When to Assess Responses to Treatments in Adaptive Interventions? An Experimental Analysis of Assess

Horii RI, Rothman AJ, Vock DM, Joseph AM, Branson M, Melzer AC, Begnaud A, Fu SS.
When to Assess Responses to Treatments in Adaptive Interventions? An Experimental Analysis of Assessment Timing in a Smoking Cessation Treatment in the Context of Lung Cancer Screening
Nicotine Tob Res. 2026 Feb 2:ntag021. doi: 10.1093/ntr/ntag021. Epub ahead of print. PMID: 41626753.

Introduction: The Program for LUng cancer screening and TObacco cessation (PLUTO) trial was a sequential, multiple assignment, randomized trial to optimize the delivery of tobacco longitudinal care (TLC), a one-year telephone coaching and combination nicotine replacement therapy program. Our analyses tested the effects of the randomized response assessment timepoint.

Methods: Participants who smoked daily and were eligible for lung cancer screening (N=636) were randomized to have their response to treatment assessed after 4 or 8 weeks of TLC. Participants' responses determined whether they could be randomized to more (TLC with prescription medication therapy management, MTM) or less (TLC delivered quarterly) intensive treatment for the remainder of the trial. We used chi-squares and generalized linear models to test whether assessment timing affected 7-day point prevalence abstinence at weeks 12, 26, 52, and 78.

Results: Participants who were assessed at week 4, rather than 8, were more likely to report abstinence at weeks 12 and 26 (ORs>1.48, p's<0.034). Among participants who were smoking at week 4, early assessment was associated with higher abstinence at weeks 12-52 (ORs>1.31, p's<0.019), and there was some evidence at weeks 12 and 52 that it was better to offer MTM earlier rather than later (ORs>1.27, p's<0.057).

Conclusions: Earlier treatment response assessment may be beneficial, especially for those who are not responsive to initial treatment, but more research is needed to understand the mechanisms, generalizability, and robustness of the effect.

Implications: The timing of response assessment in adaptive interventions may be an important, but often overlooked, factor for optimizing clinical treatment programs. In the context of tobacco longitudinal care delivered to participants who are eligible for lung cancer screening, there may be a benefit to assessing participant responses to tobacco cessation treatment earlier (after 4 weeks) rather than later (after 8 weeks), although the reasons for the benefit remain unclear.