthcare systems should promote multidisciplinary collaboration and formally integrate pharmacists into cancer care teams [21]. Furthermore, incorporating patient education as a quality indicator within healthcare services may support the improvement of educational practices and ultimately contribute to better patient outcomes.

Limitations: the use of convenience sampling from selected hospitals may restrict the generalizability of the findings to other populations and healthcare settings. In addition, the use of interviewer-administered questionnaires may introduce social desirability bias, potentially leading to overestimation of knowledge levels. The measurement of knowledge was based on a study-specific instrument which, although tested for validity and reliability, may not fully capture the multidimensional nature of chemotherapy-related knowledge. Furthermore, important factors such as health literacy, psychological status, and access to information were not assessed and may have influenced the findings. The absence of multivariable analysis also limits the ability to identify independent determinants of knowledge and self-management.

Conclusion     

This study demonstrates that although cancer patients possess a basic level of knowledge regarding chemotherapy side effects, this knowledge is not adequately translated into understanding, self-management capacity, or the implementation of appropriate preventive practices. Significant gaps remain in patients' ability to manage side effects effectively and independently. These findings highlight the need for more comprehensive, structured, and sustainable educational interventions that go beyond information delivery and focus on improving practical skills and patient empowerment. A multidisciplinary approach is essential, particularly through the optimization of pharmacists' roles in patient education, medication counseling, and supportive care, to enhance patients' knowledge, self-management abilities, and overall quality of life. Furthermore, these results provide important evidence to inform the development of clinical policies in oncology care. Strengthening patient education systems and integrating multidisciplinary care models may contribute to improved treatment effectiveness, better resource utilization, and enhanced quality of care, including psychosocial support, in a sustainable manner.

Competing interests     

The authors declare no competing interests.

Authors' contributions     

Adithyawarman Suaib contributed to conceptualization, methodology, investigation, data curation, and writing - original draft. Habibie Habibie and Arif Santoso contributed to supervision, methodology, validation, and writing - review and editing. Muh Akbar Bahar contributed to methodology, supervision, validation, and writing - review and editing. All authors have read and approved the final version of this manuscript.

Acknowledgments     

The authors would like to express their sincere gratitude to Hasanuddin University Hospital, Ibnu Sina Hospital, and Pelamonia Hospital for their support and cooperation in facilitating this study.

Tables     

Table 1: demographic and clinical characteristics of research subjects (n= 401)

Table 2: level of knowledge of chemotherapy side effects (n=401)

Table 3: association between patient characteristics and knowledge of chemotherapy side effects (N = 401)

Annex     

Annex 1: supplementary materials

References