A new report has highlighted key differences between participants in early and later stages of drug research for alcohol use disorder (AUD), which could affect study findings and confound evaluations of novel treatments. In the US, only 4% of people with diagnosed AUD receive medication to treat their condition, and currently only three drugs are approved for this purpose. Early-stage laboratory studies of new treatments, which often involve controlled alcohol use, usually enroll heavy drinkers who have not sought treatment for their AUD. Later-stage trials, however, typically enroll patients who have sought treatment (and hence better reflect those who might be prescribed an approved treatment in clinical practice). A lower motivation and ‘readiness to change’ of non-treatment seekers compared with treatment seekers could affect drinking behavior and medication adherence in research studies. As such, it is vital to compare these groups and assess for differences that could influence study outcomes. The new analysis, reported in Alcoholism: Clinical and Experimental Research, compared sociodemographic and alcohol-related clinical characteristics in non-treatment- and treatment-seeking participants in early and later-stage research studies, and assessed their clinical significance.
Non-treatment-seekers were 240 people with alcohol dependence who had been recruited via advertisements to four early laboratory treatment studies at Brown University (Rhode Island). Treatment-seekers were 1383 participants in the COMBINE study, a later-stage clinical trial of various therapeutic strategies for alcohol dependence, conducted at 11 US sites. These individuals had all previously sought treatment for alcohol problems. In each study, sociodemographic and alcohol-related clinical characteristics had been assessed at baseline, before any treatments were used. Researchers used statistical methods to compare these characteristics across the non-treatment and treatment seekers, and to assess whether any differing variables were associated with the main clinical outcomes of the COMBINE study – i.e. time to relapse (first heavy-drinking day), abstinent days, and ‘good clinical outcome’ (abstinence or moderate drinking without adverse consequences) over 16 weeks’ treatment.
Compared with treatment-seekers, the non-treatment seekers were more ethnically diverse, had fewer years of education, were less likely to be in full-time work, and were less likely to be in a committed relationship; the researchers speculate that marriage may represent a motivation for seeking treatment. Clinically, non-treatment seekers were less severely dependent on alcohol, which again may have reduced their motivation to seek treatment. They were also less likely to have a father with alcohol problems. However, non-treatment seekers reported heavier drinking during the month before study entry than their treatment-seeking counterparts, which may reflect a lower motivation to cut back on drinking before study participation. The two groups were similar in terms of sex, age, blood pressure, and maternal alcohol problems. Almost all the differing characteristics predicted at least one clinical outcome of COMBINE, and one variable (number of heavy drinking days in the month before baseline) predicted all three outcomes.
The findings reinforce previous reports of sociodemographic and clinical differences between treatment seekers and non-treatment seekers, and of a less severe presentation of alcohol dependence in the latter. The results further highlight the potential for these differences to influence study outcomes and confound evaluations of new treatments for AUD. In future, efforts to standardize recruitment across study phases, such as enrolling patients with more severe alcohol dependence in early-stage studies, would improve the translation of findings from early phase research through to clinical practice.
Differences in sociodemographic and alcohol-related clinical characteristics between treatment seekers and non-treatment seekers and their role in predicting outcomes in the COMBINE study for alcohol use disorder. C.L. Haass-Koffler, D. Piacentino, X. Li, V.M. Long, M.R. Lee, R.M. Swift, G.A. Kenna, L. Leggio (pages xxx).
ACER-20-4468.R1
