Prevalence and predictors of research participant eligibility criteria in alcohol treatment outcome studies, 1970-98.
OBJECTIVE
To describe the eligibility criteria (i.e. study participant inclusion and exclusion rules) employed in alcohol treatment outcome research and to identify predictors of their use.


METHODS
The eligibility criteria of 683 alcohol treatment outcome studies conducted between 1970 and 1998 were coded reliably into 14 general categories. Predictors of the use of eligibility criteria were then examined.


RESULTS
Patients were most often ruled ineligible for research studies because of their level of alcohol problems (39.1% of studies), comorbid psychiatric problems (37.8%), past or concurrent utilization of alcohol treatment (31.8%), co-occurring medical conditions (31.6%), and because they were deemed non-compliant and unmotivated (31.5%). The number of eligibility criteria employed in studies increased from the 1970s through the 1990s, and was positively associated with funding from the US National Institute of Alcohol Abuse and Alcoholism (NIAAA) and from the private sector, lack of an inpatient/residential treatment condition, presence of a pharmacotherapy, and use of a randomized, multiple-condition design. Principal investigators with doctoral degrees used more eligibility criteria than those with lower degrees.


CONCLUSIONS
Participant eligibility criteria are extensively employed in alcohol treatment outcome research, and vary significantly across historical periods, funders and research designs. Researchers should report the details of subject eligibility criteria and excluded patients more fully, and, evaluate how eligibility criteria affect the cost, feasibility, and generalizability of treatment outcome research.
Humphreys
Keith
K
Veterans Affairs and Stanford University Medical Centers, Palo Alto, CA 94025, USA. knh@stanford.edu
Weingardt
Kenneth R
KR
Horst
Doyanne
D
Joshi
Asha A
AA
Finney
John W
JW
D000437:Alcoholism / Q000628:therapy*; D002985:Clinical Protocols; D002986:Clinical Trials as Topic / Q000379:methods; D017831:Diagnosis, Dual (Psychiatry); D006801:Humans; D010349:Patient Compliance; D018579:Patient Selection; D012107:Research Design; D016896:Treatment Outcome