Non-invasive prenatal testing for the diagnosis of congenital abnormalities: Insights from a large multicenter study in southern China.

Although non-invasive prenatal testing (NIPT) is widely used to detect fetal abnormalities, the results of NIPT vary by population, and data for the screening efficiency of NIPT positive predictive value (PPV) from different populations is limited. Herein, we retrospectively analyzed the NIPT results in a large multicenter study involving 52,855 pregnant women. Depending on gestational age, amniotic fluid or umbilical cord blood was extracted for karyotype and/or chromosome microarray analysis (CMA) in NIPT-positive patients, and the PPV and follow-up data were evaluated to determine its clinical value. Among the 52,855 cases, 754 were NIPT-positive, with a positivity rate of 1.4%. Karyotype analysis and/or CMA confirmed 323 chromosomal abnormalities, with a PPV of 45.1%. PPV for trisomy 21 (T21), trisomy 18 (T18), trisomy 13 (T13), sex chromosomal aneuploidies (SCAs), and copy number variations (CNVs) were 78.9, 35.3, 22.2, 36.9, and 32.9%, respectively. The PPVs for T21, T18, and T13 increased with age, whereas the PPVs for SCAs and CNVs had little correlation with age. The PPV was significantly higher in patients with advanced age and abnormal ultrasound. The NIPT results are affected by population characteristics. NIPT had a high PPV for T21 and a low PPV for T13 and T18, and screening for SCAs and CNVs showed clinical significance in southern China.

Life-space mobility and post-hospitalization outcomes among older Mexican American Medicare beneficiaries.

BACKGROUND: Older adults with limited mobility are at an increased risk of adverse health outcomes, an outcome inadequately investigated in older Mexican Americans. We explored whether pre-admission life-space mobility predicts post-hospitalization outcomes among hospitalized Mexican American Medicare beneficiaries. METHODS: Life-space mobility, using the Life-Space Assessment (LSA), was analyzed using quartiles and 5-point intervals. Using the Hispanic Established Populations for the Epidemiologic Study of the Elderly (HEPESE) Waves 7 and 8 data linked to Medicare claims data, 426 older Mexican Americans with at least 2 months of Medicare coverage who were hospitalized within 2 years of completing the LSA were included. Logistic and Cox Proportional regression analyses estimated the association of pre-admission LSA with post-hospitalization outcomes. RESULTS: Prior to hospitalization, 85.4% reported limited life-space mobility. Most patients (n = 322, 75.6%) were hospitalized for medical reasons. About 65% were discharged to the community. Pre-admission LSA scores were not associated with community discharge (Odds Ratio [OR] = 1.02, 0.95-1.10). Higher pre-admission LSA scores were associated with 30-day readmission (OR = 1.11, 1.01-1.22). Patients in the highest pre-admission LSA quartile (i.e., greatest life-space mobility) were less likely to die within 2 years after hospital discharge (OR = 0.61, 0.39-0.97) compared to those with lower pre-admission LSA scores. CONCLUSIONS: Among older Mexican American Medicare beneficiaries, greater pre-admission LSA scores were associated with an increased risk of 30-day readmission and a decreased risk of mortality within 2 years following hospitalization. Future work should further investigate the relationship between LSA and post-hospitalization outcomes in a larger sample of Mexican American older adults.

Pain, obesity, and physical function in Mexican American older adults during 20 years of follow-up.

INTRODUCTION: Pain remains largely undertreated in older adults irrespective of health care setting. Mexican American adults in the United States have a high age-adjusted prevalence of obesity. However, the association of pain and obesity with physical function is understudied in this population. OBJECTIVE: To examine the association of co-occurring pain and obesity with physical function over 20 years of follow-up in a cohort of older Mexican Americans who scored ≥7 (moderate to high) in the Short Physical Performance Battery (SPPB) test and were nondisabled at baseline. DESIGN: Longitudinal population-based study. SETTING: Community-dwelling older adults from Southwestern United States. PARTICIPANTS: Mexican American adults age 65 years and older. INTERVENTIONS: Not Applicable. MAIN OUTCOME MEASURES: Physical function was assessed with the SPPB test (standing balance, timed 8-ft walk, and five repeated timed chair stands). Participants at baseline were divided into four groups: no pain-no obesity (n = 869), obesity only (n = 282), pain only (n = 216), and pain-obesity (n = 159). Generalized Estimating Equation models were used to estimate the odds ratio (OR) and 95% confidence interval (CI) of lower performance in physical function over 20 years as a function of pain-obesity grouping. RESULTS: Participants with pain only (OR = 1.61, 95% CI = 1.34-1.95) and with co-occurring pain and obesity (OR = 2.32, 95% CI = 1.83-2.95) had significantly greater odds of physical function impairment over those with no pain-no obesity or obesity only, after controlling for all covariates. CONCLUSION: Older Mexican American adults were at high risk for physical function impairment over time if they had pain or co-occurring pain and obesity. Early assessment and proper pain management as well as maintaining a healthy weight may reduce declines in physical function in older Mexican American adults.

Non-invasive prenatal testing for the diagnosis of congenital abnormalities: Insights from a large multicenter study in southern China

Although non-invasive prenatal testing (NIPT) is widely used to detect fetal abnormalities, the results of NIPT vary by population, and data for the screening efficiency of NIPT positive predictive value (PPV) from different populations is limited. Herein, we retrospectively analyzed the NIPT results in a large multicenter study involving 52,855 pregnant women. Depending on gestational age, amniotic fluid or umbilical cord blood was extracted for karyotype and/or chromosome microarray analysis (CMA) in NIPT-positive patients, and the PPV and follow-up data were evaluated to determine its clinical value. Among the 52,855 cases, 754 were NIPT-positive, with a positivity rate of 1.4%. Karyotype analysis and/or CMA confirmed 323 chromosomal abnormalities, with a PPV of 45.1%. PPV for trisomy 21 (T21), trisomy 18 (T18), trisomy 13 (T13), sex chromosomal aneuploidies (SCAs), and copy number variations (CNVs) were 78.9, 35.3, 22.2, 36.9, and 32.9%, respectively. The PPVs for T21, T18, and T13 increased with age, whereas the PPVs for SCAs and CNVs had little correlation with age. The PPV was significantly higher in patients with advanced age and abnormal ultrasound. The NIPT results are affected by population characteristics. NIPT had a high PPV for T21 and a low PPV for T13 and T18, and screening for SCAs and CNVs showed clinical significance in southern China.

Body mass index and physical frailty among older Mexican Americans: Findings from an 18-year follow up.

PURPOSES: The relationship between body mass index (BMI) and frailty in older Mexican Americans has not been previously studied. The objective of this study was to examine the relationship between BMI and frailty among non-frail older Mexican Americans at baseline over 18 years of follow up. METHODS: Longitudinal population-based study of 1,648 non-institutionalized Mexican Americans aged ≥ 67 years from the Hispanic Established Population for the Epidemiologic Study of the Elderly (1995/96-2012/13). Frailty phenotype was defined as meeting three or more of the following: unintentional weight loss of >10 pounds, weakness, self-reported exhaustion, low physical activity, and slow walking speed. BMI (kg/m2) was classified as underweight (<18.5), normal weight (18.5-<25), overweight (25-< 30), obesity category I (30-<35), and obesity category II/morbid obesity (≥35). Covariates included socio-demographics, comorbidities, cognitive function, and depressive symptoms. Generalized Estimating Equation models were performed to estimate the odds ratio (OR) and 95% confidence interval (CI) of frailty as a function of BMI category. RESULTS: Participants with underweight or obesity category II/ morbid obesity had greater odds of frailty over time compared to those with normal weight (OR = 2.39, 95% CI = 1.29-4.44 and OR = 1.62, 95% CI = 1.07-2.44, respectively) after controlling for all covariates. Participants with BMIs in the overweight or category I obesity were at lower odds of frailty over time. CONCLUSIONS: Mexican American older adults with BMIs in the underweight or obesity category II/morbid obesity were at higher odds of frailty over time. This indicates that maintaining a healthy weight in this population may prevent future frailty.

Cognitive impairment and low physical function among older Mexican Americans: findings from a 20-year follow-up☆.

PURPOSE: The aim of the study was to examine the association between cognitive impairment and low physical function over a 20-year follow-up period among older Mexican Americans. METHODS: The final sample included 1545 community-dwelling Mexican Americans age ≥ 65 years from the Hispanic Established Population for the Epidemiological Study of the Elderly, who scored moderate-high on Short Physical Performance Battery (SPPB) and were non-disabled at baseline (1993/94). Cognitive impairment was defined at each observation wave as less than equal to 21 points on the Mini Mental State Examination. General Estimating Equation was used to estimate the odds ratio of having low physical function (SPPB <7 points) over time as a function of cognitive impairment, adjusting for socio-demographics, self-reported medical conditions, body mass index, and depressive symptoms. All variables were time-varying, except sex and education. RESULTS: Participants with cognitive impairment had increased odds ratio of low physical function over time compared to those without cognitive impairment (Odds Ratio = 1.89; 95% Confidence Interval = 1.59-2.26, P <.0001), after controlling for all covariates. CONCLUSION: Despite having moderate to high physical function and being non-disabled at baseline, participants with cognitive impairment were more likely to decline in physical function over 20-years of follow-up.

Healthcare utilization and costs among high-need and frail Mexican American Medicare beneficiaries.

OBJECTIVES: To examine Medicare health care spending and health services utilization among high-need population segments in older Mexican Americans, and to examine the association of frailty on health care spending and utilization. METHODS: Retrospective cohort study of the innovative linkage of Medicare data with the Hispanic Established Populations for the Epidemiologic Study of the Elderly (H-EPESE) were used. There were 863 participants, which contributed 1,629 person years of information. Frailty, cognition, and social risk factors were identified from the H-EPESE, and chronic conditions were identified from the Medicare file. The Cost and Use file was used to calculate four categories of Medicare spending on: hospital services, physician services, post-acute care services, and other services. Generalized estimating equations (GEE) with a log link gamma distribution and first order autoregressive, correlation matrix was used to estimate cost ratios (CR) of population segments, and GEE with a logit link binomial distribution was applied to estimate odds ratios (OR) of healthcare use. RESULTS: Participants in the major complex chronic illness segment who were also pre-frail or frail had higher total costs and utilization compared to the healthy segment. The CR for total Medicare spending was 3.05 (95% CI, 2.48-3.75). Similarly, this group had higher odds of being classified in the high-cost category 5.86 (95% CI, 3.35-10.25), nursing home care utilization 11.32 (95% CI, 3.88-33.02), hospitalizations 4.12 (95% CI, 2.88-5.90) and emergency room admissions 4.24 (95% CI, 3.04-5.91). DISCUSSION: Our findings highlight that frailty assessment is an important consideration when identifying high-need and high-cost patients.

Arthritis, physical function, and disability among older Mexican Americans over 23 years of follow-up.

OBJECTIVE: Arthritis is a common chronic condition in the ageing population. Its impact on physical function varies according to sociodemographic and race/ethnic factors. The study objective was to examine the impact of arthritis on physical function and disability among non-disabled older Mexican Americans over time. DESIGN: A 23-year prospective cohort study of 2230 Mexican Americans aged 65 years and older from the Hispanic Established Population for the Epidemiologic Study of the Elderly (1993/94-2016). The independent variable was self-reported physician-diagnosed arthritis, and the outcomes included Activities of Daily Living (ADL), Instrumental Activities of Daily Living (IADL), mobility, Short Physical Performance Battery (SPPB), and handgrip strength. Covariates were sociodemographic, medical conditions, body mass index, depressive symptoms, and cognitive function. General linear mixed models were performed to estimate the change in SPPB and muscle strength. General Equation Estimation models estimated the odds ratios (OR) of becoming ADL- or IADL- or mobility - disabled as a function of arthritis. All variables were used as time-varying except for sex, education, and nativity. RESULTS: Overall, participants with arthritis had higher odds ratio (OR) of any ADL [OR = 1.35, 95% Confidence Interval (CI) = 1.09-1.68] and mobility (OR = 1.34, 95% CI = 1.18-1.52) disability over time than those without arthritis, after controlling for all covariates. Women, but not men, reporting arthritis had increased risk for ADL and mobility disability. The total SPPB score declined 0.18 points per year among those with arthritis than those without arthritis, after controlling for all covariates (p-value < .010). CONCLUSIONS: Our study demonstrates the independent effect of arthritis in increasing ADL and mobility disability and decreased physical function in older Mexican Americans over 23-years of follow-up.

Documentation of Dementia as a Cause of Death Among Mexican-American Decedents Diagnosed with Dementia.

BACKGROUND: Hispanic older adults are a high-risk population for Alzheimer's disease and related dementias (ADRD) but are less likely than non-Hispanic White older adults to have ADRD documented as a cause of death on a death certificate. OBJECTIVE: To investigate characteristics associated with ADRD as a cause of death among Mexican-American decedents diagnosed with ADRD. METHODS: Data came from the Hispanic Established Populations for the Epidemiologic Study of the Elderly, Medicare claims, and National Death Index. RESULTS: The final sample included 853 decedents diagnosed with ADRD of which 242 had ADRD documented as a cause of death. More health comorbidities (OR = 0.40, 95% CI = 0.28-0.58), older age at death (OR = 1.18, 95% CI = 1.03-1.36), and longer ADRD duration (OR = 1.08, 95% CI = 1.03-1.14) were associated with ADRD as a cause of death. In the last year of life, any ER admission without a hospitalization (OR = 0.45, 95% CI = 0.22-0.92), more physician visits (OR = 0.96, 95% CI = 0.93-0.98), and seeing a medical specialist (OR = 0.46, 95% CI = 0.29-0.75) were associated with lower odds for ADRD as a cause of death. In the last 30 days of life, any hospitalization with an ICU stay (OR = 0.55, 95% CI = 0.36-0.82) and ER admission with a hospitalization (OR = 0.67, 95% CI = 0.48-0.94) were associated with lower odds for ADRD as a cause of death. Receiving hospice care in the last 30 days of life was associated with 1.98 (95% CI = 1.37-2.87) higher odds for ADRD as a cause of death. CONCLUSION: Under-documentation of ADRD as a cause of death may reflect an underestimation of resource needs for Mexican-Americans with ADRD.

Changes in Health Care Use by Mexican American Medicare Beneficiaries Before and After a Diagnosis of Dementia.

BACKGROUND: Evidence from predominantly non-Hispanic White cohorts indicates health care utilization increases before Alzheimer's disease and related dementias (ADRD) is diagnosed. We investigated trends in health care utilization by Mexican American Medicare beneficiaries before and after an incident diagnosis of ADRD. METHODS: Data came from the Hispanic Established Populations for the Epidemiological Study of the Elderly that has been linked with Medicare claims files from 1999 to 2016 (n = 558 matched cases and controls). Piecewise regression and generalized linear mixed models were used to compare the quarterly trends in any (ie, one or more) hospitalizations, emergency room (ER) admissions, and physician visits for 1 year before and 1 year after ADRD diagnosis. RESULTS: The piecewise regression models showed that the per-quarter odds for any hospitalizations (odds ratio [OR] = 1.62, 95% CI = 1.43-1.84) and any ER admissions (OR = 1.40, 95% CI = 1.27-1.54) increased before ADRD was diagnosed. Compared to participants without ADRD, the percentage of participants with ADRD who experienced any hospitalizations (27.2% vs 14.0%) and any ER admissions (19.0% vs 11.7%) was significantly higher at 1 quarter and 3 quarters before ADRD diagnosis, respectively. The per-quarter odds for any hospitalizations (OR = 0.88, 95% CI = 0.80-0.97) and any ER admissions (OR = 0.89, 95% CI = 0.82-0.97) decreased after ADRD was diagnosed. Trends for any physician visits before or after ADRD diagnosis were not statistically significant. CONCLUSIONS: Older Mexican Americans show an increase in hospitalizations and ER admissions before ADRD is diagnosed, which is followed by a decrease after ADRD diagnosis. These findings support the importance of a timely diagnosis of ADRD for older Mexican Americans.

Characteristics Associated with Feeding Tube Placement: Retrospective Cohort Study of Texas Nursing Home Residents with Advanced Dementia.

OBJECTIVES: To investigate resident-level, provider-type, nursing home (NH), and regional factors associated with feeding tube (FT) placement in advanced dementia. DESIGN: Retrospective cohort study. SETTING AND PARTICIPANTS: NH residents in Texas with dementia diagnosis and severe cognitive impairment (N = 20,582). METHODS: This study used 2011-2016 Texas Medicare data to identify NH residents with a stay of at least 120 days who had a diagnosis of dementia on Long Term Care Minimum Data Set (MDS) evaluation and severe cognitive impairment on clinical score. Multivariable repeated measures analyses were conducted to identify associations between FT placement and resident-level, provider-type, NH, and regional factors. RESULTS: The prevalence of FT placement in advanced dementia in Texas between 2011 and 2016 ranged from 12.5% to 16.1% with a nonlinear trend. At the resident level, the prevalence of FT decreased with age [age > 85 years, prevalence ratio (PR) 0.60, 95% confidence interval (CI) 0.52-0.69] and increased among residents who are black (2.74, 95% CI 2.48-3.03) or Hispanic (PR 1.91, 95% CI 1.71-2.13). Residents cared for by a nurse practitioner or physician assistant were less likely to have an FT (PR 0.90, 95% CI 0.85-0.96). No facility characteristics were associated with prevalence of FT placement in advanced dementia. There were regional differences in FT placement with the highest use areas on the Texas-Mexico border and in South and East Texas (Harlingen border area, PR 4.26, 95% CI 3.69-4.86; San Antonio border area, PR 3.93, 95% CI 3.04-4.93; Houston, PR 2.17, 95% CI 1.87-2.50), and in metro areas (PR 1.36, 95% CI 1.22-1.50). CONCLUSIONS AND IMPLICATIONS: Regional, race, and ethnic variations in prevalence of FT use among NH residents suggest opportunities for clinicians and policy makers to improve the quality of end-of-life care by especially considering other palliative care measures for minorities living in border towns.

Frailty transitions predict healthcare use and Medicare payments in older Mexican Americans: a longitudinal cohort study.

BACKGROUND: Little is known regarding the impact of transitions in frailty on healthcare use and payment in older Mexican Americans. We address this gap in knowledge by investigating the effect of early transitions in physical frailty on the use of healthcare services and Medicare payments involving older Mexican Americans. METHODS: Longitudinal analyses were conducted using the Hispanic Established Populations for the Epidemiological Study of the Elderly (Hispanic-EPESE) survey data from five Southwest states linked to the Medicare claims files from the Centers for Medicare and Medicaid Services. Seven hundred and eighty-eight community-dwelling Mexican Americans 72 years and older in 2000/01 were studied. We used a modified Frailty Phenotype (unintentional weight loss, weakness, self-reported exhaustion and slow walking speed) to classify frailty status (non-frail, pre-frail or frail). Each participant was placed into one of 5 frailty transition groups: 1) remain non-frail, 2) remain pre-frail, 3) remain frail, 4) improve (pre-frail to non-frail, frail to non-frail, frail to pre-frail) and 5) worse (non-frail to pre-frail, non-frail to frail, pre-frail to frail). The outcomes for the one-year follow-up period (2000-2001) were: (a) healthcare use (hospitalization, emergency room [ER] admission and physician visit); and (b) Medicare payments (total payment and outpatient payment). RESULTS: Mean age was 78.8 (SD = 5.1) years and 60.3% were female in 1998/99. Males who remained pre-frail (Odds Ratio [OR] = 3.49, 1.13-10.8, remained frail OR = 6.92, 1.61-29.7) and transitioned to worse frail status (OR = 4.49, 1.74-11.6) had significantly higher hospitalization risk compared to individuals who remained non-frail. Males in the 'worsened' groups, and females in the 'improved' groups, had significantly higher Medicare payments than individuals who remained non-frail (Cost Ratio [CR] = 2.00, 1.30-3.09; CR = 1.53, 1.12-2.09, respectively]. CONCLUSIONS: Healthcare use and Medicare payments differed by frailty transition status. The differences varied by sex. Research is necessary to elucidate the relationship between frailty transitions and outcomes, sex difference and Medicare payment for older Mexican Americans living in the community.

Healthcare utilization of Mexican-American Medicare beneficiaries with and without Alzheimer's disease and related dementias.

BACKGROUND: Older adults with Alzheimer's disease and related dementias (ADRD) are high-risk to experience hospitalizations and emergency room (ER) admissions. Mexican-Americans have a high prevalence of ADRD, but there is limited information on the healthcare use of older Mexican-Americans with ADRD. We used data from a cohort of older Mexican-Americans that has been linked with Medicare files to investigate differences in hospitalizations, ER admissions, and physician visits according to ADRD diagnosis. We also identify sociodemographic, health, and functional characteristics that may contribute to differences in healthcare utilization between Mexican-American Medicare beneficiaries with and without an ADRD diagnosis. METHODS AND FINDINGS: Data came from the Hispanic Established Populations for the Epidemiological Study of the Elderly that has been linked with Medicare Master Beneficiary Summary Files, Medicare Provider Analysis and Review files, Outpatient Standard Analytic files, and Carrier files. The final analytic sample included 1048 participants. Participants were followed for two years (eight quarters) after their survey interview. Generalized estimating equations were used to estimate the probability for one or more hospitalizations, ER admissions, and physician visits at each quarter. ADRD was associated with higher odds for hospitalizations (OR = 1.65, 95%CI = 1.29-2.11) and ER admissions (OR = 1.57, 95%CI = 1.23-1.94) but not physician visits (OR = 1.23, 95%CI = 0.91-1.67). The odds for hospitalizations (OR = 1.24, 95%CI = 0.97-1.60) and ER admissions (OR = 1.27, 95%CI = 1.01-1.59) were reduced after controlling for limitations in activities of daily living and comorbidities. CONCLUSIONS: Mexican-American Medicare beneficiaries with ADRD had significantly higher odds for one or more hospitalizations and ER admissions but similar physician visits compared to beneficiaries without ADRD. Functional limitations and comorbidities contributed to the higher hospitalizations and ER admissions for older Mexican-Americans with ADRD.

End-of-Life Healthcare Utilization of Older Mexican Americans With and Without a Diagnosis of Alzheimer's Disease and Related Dementias.

BACKGROUND: Little is known about the patterns of end-of-life health care for older Mexican Americans with or without a diagnosis of Alzheimer's disease and related dementias (ADRD). Our objective was to investigate the frequency of acute hospital admissions, intensive care unit use, and ventilator use during the last 30 days of life for deceased older Mexican American Medicare beneficiaries with and without an ADRD diagnosis. METHODS: We used Medicare claims data linked with survey information from 1,090 participants (mean age of death 85.1 years) of the Hispanic Established Populations for the Epidemiologic Studies of the Elderly. Multivariable logistic regression models were used to estimate the odds for hospitalization, intensive care unit use, and ventilator use in the last 30 days of life for decedents with ADRD than those without ADRD. Generalized linear models were used to estimate the risk ratio (RR) for length of stay in hospital. RESULTS: Within the last 30 days of life, 64.5% decedents had an acute hospitalization (59.1% ADRD, 68.3% no ADRD), 33.9% had an intensive care unit stay (31.3% ADRD, 35.8% no ADRD), and 17.2% used a ventilator (14.9% ADRD, 18.8% no ADRD). ADRD was associated with significantly lower hospitalizations (odds ratio [OR] = 0.67, 95% confidence interval [CI] = 0.50-0.89) and shorter length of stay in hospital (RR = 0.77, 95% CI = 0.65-0.90). CONCLUSION: Hospitalization, intensive care unit stay, and ventilator use are common at the end of life for older Mexican Americans. The lower hospitalization and shorter length of stay in hospital of decedents with ADRD indicate a modest reduction in acute care use. Future research should investigate the impact of end-of-life planning on acute-care use and quality of life in terminally ill Mexican American older adults.

Differences in hospitalizations, emergency room admissions, and outpatient visits among Mexican-American Medicare beneficiaries.

BACKGROUND: Few studies have investigated the healthcare utilization of Mexican-American Medicare beneficiaries. We used survey data that has been linked with Medicare claims records to describe the healthcare utilization of Mexican-American Medicare beneficiaries, determine common reasons for hospitalizations, and identify characteristics associated with healthcare utilization. METHODS: Data came from wave five (2004/05) of the Hispanic Established Populations for the Epidemiological Study of the Elderly. The final sample included 1187 participants aged ≥75 who were followed for two-years (eight-quarters). Generalized estimating equations were used to estimate the probability of ≥1 hospitalization, emergency room (ER) admissions, and outpatient visits. RESULTS: The percentage of beneficiaries who had ≥1 hospitalizations, ER admissions, and outpatient visits for each quarter ranged from 10.12-12.59%, 14.15-19.03%, and 76.61-80.68%, respectively. Twenty-three percent of hospital discharges were for circulatory conditions and 17% were for respiratory conditions. Hospitalizations for heart failure and simple pneumonia were most common. Older age was associated with significantly higher odds for ER admissions (OR = 1.49, 95% CI = 1.21-1.84) but lower odds for outpatient visits (OR = 0.74, 95% CI = 0.57-0.96). Spanish language and female gender were associated with significantly higher odds for hospitalizations (OR = 1.53, 95% CI = 1.14-2.06) and outpatient visits (OR = 1.82, 95% CI = 1.43-2.33), respectively. Having a middle-school or higher level of education was associated with significantly lower odds for ER admissions (OR = 0.71, 95% CI = 0.56-0.91). Participants who were deceased within two-years had significantly higher odds for hospitalizations (OR = 6.15, 95% CI = 4.79-7.89) and ER admissions (OR = 3.63, 95% CI = 2.88-4.57) than participants who survived at least three-years. CONCLUSION: We observed high healthcare utilization among Mexican-American Medicare beneficiaries. Forty percent of all hospitalizations were for circulatory and respiratory conditions with hospitalizations for heart failure and pneumonia being the most common. Older age, gender, education, language, and mortality were all associated with healthcare utilization. Continued research is needed to identify patterns and clusters of social determinants and health characteristics associated with healthcare utilization and outcomes in older Mexican-Americans.

Mechanism of synergistic DNA damage induced by the hydroquinone metabolite of brominated phenolic environmental pollutants and Cu(II): Formation of DNA-Cu complex and site-specific production of hydroxyl radicals.

2,6-Dibromohydroquinone (2,6-DBrHQ) has been identified as an reactive metabolite of many brominated phenolic environmental pollutants such as tetrabromobisphenol-A (TBBPA), bromoxynil and 2,4,6-tribromophenol, and was also found as one of disinfection byproducts in drinking water. In this study, we found that the combination of 2,6-DBrHQ and Cu(II) together could induce synergistic DNA damage as measured by double strand breakage in plasmid DNA and 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) formation, while either of them alone has no effect. 2,6-DBrHQ/Cu(II)-induced DNA damage could be inhibited by the Cu(I)-specific chelating agent bathocuproine disulfonate and catalase, but not by superoxide dismutase, nor by the typical hydroxyl radical (•OH) scavengers such as DMSO and mannitol. Interestingly, we found that Cu(II)/Cu(I) could be combined with DNA to form DNA-Cu(II)/Cu(I) complex by complementary application of low temperature direct ESR, circular dichroism, cyclic voltammetry and oxygen consumption methods; and the highly reactive •OH were produced synergistically by DNA-bound-Cu(I) with H2O2 produced by the redox reactions between 2,6-DBrHQ and Cu(II), which then immediately attack DNA in a site-specific manner as demonstrated by both fluorescent method and by ESR spin-trapping studies. Further DNA sequencing investigations provided more direct evidence that 2,6-DBrHQ/Cu(II) caused preferential cleavage at guanine, thymine and cytosine residues. Based on these data, we proposed that the synergistic DNA damage induced by 2,6-DBrHQ/Cu(II) might be due to the synergistic and site-specific production of •OH near the binding site of copper and DNA. Our findings may have broad biological and environmental implications for future research on the carcinogenic polyhalogenated phenolic compounds.