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In this paper, we examine patterns of self-reported diagnosis of noncommunicable diseases (NCDs) and prevalences of algorithm/measured test-based, undiagnosed, and untreated NCDs in China, Ghana, India, Mexico, Russia, and South Africa. Nationally representative samples of older adults aged ≥50 years were analyzed from wave 1 of the World Health Organization's Study on Global Ageing and Adult Health (2007-2010; n = 34,149). Analyses focused on 6 conditions: angina, arthritis, asthma, chronic lung disease, depression, and hypertension. Outcomes for these NCDs were: 1) self-reported disease, 2) algorithm/measured test-based disease, 3) undiagnosed disease, and 4) untreated disease. Algorithm/measured test-based prevalence of NCDs was much higher than self-reported prevalence in all 6 countries, indicating underestimation of NCD prevalence in low- and middle-income countries. Undiagnosed prevalence of NCDs was highest for hypertension, ranging from 19.7% (95% confidence interval (CI): 18.1, 21.3) in India to 49.6% (95% CI: 46.2, 53.0) in South Africa. The proportion untreated among all diseases was highest for depression, ranging from 69.5% (95% CI: 57.1, 81.9) in South Africa to 93.2% (95% CI: 90.1, 95.7) in India. Higher levels of education and wealth significantly reduced the odds of an undiagnosed condition and untreated morbidity. A high prevalence of undiagnosed NCDs and an even higher proportion of untreated NCDs highlights the inadequacies in diagnosis and management of NCDs in local health-care systems. [ABSTRACT FROM AUTHOR]

Present shift work has been associated with coronary heart disease (CHD) among employed workers, but it remains unclear whether shift work performed in the past is still associated with CHD in retired workers. We recruited 21,802 retired workers in Shiyan, China, in 2008–2010 and 2013 and followed them for CHD events occurring up to December 31, 2018. Retired workers with longer durations of past shift work (rounded to 0.25 years) had higher CHD risks (for those with ≤5.00, 5.25–10.00, 10.50–20.00, and >20.00 years of past shift work, hazard ratios were 1.05 (95% confidence interval (CI): 0.94, 1.16), 1.08 (95% CI: 0.94, 1.25), 1.23 (95% CI: 1.07, 1.42), and 1.28 (95% CI: 1.08, 1.51), respectively). The association was substantially higher among service or sales workers than among manufacturing or manual-labor workers (for every 5-year increase in past shift work, hazard ratio = 1.11 (95% CI: 1.05, 1.16) vs. hazard ratio = 1.02 (95% CI: 0.98, 1.06)). Moreover, the risk was lower among those who were physically active than among their inactive counterparts (P for interaction = 0.019). Longer duration of past shift work was associated with higher risk of incident CHD among these retired workers, especially those from the service or sales sectors. Physical exercise might be beneficial in reducing the excess risk. [ABSTRACT FROM AUTHOR]

Blood biomarkers provide critical information about the health of older populations, especially in large developing countries where self-reports of health are often inaccurate due to lack of access to health care. However, it is very difficult to collect blood samples in representative population surveys in such countries. The China Health and Retirement Longitudinal Study (CHARLS), a nationally representative study of middle-aged and older Chinese, represents one of the first efforts to include blood biomarkers in a nationally representative survey of China. In the 2015 wave of CHARLS, 13,013 respondents located in 150 counties around China donated whole blood, which was assayed on a range of indicators. Here we describe the process of the sample collection, transportation, storage, and analysis and present basic statistics. [ABSTRACT FROM AUTHOR]

Exposure to secondhand smoke (SHS) is known to be harmful to health. However, the association between household SHS and cognitive function among middle-aged and older women in China is understudied. Lagged dependent variable regression was used to examine the association between household SHS exposure and the cognitive function of married women who had been exposed to SHS, using data from 2 waves of the China Health and Retirement Longitudinal Study (CHARLS, 2011-2013). Controlling for age, educational attainment, geographic residence, household expenditures, and chronic conditions (i.e., hypertension, diabetes, and depressive symptoms), the results indicated that longer SHS exposure was associated with a greater decline in memory over 2 years. After comparing differences across age groups, this pattern was significant for women aged 55-64 years. Furthermore, those who were illiterate, lived in rural areas, and reported depressive symptoms had a greater decline in memory. With evidence linking household SHS exposure with a higher risk of cognitive decline, effective education and public health intervention programs are urgently needed. Stronger tobacco control regulations and education about the dangers of household SHS are viable strategies to reduce the impending dementia epidemic in China. [ABSTRACT FROM AUTHOR]

The contentious political climate surrounding air pollution regulations has brought some researchers and policymakers to argue that evidence of causality is necessary before implementing more stringent regulations. Recently, investigators in an increasing number of air pollution studies have purported to have used "causal analysis," generating the impression that studies not explicitly labeled as such are merely "associational" and therefore less rigorous. Using 3 prominent air pollution studies as examples, we review good practices for how to critically evaluate the extent to which an air pollution study provides evidence of causality. We argue that evidence of causality should be gauged by a critical evaluation of design decisions such as 1) what actions or exposure levels are being compared, 2) whether an adequate comparison group was constructed, and 3) how closely these design decisions approximate an idealized randomized study. We argue that air pollution studies that are more scientifically rigorous in terms of the decisions made to approximate a randomized experiment are more likely to provide evidence of causality and should be prioritized among the body of evidence for regulatory review accordingly. Our considerations, although presented in the context of air pollution epidemiology, can be broadly applied to other fields of epidemiology. [ABSTRACT FROM AUTHOR]

The association between low-level crystalline silica (silica) exposure and mortality risk is not well understood. We investigated a cohort of 44,807 Chinese workers who had worked in metal mines or pottery factories for at least 1 year from January 1, 1960, to December 31, 1974, and were followed through 2003. Low-level silica exposure was defined as having a lifetime highest annual mean silica exposure at or under a permissible exposure limit (PEL). We considered 3 widely used PELs, including 0.05 mg/m³, 0.10 mg/m³, and 0.35 mg/m³. Cumulative silica exposure was estimated by linking a job exposure matrix with each participant's work history. For the 0.10-mg/m³ exposure level, Cox proportional hazards models showed significantly increased risk of mortality from all diseases (for each 1-ln mg/m³-years increase in logged cumulative silica exposure, hazard ratio (HR) = 1.05, 95% confidence interval (CI): 1.03, 1.07), malignant neoplasms (HR = 1.06, 95% CI: 1.03, 1.09), lung cancer (HR = 1.08, 95% CI: 1.02,1.14), ischemic heart disease (HR = 1.09, 95% CI: 1.02,1.16), pulmonary heart disease (HR = 1.08, 95% CI: 1.00,1.16), and respiratory disease (HR = 1.20, 95% CI: 1.14,1.26). The 0.05-mg/m³ and 0.35-mg/m³ exposure levels yielded similar associations. Long-term exposure to low levels (PELs ≤0.05 mg/m³, ≤0.10 mg/m³, or ≤0.35 mg/m³) of silica is associated with increased total and certain cause-specific mortality risk. Control of ambient silica levels and use of personal protective equipment should be emphasized in practice. [ABSTRACT FROM AUTHOR]