Person:

Beckfield, Jason

Objectives. We explored associations between the abolition of Jim Crow laws (i.e., state laws legalizing racial discrimination overturned by the 1964 US Civil Rights Act) and birth cohort trends in infant death rates.Methods. We analyzed 1959 to 2006 US Black and White infant death rates within and across sets of states (polities) with and without Jim Crow laws.Results. Between 1965 and 1969, a unique convergence of Black infant death rates occurred across polities; in 1960 to 1964, the Black infant death rate was 1.19 times higher (95% confidence interval [CI] = 1.18, 1.20) in the Jim Crow polity than in the non-Jim Crow polity, whereas in 1970 to 1974 the rate ratio shrank to and remained at approximately 1 (with the 95% CI including 1) until 2000, when it rose to 1.10 (95% CI = 1.08, 1.12). No such convergence occurred for Black-White differences in infant death rates or for White infants.Conclusions. Our results suggest that abolition of Jim Crow laws affected US Black infant death rates and that valid analysis of societal determinants of health requires appropriate comparison groups.

US infant death rates for 1960 to 1980 declined most quickly in (1) 1970 to 1973 in states that legalized abortion in 1970, especially for infants in the lowest 3 income quintiles (annual percentage change = -11.6; 95% confidence interval =-18.7, -3.8), and (2) the mid-to-late 1960s, also in low-income quintiles, for both Black and White infants, albeit unrelated to abortion laws. These results imply that research is warranted on whether currently rising restrictions on abortions may be affecting infant mortality.

Background: Debates exist over whether health inequities are bound to rise as population health improves, due to health improving more quickly among the better off, with most analyses focused on mortality data. Methods: We analysed 50 years of socioeconomic inequities in measured health status among US-born Black and White Americans, using data from the National Health Examination Surveys (NHES) I-III (1959–70), National Health and Nutrition Examination Surveys (NHANES) I-III (1971–94) and NHANES 1999–2008. Results: Absolute US socioeconomic health inequities for income percentile and education variously decreased (serum cholesterol; childhood height), stagnated [systolic blood pressure (SBP)], widened [body mass index (BMI), waist circumference (WC)] and in some cases reversed (age at menarche), even as on-average values rose (BMI, WC), idled (childhood height) and fell (SBP, serum cholesterol, age at menarche), with patterns often varying by race/ethnicity and socioeconomic measure; similar results occurred for relative inequities. For example, for WC, the adverse 20th (low) vs 80th (high) income percentile gap increased only among Whites (NHES I: 0.71 cm [95% confidence interval (CI) −0.74, 2.16); NHANES 2005–08: 2.10 (95% CI 0.96, 3.62)]. By contrast, age at menarche for girls in the 20th vs 80th income percentile among Black girls remained consistently lower, by 0.34 years (95% CI 0.12, 0.55) whereas among White girls the initial null difference became inverse [NHANES 2005–08: −0.49 years (95% CI −0.86, −0.12; overall P = 0.0015)]. Adjusting for socioeconomic position only modestly altered Black/White health inequities. Conclusions: Health inequities need not rise as population health improves.

Objectives. We investigated 50-year US trends in age at menarche by socioeconomic position (SEP) and race/ethnicity because data are scant and contradictory.Methods. We analyzed data by income and education for US-born non-Hispanic Black and White women aged 25 to 74 years in the National Health Examination Survey (NHES) I (1959-1962), National Health Examination and Nutrition Surveys (NHANES) I-III (1971-1994), and NHANES 1999-2008.Results. In NHES I, average age at menarche among White women in the 20th (lowest) versus 80th (highest) income percentiles was 0.26 years higher (95% confidence interval [CI] = -0.09, 0.61), but by NHANES 2005-2008 it had reversed and was -0.33 years lower (95% CI = -0.54, -0.11); no socioeconomic gradients occurred among Black women. The proportion with onset at younger than 11 years increased only among women with low SEP, among Blacks and Whites (P for trend <.05), and high rates of change occurred solely among Black women (all SEP strata) and low-income White women who underwent menarche before 1960.Conclusions. Trends in US age at menarche vary by SEP and race/ethnicity in ways that pose challenges to several leading clinical, public health, and social explanations for early age at menarche and that underscore why analyses must jointly include data on race/ethnicity and socioeconomic position. Future research is needed to explain these trends.