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

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.

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.

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.

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.