"Smoking Paradox" in stroke survivors? Uncovering the truth from a national stroke registry data

[[abstract]]Objective: Smokers with stroke were reported to have a better survival than nonsmokers, and this phenomenon was labeled as “smoking paradox”. This study is to assess its validity from a national stroke registry data. Methods: A total of 88,925 cases of stroke registered in the nationwide stroke registry system of Taiwan between 2006 and 2016, with 4,169 deaths, were analyzed. Age-specific mortality rate for current, ex- and non-smokers were calculated. NIHSS score (National Institutes of Health Stroke Scale) was measured at 3 months and 6 months Cox model was used to compare complications, mortality and outcomes between smoker and non-smoker ground. Results: Smokers constituted more than half of the men (55%) but only 5% of the women. The median age for current smokers was 60.2, for nonsmokers, 71.6, and for ex-smokers, 72.5. Smokers, with nearly 12 years younger than nonsmokers, had smaller mortality rate at younger age groups with fewer deaths, but much larger mortality after age 60, and doubled the mortality rate at the largest group after age 70. Smokers, who quit early, had similar outcome as nonsmokers. When age was controlled, current smokers had worse functional outcome (NIHSS) even at 3 months (adjusted OR, 1.08; 95% CI, 1.02-1.14). Conclusion: Smokers, but not ex-smokers, developed stroke 12 years younger than nonsmokers, an ominous sign for smokers. They had higher age-specific mortality rate and poorer outcome than nonsmokers. Quitting early nearly reversed the harms. Smoking paradox does not exist