Census counts All Complete datay Deaths* All causes Natural causesz Cardiovascular Respiratory Lung cancer Injury Other 1152 1941 3645 7794 6237 12 468 8301 2253 771 17 745 11 973 5571 3225 3918 3729 4014 4473 4638 10 446 4584 5742 5559 7812 7401 3003 3849 4131 5172 4614 999 4665 7083 8022 20 769 552 1482 3183 7056 5664 10 656 7281 1908 651 15 378 10 476 4779 2679 3387 3240 3477 3867 3963 9150 3915 4869 4713 6975 6246 2625 3300 3576 4419 4014 861 3975 6132 6969 17 937 168 567 1155 2814 2574 4881 2397 861 315 6096 4410 1878 990 1278 1254 1389 1608 1746 3789 1536 1953 1998 2784 2493 1041 1329 1491 1809 1611 348 1659 2472 2799 7278 48 156 474 1410 1125 1917 1296 414 84 2715 2115 774 318 477 531 612 774 819 1860 660 693 1317 1425 471 480 648 636 807 639 135 702 1050 1323 3210 27 96 309 759 495 1044 639 243 54 1389 1038 435 210 252 291 333 405 402 981 330 372 789 690 207 267 315 351 414 333 69 375 549 693 1686 453 294 186 186 111 903 327 180 42 1011 537 375 318 234 204 237 267 288 480 300 450 450 300 477 150 234 255 330 264 51 312 417 444 1224 483 927 1830 3387 2421 4770 4281 801 327 7923 4908 2547 1596 1926 1740 1779 1827 1779 4317 2091 2646 1794 3300 3957 1335 1638 1752 2223 2100 462 1992 3141 3453 9048 Research report Table 1 Summary data Age (decade) 30 40 50 60 70 Sex Male Female Ethnicity Maori Paciﬁc European Income (tertiles) Missing Lower Middle Upper NZDep (quintiles) Missing Rich Poor Education Missing None School Higher Smoking Missing Current Past Never Temperature (8C) 0.2 2 3 5 7 Particulate (mg/m3) 0.1 7 14 19 Totals 443 610 375 699 257 274 199 599 88 275 661 314 703 137 121 026 59 574 1 183 851 255 492 375 462 363 870 369 627 768 352 656 278 199 257 613 247 107 228 111 66 492 443 736 344 745 509 478 100 926 283 992 328 548 650 991 168 261 224 265 249 363 354 780 367 788 72 102 319 914 506 913 465 522 1 364 451 347 772 291 885 199 044 157 185 69 750 515 007 550 635 87 825 35 916 941 904 356 853 350 490 358 302 289 071 225 192 204 690 189 117 157 572 353 280 286 479 425 883 232 995 283 470 549 180 137 571 176 730 199 971 275 739 275 634 57 213 251 109 388 134 369 189 1 065 645 *Weighted counts, for deaths occurring among the census respondents with complete data. yThe complete dataset is that used for ﬁnal analyses in this paper. zAll causes of death excluding accidents and injury. RESULTS When PM10 was modelled using dummy variables, there was an approximately linear increase in mortality with increasing average PM10 exposure (ﬁgure 1). Three models are shown: (1) adjusting for sex, age and ethnicity on all observations (N¼1 364 454); (2) the same model, but restricted to observa- tions with non-missing data on other covariates (N¼1 065 645; a test of any selection bias compared with model 1); (3) fully adjusted model (N¼1 065 645; a test of possible confounding compared with model 2). There is no meaningful difference between models 1 and 2, suggesting no selection bias when 470 restricting analyses to those with full data on covariates. Adjusting for potential confounders in model 3 attenuated the OR for all non-referent groups, although the relative differences between quintiles 3, 4 and 5 were not much reduced. That is, adjusting for confounders mostly closed the gap between the referent group and quintile 3. Considering the preferred model 3, the OR increased mono- tonically and linearly with increasing PM10 level, and the 95% CI for the two highest quintiles excluded 1.0. Given the approxi- mately linear association of PM10 with mortality described above, subsequent models incorporated PM10 as a linear term, J Epidemiol Community Health 2012;66:468e473. doi:10.1136/jech.2010.112490