Randall K. Thomas

Self-reported smoking in online surveys : Prevalence estimate validity and item format effects

Objectives:We assessed validity of self-reported smoking prevalence estimates from an online sample, and explored the impact of different item response formats on estimates. Methods:Self-reported current smoking status was obtained from 110,837 respondents from the Harris Poll Online (HPOL) panel from April 2004 to January 2005. Current smoking prevalence was compared with national estimates from the 2004 Behavioral Risk Factor Surveillance System (BRFSS), 2003 National Health Interview Survey (NHIS), and 2001–2002 National Health and Nutrition Examination Survey (NHANES). All estimates were weighted to reflect the US population. A separate survey section measured smoking prevalence using randomly assigned response formats, including yes/no grid, multiple response, numeric box, category grid, and drop-down box formats. Results:24.0% (95% confidence interval [CI] = 23.7–24.4) of HPOL respondents reported current smoking. BRFSS, NHIS, and NHANES estimates found 20.9%, 21.5% (95% CI = 20.9–22.1), and 24.9% (95% CI = 22.4–27.5), respectively, reporting current smoking. An additional 4.5% of NHANES respondents reporting not smoking had cotinine levels ≥15 ng/mL, indicating current smoking. Estimates of smoking prevalence varied by prevalence period and response format. Conclusions:Prevalence estimates obtained from the HPOL panel are comparable to those from national surveys. Online response format choices result in variation in estimated behavioral prevalence. Online surveys may be useful for public health surveillance of the US population.

Cost–benefit analysis involving addictive goods: contingent valuation to estimate willingness‐to‐pay for smoking cessation

The valuation of changes in consumption of addictive goods resulting from policy interventions presents a challenge for cost-benefit analysts. Consumer surplus losses from reduced consumption of addictive goods that are measured relative to market demand schedules overestimate the social cost of cessation interventions. This article seeks to show that consumer surplus losses measured using a non-addicted demand schedule provide a better assessment of social cost. Specifically, (1) it develops an addiction model that permits an estimate of the smokers compensating variation for the elimination of addiction; (2) it employs a contingent valuation survey of current smokers to estimate their willingness-to-pay (WTP) for a treatment that would eliminate addiction; (3) it uses the estimate of WTP from the survey to calculate the fraction of consumer surplus that should be viewed as consumer value; and (4) it provides an estimate of this fraction. The exercise suggests that, as a tentative first and rough rule-of-thumb, only about 75% of the loss of the conventionally measured consumer surplus should be counted as social cost for policies that reduce the consumption of cigarettes. Additional research to estimate this important rule-of-thumb is desirable to address the various caveats relevant to this study.