A new analysis has found that many alcohol treatment studies are designed in ways that inadvertently omit women and African-Americans from participation.
The Stanford University School of Medicine researcher who led the effort said the findings should remind all scientists that strict study eligibility criteria can have unintended, negative consequences.
In reviewing data from a pool of 100,000 alcohol treatment patients, Keith Humphreys, PhD, professor of psychiatry and behavioral sciences, determined that women and African-Americans were substantially more likely to be excluded from treatment studies than men or non-African-American patients, because of eligibility requirements involving psychiatric problems, employment and housing problems, and drug use.
"Researchers' own study designs are thwarting their good-faith efforts to recruit representative patient samples," said Humphreys, whose paper will be published in the June issue of Alcoholism: Clinical and Experimental Research. "If we want health-care practice to be guided by research, we're going to have to do a better job at studying patients that clinicians actually see."
Medical studies typically exclude certain patients from participation. While some exclusions are often necessary - to protect patient safety, for example - Humphreys suspects researchers often use exclusions in their studies out of habit or tradition. In other cases, researchers may use eligibility criteria to enroll only "desirable" patients in their study, in an effort to make the trial run smoothly or to increase the chances that a favored treatment will show positive outcomes.
Humphreys said such exclusions could have dangerous implications. "If treatments are tested on, and developed for, only part of the population, that means everyone excluded is at greater risk when they use health care," said Humphreys. For this reason, the National Institutes of Health has instructed researchers to design their studies to ensure adequate enrollment of all populations, including women and racial minorities.
"The NIH, and we as a society, have decided that the burden and benefits of health research should be shared by everyone," said Humphreys, who is also on the staff of the Veterans Affairs Palo Alto Health Care System. "It's a moral and political stance and we're obligated to live up to it."
For the analysis, Humphreys and his colleagues looked at data sets from five previous alcohol treatment studies that enrolled more than 100,000 patients. They then explored the impact of six exclusion criteria commonly used in treatment outcome research: psychiatric problems, neurological problems, medical problems, drug use, non-compliance issues, and social and residential instability.