Quitline Evaluations
From ICE Primer: A Tobacco Control Research Methodology Primer
Contents |
What are quitlines?
Quitlines are telephone based tobacco cessation services that provide evidence based treatments (as described in the Clinical Guidelines for Tobacco Treatment) for tobacco users. Tobacco users contacting a quitline are assessed by trained cessation specialists and offered self-help materials, tailored counseling with ongoing support, pharmaceutical aides and/or referrals to other resources, depending on the quitline mandate and tobacco users' tobacco history and readiness to quit.
Quitlines primarily serve cigarette smokers and all subsequent reference on this site refers to cigarette smokers. Evidence of the effectivness of quitlines for other types of tobacco users is still developing.
Evaluating Quitlines
The impact of a quitline on the smoking rates of a population is determined by the reach of the program and the effectiveness of the intervention offered by the program.
Reach
Reach is defined as the “proportion of the target population who receive an evidence based treatment from a quitline”. It should not be confused with utilization, which is the proportion of the target population who call the quitline. Not all callers receive an evidence based intervention.
Reach = # of target population who receive evidence based treatment from a quitline x 100 total # in target population
Example: Reach of Canadian quitlines = 9,305 smokers who receive evidence based treatment = 1.25% 741,766 current smokers in Canada (CTUMS 2005)
Effectiveness
Effectiveness is measured by determining the quit rate among those who receive evidence based treatments from the quitline.
Quit Rate = __number of smokers who receive quitline intervention AND who stop using tobacco__ total number of smokers who received quitline intervention
The North American Quitline Consortium currently recommends a 30 day point prevalence quit rate, measured six months after the treatment has been delivered to the tobacco user.
To determine the 30 day point prevalence quit rate, smokers are asked "Have you smoked a cigarette, even a puff, in the last 30 days?' Those who answer "No" are considered to have quit and are included in the numerator.
Example: 30 day quit rate = 1,182 smokers have not smoked even a puff in the last 30 days = 12.7% 9,305 smokers who received evidence based treatment
The target population is defined by the quitline’s mandate and may differ between quitlines. It is important to know who is and is not included in the target population in order to select the correct denominator. If the target population is all tobacco users in a province, state or country, then the best estimate of the size of the target population is a provincial / state or national survey.
The tEach quitline will have a defined target population which might be all tobacco users, all cigarette smokers, only pregnant smokers, only smokers ready to quit. It needs to take into consideration reach, defined as "the proportion of the target population that receives an evidence based treatment from the quitline" (Cummins, NAQC Whitepaper COULD LINK DIRECTLY WHEN PAPER IS POSTED), and the effectiveness (long term quit rates) of the treatment.
Population Impact = Reach x Effectiveness
Reach Quitline reach is the proportion of the target population that receives evidence based treatment from the quitline. In calculating reach, the numerator is the number of smokers who are provided with evidence based treatment and the denominator is the total number of smokers in the target population.
Two components of this definition are worth noting. First the numerator includes only those smokers who receive "evidence based treatment", not all smokers who might call the quitline.
Secondly, the denominator is the total number of smokers in the target population. The accuracy and usefulness of the reach measure depends on the reliability of the population estimates used, and how representative the numerator is of the target population
Population Estimates: For quitlines which serve the entire population of smokers, then the estimate of the number of smokers in the population can often be obtained from national or provincial / state level surveys. For quitlines which serve a specific group of smokers, such as only pregnant women, or only smokers willing to set a quit date, the denominator may be difficult to determine unless there is a specific survey of that target population. If no population data are available, then an estimate of the target population is required. LINK TO SOURCES OF POPULATION DATA FOR SMOKERS
Representativeness Comparing the demographic characteristics, smoking history and current smoking behaviours, including past quit attempts, of those smokers who received evidence based services with the target population will provide evidence about the generalizability of the reach estimate. Non-randomized studies and natural experiments The North American Quitline Consortium has published a Minimal Data Set that describes the type of demographic, smoking and quitting behaviours that at minimum ought to be compared between numerator and denominator www.naquitline.org.
Quitline Effectiveness
Quitlines aim to reduce the overall number of smokers in the population and therefore long term abstinence is the desired goal. There is some debate in the field (as of July 2008) as to whether one year or six months constitute a sufficiently long time period that the risk of relapse is minimal. Current recommendations are that six months prolonged abstinence is scientifically appropriate and b.
