Age difference in the trends of smoking among California adults: Results from the California Health Interview Survey 2001-2011

Objective: To study the trends of cigarette smoking from 2001 to 2011 using a California representative sample in the US.

Methods: Data were taken from the California Health Interview Survey (CHIS), which is a population-based, biennial, random digit-dial telephone survey of non-institutionalized population. The CHIS is the largest telephone survey in California and the largest state health survey in the US. 282,931 adults (n=184,454 with age<=60 and n=98,477 with age>60) were included in the analysis. Data were weighted to be representative and adjusted for potential covariance and nonresponse biases.

Results: Among the adults age<=60, the prevalence of current smoking decreased from 18.86% to 15.4% from 2001 to 2011 (β=-0.8, p=0.0041). Men were more likely to be current smokers than women and the prevalence of current smokers decreased significantly in both gender groups (men from 22.72% to 18.76%, women from 15.01% to 12.05%). African Americans remained to have higher prevalence of current smoking compared with the other racial/ethnic groups. No reduction was observed for male smokers (β=-0.16, p=0.4898), or female smokers (β=-0.42, p=0.0654) among adults age>60. In 2011, there was a 14% reduction of every day smoking adults age<=60 (OR=0.84, 95%CI=0.76-0.93 , p=0.0006) compared to 2001, while no significant reduction of every day smoking was observed for those age>60.

Conclusions: The reductions of smoking for adults aged less than 60 are encouraging. However, there is a concern on cessation of smoking among the elderly for public health professionals and clinicians.