On 2017 Jun 26, David Marks commented:

This trial was neither randomised, nor controlled, and needs to be retracted. The trial did not compare an abrupt method to a gradual method, as stated, it compared an abrupt method with a mixed bag of complicated gradual methods about which it is impossible to draw solid conclusions. The lead authors have either declared significant conflicts of interest in products used in the research (Aveyard and West) or the ICMJE Form for Disclosure of Potential Conflicts of Interest is incorrect, being the form for the wrong study(Michie). The conclusion that abrupt cessation produces superior cessation rates to gradual cessation cannot be maintained on the basis of this flawed trial for the reasons given below. 1) The gradual-cessation group received short-acting nicotine replacement therapy (NRT) and nicotine patches before the quit day. The abrupt-cessation group received only nicotine patches before the quit day. The treatments are therefore confounded with different pre-exposure levels of NRT. 2) Eligible smokers were booked for an appointment with a research nurse during which the study was explained, eligibility was confirmed, and written informed consent was obtained. What research training did the so-called 'research nurses' receive or were the key study personnel basic grade practice nurses given the task of running the trial? 3) The gradual-cessation group were were supposed to reduce smoking to half of the baseline amount by the end of the first week (known as visit −1) and to a quarter of the baseline amount at the end of the second week (visit 0) in daily increments using a complex variety of procedures that were likely to have been confusing and difficult to follow. 4) The nurses provided the gradual-cessation group with nicotine patches, 21 mg/d, and a choice of short-acting NRT products (gum, lozenges, nasal spray, sublingual tablets, inhalator, or mouth spray) during the reduction period. For such products as gum and lozenges, the instruction was to use 1 dose per cigarette missed. Again, apart from the confounding, and different pre-exposure for the gradual-reduction group, the procedure is unnecessarily complex. 5) Before quitting, participants in the abrupt-cessation group were asked to use nicotine patches, 21 mg/d, but no short-acting NRT. Nicotine patches were used in this group before the quit day, a protocol that aimed to balance the effect between groups. Instead of aiming to balance the effect between groups, there should have been precise balancing, otherwise the trial cannot be described as 'controlled'. 6) Allocation of participants was the responsibility of the so-called 'research nurse' who put patients into blocks of 2, 4, and 6. This allocation was manifestly non-random: “After the participant granted consent, the research nurse opened sealed, numbered envelopes in turn. However, for pairs (for example, husband and wife), one person was allocated randomly and the other was allocated to the same group”. This was a clustered method of allocation, not randomisation. 7) The loss of 300 potential participants also raises questions about how the remaining 697 differed from the original applicants. 8) Unsurprisingly, given their complicated and non-matched treatment, significantly fewer participants in the gradual-cessation group attended visit 0, (67.0% [229 of 342] vs. 83.4% [296 of 355] in the abrupt-cessation group; P < 0.001). Fewer participants in the gradual-cessation group (61.4% [210 of 342]) than the abrupt-cessation group (71% [252 of 355]) (P = 0.007) made a quit attempt. In sum, the trial was a mish-mash of umatched 'treatments', one of which was actually three different treatments counted as one, both confounded by differing pre-cessation exposure to a variety of NRT products chosen by the participants themselves. The trial was carried by 'research nurses' working in GP practices using a batch method for allocating participants. A deliberately uncontrolled, improperly randomised trial, confounded by different NRT products between groups.

On 2017 Jun 26, David Marks commented:

This trial was neither randomised, nor controlled, and needs to be retracted. The trial did not compare an abrupt method to a gradual method, as stated, it compared an abrupt method with a mixed bag of complicated gradual methods about which it is impossible to draw solid conclusions. The lead authors have either declared significant conflicts of interest in products used in the research (Aveyard and West) or the ICMJE Form for Disclosure of Potential Conflicts of Interest is incorrect, being the form for the wrong study(Michie). The conclusion that abrupt cessation produces superior cessation rates to gradual cessation cannot be maintained on the basis of this flawed trial for the reasons given below. 1) The gradual-cessation group received short-acting nicotine replacement therapy (NRT) and nicotine patches before the quit day. The abrupt-cessation group received only nicotine patches before the quit day. The treatments are therefore confounded with different pre-exposure levels of NRT. 2) Eligible smokers were booked for an appointment with a research nurse during which the study was explained, eligibility was confirmed, and written informed consent was obtained. What research training did the so-called 'research nurses' receive or were the key study personnel basic grade practice nurses given the task of running the trial? 3) The gradual-cessation group were were supposed to reduce smoking to half of the baseline amount by the end of the first week (known as visit −1) and to a quarter of the baseline amount at the end of the second week (visit 0) in daily increments using a complex variety of procedures that were likely to have been confusing and difficult to follow. 4) The nurses provided the gradual-cessation group with nicotine patches, 21 mg/d, and a choice of short-acting NRT products (gum, lozenges, nasal spray, sublingual tablets, inhalator, or mouth spray) during the reduction period. For such products as gum and lozenges, the instruction was to use 1 dose per cigarette missed. Again, apart from the confounding, and different pre-exposure for the gradual-reduction group, the procedure is unnecessarily complex. 5) Before quitting, participants in the abrupt-cessation group were asked to use nicotine patches, 21 mg/d, but no short-acting NRT. Nicotine patches were used in this group before the quit day, a protocol that aimed to balance the effect between groups. Instead of aiming to balance the effect between groups, there should have been precise balancing, otherwise the trial cannot be described as 'controlled'. 6) Allocation of participants was the responsibility of the so-called 'research nurse' who put patients into blocks of 2, 4, and 6. This allocation was manifestly non-random: “After the participant granted consent, the research nurse opened sealed, numbered envelopes in turn. However, for pairs (for example, husband and wife), one person was allocated randomly and the other was allocated to the same group”. This was a clustered method of allocation, not randomisation. 7) The loss of 300 potential participants also raises questions about how the remaining 697 differed from the original applicants. 8) Unsurprisingly, given their complicated and non-matched treatment, significantly fewer participants in the gradual-cessation group attended visit 0, (67.0% [229 of 342] vs. 83.4% [296 of 355] in the abrupt-cessation group; P < 0.001). Fewer participants in the gradual-cessation group (61.4% [210 of 342]) than the abrupt-cessation group (71% [252 of 355]) (P = 0.007) made a quit attempt. In sum, the trial was a mish-mash of umatched 'treatments', one of which was actually three different treatments counted as one, both confounded by differing pre-cessation exposure to a variety of NRT products chosen by the participants themselves. The trial was carried by 'research nurses' working in GP practices using a batch method for allocating participants. A deliberately uncontrolled, improperly randomised trial, confounded by different NRT products between groups.