Comorbidities Result in Fewer Patients in Clinical Trials


Survey results show that when one or more chronic condition was present physicians discussed trial participation with less than half of patients.

Patients who have one or more chronic disease or condition are less likely to learn about or participate in a clinical trial, according to study findings published in JAMA Oncology.

Researchers conducted a web-based national survey that included 5,499 patients with either an initial diagnosis of breast, colorectal, lung or prostate cancer. Patients were asked about their demographics, staging, chronic conditions (comorbidities) and the treatment decision-making process with respect to clinical trial participation.

Most patients were women (62.2%), white (94.4%), younger than 65 years old (78.2%) and had at least one or more comorbidities (66%). The most common comorbidity was high blood pressure (35%). Other conditions included vision loss (16.6%), arthritis (15.3%), asthma (11.5%), hearing loss (11.2%), previous cancer (10.2%) and chronic obstructive pulmonary disease (6.6%). Rarer conditions included bypass surgery (1.8%), heart attack (3.4%) and heart failure (1.2%).

However, the survey also revealed a lack of conversation about clinical trials between patients and their physicians, the number of patients offered to participate in a clinical trial and the actual number of patients who participated.

The researchers learned that less than half (39.5%) of patients reported discussing a trial with their physician. Nearly 980 patients (17.8%) said they were offered trial participation and only 9% reported participating in a clinical trial.

“Our simulation analyses suggested that the modernization of trial eligibility criteria could provide an opportunity for several thousand more patients with well-managed comorbidities to participate in cancer clinical trials each year,” wrote the researchers.

For instance, researchers explained that about 70% of people in the United States who are 65 and older have high blood pressure. But, in about half the cases, the high blood pressure

is controlled. That leaves a potential large pool of candidates for clinical trials, the researchers noted.

In addition, they shared how recent evidence shows that prior cancers have limited or no effect on outcomes for new diagnoses when these patients participate in clinical trials, despite the belief that this may complicate the interpretation of outcomes.

Although hearing loss is not a comorbidity that would exclude a patient from clinical trial participation, the researchers said it could cause a barrier to communication with their physician. They suggest providing access to easy-to-understand brochures, amplification with headsets or other approaches to help improve the delivery of the message.

“The participation of more patients will speed the rate at which trials can be conducted, and thus, the rate at which new treatments and regimens are identified, benefiting all patients,” wrote the researchers. “But for most patients, simply accessing an available trial is a major hurdle, further complicated by issues of eligibility restrictions and physician and patient barriers.”

Patients can learn more about available clinical trials at or by speaking with their heath care team members.

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