studies suggesting no significant difference in rates of cancer between higher and lower socioeconomic status neighbourhoods in Canada [40], we cannot correct for presence of neoplastic disease prior to study entry. The higher risk of neoplastic mortality observed among individuals in lower-SES neighbourhoods may be partly to lower utilization of diagnostic imaging, as has been documented elsewhere in Canada [41]. Unfortunately, we cannot ascertain how this factor contributes to our findings. It will be important for future research to include this information. Finally, this study is not sufficiently powered to investigate each cause of death separately. These limitations need to be considered in light of the project’s strengths, including its prospective design, well- characterized patients, long follow-up time, and complete ascertainment of mortality. Our findings suggest that even in a country with universal healthcare services, there are marked gradients in mortality References 1. Alter DA, Chong A, Austin PC, Mustard C, Iron K, et al. (2006) Socioeconomic status and mortality after acute myocardial infarction. Ann Intern Med 144: 82–93. 2. Hemingway H, Shipley M, Macfarlane P, Marmot M (2000) Impact of socioeconomic status on coronary mortality in people with symptoms, electrocardiographic abnormalities, both or neither: the original Whitehall study 25 year follow up. J Epidemiol Community Health 54: 510–516. 3. Manderbacka K, Hetemaa T, Keskimaki I, Luukkainen P, Koskinen S, et al. (2006) Are there socioeconomic differences in myocardial infarction event rates and fatality among patients with angina pectoris? J Epidemiol Community Health 60: 442–447. 4. Morrison C, Woodward M, Leslie W, Tunstall-Pedoe H (1997) Effect of socioeconomic group on incidence of, management of, and survival after myocardial infarction and coronary death: analysis of community coronary event register. Bmj 314: 541–546. 5. Peltonen M, Rosen M, Lundberg V, Asplund K (2000) Social patterning of myocardial infarction and stroke in Sweden: incidence and survival. Am J Epidemiol 151: 283–292. 6. Weinblatt E, Ruberman W, Goldberg JD, Frank CW, Shapiro S, et al. (1978) Relation of education to sudden death after myocardial infarction. N Engl J Med 299: 60–65. 7. Williams RB, Barefoot JC, Califf RM, Haney TL, Saunders WB, et al. (1992) Prognostic importance of social and economic resources among medically treated patients with angiographically documented coronary artery disease. Jama 267: 520–524. 8. Diez Roux AV, Merkin SS, Arnett D, Chambless L, Massing M, et al. (2001) Neighborhood of residence and incidence of coronary heart disease. N Engl J Med 345: 99–106. 9. Smith GD, Hart C, Watt G, Hole D, Hawthorne V (1998) Individual social class, area-based deprivation, cardiovascular disease risk factors, and mortality: the Renfrew and Paisley Study. J Epidemiol Community Health 52: 399–405. 10. Alter DA, Naylor CD, Austin P, Tu JV (1999) Effects of socioeconomic status on access to invasive cardiac procedures and on mortality after acute myocardial infarction. N Engl J Med 341: 1359–1367. 11. Tonne C, Schwartz J, Mittleman M, Melly S, Suh H, et al. (2005) Long-term survival after acute myocardial infarction is lower in more deprived neighborhoods. Circulation 111: 3063–3070. Epub 2005 Jun 3066. 12. Dragano N, Hoffmann B, Stang A, Moebus S, Verde PE, et al. (2008) Subclinical coronary atherosclerosis and neighbourhood deprivation in an urban region. Eur J Epidemiol. 13. Myles JPG, Pyper W (2000) Neighbourhood Inequality in Canadian Cities. Ottawa, Canada: Statistics Canada. 14. Francis MC, Frohlich JJ (2001) Coronary artery disease in patients at low risk– apolipoprotein AI as an independent risk factor. Atherosclerosis 155: 165–170. 15. Lee KW, Ayyobi AF, Frohlich JJ, Hill JS (2004) APOA5 gene polymorphism modulates levels of triglyceride, HDL cholesterol and FERHDL but is not a risk factor for coronary artery disease. Atherosclerosis 176: 165–172. 16. Frohlich J, Dobiasova M (2003) Fractional esterification rate of cholesterol and ratio of triglycerides to HDL-cholesterol are powerful predictors of positive findings on coronary angiography. Clin Chem 49: 1873–1880. 17. Haft JI, Haik BJ, Goldstein JE, Brodyn NE (1988) Development of significant coronary artery lesions in areas of minimal disease. A common mechanism for coronary disease progression. Chest 94: 731–736. 18. (1992) International Statistical Classification of Disease and Related Health Problems, Tenth Revision (ICD-10). World Health Organization. 19. (2005) Chronic Disease Clock Explanation. Centre for Chronic Disease Prevention and Control, Public Health Agency of Canada. Neighbourhood and Mortality according to neighbourhood. We demonstrate the predictive strength of neighbourhood SES above and beyond key modifiable and non-modifiable risk factors for mortality, and suggest that broader approaches to recognizing and addressing socioeconomic inequalities are needed. In order to achieve more equitable healthcare and overcome disparities in resources and access, we must create an improved appreciation of social and biological factors responsible for poor health outcomes, and develop the economic, behavioral, and biomedical interventions needed to ameliorate them. Author Contributions Conceived and designed the experiments: CLH GM JSH. Performed the experiments: CLH. Analyzed the data: CLH GM JSH. Wrote the paper: CLH GM JSH. 20. (2005) Statistics Canada. 2001 Population Census. Ottawa, ON: Statistics Canada. 21. Human Early Learning Partnership. Vancouver: University of British Columbia. 22. Concato J, Peduzzi P, Holford TR, Feinstein AR (1995) Importance of events per independent variable in proportional hazards analysis. I. Background, goals, and general strategy. J Clin Epidemiol 48: 1495–1501. 23. Peduzzi P, Concato J, Feinstein AR, Holford TR (1995) Importance of events per independent variable in proportional hazards regression analysis. II. Accuracy and precision of regression estimates. J Clin Epidemiol 48: 1503–1510. 24. Grambsch PM, Therneau TM (1994) Proportional hazards tests and diagnostics based on weighted residuals. Biometrika 81: 515–526. 25. Heagerty PJ, Lumley T, Pepe MS (2000) Time-dependent ROC curves for censored survival data and a diagnostic marker. Biometrics 56: 337–344. 26. Akritas M (1994) Nearest neighbor estimation of a bivariate distribution under random censoring. Annals of Statistics 22: 1299–1327. 27. Lemeshow S, Hosmer DW Jr (1982) A review of goodness of fit statistics for use in the development of logistic regression models. Am J Epidemiol 115: 92–106. 28. Kramer AA, Zimmerman JE (2007) Assessing the calibration of mortality benchmarks in critical care: The Hosmer-Lemeshow test revisited. Crit Care Med 35: 2052–2056. 29. Winkleby MA, Cubbin C (2003) Influence of individual and neighbourhood socioeconomic status on mortality among black, Mexican-American, and white women and men in the United States. J Epidemiol Community Health 57: 444–452. 30. Winkleby M, Cubbin C, Ahn D (2006) Effect of cross-level interaction between individual and neighborhood socioeconomic status on adult mortality rates. Am J Public Health 96: 2145–2153. Epub 2006 Oct 2131. 31. McGrail KMSP, Black C (2004) The British Columbia Health Atlas, 2nd edition. Vancouver: University of British Columbia Centre for Health Services and Policy Research. 32. McGrail KM (2008) Income-related inequities: Cross-sectional analyses of the use of medicare services in British Columbia in 1992 and 2002. 33. Adler NE, Boyce WT, Chesney MA, Folkman S, Syme SL (1993) Socioeconomic inequalities in health. No easy solution. Jama 269: 3140–3145. 34. Cohen S KGA, Salonen JT (1999) The role of psychological characteristics in the relation between socioeconomic status and perceived health. . Journal of Applied Social Psychology 29: 445–468. 35. Chen E, Paterson LQ (2006) Neighborhood, family, and subjective socioeco- nomic status: How do they relate to adolescent health? Health Psychol 25: 704–714. 36. Petersen KL, Marsland AL, Flory J, Votruba-Drzal E, Muldoon MF, et al. (2008) Community socioeconomic status is associated with circulating interleu- kin-6 and C-reactive protein. Psychosom Med 70: 646–652. 37. Diez Roux AV, Jacobs DR, Kiefe CI (2002) Neighborhood characteristics and components of the insulin resistance syndrome in young adults: the coronary artery risk development in young adults (CARDIA) study. Diabetes Care 25: 1976–1982. 38. Antoni MH, Lutgendorf SK, Cole SW, Dhabhar FS, Sephton SE, et al. (2006) The influence of bio-behavioural factors on tumour biology: pathways and mechanisms. Nat Rev Cancer 6: 240–248. 39. Cohen S, Janicki-Deverts D, Miller GE (2007) Psychological stress and disease. Jama 298: 1685–1687. 40. Lemstra M, Neudorf C, Opondo J (2006) Health disparity by neighbourhood income. Can J Public Health 97: 435–439. 41. Demeter S, Reed M, Lix L, MacWilliam L, Leslie WD (2005) Socioeconomic status and the utilization of diagnostic imaging in an urban setting. Cmaj 173: 1173–1177. PLoS ONE | www.plosone.org 8 January 2009 | Volume 4 | Issue 1 | e4120