Table 2

Quit rates based on ITT and CCA for AC and Quit.ie: Using Russell Standard (CO validated) quitting and self-report quitting

MethodQuitting definitionMonthQuit.ieACP values*
No of quittersSample sizeQuit rateNo of quittersSample sizeQuit rate
ITTRussell Standard13014920.1%5715137.7%<0.001†
32214914.8%4015126.5%0.006†
62314915.4%3515123.2%0.045†
121714911.4%3315121.9%0.008†
Self-report13614924.2%6315141.7%<0.001†
32614917.5%4815131.8%0.002†
62514916.8%4215127.8%0.011†
122114914.1%3615123.8%0.016†
CCARussell Standard1306943.5%5711051.8%0.139
3224647.8%408149.4%0.433
6234156.1%357248.6%0.778
12173844.7%336352.4%0.228
Self-report13612429.0%6313447.0%0.002†
32611422.8%4813036.9%0.008†
62510823.1%4212035.0%0.025†
122110520.0%3610733.6%0.013†
  • *The alternative hypothesis is that AC has a higher quit rate than Quit.ie.

  • †The test is significant at 0.05 level.

  • AC, Allen Carr’s Easyway to Stop Smoking; CCA, complete case analysis; CO, carbon monoxide; ITT, intention-to-treat.