Association of smoking behavior and time to first cigarette with all-cause and cause-specific mortality: A cohort analysis from the NHANES 2001–2018

INTRODUCTION: Smoking is a major risk factor for death, but the impact of behavioral patterns such as time to first cigarette (TTFC) on this risk has been little studied in the US population. To address this, we investigated the association between smoking status and TTFC with all-cause, cardiovascular disease, and cancer mortality based on a national sample. METHODS: We conducted a pooled secondary data analysis of the National Health and Nutrition Examination Survey data from the United States, covering nine continuous cycles between 2001 and 2018. The initial pooled sample comprised 91355 participants. After applying a series of exclusion criteria, the final analytical cohort consisted of 39084 adult subjects. TTFC was investigated by means of a touch-screen questionnaire. Outcomes included all-cause mortality, cardiovascular disease mortality, and malignancy-related mortality. Mortality information was obtained from the National Death Index (NDI) using death certificates (https://www.cdc.gov/nchs/linked-data/mortality-files/?CDC_AAref_Val=https://www.cdc.gov/nchs/data-linkage/mortality-public.htm). RESULTS: After full adjustment, former smokers had a significantly elevated risk of mortality compared to never smokers. A U-shaped association was observed between TTFC and both all-cause and CVD mortality. For all-cause mortality, the risk was highest in smokers with TTFC