Table 3

HRs and their 95% CIs for an event (dispensed N05 medications during follow-up) in association with a 10 µg/m3 increase in NO2 and PM10, adjusted for individual-level and group-level characteristics

  Number of observations in total/in analysis/eventsNO2PM10
HR (95% CI)HR (95% CI)
All cohort*896 117/552 221/92641.087 (1.055 to 1.121)1.038 (1.003 to 1.076)
Stratified by countyStockholm360 683/209 589/34551.129 (1.068 to 1.194)1.227 (1.123 to 1.340)
Västra Götaland270 398/173 210/30661.106 (1.056 to 1.158)1.175 (1.091 to 1.266)
Skåne218 064/140 385/22901.019 (0.945 to 1.1097)0.995 (0.927 to 1.067)
Västerbotten46 972/29 500/4671.130 (0.930 to 1.373)1.894 (1.128 to 3.180)
Stratified by sexGirls436 737/268 943/47751.080 (1.035 to 1.127)1.040 (0.991 to 1.093)
Boys459 380/283 278/44891.092 (1.045 to 1.141)1.033 (0.9991 to 1.093)
Exclude SAMS areas with a population density of <1000/km2Stockholm294 728/167 711/27691.108 (1.043 to 1.177)1.180 (1.073 to 1.297)
Västra Götaland122 083/72 773/12881.071 (1.010 to 1.136)1.110 (1.007 to 1.225)
Skåne111 000/66 235/11080.890 (0.808 to 0.981)0.891 (0.812 to 0.977)
Västerbotten13 824/8803/1420.853 (0.609 to 1.193)1.127 (0.382 to 3.25)
Concentrations <15 µg/m3Stockholm303 380/177 831/29191.179 (1.053 to 1.321)1.401 (1.187 to 1.652)
Västra Götaland215 300/142 031/24941.107 (0.990 to 1.238)1.194 (0.873 to 1.634)
Skåne179 700/119 365/19741.150 (1.003 to 1.319)0.775 (0.475 to 1.266)
Västerbotten43 694/27 154/4231.124 (0.891 to 1.419)1.78 (0.889 to 3.357)
  • *SAMS (Small Areas for Market Statistics). The crude HR associated with a 10 µg/m3 increase in NO2 was 1.013 (95% CI 0.993 to 1.034) and with a 10 µg/m3 increase in PM10 was 0.982 (95% CI 0.959 to1.006). The HR adjusted for individual-level, but not group-level, characteristics associated with a 10 µg/m3 increase in NO2 was 1.087 (95% CI 1.056 to 1.119) and with a 10 µg/m3 increase in PM10 was 1.041 (95% CI 1.006 to 1.078).