PARTICIPANT SELECTION BIASES IN A RANDOMIZED CLINICAL-TRIAL OF ALCOHOLISM-TREATMENT SETTINGS AND INTENSITIES

Eligible participants and decliners in a randomized study of inpatient , intense outpatient, and standard outpatient: treatments for alcoholi cs were compared and contrasted on a series of demographic, social sta bility, psychological, legal, drug use, problem severity, and treatmen t history variables. Among 302 individuals meeting eligibility require ments, those agreeing to participate, compared with decliners, were mo re likely to be unemployed, be residentially less stable, have legal p roblems, use other drugs, have a more severe alcohol problem, have a r ecent treatment history, and were less likely to have problems with vi olence. Participants also were more likely to be male and non-white, a lthough gender and racial effects were not significant when other vari ables were controlled for. The implications of these findings for gene ralizing the results of inpatient-outpatient studies are discussed, an d the need for routine reporting of decliner characteristics in resear ch reports is stressed.