Is some provider advice on smoking cessation better than no advice? An instrumental variable analysis of the 2001 National Health Interview Survey.
OBJECTIVE
To estimate the effect of provider advice in routine clinical contacts on patient smoking cessation outcome.


METHODS
The Sample Adult File from the 2001 National Health Interview Survey. We focus on adult patients who were either current smokers or quit during the last 12 months and had some contact with the health care providers or facilities they most often went to for acute or preventive care.


METHODS
We estimate a joint model of self-reported smoking cessation and ever receiving advice to quit during medical visits in the past 12 months. Because providers are more likely to advise heavier smokers and/or patients already diagnosed with smoking-related conditions, we use provider advice for diet/nutrition and for physical activity reported by the same patient as instrumental variables for smoking cessation advice to mitigate the selection bias. We conduct additional analyses to examine the robustness of our estimate against the various scenarios by which the exclusion restriction of the instrumental variables may fail.


RESULTS
Provider advice doubles the chances of success in (self-reported) smoking cessation by their patients. The probability of quitting by the end of the 12-month reference period increased from 6.9 to 14.7 percent, an effect that is of both statistical (p < .001) and clinical significance.


CONCLUSIONS
Provider advice delivered in routine practice settings has a substantial effect on the success rate of smoking cessation among smoking patients. Providing advice consistently to all smoking patients, compared with routine care, is more effective than doubling the federal excise tax and, in the longer run, likely to outperform some of the other tobacco control policies such as banning smoking in private workplaces.
Bao
Yuhua
Y
Center for Community Partnerships in Health Promotion, Division of General Internal Medicine and Health Services Research, David Geffen School of Medicine at UCLA, Los Angeles, CA 90024-3524, USA.
Duan
Naihua
N
Fox
Sarah A
SA
D000328:Adult; D003376:Counseling; D005260:Female; D019538:Health Care Surveys; D006302:Health Services Research; D006801:Humans; D016018:Least-Squares Analysis; D008297:Male; D008875:Middle Aged; D010817:Physician-Patient Relations; D010818:Practice Patterns, Physicians' / Q000706:statistics & numerical data*; D016540:Smoking Cessation