Measuring Diagnostic Safety in Viet Nam: Identifying Missed Opportunities and Learning From Events

Measuring Diagnostic Safety in Viet Nam: Identifying Missed Opportunities and Learning From Events

A patient returns to a healthcare facility several days after an initial consultation and is diagnosed with a serious condition. Looking back, the healthcare team may wonder whether something important was missed. Were there symptoms or findings that should have prompted further investigation? Was the initial assessment reasonable based on what was known at the time? Or did the condition become more recognizable only as it evolved?

Answering these questions is rarely straightforward. Once the final diagnosis is known, earlier findings can appear more significant than they did during the original encounter. An unfavorable outcome may raise a legitimate safety concern, but it does not, by itself, establish that an error occurred or that the outcome could have been prevented.

This uncertainty makes diagnostic safety particularly difficult to measure. Some problems become apparent only after subsequent consultations, additional investigations, or changes in a patient's condition. Others may remain unrecognized, particularly when patients receive care from several healthcare organizations that do not share complete clinical information.

Traditional healthcare quality indicators provide only part of the picture. A hospital may monitor laboratory turnaround times, documentation compliance, and reported medical incidents while having limited insight into whether opportunities for more timely or appropriate diagnosis were missed.

For healthcare organizations in Viet Nam, meaningful diagnostic safety measurement requires a systematic approach to identifying potential concerns, examining the circumstances surrounding diagnostic decisions, understanding contributing factors, and using the findings to improve care.

The purpose is not simply to count errors or determine which healthcare professionals made mistakes. It is to understand where diagnostic care may be vulnerable, which findings warrant attention, and whether improvement efforts are reducing avoidable risks.

Why Diagnostic Safety Is Difficult to Measure

Diagnosis is a complex clinical process rather than a single decision that can always be assessed against an immediately observable outcome.

In Improving Diagnosis in Health Care (2015), the National Academies of Sciences, Engineering, and Medicine defined diagnostic error as a failure to establish an accurate and timely explanation of a patient's health problem or to communicate that explanation to the patient.

This definition recognizes accuracy, timeliness, and communication as essential dimensions of diagnosis. However, translating these dimensions into reliable measurements presents substantial challenges.

A diagnosis established later than expected is not necessarily evidence of inappropriate care. Some conditions are difficult to recognize during their early stages, symptoms may be nonspecific, and the information needed to establish a diagnosis may not have been available during the first encounter.

Conversely, an accurate final diagnosis does not necessarily mean that every preceding decision or communication process was appropriate. There may have been opportunities for earlier recognition, further assessment, or more effective communication.

The World Health Organization highlighted these concerns during World Patient Safety Day 2024, which focused on improving diagnosis for patient safety. Its approach recognized that diagnostic safety depends on interactions among clinical reasoning, diagnostic services, healthcare systems, and patients.

A meaningful review must therefore consider both the eventual clinical outcome and the circumstances in which decisions were made.

This is particularly important when reviewing a case after serious illness or patient harm has occurred. Knowledge of the final diagnosis may influence how reviewers interpret earlier information, making a clinical finding appear more obvious than it reasonably was at the time.

Measurement should help organizations understand these complexities rather than reduce every unexpected or delayed diagnosis to a presumed failure.

Understanding Missed Opportunities in Diagnosis

The concept of a missed opportunity in diagnosis provides a useful starting point for examining potential diagnostic safety concerns.

A possible missed opportunity may be identified when information reasonably available during the diagnostic process suggests that an additional assessment, a different clinical consideration, more timely action, or clearer communication could have been appropriate.

The emphasis is on examining whether there was an opportunity to improve diagnosis, rather than beginning with a conclusion about individual performance.

Consider a hypothetical patient who initially presents with nonspecific symptoms and later receives a serious diagnosis. During a retrospective review, the healthcare team identifies an earlier finding that appears relevant to the condition.

This may justify examining the original encounter more closely. However, the finding should not automatically be treated as evidence that the clinician made an incorrect decision.

Reviewers need to consider whether the information was available, how reliable it was, whether it had been communicated, what other clinical findings were present, and which decisions were reasonable under the circumstances. The patient's condition may also have changed substantially between encounters.

An important concern is hindsight bias. Once reviewers know the eventual diagnosis, they may unintentionally overestimate the significance of earlier findings or underestimate the uncertainty faced by the original healthcare team.

Reducing this bias requires reconstructing the clinical situation as it existed at the time, rather than judging earlier decisions using information acquired afterward.

The terminology also matters. Missed diagnostic opportunities, diagnostic errors, diagnostic safety events, near misses, and diagnostic-related harm are related concepts, but they are not necessarily interchangeable.

Some frameworks define diagnostic safety events partly through missed opportunities to establish or communicate an appropriate diagnosis. A diagnostic error may occur without identifiable patient harm, while an adverse clinical outcome may arise despite reasonable diagnostic care. A potential problem may also be recognized and addressed before harm occurs.

Definitions and operational criteria vary across research methods, measurement tools, and regulatory systems.

Healthcare organizations should therefore establish clear working definitions before collecting data. Without consistent criteria, the same clinical situation may be classified differently by different reviewers, making findings difficult to interpret and improvement difficult to evaluate.

Identifying Concerns That Routine Reporting May Miss

Healthcare organizations commonly use incident reporting systems to identify patient safety problems. These systems are valuable, but they are unlikely to capture every diagnostic safety concern.

Some problems are not recognized when they occur. Others become apparent only when patients return with persistent symptoms, receive different diagnoses, or undergo further assessment at another healthcare facility.

Reporting practices may also be influenced by workload, organizational culture, uncertainty about what constitutes a reportable event, and concerns about how the information will be used.

The Agency for Healthcare Research and Quality developed Measure Dx: A Resource to Identify, Analyze, and Learn From Diagnostic Safety Events in 2022 to help healthcare organizations approach this challenge more systematically.

Measure Dx provides guidance on preparing for measurement, assessing organizational readiness, selecting appropriate strategies, reviewing cases, and translating findings into improvement activities.

One of its most useful principles is that diagnostic safety concerns should be explored through multiple sources of information.

Existing incident reports may reveal recognizable failures or events involving harm. Morbidity and mortality reviews, clinical audits, case conferences, and quality investigations may identify diagnostic questions that were not initially reported as safety events.

Healthcare professionals can contribute observations about diagnostic uncertainty, communication difficulties, or situations in which a potential problem was recognized before harm occurred.

Patients and families may also identify concerns that are not readily apparent in clinical records, particularly when they experienced difficulties obtaining explanations, communicating symptoms, or accessing further assessment.

Retrospective medical record reviews offer another source of information. However, examining large numbers of records without a clearly defined purpose may require considerable resources while producing relatively little actionable learning.

Organizations may benefit from selecting cases based on specific clinical concerns or event patterns that warrant closer examination.

An unexpected hospital admission following a recent outpatient assessment might justify reviewing the earlier encounter. A substantially revised diagnostic report or an important change in diagnosis may also offer an opportunity for learning.

These are reasons to ask questions, not evidence that an error has already been established.

A useful diagnostic safety program should identify meaningful cases for review without treating every unexpected clinical development as a failure.

Using Clinical Data to Select Cases for Review

Electronic health records, administrative data, and other clinical information systems can help healthcare organizations identify patterns that may be difficult to recognize through voluntary reporting alone.

Selected combinations of encounters, diagnoses, investigations, and subsequent clinical events may suggest situations in which a potential diagnostic concern deserves closer attention.

In diagnostic safety research, these approaches are commonly described as trigger tools or electronic triggers.

A trigger might identify an unexpected return visit, a serious diagnosis following a recent assessment for related symptoms, or another sequence of events associated with a possible missed diagnostic opportunity.

The trigger itself does not determine whether the earlier clinical care was inappropriate.

A patient returning after an initial consultation may have experienced the natural progression of a condition despite reasonable management. The earlier symptoms may have been too nonspecific to support further investigation, or important findings may have developed only after the first encounter.

Similarly, a dataset may suggest that an expected clinical action did not occur when the action was actually completed elsewhere or recorded in another information system.

These limitations are particularly relevant when patients receive services from multiple healthcare organizations.

AHRQ's Symptom-Disease Pair Analysis (SPADE) methodology provides one example of using clinical encounter patterns to identify possible missed diagnostic opportunities.

In December 2025, AHRQ released a Python-based research tool applying SPADE methods to linked emergency department and inpatient claims data. The tool focuses on selected symptom–disease relationships involving stroke and acute myocardial infarction.

Its purpose is to support research, identify potentially relevant patterns, and help select cases for further review. It is not intended to establish definitive diagnostic error rates or provide a basis for comparing hospitals.

The usefulness of electronic case identification depends on data completeness, accurate linkage between patients and encounters, clinically relevant selection criteria, and the ability to review flagged cases responsibly.

A tool designed for one disease or clinical setting may not perform equally well in another.

Organizations must also consider the burden created by false signals. A system that identifies many cases requiring review but reveals few meaningful concerns may consume substantial clinical and quality improvement resources.

For facilities without advanced information systems, carefully selected manual reviews may provide a more practical starting point.

The objective is not to generate the largest possible number of suspected cases. It is to identify situations that can be examined fairly and are likely to provide useful information for improvement.

Reviewing Cases Fairly and Systematically

Identifying a possible diagnostic safety concern is only the beginning. The quality of learning depends on how the case is reviewed.

A useful review should reconstruct the clinical circumstances, including the patient's presentation, information available during the original encounter, decisions made, subsequent findings, and relevant organizational conditions.

Reviewers should distinguish what was known at the time from information that became available later. This helps reduce hindsight bias and supports a more balanced assessment of clinical decisions.

Structured review methods may improve consistency. The Revised Safer Dx Instrument, developed through diagnostic safety research, provides a systematic approach to examining possible diagnostic errors and related process concerns.

Such tools can help reviewers consider relevant aspects of the diagnostic process, but they do not eliminate uncertainty or replace professional judgment.

Two qualified reviewers may reasonably interpret a complex case differently, particularly when clinical records are incomplete, the patient's presentation was ambiguous, or several management options were defensible.

Healthcare organizations should consider involving appropriately qualified reviewers, obtaining relevant specialist input when necessary, and establishing a process for discussing disagreements or uncertain findings.

Multidisciplinary participation can strengthen the review.

Clinicians may explain the reasoning behind important decisions. Laboratory and imaging professionals may clarify the availability, interpretation, or communication of diagnostic information. Nurses may contribute observations about changes in the patient's condition or concerns expressed during care. Quality and patient safety personnel can help identify organizational factors that may have influenced the event.

These perspectives can reveal circumstances that are difficult to understand from the medical record alone.

A review should also distinguish the presence of a diagnostic process concern from the occurrence and severity of harm.

A potential missed opportunity may exist without identifiable patient injury. If harm occurred, determining whether it resulted from the diagnostic process, and whether it could reasonably have been prevented, may require additional clinical assessment.

Not every review will produce a definitive conclusion.

Where information is insufficient, an indeterminate assessment may be more appropriate than forcing the case into a category that implies greater certainty than the evidence supports.

A credible learning system must be able to acknowledge uncertainty. It should also recognize that the purpose of structured review is to improve the quality of assessment, not to remove every difference in professional judgment.

Understanding the Conditions Behind Diagnostic Safety Events

Diagnostic safety concerns often arise through interactions between clinical judgment and the conditions in which care is delivered.

A clinician may have considered an appropriate diagnosis but lacked access to relevant previous information. A finding may have been communicated through an established channel but not reached the intended recipient. A recommended investigation may have been difficult to arrange because the required service was unavailable.

These circumstances do not eliminate professional responsibility. They demonstrate why an assessment limited to individual clinical decisions may produce an incomplete explanation.

Workload, staffing, access to diagnostic services, supervision, information systems, communication practices, and organizational culture can all influence diagnostic performance.

A systems-based review seeks to understand how these factors contributed to the concern.

Several apparently unrelated cases may reveal the same underlying vulnerability. A particular type of clinical information may repeatedly be unavailable during decision-making, or teams may have inconsistent expectations about who is responsible for reviewing important findings.

Recognizing such patterns gives organizations a stronger foundation for improvement than treating each case as an isolated incident.

Additional education may be appropriate when a genuine knowledge gap is identified. However, education alone is unlikely to resolve a recurring communication failure if responsibilities remain unclear or the workflow continues to make information difficult to access.

The response should reflect the problem revealed by the review.

A systems-based approach must also remain compatible with professional accountability. Where concerns require formal incident reporting, professional assessment, or another legally prescribed process, those responsibilities must be addressed.

Organizational learning and formal determinations of professional or legal responsibility may arise from the same case, but they serve different purposes.

Choosing Measures That Support Improvement

Once an organization begins identifying diagnostic safety concerns, it needs to decide what should be measured and how the findings will be used.

A single indicator claiming to represent the overall diagnostic error rate may appear useful, but it can be difficult to define, validate, and interpret.

Different identification methods capture different types of events. Voluntary reporting depends on awareness and reporting behavior, while targeted medical record reviews depend on case selection and reviewer judgment.

An increase in detected diagnostic safety concerns may therefore reflect better surveillance rather than worsening care.

For example, an organization that introduces a more accessible reporting system and structured case reviews may initially identify more potential problems than before. This may indicate that previously unrecognized concerns are becoming visible.

Conversely, a low number of reported events is not reliable evidence that diagnostic care is safe.

Useful measurement begins with a clearly defined question.

An organization may want to know whether a particular type of concern is recurring, whether its review process is identifying meaningful learning opportunities, or whether an intervention has reduced a previously recognized risk.

The measures selected should reflect that purpose.

Process measures might examine whether selected clinically important findings receive appropriate review, whether particular diagnostic actions occur within clinically justified timeframes, or whether cases identified for review receive a completed professional assessment.

Other measures may describe the types of concerns detected, the contributing factors identified, or the implementation and evaluation of agreed improvement actions.

Outcome measures can also contribute, but they require careful interpretation. Patient outcomes are influenced by disease severity, underlying health conditions, access to care, and factors that may be unrelated to the diagnostic process.

Balancing measures are particularly important.

An intervention intended to improve earlier disease recognition may unintentionally increase unnecessary investigations, referrals, workload, or delays elsewhere in the healthcare system.

An apparent improvement in one indicator should therefore be considered alongside potential unintended consequences.

Measurement also requires clear definitions of the population being studied, data sources, inclusion and exclusion criteria, numerators, denominators, and observation periods.

Without these details, results may be difficult to reproduce or interpret.

For example, the proportion of reviewed cases containing a potential missed diagnostic opportunity cannot automatically be interpreted as the prevalence of diagnostic errors among all patients.

If cases were selected because of unexpected outcomes or electronic triggers, the findings will reflect that selection process. They may be useful for identifying vulnerabilities, but they do not provide a representative estimate of diagnostic error prevalence.

Comparisons between departments or healthcare organizations present additional difficulties. Differences in patient populations, clinical complexity, documentation quality, reporting behavior, and detection methods can influence the results.

Diagnostic safety measurement should make uncertainty more understandable, not create an appearance of precision that the evidence cannot support.

What International Developments Mean in 2026

International efforts to measure diagnostic safety continue to develop, although important methodological limitations remain.

In February 2026, the U.S. Centers for Disease Control and Prevention published its Core Elements of Hospital Diagnostic Excellence, identifying the recognition, monitoring, and learning from diagnostic safety events as important components of organizational improvement.

The framework includes tracking and reporting among its six core elements. It emphasizes the need for healthcare organizations to understand whether diagnostic excellence activities are being implemented and whether those activities are contributing to improvement.

The CDC also recognizes that there are currently no broadly used diagnostic safety event measures suitable for comparing hospital performance. Organizations are therefore encouraged to develop internal measures aligned with their improvement priorities and the activities being undertaken.

AHRQ has also advanced the development of diagnostic excellence measures.

In February 2026, it released beta technical specifications for exploratory cancer-related diagnostic excellence measures. These address timely follow-up after selected cancer screening results, late-stage cancer diagnosis, and new cancer diagnoses associated with acute presentations.

The measures are intended to identify patterns that may warrant closer examination.

For example, a higher proportion of cancers diagnosed during or shortly after an emergency department visit or unplanned hospital admission may raise questions about earlier access to care, symptom recognition, and opportunities for timely assessment.

However, this pattern does not establish that earlier diagnostic errors occurred.

Some cancers progress rapidly, produce nonspecific symptoms, or remain difficult to recognize despite appropriate care. Late-stage diagnosis may also reflect several interacting factors, not all of which represent preventable diagnostic failures.

AHRQ describes these measures as exploratory and subject to further testing and refinement.

They are intended primarily to support internal surveillance and quality improvement, not payment, public reporting, or external accountability.

Their use in Viet Nam would require careful consideration of local patient populations, clinical pathways, disease coding, cancer registry information, data completeness, and the validity of the measures in the intended setting.

These developments should not be interpreted as evidence that healthcare organizations now have a definitive method for calculating diagnostic error rates.

Their significance lies in expanding the range of questions that can be investigated systematically while making the limitations of measurement more explicit.

Patients Can Reveal What Organizational Data Miss

Patients and families may experience diagnostic problems in ways that are not fully captured by medical records or administrative data.

A clinical record may show that an investigation was ordered or a referral was issued. It may not explain whether the patient understood the reason for that action, encountered difficulties arranging the next appointment, or felt that an important concern had not been addressed.

Patient experiences can therefore provide information that complements clinical and organizational records.

AHRQ and the CDC recognize patient and family engagement as important to diagnostic safety improvement.

Recent research has also explored ways to measure patients' experiences of the diagnostic process.

In September 2026, researchers reported the development and testing of the Patient-Reported Outcome Measures of Timely Experience of Diagnosis (PROMOTE-Dx) for Cancer. This work examined survey-based measures intended to capture patients' experiences of timely cancer diagnosis.

Such measures may contribute a perspective that is difficult to obtain from clinical data alone. However, their applicability outside the populations and settings in which they were developed requires appropriate evaluation, including linguistic and cultural adaptation where relevant.

Healthcare organizations in Viet Nam can consider how existing patient feedback and safety reporting mechanisms might help identify possible diagnostic concerns.

These arrangements should allow patients to raise questions respectfully and without unnecessary barriers. Clinically urgent concerns should be directed promptly to appropriately qualified healthcare professionals rather than remaining solely within an administrative feedback process.

Patient reports, like other information sources, require careful interpretation.

A concern expressed by a patient is not automatically evidence of a diagnostic error. Equally, it should not be dismissed simply because the available documentation suggests that routine procedures were completed.

The patient's perspective may reveal a communication gap, an unrecognized barrier to care, or a misunderstanding that affected the diagnostic process.

Where a review involves an individual patient's care, communication with the patient and family should be managed in accordance with clinical circumstances, patient rights, professional responsibilities, and applicable legal requirements.

Patient participation should strengthen organizational learning, not shift responsibility for detecting and managing diagnostic safety problems onto patients.

Turning Findings Into Meaningful Improvement

Identifying diagnostic safety concerns is valuable only when the information contributes to better understanding or safer care.

A review may reveal an individual clinical issue, a recurring organizational weakness, or uncertainty that warrants further examination.

Not every review will result in a corrective action. In some cases, the available information may be insufficient to determine whether care could reasonably have been different. In others, the review may conclude that the clinical assessment was appropriate despite an unfavorable outcome.

These conclusions should be accepted when supported by the evidence.

When a concern is sufficiently established, the next question is what can realistically be improved.

The response should reflect the findings of the review.

A recurring clinical knowledge gap may justify targeted education or specialist discussion. A problem involving unavailable information may require improvements in documentation or information access. An organizational weakness may require changes in responsibilities, supervision, or monitoring.

Recommendations should address the factors that contributed to the concern rather than rely on generic actions that may have little effect.

The feasibility of proposed changes is also important.

An intervention requiring technology, personnel, or services unavailable to the organization may be difficult to implement or sustain. Testing a change on a manageable scale can help identify operational difficulties before broader adoption.

Follow-up should examine whether the improvement was implemented as intended, whether the original concern has been reduced, and whether unintended consequences have emerged.

Feedback to those who reported or reviewed the cases can support continuing engagement.

Healthcare professionals are more likely to participate in diagnostic safety reporting when they see that concerns are examined fairly and lead to useful organizational responses.

A culture of learning does not require avoiding difficult conclusions. It requires an honest assessment of available evidence, proportionate responses, and a commitment to acting on credible findings.

A Practical Starting Point for Healthcare Organizations in Viet Nam

Healthcare organizations in Viet Nam vary considerably in their readiness to measure diagnostic safety.

Some hospitals have established quality management departments, clinical audit activities, electronic medical records, and structured incident reporting systems. Smaller facilities may have more limited data infrastructure or fewer personnel dedicated to quality and patient safety.

These differences should influence the scale and methods of measurement.

An organization does not necessarily need an advanced electronic surveillance system to begin learning from diagnostic safety concerns.

A reasonable starting point is to identify a clinically important area where potential diagnostic problems could have significant consequences and where relevant information can be examined responsibly.

A hospital might begin by reviewing selected cases already discussed through its quality and patient safety processes, adding a structured examination of possible diagnostic learning opportunities.

An outpatient clinic might examine unexpected repeat consultations or cases involving substantial changes in a working diagnosis.

A specialist service might review selected cases where subsequent findings significantly altered an earlier diagnostic conclusion.

These are possible strategies for selecting cases, not evidence that errors occurred.

The organization should establish why particular cases are being reviewed, what information is required, who has the appropriate qualifications to assess them, and how findings will be documented and used.

The initial scope should remain manageable. A carefully conducted review of a small group of relevant cases may provide more useful learning than a large dataset that cannot be interpreted reliably.

Multidisciplinary participation should reflect the clinical issues involved. Leadership support is also important because meaningful review requires time, appropriate access to information, clear responsibilities, and a process for responding to findings.

Data limitations must be acknowledged, particularly when patients obtain services from multiple healthcare providers.

A facility may identify a potential diagnostic concern without having access to subsequent consultations or investigations performed elsewhere. The resulting conclusions should remain proportionate to the evidence available.

Healthcare organizations should also avoid assuming that a measurement method developed using U.S. electronic health records or insurance claims data will perform similarly with Vietnamese hospital information systems.

Differences in clinical documentation, coding practices, available datasets, and patterns of healthcare use may affect both case identification and interpretation.

As experience develops, organizations may refine their methods, improve data quality, and introduce more consistent measures.

The purpose should be to build a credible and sustainable learning process rather than attempt to produce precise estimates of diagnostic error prevalence from incomplete information.

Legal, Ethical, and Professional Considerations in Viet Nam

Diagnostic safety measurement must operate within the legal and professional framework governing healthcare, medical incident prevention, confidentiality, and personal data protection in Viet Nam.

The Law on Medical Examination and Treatment No. 15/2023/QH15 provides relevant requirements concerning patient rights, professional responsibilities, medical records, and patient safety.

Article 71 addresses the prevention of medical incidents through identification, reporting, analysis of causes, and the development of recommendations and preventive measures. It also establishes responsibilities for medical incident prevention within healthcare facilities.

These provisions provide an important legal foundation for patient safety activities. However, international terminology used in diagnostic safety research should not automatically be equated with the classifications and obligations established under Vietnamese law.

Circular No. 43/2018/TT-BYT provides guidance on preventing medical incidents in healthcare facilities, including reporting, analysis, feedback, and preventive action. As the Circular has been recorded as partially no longer effective, its application must be assessed according to the provisions that remain in force and any relevant subsequent regulations.

A potential missed diagnostic opportunity identified through Measure Dx, the Revised Safer Dx Instrument, or another international research method does not automatically establish that the event meets the criteria for mandatory medical incident reporting in Viet Nam.

Whether a reporting obligation applies must be determined under the relevant Vietnamese requirements and the circumstances of the case.

Likewise, identifying a diagnostic safety concern does not automatically establish a legally recognized professional technical error, negligence, or liability.

These matters require separate assessment under applicable laws, professional standards, and prescribed procedures.

Healthcare organizations should distinguish internal diagnostic safety reviews from formal incident reporting, professional assessment, complaint resolution, and other legally required processes.

Where mandatory reporting or another legal obligation applies, an internal quality improvement activity does not replace it.

The handling of patient information also requires particular care.

Diagnostic safety reviews may involve identifiable medical records, detailed clinical histories, healthcare professional accounts, and sensitive information about the circumstances of care.

Viet Nam's Law on Personal Data Protection No. 91/2025/QH15 and Decree No. 356/2025/ND-CP, both effective January 1, 2026, form part of the applicable framework governing personal data processing, including health-related information.

Healthcare organizations conducting diagnostic safety reviews should assess the applicable legal basis and purposes of processing, determine appropriate access permissions, apply relevant security safeguards, and comply with applicable requirements concerning retention, disclosure, and other processing activities.

Using aggregated or appropriately de-identified information may reduce privacy risks. However, removing names alone does not necessarily prevent individuals from being identified or eliminate all legal obligations.

Additional requirements may arise when information is shared between healthcare organizations, used for research, or intended for external publication.

Activities that constitute research may require separate ethical and regulatory review, depending on their design, purpose, and applicable requirements.

Organizations should also avoid assuming that documents generated for internal quality improvement are automatically protected from disclosure or exempt from other professional and legal responsibilities.

A supportive learning environment and compliance with applicable law are both essential to responsible diagnostic safety measurement.

Building a Culture That Learns From Diagnostic Safety Events

Diagnostic safety measurement is most useful when it helps healthcare organizations recognize and understand problems that would otherwise remain difficult to see.

An unexpected clinical outcome, a reported concern, or a signal identified through routine data may provide a reason to review a case. None should be treated as a complete explanation on its own.

The organization must still examine what information was available, which decisions were reasonable, whether an important opportunity may have been missed, and what contributing factors could be addressed.

This requires professional judgment, structured review, appropriate data, multidisciplinary cooperation, and a willingness to acknowledge uncertainty.

It also requires restraint in interpreting results. More identified events may reflect better detection, while fewer reports may reveal little about the true level of diagnostic risk.

For healthcare organizations in Viet Nam, a meaningful approach can begin with clearly defined questions, manageable review activities, and realistic opportunities for improvement.

The CDC's 2026 diagnostic excellence framework, AHRQ's Measure Dx resource, and emerging diagnostic safety measurement methods offer useful international foundations. Their value lies in informing locally appropriate improvement rather than prescribing one measurement system for every healthcare organization.

Measuring diagnostic safety is not simply about counting diagnostic errors. It is about identifying possible missed opportunities, understanding the circumstances in which they arose, and using that knowledge to improve care.

Progress should be judged not only by whether an organization identifies potential problems, but also by the quality of its reviews, the appropriateness of its responses, and the evidence that improvement activities have reduced relevant risks.

Developing this capability is an important part of advancing diagnostic excellence in Viet Nam.

Evidence and Policy Context

This article draws on established international evidence and professional guidance, including the National Academies of Sciences, Engineering, and Medicine's Improving Diagnosis in Health Care (2015); the World Health Organization's World Patient Safety Day 2024 materials on improving diagnosis for patient safety; the Agency for Healthcare Research and Quality's Operational Measurement of Diagnostic Safety: State of the Science (2020); AHRQ's Measure Dx: A Resource to Identify, Analyze, and Learn From Diagnostic Safety Events (2022); research on the Revised Safer Dx Instrument; and the U.S. Centers for Disease Control and Prevention's Core Elements of Hospital Diagnostic Excellence (2026).

The discussion also considers AHRQ's Symptom-Disease Pair Analysis (SPADE) research resources released in December 2025, its exploratory cancer-related diagnostic excellence measure specifications published in February 2026, and the September 2026 report on the development of Patient-Reported Outcome Measures of Timely Experience of Diagnosis (PROMOTE-Dx) for Cancer.

The Vietnamese legal context includes the Law on Medical Examination and Treatment No. 15/2023/QH15; Circular No. 43/2018/TT-BYT on medical incident prevention in healthcare facilities, subject to the provisions remaining in force; the Law on Personal Data Protection No. 91/2025/QH15; and Decree No. 356/2025/ND-CP.

International diagnostic safety concepts and measurement tools are presented as evidence-informed approaches to quality improvement. They are not mandatory Vietnamese measurement standards, legal classifications of medical incidents, or substitutes for applicable regulations and professional responsibilities.

Professional Scope and Disclaimer

This article is published by Diagnostic Excellence Vietnam (DxEx.vn) for professional education, knowledge-sharing, and general information. It examines diagnostic safety measurement, the identification of missed opportunities, and organizational learning from the perspectives of healthcare quality, patient safety, governance, risk management, and evidence-informed improvement.

The content does not constitute individualized medical advice, clinical diagnosis, treatment recommendations, legal advice, a determination of professional error, or a legally binding interpretation of Vietnamese regulations. Diagnostic Excellence Vietnam (DxEx.vn) is not a healthcare provider, regulatory authority, or accreditation or certification body.

Clinical case reviews, medical incident reporting, personal data processing, research activities, and organizational improvement remain subject to applicable Vietnamese laws, professional standards, institutional responsibilities, and the judgment of appropriately qualified professionals and authorized healthcare organizations.