Close this search box.

Navigating the Path to Successful Medical Screenings: Understanding Potential Hurdles and How to Overcome Them – BioPharma Services

Hourglass and calendarHourglass and calendar

Choosing to participate in medical studies and clinical trials is an admirable decision, as it plays a vital role in advancing healthcare and scientific knowledge. However, embarking on this journey requires careful consideration, especially when it comes to understanding the medical screening process and the potential reasons for disqualification. BioPharma Services prepared this comprehensive article, we will delve into the world of medical screenings, exploring the various factors that can lead to disqualification and providing invaluable advice on how to prepare effectively.

1 – The Importance of Full Disclosure and a Complete Medical History

A hand is holding a pencil pointed at a calendar, which has some crosses on itA hand is holding a pencil pointed at a calendar, which has some crosses on it

One of the most common reasons for failing a medical screening is an incomplete or inaccurate medical history. The individuals conducting the study rely heavily on this information to determine whether you are a suitable participant. Failing to provide a thorough and truthful medical history can result in disqualification. Here’s what you need to be aware of:

  • Honesty is Key: First and foremost, honesty is paramount. You must truthfully disclose past illnesses, surgeries, medications, and allergies. Omitting or distorting information can have serious consequences, not only for your participation but also for the integrity of the study itself.
  • Medication Disclosure: Equally important is the full disclosure of your current medication regimen, including both prescription and over-the-counter drugs. Some medications may interact negatively with the study drug, potentially compromising safety or efficacy.
  • Allergy Alerts: Any known allergies to medications or substances must be communicated to the study team. Neglecting to mention allergies can lead to severe adverse reactions. Transparency in this regard is crucial for your safety.

To ensure success in this aspect of the screening process, meticulously review your medical history and provide all requested information.

2 – Existing Health Conditions

Certain pre-existing health conditions can render you ineligible for a study, depending on the study’s focus. These conditions may include chronic diseases, autoimmune disorders, mental health conditions, or pregnancy. Understanding the study’s inclusion and exclusion criteria is essential. Let’s explore this further:

A hand is holding a pencil pointed at a calendar, which has some crosses on itA hand is holding a pencil pointed at a calendar, which has some crosses on it

  • 3 – Challenges with Medication and Compatibility

    The interaction between medications can pose significant challenges during medical screenings. Even if you have diligently disclosed your medications, certain combinations may still lead to disqualification. Here’s what you need to be aware of:

    • Medication Interactions: The study drug may interact with your current medications, resulting in adverse effects or reduced effectiveness. This potential interaction must be carefully evaluated.
    • Over-the-Counter Meds: Even seemingly harmless over-the-counter drugs like pain relievers or antihistamines can interact negatively with the study drug. Vigilance is required in disclosing all medications, including non-prescription ones.
    • Supplements: Certain supplements can interfere with the study drug’s mechanism of action or cause unanticipated side effects. Transparency regarding supplement usage is essential.

    To mitigate the risk of medication-related issues, engage in open and detailed discussions with the study team regarding your medication list.

4 – How Lifestyle Choices can Affect your Study Participation

A hand is holding a pencil pointed at a calendar, which has some crosses on itA hand is holding a pencil pointed at a calendar, which has some crosses on it

Your lifestyle choices and habits can significantly impact your eligibility for medical studies. Let’s explore some lifestyle factors that can influence your screening:

  • Smoking: Many studies exclude smokers due to the potential impact of smoking on study results. Quitting smoking for a period of time prior to the study may be necessary to qualify for certain studies.
  • Recreational Drugs: Use of recreational drugs prior to screening is restricted and if you test positive for drugs during the screening, it means you didn’t pass the test.  
  • Diet Restrictions: It is crucial for participants to adhere to  dietary guidelines, which include abstaining from caffeine, alcohol, and poppy seeds prior to screening for the following reasons:


  • Interference with Blood Pressure: Caffeine can temporarily increase blood pressure, which might affect baseline measurements taken during the screening.
  • Stimulation: Caffeine is a stimulant, and its consumption can influence vital signs, making it difficult to establish a participant’s true baseline health metrics.


  • Dehydration: Alcohol is a diuretic, which means it can lead to dehydration. Dehydration can affect blood test results and make it challenging to obtain accurate readings during the screening.
  • Liver Function: Alcohol consumption can affect liver enzyme levels, potentially leading to abnormal liver function test results.

Poppy Seed:

  • False Positive Drug Test: Poppy seeds contain trace amounts of opiates, which can result in a false positive on certain drug tests. This can create confusion and potentially disqualify a participant if they test positive for substances they haven’t actually used.

By abstaining from these substances for 48 hrs before a medical screening, we can ensure that the screening process provides accurate and reliable baseline data about your health status. This accuracy is vital for assessing the impact of the study intervention and any potential side effects.

  • BMI Restrictions: In certain clinical screenings, participants may need to adhere to BMI restrictions or guidelines. BMI, which measures weight in relation to height, is employed to evaluate body composition. Extreme BMI values, whether too low or too high, can lead to changes in metabolism that could impact the study’s outcomes or safety concerns. Adhering to BMI guidelines is crucial to ensure that participants fall within the designated range for accurate study assessments and to mitigate potential health risks linked to extreme BMI values.
  • Physical Activity: Strenuous exercise can temporarily affect vital signs  and lab values such as heart rate, blood pressure, and respiratory rate. These measurements are essential for establishing a participant’s baseline health status. Engaging in intense physical activity shortly before the screening may lead to elevated readings that do not reflect the participant’s typical resting state.

Intense exercise, especially activities that involve muscle contractions like weightlifting or high-intensity interval training, can lead to a temporary increase in creatinine levels. This occurs because the muscles produce more creatinine during periods of increased physical activity. 

To enhance your chances of passing the screening in this regard, you are recommended to refrain from intense exercise for three days prior to your screening appointment.

5 – Recent Illness or Infection (Prioritising Health and Safety)

A hand is holding a pencil pointed at a calendar, which has some crosses on itA hand is holding a pencil pointed at a calendar, which has some crosses on it

Current illness or recent infections can pose obstacles to participation. Common reasons for temporary disqualification include:

  • Contagious Illness: Active contagious illnesses can jeopardise the health of both you and other study participants. Isolation and recovery may be necessary before joining the study.
  • Fever: Often a sign of infection, can be grounds for temporary disqualification. It’s essential to address the underlying illness and regain health before considering participation.

Should illness strike or you’ve recently battled an infection, promptly inform the recruitment department. They will provide guidance on the appropriate course of action and the timing of your participation.

6 – Allergies and Sensitivities Should be Disclosed

Allergies or sensitivities to medications, foods, or environmental factors can be a significant consideration during medical screenings. Here’s how to navigate this:

  • Medication Allergies: Be sure to inform the study team of any known allergies to specific medications or their components. This information is vital for your safety.
  • Environmental Allergens: If the study environment contains substances or allergens to which you are sensitive, the study team should be informed to assess potential risks.
  • Food Allergies: Certain studies may necessitate adherence to specific diets. If you have food allergies, it is imperative to communicate them to the study team to ensure safety and compliance.

Openly discussing your allergies and sensitivities with the study team is essential to determine whether participation is safe and feasible.

7 – Psychological Evaluations – Meeting Cognitive and Mental Health Criteria

A man holds a piece of paper head-shaped, there's a smiley face where the brain is supposed to be.A man holds a piece of paper head-shaped, there's a smiley face where the brain is supposed to be.

In studies focusing on mental health or behaviour, participants may undergo psychological assessments. Meeting specific criteria related to cognitive function and mental health is imperative. Here’s how to prepare:

  • Honesty During Evaluations: During interviews and assessments, honesty is paramount. Providing accurate information about your cognitive function and mental health is crucial to assess your eligibility accurately.
  • Seek Professional Help: If you have concerns about your mental health, consider seeking professional help prior to your participation.

8 – Legal and Ethical Considerations – Transparency is Key

Navigating legal and ethical considerations is essential for successful participation in medical studies. Here’s what you need to be aware of:

  • Criminal History: Certain studies may have restrictions regarding participants with specific criminal histories. It is crucial to be aware of and transparent about any criminal record.
  • Previous Participation: If you have previously participated in a similar study, it may impact your eligibility for subsequent studies. Transparency about your prior involvement is necessary.
  • Conflicts of Interest: Financial or personal conflicts of interest related to the study must be disclosed to the study team. Transparency in this regard ensures the ethical conduct of the research.

9 – Out-of-Range vitals and ECG Readings

Clinical trials demand absolute health in early phases, screening out participants with vital signs and ECG readings beyond predefined ranges. Rejection doesn’t signify overall health issues but rather a misfit for that study’s criteria. Remember, out-of-range readings may not reflect your general well-being. Consult your physician for insights, and explore other trials tailored to your health profile. Each study has unique criteria, offering diverse opportunities to contribute to medical advancements.

10 – Navigating Trials with Grace

A man holds a piece of paper head-shaped, there's a smiley face where the brain is supposed to be.A man holds a piece of paper head-shaped, there's a smiley face where the brain is supposed to be.

Participating in clinical trials is a unique journey that requires not just a healthy body but a considerate mindset. Being patient, calm, and composed as a trial participant is key. It’s equally important to extend gentle behaviour towards staff and fellow participants. Remember, any lapses in good conduct won’t be tolerated. Let’s foster a positive environment together, ensuring a harmonious and rewarding experience for everyone involved.

A clinical study team member looks at the camera while volunteers are being attended to in the background.A clinical study team member looks at the camera while volunteers are being attended to in the background.

Ready to be a part of vital scientific progress while ensuring your safety?
Register below, and our friendly recruiters will reach out to assess your eligibility for upcoming clinical trials. Together, we can combine commitment with safety measures to advance scientific research. Join us on this important journey!

Engaging in medical research serves as both a contribution to scientific progress and an opportunity to proactively manage your well-being. It is essential to approach screenings with integrity, openness, and a dedicated adherence to the study’s guidelines. By doing so, you not only increase your likelihood of meeting the study’s criteria but also assume a pivotal role in the progression of healthcare and the expansion of scientific understanding. At BioPharma, we hold your participation in our clinical research in high regard and deeply appreciate your contribution to advancing healthcare. Click below to register and to be considered in a study you might be eligible for.

Written by Mai Ahmed and Shaimya Kasinathan, Clinical Recruiters, and Rohit Chavan, Medical Screening Technician at BioPharma Services.

BioPharma Services, Inc., a Think Research Corporation and clinical trial services company, is a full-service Contract Clinical Research Organization (CRO) based in Toronto, Canada, specializing in Phase 1 clinical trials 1/2a and Bioequivalence clinical trials for international pharmaceutical companies worldwide. BioPharma has clinical facilities both in the USA and Canada with access to healthy volunteers and special populations.

More Posts