Figure 1.

Markov chain diagram.

Notes: Health state descriptions:

Eligible smoker: Adult smokers who are eligible to quit smoking with a smoking cessation therapy during the current year. This includes:

1. 1. smokers who have never attempted to quit,
2. 2. smokers who have previously attempted to quit and failed,
3. 3. successful quitters who subsequently relapsed.

Ineligible smoker: This tunnel state is used when modeling one covered quit attempt per year. A tunnel state is a state that can be occupied for only one cycle, which represents both the disease state the individual is in and the number of previous cycles spent in the state.²⁹ The use of tunnel states helps to build artificial memory in Markov approaches, which normally have no memory over time. This state holds smokers who are not eligible to quit smoking because they failed a quit attempt <12 months prior to their current quit attempt. When modeling two quit attempts per year, smokers return to “Eligible Smoker” in the first cycle after their relapse.

Initial quitter: A tunnel state for smokers who have attempted to quit in the current year, and are currently abstinent from smoking during the current cycle but who have not yet met the criteria for “Successful Quitter”.

Successful quitter: Consists of initial quitters who have abstained from smoking for the required length of time to meet the clinical definition of success and who have not relapsed. The model assumes that a person becomes a “Successful Quitter” after being abstinent from smoking for 1 full year.

Dead: Captures death due to all-cause mortality, based on age- and gender-adjusted rates from US life tables from the Centers for Disease Control and Prevention. Reprinted by permission from Springer Nature. Adv Ther, Estimated budget impact of adopting the affordable care act’s required smoking cessation coverage on United States healthcare payers, Baker CL, Ferrufino CP, Bruno M, Kowal S, 2017;34(1):156–170, copyright 2018.¹³,²¹