Understanding Underreporting of Adverse Drug Reactions in the Philippines: A Mixed Methods Study

Abstract

Background

Adverse drug reaction (ADR) reporting is a crucial element in ensuring medication safety and effective pharmacovigilance. However, underreporting of ADRs remains a significant challenge in the Philippines despite efforts made by the national pharmacovigilance center (NPVC). This study aims to explore the factors contributing to underreporting of ADRs among healthcare professionals (HCPs) in the Philippines, with a focus on understanding their knowledge, attitudes, and practices (KAP), as well as evaluating the usability of the online ADR reporting system.

Methods

A mixed-methods approach was employed, integrating quantitative and qualitative research methods. The study involved a KAP survey and focus group discussions (FGDs) with HCPs, including pharmacists, nurses, and physicians. The survey gathered quantitative data on KAP related to ADR reporting, while FGDs provided qualitative insights into contextual factors, misconceptions, and barriers. In addition, a system usability survey (SUS) was conducted among participants at the 1st Philippine Pharmacovigilance Summit to assess the usability of the online ADR reporting system. Data collection spanned 4 weeks, followed by thematic analysis of FGD data and descriptive statistical analysis of survey and SUS data.

Results

The study revealed that HCPs generally recognize the importance of ADR reporting for FDA-approved drugs, vaccines, and antineoplastics, but there is a knowledge gap regarding the reporting of FDA-unapproved drugs. Awareness of the NPVC is limited, with less than half of HCPs (n = 4363) aware of its existence, and even fewer understanding its roles. Reporting practices are inconsistent, with many relying on paper-based methods, and a significant portion of HCPs are unaware of available reporting options. While 71.08% of participants expressed a high likelihood of reporting ADRs if familiar with the process, only 21.54% had actually reported one. Thematic analysis from focus group discussions identified several barriers to effective ADR reporting, including insufficient training, inconsistent practices, fear of legal repercussions, and low adoption of digital tools. The SUS results showed an “okay” usability rating for the online ADR reporting system, with a score of 68.81 (grade C). This shows that while many users found the tool acceptable and fairly easy to use, nearly half of the respondents felt it was too complex.

Conclusions

This study reveals significant knowledge gaps among HCPs in the Philippines regarding ADR reporting. While HCPs acknowledge the importance of ADR reporting for patient safety, many perceive the process as complex and burdensome, which discourages consistent participation. The study highlights key barriers, including legal concerns and complexity of online reporting tools. A key policy implication is the need for government agencies, such as the Food and Drug Administration (FDA) and the Department of Health (DOH), to simplify the ADR reporting process and enhance the design of reporting tools, making them more user-friendly and efficient for healthcare professionals.

Key Points

The study found that while HCPs acknowledge the importance of ADR reporting, significant knowledge gaps, limited awareness, and inconsistent reporting practices persist.

The perceived complexity of the reporting process, along with legal concerns and a lack of organizational support, further discourage HCPs from consistently reporting ADRs.

Simplifying the reporting process, improving the usability of online tools, integrating ADR protocols into daily workflows, and providing comprehensive training can help overcome barriers and enhance ADR reporting practices.

Introduction

Adverse Drug Reactions (ADRs) are defined as noxious and unintended responses to a medicinal product [1]. Recent studies have shown that ADRs account for approximately 6.1% of hospital admissions, a figure consistent with previous meta-analyses indicating that 5–10% of such admissions are due to ADRs. Notably, around half of these cases are preventable [2]. This underscores the crucial role of ADR reporting in ensuring medication safety.

Spontaneous reporting remains the cornerstone of any national pharmacovigilance system. However, underreporting is a persistent issue globally. A systematic review identified inadequate knowledge and negative attitudes among healthcare professionals (HCPs) as the primary factors contributing to this phenomenon [3, 4]. Inadequate knowledge encompasses several key areas. Many HCPs lack a clear understanding of the significance of ADR reporting in enhancing patient safety and improving pharmacovigilance systems. There is often limited awareness of the procedures and channels for reporting, with some believing it to be the exclusive responsibility of certain professions, such as pharmacists or regulatory authorities. Furthermore, insufficient training on how to identify, document, and report ADRs exacerbates this gap, leaving many HCPs unsure of what constitutes a reportable reaction or how to properly submit a report [5]. Addressing these gaps requires targeted educational interventions, such as regular training sessions, clear guidelines, and accessible resources to equip HCPs with the necessary skills and knowledge [5].

Negative attitudes also significantly hinder effective reporting. HCPs may perceive the process as overly time consuming, particularly in high-pressure healthcare settings where they face competing priorities [6]. Concerns about potential legal or professional repercussions from submitting an ADR report further discourage participation. Some HCPs question the value of their reports, doubting whether individual contributions meaningfully impact the broader pharmacovigilance system [5, 7]. In addition, the absence of feedback mechanisms—such as updates on how submitted reports are utilized or their outcomes—often leads to frustration and reduced motivation to engage in future reporting [5]. To mitigate these challenges, implementing robust feedback systems, fostering a non-punitive reporting culture, and emphasizing the tangible benefits of reporting could significantly improve HCP engagement [5, 7].

In the Philippines, ADR reporting remains below global benchmarks. Despite joining the World Health Organization (WHO) Programme for International Drug Monitoring (PIDM) in 1995 and implementing tools such as VigiFlow for electronic submissions, the country continues to face low reporting rates. For instance, in 2011, only 3351 reports were recorded—far below the expected 18,970 based on population size [8, 9]. While reporting increased during the coronavirus disease 2019 (COVID-19) pandemic, with 5644 reports recorded in 2023, the overall rate remains suboptimal. Recent data suggests that the Philippines, classified as a lower-middle-income country, has an ADR reporting rate of only 3 per million population, significantly lower than the average of 12 per million for countries with similar socioeconomic status [10, 11]. In addition, a global pharmacovigilance analysis ranked the Philippines among the eight countries with a declining number of ADR reports over time, underscoring a stagnation despite international efforts to enhance reporting practices [12].

Recent trends indicate a steady rise in online ADR reporting. Pharmacists have consistently submitted the most reports, increasing from 13 in 2015 to 85 in 2023. Consumer participation has also grown significantly, with 283 reports in 2023 compared with just 1 in 2015. Contributions from physicians and other HCPs have risen modestly, while reports from lawyers remain minimal. These trends suggest increased engagement in online reporting, particularly during the COVID-19 pandemic, but underscore the need for targeted interventions to address persistent underreporting (Fig. 1).

Fig. 1.

Total online ADR reports in the Philippines.

Source: Food and Drug Administration, 2024

While recent trends show an increase in online ADR reporting, particularly among pharmacists and consumers, there remains a significant need for targeted interventions to address underreporting. Physicians and nurses, who are primarily responsible for direct patient care, and pharmacists, who manage dispensing and counseling [13], are crucial in detecting and reporting ADRs. Therefore, this study aims to assess the knowledge, attitudes, and practices (KAP) of select healthcare professionals in the Philippines regarding ADR reporting and evaluate the usability of the online ADR reporting system. By examining these factors, this study seeks to fill a gap in the existing literature by providing detailed insights into the specific barriers to ADR reporting within the Philippine context. Furthermore, it aims to offer practical recommendations to improve the country’s pharmacovigilance practices, thus contributing to more effective ADR monitoring and patient safety initiatives.

Methods

Study Design

The study employed a mixed-methods approach [14, 15], integrating qualitative and quantitative research to comprehensively understand ADR reporting practices among HCPs. The KAP component included surveys and focus group discussions (FGDs) to gather quantitative data on knowledge, attitudes, and practices, as well as qualitative insights into contextual factors, misconceptions, and barriers to ADR reporting. In addition, the system usability survey (SUS) was used to assess the usability of the online ADR reporting system among HCPs.

Sampling Design and Study Population

A purposive sampling approach [16] was used to select HCPs—specifically pharmacists, nurses, and physicians—who met the following criteria: holding a valid license, currently practicing, providing a verified email address, and giving informed consent. These HCPs were chosen owing to their central role in ADR detection and reporting. Pharmacists are responsible for dispensing and counseling on medications, while physicians and nurses provide direct patient care and are vital in monitoring and managing patient responses to drugs [13]. This targeted selection ensures that the study captures insights from those most directly involved in pharmacovigilance, addressing key barriers to ADR reporting and contributing to the improvement of the Philippines’ pharmacovigilance practices.

Participants were recruited through partnerships with key professional organizations, including the Philippine Medical Association, Philippine Nurses Association, and Philippine Pharmacists Association. Recruitment was facilitated via these organizations’ official social media platforms and a dedicated study page.

The KAP survey was conducted online via Google Forms, with all participants required to provide informed consent before participating. Participants were also invited to complete the KAP survey during the 1st Philippine Pharmacovigilance Summit, which took place virtually. A total of 4364 HCPs participated in the survey. This sample size is significantly larger than the 350 HCPs surveyed in a similar study conducted in another developing country, which focuses on ADR monitoring practices [13].

For the SUS component, a separate invitation was sent to summit attendees (N = 4373) during the 1st Philippine Pharmacovigilance Summit. However, only respondents who had prior experience using the online ADR reporting system—verified through initial screening questions—were eligible to complete the SUS survey. Participants were also required to provide consent before participating. A total of 499 participants met these criteria and were invited to engage in the survey. These individuals were asked to use the ADR online reporting system during the summit and provide feedback based on their experience. According to a study on usability [17], a sample size of at least 5–10 users is typically sufficient to identify most usability issues with a system, while a sample size of around 50 users can offer more robust insights into system performance. Given the 499 participants who were directly engaged with the system, the study aimed to gather comprehensive feedback to ensure a more reliable and valid assessment of the system’s usability.

The study also included a qualitative component through FGDs. A smaller subset of 11 participants—5 pharmacists, 3 nurses, and 3 physicians—was selected on the basis of their active involvement in ADR reporting. Survey respondents who indicated a willingness to participate in further discussions were directly invited to join the FGDs. While this is a relatively small sample, qualitative research benefits from smaller groups, as they allow for in-depth exploration of individual experiences and perspectives. As highlighted in a previous study, qualitative data from focus groups can provide rich, detailed insights that complement quantitative findings [14], helping to address specific barriers to ADR reporting and enhance understanding of healthcare professionals’ attitudes and practices.

Data Collection

Study Instruments

This study utilized a pre-tested KAP survey questionnaire, administered in English, with sections on knowledge, attitudes, practices, barriers, strategies, and socio-demographics. The KAP questionnaire was specifically validated for this context by consulting six experts in the field of pharmacovigilance, ensuring that the content was both relevant and comprehensive for the target population. Furthermore, the reliability of the questionnaire was assessed using Cronbach’s alpha, which yielded a score of 0.87, indicating high internal consistency and confirming the appropriateness of the instrument for measuring the intended variables.

To complement the quantitative data with contextual insights, FGDs were conducted using guided questions to explore practical experiences, perceptions, and barriers to ADR reporting. Additionally, the study employed the SUS, a validated tool, to evaluate system usability through a ten-question survey scored from 0 to 100, identifying areas for improvement in the user experience [18]. The SUS was selected owing to its wide acceptance in evaluating the usability of online tools and systems, offering a simple yet effective method for assessing the perceived ease of use and overall satisfaction with the ADR online reporting system. The scale's robustness in capturing usability issues has made it a standard tool for assessing user experience in both research and industry settings, making it particularly suitable for this study's evaluation of an online platform designed to facilitate ADR reporting.

Data Collection Procedure

Data collection was conducted from 4 March to 31 March 2022, covering the period before, during, and after the 1st Philippine Pharmacovigilance Summit. The study employed online surveys to assess KAP related to ADR reporting. Before participation, all respondents were required to review an informed consent form outlining the study’s objectives, confidentiality safeguards, and their right to withdraw at any time. The survey system was configured to allow progression only if the respondent explicitly agreed to the consent terms; otherwise, no data was recorded or submitted.

The KAP survey was administered via Google Forms and was accessible through personal computers, tablets, or smartphones. To ensure broad geographic reach, survey links were disseminated via national professional organizations, institutional partners, and social media platforms. All survey questions were mandatory to guarantee complete data for analysis.

For the SUS component, a separate invitation to participate was sent to attendees of the 1st Philippine Pharmacovigilance Summit. The SUS was administered via Google Forms, ensuring accessibility for participants using various devices. Only respondents who completed the SUS survey and met the inclusion criteria were considered. These criteria included prior experience using the online ADR reporting system, verified through eligibility screening questions at the beginning of the survey. Only those who indicated prior system use and provided consent were permitted to proceed to the SUS section, ensuring the validity and relevance of the usability data collected.

To complement the survey findings, FGDs were conducted from April to July 2024 to explore healthcare professionals’ experiences with ADR reporting. Participants were selected on the basis of their involvement in ADR reporting, and survey participants who had expressed interest in joining future discussions were invited directly to participate. The FGDs for pharmacists and doctors were conducted online via a digital platform, while those for nurses were held face-to-face. All sessions were recorded for analysis—online FGDs were recorded through the platform, while face-to-face interviews were recorded using a recording device. Each interview lasted approximately 60 min.

Data saturation was used as a guiding principle to determine when to stop follow-up questions during the FGDs. The researchers stopped asking follow-up questions when no new information or insights emerged, and when participants’ responses became repetitive or redundant. This indicated that a comprehensive understanding of the topic had been reached, ensuring that further questioning would not yield significantly different perspectives. All participants provided informed consent before the FGDs, including approval for the session recordings, which were used for further data analysis.

Data Analysis

Quantitative (Survey and SUS)

Descriptive statistics were used to analyze the quantitative data from both the KAP and SUS survey. The KAP survey data included summarizing the demographic characteristics of the study population, their knowledge, attitudes, and practices regarding ADR reporting, as well as identifying barriers and strategies related to pharmacovigilance. The SUS evaluated the usability of the online ADR reporting system through responses to a set of ten questions. The Statistical Package for Social Sciences (SPSS) [19] was utilized to calculate the SUS scores using the formula SUS score = [(sum of the scores from individual questions − 5) × 2.5], resulting in a range from 0 to 100 [20].

Qualitative (FGD)

A thematic analysis was employed to examine the qualitative data collected from the FGDs, with the goal of identifying recurring themes or patterns [21]. The analysis followed a structured process, beginning with the transcription of all recorded discussions. The researcher then proceeded with an initial open coding phase, where data were segmented into meaningful units and assigned codes that emerged directly from the content [21]. These codes were primarily semantic, meaning they were based on explicit meanings within the data, capturing surface-level information. The process was iterative, with codes being revisited and refined as the analysis progressed to ensure the analysis remained grounded in the data itself. In some cases, latent coding was used to interpret underlying meanings, revealing implicit themes or insights that were not directly stated but were inferred from the context of the discussions.

To enhance the rigor of the coding process, two independent researchers were involved. After the initial coding, both researchers compared their findings and resolved any discrepancies through discussions and consensus-building. This process ensured inter-rater reliability, consistency, and minimized subjective bias. The final thematic categories were derived by synthesizing the codes and identifying patterns that aligned with the study’s research questions.

For data analysis, AILYZE Lite [22]—an online tool for qualitative data analysis—was used. While AILYZE Lite is less commonly employed in qualitative research compared with more widely known software, its use was justified in this study owing to its ability to efficiently manage and analyze a large volume of text data while remaining user-friendly for the research team. The tool’s output was cross-checked manually by the researchers, and the results were validated by comparing them with the initial coding and through manual verification. This ensured the credibility and accuracy of the findings.

Results

Knowledge, Attitudes, and Practices Among Healthcare Professionals Towards ADR Reporting

Quantitative (Survey)

Demographic Profile of the Respondents

The results of the KAP survey are based on 4364 completed responses, representing participants who fully engaged with the survey from start to finish. These responses provide valuable insights into the current state of knowledge, attitudes, and practices regarding ADR reporting among HCPs. The demographic profile, as shown in Table 1, reveals a diverse age distribution, with the majority of HCPs being young professionals aged 20–39 years, accounting for 75.77% of the total respondents, including 50.71% aged 20–29 years. In contrast, only 1.83% of the respondents are aged 60 years or older. The sample also reflects a significant gender imbalance, with females comprising 84.99% and males 15.01%. Pharmacists make up the largest group at 88.34%, followed by nurses at 10.17%, and physicians at 1.49%. Experience levels are well distributed, with 27.43% having 2–4 years of experience and 24.41% with 5–9 years, indicating a mix of both newcomers and seasoned professionals.

Table 1.

Socio-demographic characteristics of the participants

Profile	n	%
Age (in years)
20–29	2213	50.71
30–39	1094	25.06
40–49	699	16.02
50–59	278	6.37
> 60	80	1.83
Sex
Male	655	15.01
Female	3709	84.99
Profession
Pharmacist	3855	88.34
Nurse	444	10.17
Physician	65	1.49
Years of experience as healthcare worker
0–1	548	12.56
2–4	1197	27.43
5–9	1109	24.41
10–14	546	12.51
15–19	324	7.42
20 or more	640	14.67

N = 4364

Knowledge of Healthcare Professionals towards Adverse Drug Reaction Reporting

The findings, as shown in Table 2, reveal varying levels of knowledge among HCPs about ADR reporting; most understand the importance of reporting ADRs for FDA-approved drugs (91.80%), existing drugs (88.57%), vaccines (90.65%), and antineoplastics (84.60%), but fewer see the need for reporting on FDA-unapproved drugs (73.63%), showing gaps in vigilance. Awareness of the NPVC is low, with only 46.29% aware of its existence and 35.59% familiar with its roles, indicating a need for greater promotion of its role in medication safety. Reporting practices are inconsistent, with 74.40% of professionals having guidelines and 25.60% lacking them, and many relying on paper-based methods (41.73%) as their only option, rather than digital tools such as online ADR reporting (18.79%). In addition, 4.93% are unaware of any reporting options, highlighting the need for more accessible digital platforms. HCPs mainly rely on sources such as the FDA website (74.20%) and textbooks (65.47%), while the use of international agencies (33.23%) and pharmacovigilance databases (7.24%) remains low. These findings suggest the need to increase awareness of the NPVC, promote digital reporting tools, and improve access to reliable ADR information to enhance pharmacovigilance and patient safety.

Table 2.

Knowledge of healthcare professionals on ADR reporting

Category	Statements/questions	n	%
Types of ADRs to be reported	ADRs to herbal medicine, herbal supplement, and traditionally used herbal products	3480	79.74
	ADRs to newly FDA-approved drugs (prescription and nonprescription drugs)	4006	91.80
	ADRs to existing FDA-approved drugs (prescription and nonprescription drugs)	3865	88.57
	ADRs to vaccines	3956	90.65
	ADRs to antineoplastics	3692	84.60
	ADRs to FDA-unapproved drugs (prescription and nonprescription drugs)	3213	73.63
Knowledge on NPVC	Are you aware of the NPVC in the Philippines?	2020 (Yes)	46.29
	Are you aware of the roles, programs, and projects of the NPVC?	1553 (Yes)	35.59
Knowledge on ADR reporting in the workplace	Are there guidelines available in your workplace pertaining to ADR reporting?	3247 (Yes)	74.40
Available reporting options in the workplace	Paper-based reporting only	1355	41.73
	Online ADR reporting only	610	18.79
	Telephone call to the NPVC only	46	1.42
	Paper-based reporting and online ADR reporting system	642	19.77
	Paper-based reporting and telephone call to the NPVC	48	1.48
	Paper-based reporting, online ADR reporting, and telephone call to the NPVC	298	9.18
	Online ADR reporting and telephone call to the NPVC	88	2.71
	No idea	160	4.93
Sources of information for ADRs to newer drugs	Textbooks, journals (both printed and online)	2857	65.47
	FDA Philippines website and its related platform	3238	74.20
	Foreign regulatory agencies (e.g., US FDA, European Medicines Agency)	1450	33.23
	Internet (other than regulatory agencies website and their platforms)	2969	68.03
	Seminars/conferences	2639	60.47
	Drug advertisements, product catalog, and product inserts	2154	49.36
	VigiAccess™	316	7.24
	HCPs and medical representatives	2111	48.37

N = 4364

Attitudes of Healthcare Professionals toward Adverse Drug Reaction Reporting

The data in Table 3 reveal that 71.08% of participants are very likely, and 25.96% are likely to report an ADR if they know how, indicating a strong commitment to pharmacovigilance. Only a small percentage are unlikely and very unlikely to report. These findings demonstrate a proactive attitude towards ADR reporting, crucial for enhancing patient safety and strengthening the pharmacovigilance system.

Table 3.

Likelihood of reporting ADR by HCPs

Question	Participant’s answer n (%)
	Very unlikely	Unlikely	Likely	Very likely
If you suspected an adverse reaction associated with a medication AND knew how to report the reaction, how likely would you be to report the event?	16 (0.37)	113 (2.59)	1133 (25.96)	3102 (71.08)

N = 4364

The data in Table 4 show that many HCPs believe most potential ADRs are known when a new medication is introduced, indicating confidence in pre-market evaluations. However, continuous post-market reporting remains essential, as many ADRs only become apparent after widespread use. The majority (80.4%) strongly agree that ADR reporting is crucial for patient safety, reflecting a strong commitment to pharmacovigilance. Notably, 35.1% of participants, who either agree or strongly agree, indicate that they do not know whose responsibility it is to report a suspected ADR, revealing confusion and a need for clearer guidelines on reporting roles. Participants are more likely to report serious or severe ADRs, particularly in high-risk populations (infants, pregnant women, and older adults), ADRs related to vaccines, and those highlighted by specific alerts. These findings suggest a generally positive attitude towards ADR reporting but also highlight the need for clearer responsibilities and more consistent practices to enhance patient safety.

Table 4.

Attitudes of HCPs towards ADR reporting

Statements	Participant’s answer n (%)
	Strongly disagree	Disagree	Agree	Strongly agree
1. I know when a new medication is introduced, the majority of potential ADRs are already known.	451 (10.30)	1005 (23.0)	1870 (42.9)	1038 (23.80)
2. I know when reporting a suspected ADR contributes to patient safety.	17 (0.40)	102 (2.30)	737 (16.90)	3508 (80.40)
3. I do not know whose responsibility it is to report a suspected ADR.	1545 (35.40)	1287 (29.50)	1049 (24.00)	483 (11.10)
4. I would be more likely to report a suspected ADR if it was serious or if it was severe.	176 (4.00)	315 (7.20)	1036 (23.70)	2837 (65.0)
5. I would be MORE likely to report a suspected ADR if the adverse reaction occurred in an infant.	146 (3.30)	242 (5.50)	980 (22.50)	2996 (68.70)
6. I would be MORE likely to report a suspected ADR if the adverse event occurred in a pregnant woman than in a woman who was not pregnant.	388 (8.90)	484 (11.10)	1223 (28.00)	2269 (52.00)
7. I would be MORE likely to report a suspected ADR if the adverse event occurred in a person 65 years or older than in a patient less than 65 years of age.	377 (8.60)	551 (12.60)	1248 (28.60)	2188 (50.10)
8. I would be MORE likely to report a suspected ADR if it was a vaccine.	194 (4.40)	286 (6.60)	1136 (26.00)	2748 (63.00)
9. I would be MORE likely to report a suspected ADR if I was alerted to be looking for a specific adverse event	144 (3.30)	308 (7.10)	1383 (31.70)	2529 (58.00)
10. I would be MORE likely to report a suspected ADR if it was a newly approved medicine with new active pharmaceutical ingredient	96 (2.20)	179 (4.10)	1140 (26.10)	2949 (67.60)

N = 4364

Practices of HCPs toward ADR Reporting

Table 5 shows that only 21.54% of HCPs have reported suspected ADRs, while 78.46% have not, revealing a significant gap in reporting practices. Among those who reported, 40.11% did so to the NPVC, 27.45% to the drug manufacturer, and 61.60% to their institution, indicating varied reporting channels. Most reported only once (61.49%) or two to five times (33.30%), with few reporting more frequently. Of those who have not reported, 68.75% know how, suggesting potential for future engagement. In the past year, 42.19% observed suspected ADRs. Digital platforms are preferred for reporting, with 77.31% favoring online websites and 54.14% using mobile apps, while fax is least preferred. These findings highlight the need for greater awareness, training, and accessible digital tools to improve ADR reporting.

Table 5.

Practices of HCPs on ADR reporting

Category	Statements/questions	n	%
Reporting of ADRs	Have you ever reported what you suspected to be an ADR?	Yes: 940	21.54
		No: 3424	78.46
Follow-up on reporting location	NPVC/FDA	377	40.11
	Drug company/manufacturer	258	27.45
	Company/institution that I’m connected with	579	61.60
Follow-up on reporting frequency	At least once (1)	578	61.49
	2–5 times	313	33.30
	6–10 times	26	2.77
	11 or more	23	2.45
Follow-up on reporting process	If not, and you have suspected an adverse event associated with a medication, would you know how to report it?	Yes: 2354	68.75
		No: 1070	31.25
Observation of suspected ADRs	Over the past year, have you seen a patient whose symptoms you suspected to be an adverse event associated with a medication?	Yes: 1841	42.19
		No: 2523	57.81
Preferred reporting method	Fax	86	1.97
	Online (website)	3374	77.31
	Online (thru mobile app)	2363	54.14
	Mail-in form	903	20.69
	Call NPVC to report	869	19.91
	Text NPVC to report	708	16.22

N = 4364

Barriers and Strategies toward ADR Reporting

Figure 2 shows several reasons and barriers that prevent HCPs from reporting suspected ADRs. The most common barrier is never having had a patient with a suspected ADR (48.85%), indicating a need for ongoing training and awareness. Other barriers include difficulty deciding if an ADR has occurred (34.81%), uncertainty about whether a specific drug caused the reaction (32.26%), and concerns about the seriousness of the event (8.13%), suggesting that some professionals may underestimate the importance of reporting less severe ADRs. Technological barriers, such as difficulty accessing a report form (27.04%) or submitting it (16.45%), point to the need for more accessible and efficient reporting processes. In addition, concerns about legal liability (18.56%) indicate a need for clearer legal protections for those involved in ADR reporting.

Fig. 2.

Barriers in ADR reporting in the Philippines

Figure 3 shows the strategies that HCPs believe would encourage them to report suspected ADRs. The majority (81.40%) see better access to ADR reporting forms as crucial, indicating a need for more streamlined and readily available tools. In addition, 77.31% highlight the importance of reference materials on what, where, and how to report ADRs. The need for specific training on ADR reporting (69.90%) underscores the necessity for education in pharmacovigilance. Updated technological tools, such as mobile apps or software (65.50%), are also viewed as valuable for making reporting easier and more efficient. Providing incentives and reward programs (30.80%) could further motivate professionals to engage in ADR reporting.

Fig. 3.

Strategies for improving ADR reporting in the Philippines

Qualitative (FGD)

The FGDs provided valuable qualitative insights into attitudes, practices, and challenges related to ADR reporting systems. Table 6 summarizes the thematic analysis, categorizing key themes. The knowledge theme revealed varying levels of understanding about ADRs and reporting tools, highlighting the need for targeted training. The attitude theme showed awareness of ADR reporting’s importance but also identified barriers such as fear of repercussions and cultural norms. The practice theme pointed to inconsistent reporting methods and reliance on informal channels, suggesting a need for standardized protocols and digital tools. The barriers’ theme highlighted challenges such as time constraints, lack of training, and unclear guidelines. Finally, the strategies’ theme suggested solutions such as training programs, user-friendly tools, incentives, collaboration, and public awareness efforts to improve ADR reporting.

Table 6.

Themes emerged during FGDs

Category	Themes	Illustrative quote
Knowledge	Varying levels of understanding and awareness on ADRs	(P9) I understand an ADR to be any harmful or unintended effect of a medication, whether it's expected or not. (P1) I’m not always sure what qualifies as an ADR that needs to be reported. I know serious ones like anaphylaxis should be reported, but I'm unsure about milder reactions like nausea or headaches.
	Knowledge gaps in reporting processes and digital tools	(P4) I know that the FDA requires us to report ADRs, but I don't know the exact steps or forms to use. (P3) I've heard about the online ADR reporting system, but I have never been trained on how to use it, and it’s not something that we’ve been instructed to use regularly. Another participant echoed. (P7) I don't even know where to find the online reporting or how it works. I think most of us would be more willing to use it if we were shown how.
	Insufficient training and ongoing professional development	(P2) I’ve been in practice for over ten years, but I’ve only received training on ADR reporting once, and that was a long time ago. We need regular updates and refreshers because things change, and it's easy to forget what the current requirements are.
	Understanding of common ADRs and high-risk drug classes	(P11) I know that antibiotics, especially penicillin’s and cephalosporins, are common culprits for allergic reactions. (P1) I'm not sure which medications are most likely to cause ADRs. I just rely on what the doctors tell us, and we watch for the symptoms they mention.
Attitude	Recognition of importance versus practical and perceptual barriers	(P8) We understand that reporting ADRs is crucial, especially for tracking drug safety and protecting patients, but in reality, it feels like it's something we do only if we have the time.
	Fear of legal and professional repercussions	(P3) There's always a worry that if you report something, it could come back to you — maybe the company will ask you questions, or worse, there could be some legal implications if it's seen as negligence.
	Lack of feedback and acknowledgment from regulatory bodies	(P6) It feels like we are sending reports into a black hole — there’s no feedback or acknowledgment.
	Deflection of responsibility for ADR reporting	(P3) We often think that it's the doctor's job to report ADRs since they are the ones prescribing the medication. We just dispense the drugs and advise the patients.
	Influence of cultural norms and stigma	(P5) There is still a stigma attached to reporting in some places — it’s sometimes seen as admitting fault or failure.
Practice	Inconsistent and selective reporting practices	(P1) We only report the most severe cases or those that seem really out of the ordinary.
	Reliance on informal and alternative reporting channels	(P11) We do know there is a form to fill out for ADRs, but honestly, it’s a lengthy process, and we don’t always have the time, especially in a busy ward. It feels like an added burden, so we just make a note in the patient's chart and move on (P6) We often encourage patients to go back to their doctor if they experience any adverse effects.
	Low utilization of digital reporting tools	(P8) We have not adopted the online ADR reporting system because, frankly, none of us have been trained on it, and it’s not clear how we’re supposed to integrate it into our daily routines
	Variability in reporting based on practice setting	(P4) We see ADRs almost daily, particularly with antibiotics, pain medications, and blood pressure drugs. Many of these reactions are mild, but occasionally we have severe cases like severe allergic reactions or internal bleeding.
Barriers	Time constraints and workload pressure	(P7) Taking extra time to fill out an ADR report is just not feasible most days
	Lack of knowledge, training, and awareness	(P2) I’ve been in practice for over 10 years, but I’ve only received training on ADR reporting once, and that was a long time ago. We need regular updates and refreshers because things change, and it’s easy to forget what the current requirements are
	Complexity and burdensome nature of the reporting process	(P4) We find the reporting forms too detailed and confusing at times. If it were more straightforward, like a simple online form or a mobile app, I think more people would report
	Inadequate infrastructure and technological barriers	(P11) We don’t have the resources or the technology to access online tools, so we rely on paper forms, which take longer to process and often get lost or delayed
	Lack of clear guidelines and standardized protocols	(P8) Sometimes, it’s unclear who should report the ADR—the nurse, the pharmacist, or the doctor? Without clear roles and responsibilities, reports can fall through the cracks
Strategies	Targeted training programs	(P3) We need specific training sessions for pharmacists and other healthcare workers on how to report ADRs properly. This should include understanding the kinds of reactions that need to be reported and how to use the tools available
	User-friendly reporting tools	(P5) Developing a mobile app or an integrated system within electronic health records could make it much easier to report ADRs quickly, without having to fill out lengthy forms
	Incentive programs	(P10) If there were small incentives, even just acknowledgments from the FDA or the hospital administration, it could motivate more healthcare workers to take ADR reporting seriously
	Collaborative efforts with professional organizations	(P11) Public forums or joint initiatives between the FDA and healthcare organizations could raise awareness and foster a culture of safety and responsibility in ADR reporting
	Feedback and communication channels	(P5) If we don't know what happens after we report an ADR, it feels like we are just sending information into a void. It would help if there were a system where we could get updates on the status of our reports
	Utilizing public awareness campaigns	(P1) Using social media and other platforms to educate the public and healthcare workers about ADR reporting could reach a wider audience

N = 11

SUS of the Online ADR Reporting System

The results of the SUS are based on responses from 499 participants who self-responded and passed the inclusion criteria out of a total of 4373 attendees of the 1st Philippine Pharmacovigilance Summit. Only those who had prior experience using the online ADR reporting system, verified through initial screening questions, and who provided consent, were eligible to complete the survey. Participants were asked to use the ADR online reporting system during the summit and provide feedback based on their experience. These findings offer a comprehensive evaluation of the system’s usability of the online ADR reporting system, highlighting its strengths and identifying areas for potential improvement in the ADR reporting process.

Table 7 summarizes the results of a SUS assessment for the FDA’s online ADR reporting system. Most participants (55.71% strongly agreed and 33.67% agreed) said they would like to use the tool frequently, resulting in a SUS score of 68.81, which is considered “okay” or a grade C for usability. This shows that while many users found the tool acceptable and fairly easy to use, nearly half (48.29%) felt it was too complex, indicating a need for a simpler design.

Table 7.

SUS of FDA’s online ADR reporting

Statements	Participant’s answer n (%)					SUS score
	Strongly disagree	Disagree	Neutral	Agree	Strongly agree	M (SD)	SUS grade
1. I think I would like to use this tool frequently	2 (0.40)	5 (1.00)	46 (46)	168 (33.67)	278 (55.71)	68.81 (15.52)	Okay and grade C
2. I found the tool unnecessarily complex	111 (22.24)	130 (26.05)	125 (25.05)	101 (20.24)	32 (6.41)
3. I thought the tool was easy to use	5 (1.00)	12 (2.40)	117 (23.45	195 (39.08)	170 (34.07)
4. I think that I would need the support of a technical person to be able to use this system	104 (20.84)	107 (21.44)	122 (24.45)	99 (19.84)	67 (13.43)
5. I found the various functions in this tool were well integrated	0 (0.00)	6 (1.20)	70 (14.03)	219 (43.89)	204 (40.88
6. I thought there was too much inconsistency in this tool	112 (22.44)	154 (30.86)	140 (28.06)	70 (14.03)	23 (4.61)
7. I would imagine that most people would learn to use this tool very quickly	5 (1.00)	13 (2.61)	94 (18.84)	178 (35.67)	209 (41.88)
8. I found the tool very cumbersome to use	176 (35.27)	167 (33.47)	100 (20.04)	44 (8.82)	12 (2.40)
9. I felt very confident using the tool	4 (0.80)	9 (1.80)	122 (24.45)	185 (37.07)	179 (35.87)
10. I needed to learn a lot of things before I could get going with this tool	56 (11.22)	70 (14.03)	119 (23.85)	151 (30.26)	103 (20.64)

N = 499. SUS score interpretation: > 80.3 (grade A—excellent), 68–80.3 (grade B—Good), 68 (grade C—okay), 51–68 (grade D—poor), and < 51 (grade F—awful)

Although 73.15% found the tool easy to use, 40.28% said they would need technical support, suggesting that training and support are essential for boosting user confidence. On the positive side, 72.94% felt confident using the tool, and 77.55% believed that most people would quickly learn how to use it. Overall, the results suggest a generally positive view of the tool’s usability, but they also highlight the need for ongoing improvements, user-focused design, and better support to make ADR reporting easier and more effective.

Discussion

The findings reveal a significant lack of knowledge among HCPs regarding ADR reporting mechanisms, particularly the NPVC and its functions. While a modest majority were aware of the NPVC, far fewer understood its role, or the steps involved in ADR reporting. This knowledge gap echoes findings from low- and middle-income countries (LMICs) such as Thailand and Ghana, where limited awareness of pharmacovigilance systems hinders reporting efforts [13, 23]. The unfamiliarity with digital reporting platforms further compounds this issue, as many HCPs lack the confidence to use such tools effectively. These insights point to the urgent need for targeted training interventions—such as those successfully implemented in Nigeria and India [24, 25]—that not only build knowledge but also develop hands-on skills in using reporting systems. Such training should emphasize the clinical and public health significance of reporting all ADRs, including minor or expected reactions, to reinforce the broader role of pharmacovigilance in patient safety.

A unique and culturally rooted barrier identified in this study is the stigma surrounding drug-related failures. In the Philippines, acknowledging or reporting an ADR is often perceived as an admission of professional incompetence or error. This cultural reluctance, driven by fear of personal or institutional repercussions, significantly impedes open communication and reporting. This contrasts with Western healthcare environments, where transparency and reporting are seen as essential to improving care. As demonstrated by international experiences [26, 27], fostering a culture of safety—where ADR reporting is normalized and encouraged as part of quality improvement—can meaningfully increase reporting rates. Addressing this cultural barrier requires institutional leadership and advocacy to shift norms toward greater openness and support.

In addition to cultural factors, practical barriers such as the complexity and time-consuming nature of ADR reporting were consistently cited. HCPs often see reporting as burdensome, competing with their primary responsibilities of patient care—an issue widely documented in global literature [28, 29]. Administrative indifference and the absence of feedback further discourage engagement. Without knowing the outcomes or impacts of their reports, many professionals view the process as futile. This is a well-known deterrent in pharmacovigilance and must be countered with better feedback loops and communication [26, 27]. Legal concerns and fear of professional consequences further reduce reporting rates, especially in environments lacking clear protective policies or institutional support [23].

Focus group discussions revealed that ADR reporting tends to occur only for severe or life-threatening reactions, with milder or expected ADRs often overlooked. This selective reporting mirrors trends in other countries, such as the UK and Pakistan, where only critical ADRs are typically documented [30, 31]. Delegating the task of reporting to other departments or even patients was also mentioned, resulting in incomplete and inconsistent data. To address this, standardized, well-communicated protocols must be developed to clarify who is responsible for ADR reporting and to ensure that all cases—regardless of severity—are systematically captured.

The usability assessment of the FDA’s online ADR reporting system yielded a mean SUS score of 68.81, suggesting that while the tool is generally usable, it is far from optimal. Nearly half of respondents described the system as unnecessarily complicated, a concern aligned with similar findings in other digital health tool evaluations [32, 33]. Although many users expressed confidence in their ability to navigate the system, they also reported a need for technical support and a more intuitive interface. Lessons from usability improvements in the USA and Europe suggest that simplifying the tool’s design and integrating it with existing electronic health record (EHR) systems can greatly enhance adoption and data quality [34]. These design improvements, along with routine technical support and periodic system updates, can ease the burden on HCPs and foster regular reporting behaviors.

To overcome the barriers identified, the study proposes a multi-pronged set of recommendations. Streamlining the reporting process and integrating it into routine clinical workflows would reduce the perceived burden and increase participation—an approach supported by international best practices [33, 34]. Comprehensive training that balances theoretical knowledge with practical digital literacy would help bridge both awareness and skills gaps [35, 36]. Fostering a supportive institutional culture—through leadership endorsement, peer role models, and recognition programs—can shift attitudes and increase motivation for pharmacovigilance engagement [25, 37]. Crucially, establishing effective feedback mechanisms, such as notifying HCPs of report outcomes or acknowledging submissions, would enhance the perceived value of participation, as evidenced by systems in the Netherlands and Sweden [26, 27].

This study—recognized by the researchers as the first in the Philippines to involve a large and diverse sample of healthcare professionals for a KAP survey on ADR reporting—also represents the first known effort to assess the usability of the online ADR reporting system using the SUS. Conducted in partnership with a recognized professional organization, the study leveraged established networks to reach a broad base of healthcare professionals, thereby enhancing credibility and participant engagement. Although the qualitative component involved a relatively small number of participants, it was designed to complement the survey findings by providing deeper insights into the technical, organizational, and cultural challenges healthcare professionals face in ADR reporting. The integration of both quantitative and qualitative data enriched the overall understanding of the barriers to effective pharmacovigilance. As such, this research contributes significantly to the growing body of literature on pharmacovigilance in LMICs and offers a strong foundation for policy and system-level improvements. Future studies are encouraged to test and measure the impact of proposed interventions—such as enhanced training, system redesign, and feedback loops—on actual ADR reporting behaviors and data quality.

Limitations

The study’s limitations include its focus on the Philippine context, which restricts generalizability to other healthcare systems, and the relatively small number of focus group participants, though data saturation was achieved. The disproportionate representation of healthcare professionals in the FGDs was intentional but may still affect the balance of perspectives. In addition, the timeline gap between the survey and FGDs, while necessary for analysis, may introduce temporal discrepancies. Future research should include larger samples for FGDs to enhance qualitative findings.

Conclusions

Underreporting of ADRs in the Philippines is a complex issue caused by factors such as knowledge gaps among HCPs, perceived difficulties in the reporting process, legal concerns, and the complexity of online reporting tools. To address this, government agencies such as the Food and Drug Administration (FDA) and the Department of Health (DOH) should simplify reporting procedures, while the FDA, in partnership with tech developers, should enhance the design of ADR reporting tools. Professional organizations, universities, and healthcare administrators must provide continuous training for HCPs on ADR reporting, and hospital administrators should integrate ADR protocols into daily clinical workflows. Academic institutions, in collaboration with professional groups, should also include ADR reporting in healthcare curricula. Lastly, FDA, DOH, hospitals, and policymakers should foster a culture of proactive reporting by offering incentives and feedback to encourage consistent participation. These coordinated efforts will help improve ADR reporting and enhance patient safety in the Philippines.

Declarations

Ethical Standard

This study was conducted in accordance with the ethical principles outlined in the Declaration of Helsinki, ensuring respect for individuals, beneficence, and justice. Ethical approval for the research was obtained from the appropriate institutional review board prior to the commencement of the study, and informed consent was obtained from all participants.

Conflict of Interest

Some of the authors (M.R.L., J.A.C., L.A.L.D., R.A.O., and J.E.V.) are employed by the Food and Drug Administration of the Philippines and the National Pharmacovigilance Center and were not involved in conducting the focus group discussions. M.H.A., V.G.C., R.A.P., J.F., and M.A.G. have no conflicts of interest that are directly relevant to the content of the study.

Funding

This research project received financial support from the UNICEF/UNDP/World Bank/WHO Special Programme for Research and Training in Tropical Diseases (TDR).

Data Availability

The online ADR reporting data are not publicly available. Requests to access the data should be directed to the Food and Drug Administration Philippines.

Ethical Approval

The ethics approval for this study was obtained from the World Health Organization (TDR1PV) Research Ethics Review Committee and the Philippine Women’s University (ERC2021_0001.1) Ethics Review Boards.

Consent to Participate

All participants provided informed consent prior to participating in the study.

Consent for Publication

This work does not contain any individual person’s data in any form (including any individual details, images, or videos).

Author Contributions

All authors have made substantial contributions to the study. Their specific contributions are detailed as follows: M.R.L.: conceptualization, literature review, methodology, data collection, formal analysis, writing—original draft preparation, finalization of the manuscript, and project administration. M.H.A.: conceptualization, literature review, methodology, data collection, formal analysis, writing—original draft preparation, finalization of the manuscript, and project administration. V.G.C.: conceptualization, investigation, data curation, and writing—review and editing. J.A.C.: data collection, validation, and writing—review and editing. L.A.L.D.: data collection, validation, and writing—review and editing. R.A.C.: data curation, visualization, and writing—review and editing. J.F.: conceptualization, investigation, data curation, and writing—review and editing. M.A.G.: investigation, data curation, and writing—review and editing. J.E.V.: resources, data validation, and writing—review and editing. M.G.S.: investigation, data curation, and writing—review and editing. R.A.O.: investigation, data curation, and writing—review and editing. All authors have read and approved the final manuscript. They agree to be accountable for all aspects of the work, ensuring accuracy and integrity in the study.