Table 2.
Primary and Secondary Outcomes of Learn to Quit’s Pilot Randomized Controlled Trial
| Learn to Quit | QuitGuide | Effect | p-value | |
|---|---|---|---|---|
| Usability and engagement | M (SD) | M (SD) | ||
| System Usability Scale | 85.2 (15.5) | 78.4 (16.5) | Cohen’s da = 0.53 | .046* |
| Days used | 34.1 (27.7) | 32 (24.5) | Cohen’s d = 0.08 | .754 |
| App interactionsb | 335 (303) | 205 (172) | RRc = 1.8 (1.2, 2.6) | .001* |
| App duration in hoursb | 4.24 (4.29) | 2.14 (1.72) | RR = 2.1 (1, 4.3) | .044* |
| Technical coaching (% Complete) | 90.2% (3.6/4) | 96.5% (3.9/4) | Cohen’s d = 0.4 | .127 |
| Smoking behavior | M (SD) | M (SD) | Cohen’s d | |
| Reductions in CPD | 12.3 (11.5) | 5.9 (5.9) | 0.68 | .010* |
| Quit attempts | 5.30 (4.57) | 8.96 (6.18) | 0.68 | .009* |
| C-NRT adherenced | M (SD), Percent | M (SD), Percent | ||
| Days of patch use | 21.3 (10.8), 36% | 28.8 (12.2), 48% | 0.13 | .625 |
| Days of lozenge use | 6.5 (9.5), 92% | 8.5 (10.2), 120% | 0.03 | .914 |
| Smoking abstinencee | OR (95% CI) | |||
| 30-day PPAf, week 16 | 12.1% (4/33) | 3.4% (1/29) | 3.86 (0.41, 36) | .239 |
| 30-day PPA, week 16 (adjustedg model) | 8.76 (0.78, 97.8) | .077 | ||
| 7-day PPA, week 4 | 9.1% (3/33) | 17.2% (5/29) | 0.48 (0.10, 2.21) | .347 |
| 7-day PPA, week 8 | 18.2% (6/33) | 0% (0/29) | 13.9 (0.75, 259) | .077 |
| 7-day PPA, week 12 | 9.1% (3/33) | 6.9% (2/29) | 1.35 (0.21, 8.7) | .752 |
| 7-day PPA, week 16 | 12.1% (4/33) | 3.4% (1/29) | 3.86 (0.41, 36) | .239 |
CI = confidence interval; C-NRT = Combined Nicotine Replacement Therapy; CO = carbon monoxide; CPD = cigarettes per day; OR = odds ratio; PPA = point prevalence abstinence; ppm = parts per million; RR = risk ratio. Unless otherwise specified all statistical models for continuous variables used Analysis of Variance. OR indicates odds ratio in logistic regression for binary variables.
aCohen’s d and p-values are based on robust estimation methods.
bGroup means were extracted from averages of individual use over time and then from an average across individuals.
cRR and corresponding 95% CI resulting from zero inflated negative binomial models of app engagement data.
dPercent was calculated by dividing self-reported days of patch use from baseline to week 8 by 60 days (8 weeks), and days of lozenge use from baseline to week 8 divided by 7 days.
eAll abstinence rates were biochemically verified (CO < 5 ppm).
fPPA: point-prevalence abstinence rates.
gThe model adjusted for baseline levels of CPD, employment disability, schizophrenia spectrum and psychotic symptoms.
*p values < .05.