Accepted for/Published in: JMIR mHealth and uHealth
Date Submitted: Jul 30, 2018
Open Peer Review Period: Aug 3, 2018 - Sep 26, 2018
Date Accepted: Nov 22, 2018
(closed for review but you can still tweet)
To Text or Not to Text?: An electronic message intervention to improve treatment adherence vs matched historical controls.
ABSTRACT
Background:
Ensuring treatment adherence is important for the internal validity of clinical trials. In intervention studies where touch points decrease over time, there is even more of an adherence challenge. Trials with multiple cohorts offer an opportunity to innovate on ways to increase treatment fidelity without compromising the integrity of the study design, and previous cohorts can serve as historical controls. Electronically delivered nudges offer low-cost opportunities to increase treatment adherence.
Objective:
The purpose of this paper is to evaluate the effectiveness of electronic (E) messages on treatment adherence to the last cohort of a parent weight loss intervention during the second half of a year-long trial, when intervention checkpoint frequency decreases. Treatment adherence is measured by intervention class attendance and adherence to the intervention diet.
Methods:
All participants in the last cohort (cohort 5, n=128) of a large randomized weight loss study were offered an E-message intervention to improve participant adherence during the last 6 months of a 1-year weight loss program. Three to 4 electronic weekly messages asked participants about intervention diet adherence. A propensity score model was estimated using the 97 participants who opted to receive E-messages and those 31 who declined in Cohort 5, and pair matched Cohort 5 E-message participants to a control group from Cohorts 1-4. Eighty-eight participants had complete data, yielding n=176 in the final analyses. A two-sample t-test assessed differences between the intervention and matched control group in: 1) proportion of class attendance from 6 to 12 months, (2) diet adherence measured as total carb grams for LC and total fat grams for LF at 12 months, (3) 12-month minus 6-month weight change. Spearmen correlations assessed the dose-response relationship between proportion of text messages responded and the three outcomes.
Results:
The results suggest that receiving E-messages had no effect on treatment adherence measured by proportion of class attendance after 6 months, (mean difference of E-message group vs control) 4.63%, 95% CI (-4.43,13.68), P=.31; or adherence, LC -2.5g carb, 95% CI (-29.9, 24.8), P=.85; LF +6.2g fat, 95% CI (-4.1, 17.0), P=.26), or the secondary outcome of weight loss in the last 6 months, mean difference=0.3 kgs., 95% CI (-1.0, 1.5), P=.68. There was a positive significant response correlation between percentage of messages to which participants responded and class attendance (r =0.45, P<.001).
Conclusions:
While the current E-message intervention did not improve treatment adherence, future studies can learn from this pilot, and may incorporate more variety in the prompts and more interaction to promote more effective user engagement. Uniquely, this study demonstrated potential for innovating within a multi-cohort trial using propensity score-matched historical control subjects. Clinical Trial: n/a
Citation
Per the author's request the PDF is not available.
Copyright
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