Table 3.
Observational estimates for the associations between smoking and cognitive capabilities
| Regression coefficient (95% CI) |
|||||
|---|---|---|---|---|---|
| Outcome | Model† | Cigarette per day | Current vs ex-smoker | Current vs never smoker | Ever vs never smoker |
| Crystallised measures | |||||
| Mill Hill | M1 | −0.003 (−0.012 to 0.005) | −0.140*** (−0.216 to −0.063) | −0.192**** (−0.266 to −0.117) | −0.092*** (−0.142 to −0.043) |
| M2 | −0.004 (−0.013 to 0.005) | −0.146*** (−0.223 to −0.070) | −0.194**** (−0.269 to −0.119) | −0.090*** (−0.140 to −0.040) | |
| NART | M1 | −0.004 (−0.010 to 0.001) | −0.174**** (−0.261 to −0.088) | −0.159** (−0.262 to −0.056) | −0.041 (−0.097 to 0.016) |
| M2 | −0.004 (−0.010 to 0.002) | −0.194**** (−0.265 to −0.123) | −0.142* (−0.260 to −0.023) | −0.028 (−0.086 to 0.030) | |
| Fluid measures | |||||
| Gf | M1 | −0.002 (−0.011 to 0.007) | −0.173**** (−0.221 to −0.124) | −0.147**** (−0.205 to −0.088) | −0.036* (−0.067 to −0.006) |
| M2 | −0.002 (−0.011 to 0.007) | −0.178**** (−0.228 to −0.129) | −0.137**** (−0.199 to −0.074) | −0.029 (−0.059 to 0.002) | |
| AH4 | M1 | 0.000 (−0.008 to 0.009) | −0.139**** (−0.195 to −0.082) | −0.135**** (−0.196 to −0.073) | −0.047* (−0.090 to −0.003) |
| M2 | 0.000 (−0.009 to 0.009) | −0.148**** (−0.206 to −0.090) | −0.129**** (−0.192 to −0.065) | −0.040 (−0.084 to 0.004) | |
| Semantic fluency | M1 | −0.002 (−0.008 to 0.003) | −0.139**** (−0.175 to −0.104) | −0.105*** (−0.162 to −0.047) | −0.019 (−0.059 to 0.021) |
| M2 | −0.002 (−0.007 to 0.003) | −0.136**** (−0.172 to −0.100) | −0.095** (−0.155 to −0.035) | −0.012 (−0.053 to 0.029) | |
| Phonemic fluency | M1 | −0.005 (−0.015 to 0.006) | −0.028 (−0.378 to 0.322) | 0.041 (−0.289 to 0.372) | 0.031 (−0.022 to 0.084) |
| M2 | −0.005 (−0.015 to 0.005) | −0.063 (−0.355 to 0.228) | 0.056 (−0.295 to 0.407) | 0.037 (−0.016 to 0.091) | |
| Search speed‡ | M1 | −0.005* (−0.009 to −0.001) | −0.122*** (−0.188 to −0.057) | −0.148** (−0.239 to −0.057) | −0.059** (−0.099 to −0.019) |
| M2 | −0.006** (−0.010 to −0.002) | −0.122*** (−0.192 to −0.052) | −0.142** (−0.232 to −0.051) | −0.054** (−0.091 to −0.016) | |
| Word recall | M1 | −0.005 (−0.010 to 0.000) | −0.144*** (−0.222 to −0.067) | −0.138**** (−0.192 to −0.083) | −0.044*** (−0.071 to −0.018) |
| M2 | −0.005 (−0.010 to 0.000) | −0.143*** (−0.222 to −0.064) | −0.134**** (−0.191 to −0.078) | −0.042** (−0.069 to −0.016) | |
*p<0.05, **p<0.01, ***p<0.001, ****p<0.0001.
†Models: (M1) age, sex and SEP adjusted, (M2) M1 + disease adjusted.
‡Natural log transformed.
AH4, Alice-Heim 4-I test; GF, general fluid; NART, National Adult Reading Test; SEP, socioeconomic position.