Objective To examine the relation between birth weight and measured intelligence at age 7 years in children within the normal range of birth weight and in siblings. Design Cohort study of siblings of the same sex. Setting 12 cities in the United States. Subjects 3484 children of 1683 mothers in a birth cohort study during the years 1959 through 1966. The sample was restricted to children born at >37 weeks gestation and with birth weights of 1500-3999 g. Main outcome measure Full scale IQ at age 7 years. Results Mean IQ increased monotonically with birth weight in both sexes across the range of birth weight in a linear regression analysis of one randomly selected sibling per family (n = 1683) with adjustment for maternal age, race, education, socioeconomic status, and birth order. Within same sex sibling pairs, differences in birth weight were directly associated with differences in IQ in boys (812 pairs, predicted IQ difference per 100 g change in birth weight = 0.50, 95% confidence interval 0.28 to 0.71) but not girls (871 pairs, 0.10, − 0.09 to 0.30). The effect in boys remained after differences in birth order, maternal smoking, and head circumference were adjusted for and in an analysis restricted to children with birth weight > 2500 g. Conclusion The increase in childhood IQ with birth weight continues well into the normal birth weight range. For boys this relation holds within same sex sibships and therefore cannot be explained by confounding from family social environment.

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IMPORTANCE Cardiovascular deaths and influenza epidemics peak during winter in temperate regions. OBJECTIVES To quantify the temporal association between population increases in seasonal influenza infections and mortality due to cardiovascular causes and to test if influenza incidence indicators are predictive of cardiovascular mortality during the influenza season. DESIGN, SETTING, AND PARTICIPANTS Time-series analysis of vital statistics records and emergency department visits in New York City, among cardiovascular deaths that occurred during influenza seasons between January 1, 2006, and December 31, 2012. The 2009 novel influenza A(H1N1) pandemic period was excluded from temporal analyses. EXPOSURES Emergency department visits for influenza-like illness, grouped by age (≥0 years and ≥65 years) and scaled by laboratory surveillance data for viral types and subtypes, in the previous 28 days. MAIN OUTCOMES AND MEASURES Mortality due to cardiovascular disease, ischemic heart disease, and myocardial infarction. RESULTS Among adults 65 years and older, who accounted for 83.0% (73 363 deaths) of nonpandemic cardiovascular mortality during influenza seasons, seasonal average influenza incidence was correlated year to year with excess cardiovascular mortality (Pearson correlation coefficients ≥0.75, P≤.05 for 4 different influenza indicators). In daily time-series analyses using 4 different influenza metrics, interquartile range increases in influenza incidence during the previous 21 days were associated with an increase between 2.3% (95% CI, 0.7%–3.9%) and 6.3% (95% CI, 3.7%–8.9%) for cardiovascular disease mortality and between 2.4% (95% CI, 1.1%–3.6%) and 6.9% (95% CI, 4.0%–9.9%) for ischemic heart disease mortality among adults 65 years and older. The associations were most acute and strongest for myocardial infarction mortality, with each interquartile range increase in influenza incidence during the previous 14 days associated with mortality increases between 5.8% (95% CI, 2.5%–9.1%) and 13.1% (95% CI, 5.3%–20.9%). Out-of-sample prediction of cardiovascular mortality among adults 65 years and older during the 2009–2010 influenza season yielded average estimates with 94.0% accuracy using 4 different influenza metrics. CONCLUSIONS AND RELEVANCE Emergency department visits for influenza-like illness were associated with and predictive of cardiovascular disease mortality. Retrospective estimation of influenza-attributable cardiovascular mortality burden combined with accurate and reliable influenza forecasts could predict the timing and burden of seasonal increases in cardiovascular mortality.

Objective To assess the impact of fast food restaurants adding calorie labelling to menu items on the energy content of individual purchases.Design Cross sectional surveys in spring 2007 and spring 2009 (one year before and nine months after full implementation of regulation requiring chain restaurants' menus to contain details of the energy content of all menu items).Setting 168 randomly selected locations of the top 11 fast food chains in New York City during lunchtime hours. Participants 7309 adult customers interviewed in 2007 and 8489 in 2009.Main outcome measures Energy content of individual purchases, based on customers' register receipts and on calorie information provided for all items in menus.Results For the full sample, mean calories purchased did not change from before to after regulation (828 v 846 kcal, P=0.22), though a modest decrease was shown in a regression model adjusted for restaurant chain, poverty level for the store location, sex of customers, type of purchase, and inflation adjusted cost (847 v 827 kcal, P=0.01). Three major chains, which accounted for 42% of customers surveyed, showed significant reductions in mean energy per purchase (McDonald's 829 v 785 kcal, P=0.02; Au Bon Pain 555 v 475 kcal, P<0.001; KFC 927 v 868 kcal, P<0.01), while mean energy content increased for one chain (Subway 749 v 882 kcal, P<0.001). In the 2009 survey, 15% (1288/8489) of customers reported using the calorie information, and these customers purchased 106 fewer kilocalories than customers who did not see or use the calorie information (757 v 863 kcal, P<0.001).Conclusion Although no overall decline in calories purchased was observed for the full sample, several major chains saw significant reductions. After regulation, one in six lunchtime customers used the calorie information provided, and these customers made lower calorie choices. IntroductionObesity prevalence in the United States is at an all-time high for both adults and children; the most recent data report that a third of adults and 17% of children and teenagers are obese. In an effort to refocus the fight against obesity, elected officials and public health professionals are shifting towards legislative policies that alter the food environment to facilitate healthier nutritional choices.3 Among such initiatives are soda taxes, restrictions on food marketing to children, updating nutrition guidelines for schools and public procurement, regulation of vending machines, and moratoria on licensing fast food establishments. [4][5][6] Requiring chain restaurants to print the energy content of their meals is one such intervention. Since New York City's regulation was passed in 2006, which required chain restaurants to include the calorific value for all items on menus and menu boards, other US jurisdictions have introduced similar policies.7 The Patient Protection and Affordable Care Act, approved in March 2010, will require calorie labelling at chain restaurants nationwide. In the United Kingdom, 28 organisations have pledged to implement sim...

In this study we quantify economic benefits from projected improvements in worker productivity resulting from the reduction in children's exposure to lead in the United States since 1976. We calculated the decline in blood lead levels (BLLs) from 1976 to 1999 on the basis of nationally representative National Health and Nutrition Examination Survey (NHANES) data collected during 1976 through 1980, 1991 through 1994, and 1999. The decline in mean BLL in 1- to 5-year-old U.S. children from 1976-1980 to 1991-1994 was 12.3 microg/dL, and the estimated decline from 1976 to 1999 was 15.1 microg/dL. We assumed the change in cognitive ability resulting from declines in BLLs, on the basis of published meta-analyses, to be between 0.185 and 0.323 IQ points for each 1 g/dL blood lead concentration. These calculations imply that, because of falling BLLs, U.S. preschool-aged children in the late 1990s had IQs that were, on average, 2.2-4.7 points higher than they would have been if they had the blood lead distribution observed among U.S. preschool-aged children in the late 1970s. We estimated that each IQ point raises worker productivity 1.76-2.38%. With discounted lifetime earnings of $723,300 for each 2-year-old in 2000 dollars, the estimated economic benefit for each year's cohort of 3.8 million 2-year-old children ranges from $110 billion to $319 billion.