Clinical trials are essential for generating reliable evidence, but many trials still face avoidable barriers: complex protocols, unnecessary data collection, slow approval processes, limited participants’ diversity, and delayed reporting of results. The WHO Guidance for Best Practices for Clinical Trials addresses these issues by refocusing attention on what makes a trial truly useful: scientific validity, participant protection, feasibility, transparency, and proportionate quality management.
Published in 2024 in response to World Health Assembly Resolution WHA75.8, the guidance aims to improve the process of generating clinical evidence, reduce research waste, and strengthen clinical trial systems so they can support both routine health needs and public health emergencies. It is not a regulatory standard and does not replace existing guidance, but provides a complementary framework for clinical trials.
The key message for clinical trials professionals is practical: good trials are not defined by excessive documentation, complex procedures, or one-size-fits-all oversight. They are defined by whether they answer relevant questions, protect participants, are feasible in context, manage quality proportionately, and generate reliable results that can support meaningful decisions.
What Makes a Good Clinical Trial?
The guidance identifies five core principles that define a good clinical trial.
1. Scientifically Sound and Relevant
A good trial should answer a genuine and important uncertainty about the effects of a health intervention. This requires a clear research question, appropriate trial design, adequate statistical power, meaningful outcomes, and a pre-specified statistical analysis plan. For comparative studies, randomisation remains the preferred approach where appropriate, supported by robust allocation concealment to reduce selection bias. Where full blinding is not feasible, blinded outcome assessment should still be considered.
The guidance also stresses that data collection should be proportionate. Clinical trial teams should focus on data that genuinely supports the research question, safety evaluation, and interpretation of results, rather than collecting data simply because it is possible.
2. Respectful of Participants’ Rights and Well-being
Good clinical trials must protect participants’ rights, dignity, safety, and well-being throughout the trial. The guidance emphasises that participants should receive timely, relevant, and understandable information before, during, and after the study. The consent process should explain why the trial is being conducted, what questions it seeks to answer, what participation involves, and the potential benefits and risks.
Consent materials should prioritise participants’ needs, avoid unnecessary legalistic or technical language, and be as concise and accessible as possible. Where appropriate, assent processes, electronic consent, or alternative communication formats may be used.
The guidance also highlights that “withdrawal” can mean different things, so researchers should clarify what participants wish to stop or continue, while balancing individual rights with the ethical need to preserve reliable scientific results.
3. Collaborative and Transparent
Transparency is central to trustworthy clinical research. The clinical trials should be registered on a publicly available registry before enrolment begins. The clinical trial information should be kept up to date, and results should be publicly reported in a timely manner, whether the findings are positive, negative, or inconclusive.
The guidance supports reporting in line with recognised standards such as CONSORT (recommendations for reporting randomized clinical trials) and encourages open-access publication where possible. Protocols, statistical analysis plans, funding sources, and conflicts of interest should also be made available where appropriate. Data sharing should be effective, ethical, and equitable, with suitable protection for participant privacy in line with local laws.
4. Feasible for the Trial Context
A clinical trial that cannot be delivered in practice is unlikely to produce reliable evidence. Trial design should reflect the setting in which the study takes place, including local health needs, healthcare access, community preferences, site capacity, and public understanding of clinical trials. Meaningful patient and public engagement can help ensure the trial is relevant, acceptable, and accessible.
Operationally, the guidance encourages use of existing healthcare resources, expertise, professional standards, and quality oversight wherever appropriate. Trial processes that align with routine care are often more efficient, reliable, and less error-prone. While all trial staff must be suitably qualified, routine care activities may not require unnecessary extra training, procedures, or checks.
5. Effective and Proportionate Quality Management
Quality should be built into trial design from the beginning, not detected retrospectively after problems occur. The guidance defines quality as “fitness for purpose”: the ability of a clinical trial to produce reliable results that are robust enough to support informed decision-making.
This supports a risk-based and proportionate approach to quality management. Oversight should focus on issues that could materially affect participant safety, participant rights, or the credibility of trial results. More documentation, more monitoring, or more complex processes do not automatically mean better quality. In some cases, they may create unnecessary burden without improving the reliability of the generated clinical evidence.
Six Practical Recommendations for Clinical Trial Teams
1. Build Stronger Clinical Trial Ecosystems
The guidance calls for sustained investment in the infrastructure needed to conduct reliable clinical trials. Countries should develop well-functioning national clinical research institutions and clinical trial units that can support different health priorities. Funding should be sustained and transparent, with planning for equitable post-trial access to interventions, especially for populations in low- and middle-income countries. Strong clinical trial infrastructure also allows research systems to remain active during routine periods and pivot quickly during public health emergencies. Streamlined regulatory and ethics approval processes, including parallel submissions, joint reviews, and reliance mechanisms, are recommended to reduce duplication and shorten timelines.
2. Embed Patient and Community Engagement
Patient and community engagement should be embedded throughout the clinical trial lifecycle, not treated as an optional extra. Engagement should begin from priority-setting and protocol development, and continue through trial conduct and results communication. Patients, carers, and community representatives can help define relevant research questions, assess trial feasibility, select meaningful outcomes, and improve consent materials. The guidance treats engagement expertise as a core requirement in trial design, not a peripheral communications function. Importantly, participants and communities should receive feedback on how their input or data were used. Without feedback to involved parties, trust may be weakened and future research participation may decline.
3. Improve Trial Inclusivity
Inclusion should be the default, and exclusion should require explicit scientific or safety justification. Clinical trials have historically underrepresented children, pregnant and lactating women, older adults, people in low- and middle-income countries, and groups facing social, economic, or health-related barriers. This reduces the generalisability of findings and leaves evidence gaps for populations that may carry high disease burden. Children should be considered from the outset of clinical development, not as an afterthought. Pregnant and lactating women should not be excluded solely because of physiological differences where the intervention may benefit them. Decentralised and point-of-care designs may help improve accessibility and enrolment diversity.
4. Strengthen Collaboration, Coordination and Networking
Good clinical trials require effective collaboration between sponsors, investigators, regulators, ethics committees, funders, patient groups, and healthcare systems. The guidance emphasises that partnerships across commercial, academic, healthcare should be fair and respectful of local priorities. Clinical research networks and disease-specific consortia can accelerate evidence generation, reduce duplication, share standards, and build capacity where it is limited. Equitable leadership is also important. Local researchers, funders, and communities should share responsibility for trial prioritisation, design, implementation, and reporting, rather than only participating as recruitment sites.
5. Apply Risk-Proportionate Quality Management
The guidance challenges the assumption that more documentation, more monitoring, or more complex procedures automatically mean better quality. Excessive bureaucracy and over-interpretation of regulations can make trials harder to conduct without improving the reliability of the clinical evidence. Instead, clinical trial oversight should be risk-based and proportionate. Teams should identify critical data and processes early, then focus monitoring, audit, and inspection activities on issues that could meaningfully affect participant safety or trial results. Central statistical monitoring, targeted site visits, and proportionate source data review may be more effective than uniform source data verification. Quality should mean ‘fitness for purpose’, not paperwork volume.
6. Consider Innovative Trial Designs Where Appropriate
The guidance encourages the use of innovative trial designs where they improve efficiency, inclusion of participants, or generation of relevant clinical evidence. Traditional parallel-group randomized clinical trials remain important, but they are not always the best option. Adaptive trials allow pre-specified changes as data accumulate, while platform trials can evaluate multiple interventions within a shared structure. Decentralised trials reduce participant burden by moving some activities closer to home, and point-of-care trials embed research into routine clinical practice. The guidance also recognises the growing role of digital technology, electronic health records, wearable biosensors, and artificial intelligence tools in improving trial efficiency, recruitment, outcome assessment, and data quality.
Closing Thoughts
The WHO Guidance for Best Practices for Clinical Trials reminds the clinical research community that good trials are not necessarily the most complex, heavily monitored, or studies with extensive documentation. Good clinical trials are those that ask meaningful questions, are scientifically robust, protect participants, reflect real-world populations, remain feasible in their context, and generate results that can be trusted and used.
For clinical trial teams, the key practical message is to focus on what matters. This means designing trials around important decisions, collecting meaningful data, engaging patients and communities early, applying proportionate quality management, and transparency in reporting results.
For organisations planning or conducting clinical trials, these recommendations provide a useful framework for improving protocol design, feasibility, regulatory planning, quality oversight, and participant-centred clinical trial delivery. Ultimately, the guidance encourages the industry to move beyond compliance alone and work towards evidence generation that better serves patients, healthcare systems, and public health.
Author: Wai Theng Lee, Clinical Research Partnerships Manager
