The Importance of Filter Collection for Accurate Measurement of Cigarette Smoking

Abstract

Objectives We examined the impact of cigarette filter collection on reports of cigarettes per day (CPD) versus self-reported CPD and to assess the utility of a pre-intervention baseline period in smoking studies. Methods Using baseline data from 522 non-treatment seeking smokers, we assessed differences in self-reported CPD via phone screen (CPD PS) and during baseline (CPD BL). We analyzed self-reported cigarette measures to predict carbon monoxide (CO), a measure of smoke exposure. Results On average, CPD PS was 2.8 CPD more than CPD BL, and reporting multiples of 10 were more often found in CPD PS compared with CPD BL (54.7% vs17.2%, respectively). CPD BL was more strongly associated with CO than self-report CPD. Number of cigarettes smoked today, time since last cigarette, and nicotine dependence were significantly associated with CO. Conclusions CPD BL using filter collection is a more accurate measure of cigarette consumption than self-report, which may have implications for assessment of nicotine dependence. When feasible, studies should include a pre-intervention baseline period for comparison data with study outcomes. In addition to CPD BL, studies should assess time since last cigarette and the number of cigarettes smoked today when using CO as a biological measure of smoke exposure.

Three approaches to quantifying cigarette consumption: Data from nondaily smokers.

“…When static measures are called for, consumption is often assessed by simply asking subjects how much they smoke each day, on average. Yet, such summary measures have been shown to be problematic, particularly suffering from digit bias, whereby subjects tend to report numbers rounded to multiples of 10 or five (Saddleson, Wileyto, Darwar, Ware, & Strasser, 2017; Shiffman, 2009b). Such summaries also fail to capture the considerable day-to-day variation that is typical of smoking (Hughes, Shiffman, Naud, & Peters, 2017; Shiffman et al, 2012).…”

“…Blank et al (2016) demonstrated that this measure was not subject to digit bias; showed significant within-subject variability; and, unlike global reports of cigarette consumption, was associated with biochemical measures of smoke exposure. Saddleson et al (2017) also argued for the value of collecting cigarette butts but found that counts of butts resulted in significantly lower estimates of cigarette consumption than with TLFB.…”

Measurement of cigarette smoking: Comparisons of global self-report, returned cigarette filters, and ecological momentary assessment.

“…One of these techniques is product collection, such as when participants store spent cigarette filters to return to the laboratory (e.g., Blank & Eissenberg, 2010;Breland et al, 2003). Comparisons of filter collection and global self-report suggest that smokers over-report their average CPD by ˜1-2 cigarettes (Clark et al, 1996;Etter & Perneger, 2001;Saddleson et al, 2017), but that such values are highly correlated and do not differ significantly (Blank et al, 2016;Shiffman & Scholl, 2018). Notably, digit bias occurs for global self-reports but not for filter collection, suggesting that the latter may be a more reliable method for CPD measurement (Blank et al, 2016;Saddleson et al, 2017;Shiffman & Scholl, 2018).…”

“…Comparisons of filter collection and global self-report suggest that smokers over-report their average CPD by ˜1-2 cigarettes (Clark et al, 1996;Etter & Perneger, 2001;Saddleson et al, 2017), but that such values are highly correlated and do not differ significantly (Blank et al, 2016;Shiffman & Scholl, 2018). Notably, digit bias occurs for global self-reports but not for filter collection, suggesting that the latter may be a more reliable method for CPD measurement (Blank et al, 2016;Saddleson et al, 2017;Shiffman & Scholl, 2018). Some suggest that filter collection is a better predictor of biological measures of nicotine/tobacco exposure than global self-report (Blank et al, 2016;Saddleson et al, 2017), while others indicate that they are comparable (Shiffman & Scholl, 2018).…”

“…Notably, digit bias occurs for global self-reports but not for filter collection, suggesting that the latter may be a more reliable method for CPD measurement (Blank et al, 2016;Saddleson et al, 2017;Shiffman & Scholl, 2018). Some suggest that filter collection is a better predictor of biological measures of nicotine/tobacco exposure than global self-report (Blank et al, 2016;Saddleson et al, 2017), while others indicate that they are comparable (Shiffman & Scholl, 2018). However, biological measures are influenced by environmental CO (Sichletidis et al, 2007) and differences in nicotine metabolism across users (Benowitz & Jacob, 1994), limiting their reliability.…”