1. Use Slopes to Track the “Fundamental Cause” of Group Disparities in Health Linda S. Gottfredson University of Delaware Newark, DE 19716 USA International Society for Intelligence Research Madrid, December 19, 2009

2. “Fundamental cause” The relation between social class and health is so general (cannot be explained by income, access to care, etc.) that there must be a highly generalizable “fundamental cause” A highly generalizabl e cause accounting for the remarkably general relation between

3. g as the “fundamental cause” Hypothesis: – group differences in g are the fundamental cause of group differences in health Common “disproof:” – “If correct…one might have expected the relation between IQ and mortality to act through known risk factors. This does not appear to be the case. In fact, a recent analysis…shows that this relationship is abolished when education and income are in the same model” (Marmot & Kivimaki, 2009)

4. 4 Example: Disparities in health behavior by education; all races & sexes: % who smoke, 2006 (age adjusted) (CDC, Health in the United States, 2008, Table 64) % Education LoHi

5. Lung cancer mortality, Men 25-64, 1950- 1998 by social class of county, USA (age adjusted) Gradients sometimes flip over

6. 6 Typical health disparities by education; in all races & sexes: % of non-ill 51-year-olds expected to have this chronic illness by age 63 (USA, ages 51-61 in 1992; Hayward et al, 2000 ) Hypertension Diabetes white COPD black Cancer Men Women % Years Negative gradients—rare

7. 7 Hypertension Diabetes white COPD black Cancer Men Women % Years Race difference —hypertension Sex difference —diabetes Common policy goal : All gradients flat

8. 88 “Disparity” = group differences on health outcome X “Explaining” between-group variation Means, rates, etc. 16 yrs 12 yrs 8 yrs

9. 99 “Disparity” = group differences on health outcome X “Explaining” between-group variation Means, rates, etc. 16 yrs 12 yrs 8 yrs

10. 10 a b c d d f g This is not about individual differences in health Not “explaining” within-group variation Within-group and between-group variance may arise from different mix of causes

11. 11 Many families of health disparities HEALTH HABITS MORTALITY KNOWLEDGE CHRONIC ILLNESSES INJURIES INFECTIOUS DISEASES ADHERENCE

12. Example 1 (Erikson & Torssander, 2008) Mortality in Sweden, 1991-2003 Among all individuals ages 30-59 in 1990 So– born 1930-1960; still alive 1990 died ~ ages 31-73 (N ~ 130,000 deaths) Social class = occupational level (1-6) Universal health care Ethnically homogeneous Whole cohort (not sample) Uniform classification of deaths Removes 2 common sources of variance in disparities Reduces error variance

13. Broad categories of death 1991-2003, Sweden Social class disparities among individuals ages 30-59 in 1990 Causes (selected) Men (N=80,040) Women (N=49,654) Hazards ratios by social class% % 23456 (lo) 2345 Neoplasms 1.11.21.4 1.5351.01.11.21.3 58 Infections 1.31.4 1.12.211.21.81.92.02.31 Nervous system 1.11.21.42.12.221.01.11.31.61.52 Circulatory 1.31.51.81.92.5351.31.72.02.22.619 Musculoskeletal 1.92.01.73.22.6<11.32.5 2.0 1 External 1.21.42.01.92.5131.11.2 1.41.88 Respiratory 1.21.62.32.93.031.41.92.4 3.04 Endocrine 1.31.81.93.93.121.32.02.63.13.72 Mental/behav 1.41.73.83.15.321.11.7 2.42.91 TOTAL1.21.41.71.82.11001.11.31.41.61.7100 (Erikson & Torssander, 2008) 1=Higher managerial/professional, 2=lower managerial/professional, 3= intermediate, 4=lower supervisory/skilled manual, 5=routine non-manual, 6=unskilled manual

14. Three major causes of death 1991-2003, Sweden Social class gradients for individuals ages 30-59 in 1990 Hi Occupational class Lo Hazards ratio

15. Three major causes of death 1991-2003, Sweden Social class gradients for individuals ages 30-59 in 1990 Hi Occupational class Lo Hazards ratio Slope (ß).18.19.17.10.08.06

16. Causes of death 1991-2003, Sweden Social class disparities among individuals ages 30-59 in 1990 Causes (selected) Men (N=80,040) Women (N=49,654) Hazards ratios by social class%Slope ( ß ) Hazards ratios by social class%Slope ( ß ) 23456 (lo) 2345 Neoplasms1.11.21.4 1.535.081.01.11.21.3 58.06 Infections1.31.4 1.12.21.101.21.81.92.02.31.17 Nervous system1.11.21.42.12.22.161.01.11.31.61.52.10 Circulatory1.31.51.81.92.535.171.31.72.02.22.619.18 Musculoskeletal1.92.01.73.22.6<1.171.32.5 2.0 1.14 External1.21.42.01.92.513.191.11.2 1.41.88.10 Respiratory1.21.62.32.93.03.241.41.92.4 3.04.21 Endocrine1.31.81.93.93.12.251.32.02.63.13.72.26 Mental/behavioral1.41.73.83.15.32.331.11.7 2.42.91.22 TOTAL1.21.41.71.82.1100.151.11.31.41.61.7100.10 (Erikson & Torssander, 2008) 1=Higher managerial/professional, 2=lower managerial/professional, 3= intermediate, 4=lower supervisory/skilled manual, 5=routine non-manual, 6=unskilled manual Slopes = linear regression of HRs on class categories

17. Distribution of all 101 class-mortality slopes (50 men, 51 women) NOT independent (includes broad categories plus high-volume sub-categories) Slopes (ß) Mean =.16 SD =.09 - + But recall population— Universal health care Ethnically homogeneous Cohort born 1930-1960 Died ~ ages 31-73 Need to explain this variation (in gradients)

18. Distribution of class-mortality slopes Ages 30-59 in 1990, died 1991-2003, Sweden Men: Women: Men: Women: 35 specific causes of death 15 broad categories of death - + slopes 0.0 0.1 0.2 0.3 0.4 Variability in size of gradients across causes

19. Distribution of class-mortality slopes Ages 30-59 in 1990, died 1991-2003, Sweden Men: Women: Men: Women: 35 specific causes of death 15 broad categories of death - + slopes 0.0 0.1 0.2 0.3 0.4 More variability across specific causes

20. Distribution of class-mortality slopes Ages 30-59 in 1990, died 1991-2003, Sweden Men: Women: Men: Women: 35 specific causes of death 15 broad categories of death - + slopes 0.0 0.1 0.2 0.3 0.4 Mean SD 0.17 0.10 0.14 0.09 0.17 0.08 0.17 0.06 Sex differences in class gradients

21. Plot of slopes for men vs. women, broad categories of death Women Men r =.38 = all deaths Hazards ratios range from 1.3 to 5.3

22. Plot of slopes for men vs. women, specific categories of death (where N > 100, each sex) r =.86 Men Women 0.3 0.2 0.1 0 Hazards ratios range from 0.9 to 6.3 Steeper for women Steeper for men

23. Class gradients: Specific neoplasms Neoplasms Women Men 0.3 0.2 0.1 0 = All neoplasms

24. Class gradients: Specific neoplasms Women Men colon lymph skin pancreas rectum kidney bladder esophagus liver stomach lung, larynx lip/oral 0.3 0.2 0.1 0 = All neoplasms

25. Women Men colon lymph skin pancreas rectum kidney bladder esophagus liver stomach larynx lip/oral 0.3 0.2 0.1 0 = All neoplasms breast, ovary prostate other uterus cervix

26. Class gradients: Specific circulatory causes Circulatory Women Men 0.3 0.2 0.1 0 = All circulatory

27. Class gradients: Specific circulatory causes Circulatory Women Men other heart stroke heart attack 0.3 0.2 0.1 0 = All circulatory

28. Class gradients: Specific external causes External Women Men 0.3 0.2 0.1 0 = All external injuries & accidental poisoning

29. Class gradients: Specific external causes External Women Men homicide suicide falls accidental poisoning undetermined intent traffic accidents 0.3 0.2 0.1 0

30. 30 20062003-2005 Sudden cause (“external”) Age of sample matters Causes of death differ by age: males in USA (CDC, Health data interactive) Incubating cause (“internal”) Swedish sample

31. Specific causes in other broad categories (digestive, endocrine, mental, respiratory) Women Men diabetes alcohol ulcer asthma pneumonia chronic liver disease chronic lower respiratory Other specific causes 0.3 0.2 0.1 0 drug dependence

32. Most frequent specific internal causes of death: All are “entirely preventable” by patient (Eurostat report) Women Men ulcer asthma pneumonia chronic liver disease 0.3 0.2 0.1 0 esophagus lung, larynx lip/oral colon pancreas kidney bladder skin stomach breast, ovary other uterus cervix prostate chronic lower respiratory diabetes stroke alcohol drug dependence 5 8 17% other heart heart attack homicide suicide falls accidental poisoning undetermined intent traffic accidents 5

33. Example 2 (Gottfredson, 2004) Mortality in US, 1980-1986 All ages External causes only Social class = neighborhood income level (1-6) Differential access to health care Ethnically diverse

34. Slopes (ß) Mean =.12 SD =.20 - + Class-mortality gradients, for 55 specific external causes, US population, 1980-1986 classes = 6 levels of neighborhood income

35. Suicide Drugs, alcohol, poisons Falls Homicide Undetermined intent: firearm, poison Vehicles/pedestrian, drowning Burns, cold, choke, neglect, firearm Cut, crushed, machines, electric Slope Class-mortality gradients, by general type of external cause, US population, 1980-1986 classes = 6 levels of neighborhood income Mean -.15 -.04.02.12.10.15.30.29 elderly Working- age men

36. Suicide Drugs, alcohol, poisons Falls Homicide Undetermined intent: firearm, poison Vehicles/pedestrian, drowning Burns, cold, choke, neglect, firearm Cut, crushed, machines, electric Slope Class-mortality gradients, by general type of external cause, US population, 1980-1986 classes = 6 levels of neighborhood income Mean -.15 -.04.02.12.10.15.30.29 M F F M M M F F F, M = Swedish mean slopes

37. Changes in: Options & information: preventability (don’t smoke) detection (pap smear) controllability (diet, insulin) Population composition: age cohort ethnicity Slope Source of hypotheses I: Migration of slopes over time and cohorts Meta-analysis of slopes

38. PredictorsDistribution of: Host exposurePassive (hazards)Active Personal choice Host susceptibilityBiological Cognitive g (or surrogates) Vector burdenBiological (virulence)Cognitive Task complexity Statistical artifactsSampling error Measurement error Restriction in range 38 Source of hypotheses II: g theory + epidemiological perspective

39. Thank you