Trial reportJournal of substance abuse treatment2019
Understanding site variability in a multisite clinical trial of a technology-delivered psychosocial intervention for substance use disorders.
Trial report in Journal of substance abuse treatment, 2019. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 4 papers.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
4 citing papers in PubMed.
- Practice Variability in the SHARING Choices Pragmatic Trial of Primary Care Advance Care Planning.Journal of the American Geriatrics Society · 2026Trial
- Heterogeneity of Treatment Outcomes Across Therapists and Sites in a Randomized Multicentre Psychotherapy Trial.Clinical psychology & psychotherapyTrial
- Study protocol for the randomized controlled trial of EMBOLDEN: a multifaceted intervention aimed at Enhancing physical and community MoBility in OLDEr adults with health inequities using commuNity co-design.Frontiers in public health · 2025Article
- High-dimensional variable selection accounting for heterogeneity in regression coefficients across multiple data sources.The Canadian journal of statistics = Revue canadienne de statistique · 2024Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
5 authors.
Funding
Abstract
backgroundSignificant fixed effects of site (main effects of site and/or site by treatment interactions) on primary outcome have been identified in the majority of studies performed by NIDA's National Drug Abuse Treatment Clinical Trials Network. While rarely explored, identifying patient- and site-level variables that are associated with site effects can provide information about the context in which outcome is optimized.
methodsIn a 10-site clinical trial that evaluated the effectiveness of a web-based psychosocial intervention compared to usual treatment of patients (N = 507) with substance use disorders, the primary outcome analysis revealed significant main effect of site, modeled as a fixed effect, on the outcome of abstinence (Campbell et al., 2014). In the current analysis, we use a two-level, hierarchical generalized linear model (HGLM) to identify patient- and site-level variables associated with abstinence outcome, while modeling site as a random factor.
resultsThe site-specific percentage of patients abstinent in the last 4 weeks of the study varied from 6.1% to 40%. However, only 6.7% (p = 0.08) of variability in end-of-study abstinence was accounted for by site, indicating a small-moderate effect. Among patient-level predictors, older age (OR = 1.40; 95% CI = 1.15, 1.71; p = 0.0009), abstinence at baseline (OR = 2.77; 95% CI = 1.73, 4.45; p < 0.0001), and among site-level predictors, higher annual clinic admissions (OR = 1.28; 95% CI = 1.03, 1.59; p = 0.0251) were significantly associated with increased likelihood of abstinence. When controlling for these three variables in a HGLM, only patient age and abstinence at baseline remained significant, and random factor site explained only 1.4% of variability in end-of-study abstinence, a 79% reduction in magnitude.
conclusionsThe findings suggest that only some amount of variability in abstinence outcomes among sites can be explained by a combination of patient- and site-level variables. Our findings support the case that variability between sites is a natural phenomenon, and our methodological recommendation is that site be modeled as a random factor when analyzing multi-site clinical trials.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.