"Am I eligible for a clinical trial?" is one of the first questions patients ask when they learn about respiratory research — and it is often the hardest to answer from a website alone. Every clinical trial is built around a specific set of eligibility criteria that help ensure a study is both safe for participants and scientifically sound. This guide explains, in plain language, how eligibility criteria work, what categories of requirements you will typically encounter, and why only a hands-on screening visit — not a general description — can confirm whether a specific trial is right for you.

Dr. Frank Hull, who brings more than 20 years of pulmonary clinical research experience to our Plantation, FL research facility, oversees eligibility screening for every study conducted through Lung Research Florida. Understanding how this process works can help you feel more prepared and ask better questions when you reach out to our team.

What Eligibility Criteria Are, and Why They Exist

Eligibility criteria are the specific requirements a clinical trial protocol sets for who can, and cannot, take part in a study. They are written by the study sponsor and researchers, then reviewed by an independent Institutional Review Board (IRB), before a single patient is enrolled. Criteria serve two main purposes: protecting participant safety by excluding people for whom the investigational treatment or study procedures could pose an unreasonable risk, and preserving scientific integrity by enrolling a population similar enough that the results can be meaningfully interpreted.

It helps to think of eligibility criteria less as a pass/fail test and more as a description of the population a particular study was designed to evaluate. Criteria vary from one trial to the next, even among trials studying the same condition, because each protocol is built around a specific investigational treatment and research question.

Inclusion Criteria vs. Exclusion Criteria

Every clinical trial protocol organizes its eligibility requirements into two categories.

Inclusion Criteria

Inclusion criteria are characteristics a person must have to be considered for a study, such as a defined age range, a confirmed diagnosis of the condition under study, and a certain level of disease activity or symptom severity documented through testing.

Exclusion Criteria

Exclusion criteria are factors that would rule a person out of a particular study, even if they meet the inclusion requirements — often certain other medical conditions, medications that could interact with the investigational treatment, pregnancy or breastfeeding (depending on the study), or recent participation in another trial. Exclusion criteria exist primarily to protect participant safety.

Common Eligibility Categories in Respiratory Clinical Trials

While every protocol is different, most respiratory clinical trials — including the studies conducted at our Plantation office — evaluate candidates across a similar set of general categories.

Age Range

Nearly every trial specifies a minimum and maximum age, set based on how the condition typically presents and the age groups studied in earlier phases of the investigational treatment's development.

Confirmed Diagnosis

You generally need a documented diagnosis of the specific condition being studied, sometimes supported by prior test results, imaging, or a specialist's evaluation, rather than symptoms alone.

Current Disease Control and Treatment History

Many studies are designed for patients whose symptoms are not adequately controlled by current standard-of-care treatment, or who have tried certain therapies already. Others require a stable medication regimen for a minimum period before screening.

Overall Health and Other Medical Conditions

Your general health, other diagnoses, and certain lab or vital sign findings can affect eligibility, since the research team must weigh whether study procedures or the investigational treatment would be appropriate for your overall clinical picture.

Eligibility Criteria Across Our Current Areas of Research

To illustrate how these categories play out in practice, here are the general age ranges for the respiratory research areas currently studied at Lung Research Florida. These are starting points only — each protocol includes many additional inclusion and exclusion criteria beyond age, and current enrollment status changes over time.

• Severe asthma biologic therapy studies: generally adults ages 18–75 with a confirmed severe asthma diagnosis
• COPD anti-IL-33 investigational therapy studies: generally adults ages 40–80 with confirmed COPD
• Chronic cough P2X3-targeted investigational therapy studies: generally adults ages 18–80 with refractory or unexplained chronic cough
• Bronchiectasis bispecific antibody investigational therapy studies: generally adults ages 18–85 with confirmed bronchiectasis

These age ranges represent only one inclusion criterion among many. Diagnosis confirmation, treatment history, symptom frequency, and exclusionary health conditions all factor into whether a specific trial is a potential fit, and each study has its own detailed protocol that a research coordinator can walk you through.

How a Screening Visit Determines Your Individual Eligibility

General eligibility criteria, like the ones described above, can only tell you whether a study might be a reasonable fit — they cannot confirm your individual eligibility. That determination is made through a formal screening process:

1. Phone pre-screening: A research coordinator asks general questions about your diagnosis, age, symptoms, and treatment history to identify studies worth exploring further.
2. In-person screening visit: At our Plantation, FL office, you undergo a physician evaluation, a review of your medical history and current medications, and study-specific testing, which may include pulmonary function testing, blood work, or symptom questionnaires.
3. Eligibility confirmation: Only after reviewing your actual results against the full study protocol can the study physician and coordinator confirm whether you meet that trial's eligibility criteria.

Because eligibility depends on your specific test results and health history, no website or general conversation can substitute for this process. A study coordinator will confirm your individual eligibility only after this evaluation is complete.

If You Do Not Meet Every Criterion

It is common for a patient to meet some, but not all, published criteria for a given study, or to wonder whether a borderline lab value or medication would disqualify them. Rather than assuming you do not qualify, discuss your situation with a research coordinator: some criteria allow for clinical judgment, and even if one study is not currently a fit, another active or upcoming trial might be.

Eligibility Screening for Patients in Plantation and Broward County

Patients throughout Broward County — including Plantation, Fort Lauderdale, Sunrise, Davie, and Weston — can complete pre-screening for our respiratory studies without traveling to a distant academic center. Screening visits take place at our South Florida research office, and Dr. Hull's team is available to answer questions about eligibility for severe asthma, COPD, chronic cough, or bronchiectasis trials. If you are new to the process, our step-by-step participant guide covers what happens from first contact through study completion, and our page on informed consent explains what you will review before any study procedure begins.

Remember that participation is entirely voluntary, and you are free to ask questions, decline to proceed, or withdraw at any point — even after enrollment. No clinical trial can guarantee a specific outcome, and eligibility criteria exist to protect you, not to create obstacles.

Frequently Asked Questions

What are eligibility criteria in a clinical trial?

Eligibility criteria are the specific requirements a person must meet, or must not meet, to safely and appropriately take part in a clinical trial. They are divided into inclusion criteria and exclusion criteria and exist to protect participant safety and produce reliable study results.

How do I find out if I am eligible for a clinical trial?

The only way to know your individual eligibility is through a screening process — a brief phone pre-screening followed by an in-person screening visit with a medical history review, physical exam, and study-specific testing. A study coordinator confirms eligibility based on your actual results.

Can I still qualify if I do not meet every listed criterion?

Possibly. Published criteria describe the general population a study is designed for, but only a screening visit can confirm how your specific health history applies. It is worth discussing your situation with a research coordinator rather than assuming you do not qualify.

Why do clinical trials have age range requirements?

Age ranges are set based on how a condition typically presents and how the investigational treatment was studied in earlier research phases, helping ensure the results collected can be reliably interpreted.

For broader questions about safety, compensation, and the overall trial process, visit our full Clinical Trials FAQ.

Clinical trial participation is voluntary and can be discontinued at any time. Meeting general eligibility criteria does not guarantee enrollment in any specific study, and no clinical trial can guarantee a specific outcome. This information is for educational purposes only. Please consult your physician or a study coordinator with specific questions about your individual eligibility.