Higher Median Household Income Research Articles

Socioeconomic disparities in the decline in invasive breast cancer incidence.

Breast cancer incidence in the United States has declined dramatically since the year 2002. To improve our understanding of the underlying factors driving breast cancer trends, we explored potential socioeconomic disparities in the recent decline in incidence. We examined the decline in breast cancer incidence according to county-level socioeconomic indicators using data from the Surveillance, Epidemiology and End Results (SEER) program. Since socioeconomic status is associated with mammography screening, we also examined the relation between incidence of ductal carcinoma in situ (DCIS; a strong marker of mammography utilization) and the decline in invasive breast cancer. The reduction in invasive breast cancer incidence between 1998-2001 and 2003-2006 in the SEER 9 registries was greatest among women living in counties with higher median household income (-16% change for > or = $85,000 vs. -4% for <$35,000; P(trend) < 0.01) and a higher percentage of adults aged 25 years or older with a bachelor's degree (-13% change for > or = 40% vs. -8% for <15%; P(trend) < 0.01). Counties with higher DCIS incidence during 1985-2001 had a larger decrease in invasive breast cancer incidence (absolute decrease 1.7 percentage points greater per 5 per 100,000 increase in DCIS incidence; P = 0.01). This association was present for both ER-positive and ER-negative invasive cancers (P < 0.05). In summary, the decline in breast cancer incidence has been largest in areas with high socioeconomic status and high screening utilization rates. These results are consistent with the hypothesis that a saturation of screening mammography utilization contributed to the overall decline in breast cancer incidence.

Sociodemographic Characteristics of Communities Served by Retail Clinics

As a rapidly growing new health care delivery model in the United States, retail clinics have been the subject of much debate and controversy. Located physically within a retail store, retail clinics provide simple acute and preventive services for a fixed price and without an appointment. Some hope that retail clinics can be a new safety-net provider for the poor and those without a primary care physician. To better understand the potential for retail clinics to achieve this goal, we describe the sociodemographic characteristics of the communities in which they operate. We created an inventory of all retail clinics in the United States and determined the proportion that are in a health professional shortage area (HPSA). We defined each retail clinic's catchment area as all census blocks that were less than a 5-minute driving distance from the clinic. We compared the sociodemographic characteristics of the population within and outside of these retail clinic catchment areas. Of the 982 clinics in 32 states, 88.4% were in an urban area and 12.5% were in an HPSA (20.9% of the US population lives within an HPSA). Compared with the rest of the urban population, the population living within a retail clinic catchment area has a higher median household income ($52,849 vs $46,080), is better educated (32.6% vs 24.9% with a college degree), and is as likely to be uninsured (17.7% vs 17.0%). In a multivariate model, the census block's median household income had the strongest association with whether the census block was in a retail clinic catchment area (odds ratio, 3.63; 95% CI, 3.26-4.05; median income, > or =$54,779 vs <$30,781, respectively). We found that relatively few retail clinics are located in HPSAs and that, compared with the rest of the urban population, the population living in close proximity to a retail clinic has a higher income.

The joint influence of area income, income inequality, and immigrant density on adverse birth outcomes: a population-based study

BackgroundThe association between area characteristics and birth outcomes is modified by race. Whether such associations vary according to social class indicators beyond race has not been assessed.MethodsThis study evaluated effect modification by maternal birthplace and education of the relationship between neighbourhood characteristics and birth outcomes of newborns from 1999–2003 in the province of Québec, Canada (N = 353,120 births). Areas (N = 143) were defined as administrative local health service delivery districts. Multi-level logistic regression was used to model the association between three area characteristics (median household income, immigrant density and income inequality) and the two outcomes preterm birth (PTB) and small-for-gestational age (SGA) birth. Effect modification by social class indicators was evaluated in analyses stratified according to maternal birthplace and education.ResultsRelative to the lowest tertile, high median household income was associated with SGA birth among Canadian-born mothers (odds ratio (OR) 1.13, 95% confidence interval (CI) 1.06, 1.20) and mothers with high school education or less (OR 1.13, 95% CI 1.02, 1.24). Associations between median household income and PTB were weaker. Relative to the highest tertile, low immigrant density was associated with a lower odds of PTB among foreign-born mothers (OR 0.79, 95% CI 0.63, 1.00) but a higher odds of PTB among Canadian-born mothers (OR 1.14, 95% CI 1.07, 1.21). Associations with income inequality were weak or absent.ConclusionThe association between area factors and birth outcomes is modified by maternal birthplace and education. Studies have found that race interacts in a similar manner. Public health policies focussed on perinatal health must consider the interaction between individual and area characteristics.

Selected Community Characteristics and Underage Drinking

This study assessed the relationship between community characteristics and alcohol use among 6,636 youth, aged from 14 to 20, in 2004. After adjusting for individual-level characteristics, youth from communities with a greater proportion of grandparents as caregivers, larger numbers of married couple families, and higher employment rates were significantly less likely to report past 30-day alcohol use. Youth from communities with higher median household income were significantly more likely to report past 30-day alcohol use. Adolescents in communities with a greater percentage of whites were significantly more likely to report binge drinking. The results indicate that the community context is an important predictor of alcohol use.

Can Heterogeneity of Populations Explain Differences in Mortality?

We investigate whether heterogeneity can explain the differences in mortality between the United States and a more homogeneous country, i.e. Japan. The background of the analysis is the growing gap between life-expectancy in the United States and the world record leader since the 1980s. This development is mirrored in the decelerated improvements made against mortality during the last 25 years - especially for women. Our hypothesis is that it is possible to have survival improvements at a steady pace across all population subgroups. The proportion of the population subgroups which perform relatively well decreased over time whereas poor performing subgroups became more important. The consequence of this compositional change since the 1980s would be the observed levelling off in survival improvements on the population level. Since official mortality estimates in the US are of poor quality, we estimate mortality rates via the extinct cohort method using Medicare enrollment data from the Social Security Administration due to their higher quality. If our hypothesis was true, we should see little differences in the development of mortality rates between the best performing subgroups in the United States and Japan. We compared mortality rates between Japanese women and white women in the US from states who (a) either had the highest life expectancy or (b) the highest median household income or (c) the largest gross state product per head. Regardless of the choice of indicator, mortality rates levelled-off in the United States for those best performance subgroups as for the whole population. The preliminary conclusion is therefore that compositional changes (heterogeneity) in the US population can not explain the widening gap between US life expectancy and best practice life expectancy.

Nursing Home Deficiencies: An Exploratory Study of Interstate Variations in Regulatory Activity

ABSTRACT This study examines nursing home regulatory activity by the states, assesses interstate variations in the volume and severity of nursing home deficiencies, and explores state-level factors that may account for these differences. Nursing home deficiency citation data over a 5-year period (2000–2004) were obtained from the Centers for Medicare and Medicaid Services. We examined interstate variations in regulatory activity and identified predictors of deficiency volume and severity at the state level (demographics, elected officials, industry characteristics, etc.) using the linear mixed model. Deficiency volume remained stable across the 50 states from 2000 to 2004, while deficiency severity decreased significantly. California had the highest volume of deficiencies per nursing home; Wisconsin had the lowest. New Hampshire had the highest percentage of severe deficiencies; California had the lowest. Higher deficiency volume was found in states with lower median household income, a lower proportion of residents aged 85 and older, and a Democratic legislature. Higher deficiency severity was associated with higher median household income and a higher proportion of Medicaid nursing home residents in a state. In contrast, greater state agency funding, higher state standards for nursing home administrators, and a Democratic and more professional legislature predicted lower deficiency severity. Nursing home residents in the United States receive unequal protection from abuse and neglect, and this is partly due to their state of residence. Interstate variations in deficiency volume and severity are due to a complex set of factors beyond nursing home quality.

School Level Contextual Factors Are Associated With the Weight Status of Adolescent Males and Females

To determine whether school context influences the BMI of adolescent males and females. Our sample was 17,007 adolescents (aged 12-19) from the National Longitudinal Study of Adolescent Health (Add Health). We used gender-stratified multilevel modeling to examine the contribution of schools to the overall variance in adolescent BMIs, calculated from self-reported weight and height. We then examined the associations of individual attributes with BMI after controlling for the average BMI of the school and the association of two school-level variables with BMI. Participants attended schools that were segregated by race/ethnicity and socioeconomic status (SES). In females, when controlling only for individual-level attributes, individual household income was inversely associated (beta = -0.043, P = 0.01) while Hispanic (beta = 0.89, P < 0.001) and black (beta = 1.61, P < 0.001) race/ethnicity were positively associated with BMI. In males, Hispanic (beta = 0.67, P < 0.001) race/ethnicity was positively associated with BMI; there was no difference in the BMIs of blacks compared with whites (beta = 0.24, P = 0.085). After controlling for the school racial/ethnic makeup and the school level median household income, the relationship between individual race/ethnicity and BMI was attenuated in both male and female adolescents. Higher school level median household income was associated with lower individual BMIs in adolescent girls (gamma = -0.37, P < 0.001) and boys (gamma = -0.29, P < 0.001) suggesting a contextual effect of the school. Male and female adolescents attending schools with higher median household incomes have on average lower BMIs. Resources available to or cultural norms within schools may constitute critical mechanisms through which schools impact the BMI of their students.

Recruitment in the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial: the First Phase of Recruitment at Henry Ford Health System

Recruitment of healthy subjects to long-term randomized controlled trials (RCTs) of cancer prevention or early detection has proven to be a difficult task. To quantify recruitment yield as well as characteristics of successfully recruited participants, we examined recruitment outcomes at 1 of the 10 centers participating in the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial, a National Cancer Institute-funded RCT of cancer screening modalities. During the early recruitment phase of PLCO (1993-1997), data on recruitment outcome were collected at the Henry Ford Health System (HFHS) in Detroit, Michigan. In this phase, HFHS identified potential participants using patient databases. Records were used to assess recruitment success by age, sex, race, household income (using area-based U.S. Census data), and preexisting morbidity. Logistic regression was used to assess whether enrollment success differed significantly according to these factors. Of 74,139 persons ages 55 to 74 invited by HFHS to participate, 8,250 (11%) ;enrolled. In multivariate analyses, the odds of enrolling were modestly but significantly higher for women, Caucasians, persons in their 60's, and persons living in census blocks with higher median household income. Persons with two or more preexisting morbidities had significantly lower odds of enrolling compared to those with one or no preexisting morbidities. These data suggest that only a small fraction of persons invited to enroll in long-term RCTs of cancer screening modalities actually do so. In this urban, Midwestern setting, certain characteristics including age, race, and income influenced recruitment success, albeit modestly.

Use of Cardiac Rehabilitation by Medicare Beneficiaries After Myocardial Infarction or Coronary Bypass Surgery

Cardiac rehabilitation (CR) is effective in prolonging survival and reducing disability in patients with coronary heart disease. However, national use patterns and predictors of CR use have not been evaluated thoroughly. Using Medicare claims, we analyzed outpatient (phase II) CR use after hospitalizations for acute myocardial infarctions or coronary artery bypass graft surgery in 267,427 fee-for-service beneficiaries aged > or = 65 years who survived for at least 30 days after hospital discharge. We used multivariable analyses to identify predictors of CR use and to quantify geographic variations in its use. We obtained unadjusted, adjusted-smoothed, and standardized rates of CR use by state. Overall, CR was used in 13.9% of patients hospitalized for acute myocardial infarction and 31.0% of patients who underwent coronary artery bypass graft surgery. Older individuals, women, nonwhites, and patients with comorbidities (including congestive heart failure, previous stroke, diabetes mellitus, or cancer) were significantly less likely to receive CR. Coronary artery bypass graft surgery during the index hospitalization, higher median household income, higher level of education, and shorter distance to the nearest CR facility were important predictors of higher CR use. Adjusted CR use varied 9-fold among states, ranging from 6.6% in Idaho to 53.5% in Nebraska. The highest CR use rates were clustered in the north central states of the United States. CR use is relatively low among Medicare beneficiaries despite convincing evidence of its benefits and recommendations for its use by professional organizations. Use is higher after coronary artery bypass graft surgery than with acute myocardial infarctions not treated with revascularization procedures and varies dramatically by state and region of the United States.

Where Do Graduating Pediatric Residents Seek Practice Positions?

To profile the characteristics of areas that graduating pediatric residents target in their job searches and to explore whether residents applying to primary care markets with higher pediatrician supplies experience job-search difficulty. A national random sample of 500 graduating categorical pediatric residents was surveyed. The communities that the pediatric residents targeted for jobs were linked to local-area characteristics by using Dartmouth Primary Care Service Areas (PCSAs), which are discrete markets that represent patient travel patterns for primary care services. PCSA population and providers were characterized by using data from the 2000 US Census and American Medical Association/American Osteopathic Association Physician Masterfiles. A total of 308 graduating residents (62%) completed the survey. Of the respondents, 136 (44%) applied for general-practice positions. The characteristics of the PCSAs that residents applied to differed from the PCSAs without an application. Residents' first-choice areas had higher ratios of general pediatricians, had higher median household incomes, and were more likely to be urban areas. Residents applying to higher-supply areas were significantly more likely to report moderate or considerable difficulty in their job searches than were residents applying to lower-supply areas. Residents applying to medium- and higher-supply areas sent out more total applications for positions and received lower starting salaries than did residents applying to lower-supply areas. Residents continue to prefer high-supply areas in their job searches, despite experiencing greater search difficulty in these areas. Current targeted incentives and market forces are unlikely to redress geographic variation in pediatrician supply.

Tobacco Outlet Density, Cigarette Smoking Prevalence, and Demographics at the County Level of Analysis

The geographic associations between tobacco outlet density, cigarette smoking prevalence, and demographic variables at the county unit of analysis were examined. End of year 2002 data were derived from licenses of 4745 tobacco selling retail outlets in all 99 Iowa counties. The 2000 census and the 2002 Iowa Behavioral Risk Factor Surveillance System (IBRFSS) were used to gather data for demographic variables and smoking prevalence rates. The IBRFSS telephone interviews were conducted from January through December in 2002 with a random sample of 3662 Iowa residents. As expected, results showed that counties with higher density of tobacco outlets and smoking prevalence also tended to have a higher percentage of minority residents. Contrary to previous studies, however, counties with higher tobacco outlet density and smoking prevalence also tended to have higher median household income. Findings are discussed in light of the state's low income inequality. Implications of the study and directions for future research are discussed.

Reconcilable Differences: A Cross-sectional Study of the Relationship Between Socioeconomic Status and the Magnitude of Short-Acting β-Agonist Use in Asthma

To assess the association between socioeconomic status (SES) and short-acting (SA) beta-agonist use, controlling for asthma severity. Cross-sectional study. Vancouver, BC, Canada. Two hundred two asthmatics between 19 years and 50 years of age and residing in the greater Vancouver regional district. The quantity of SA beta-agonist used in the previous year was collected by self-report; pulmonary function and beta-receptor genotype were measured on each participant. SES was measured at both the individual and population levels. Five methods of adjustment for asthma severity were used, as follows: the Canadian Asthma Consensus Guidelines, three previously developed asthma-severity scores, and forward stepwise multiple regression modeling. Polychotomous logistic regression was used to assess all relationships. Independent of the method used to measure SES or adjust for asthma severity, lower SES was consistently and significantly associated with the use of greater amounts of SA beta-agonist. Adjusting for severity using the multivariate model explained the most variance of SA beta-agonist use (R(2) adjusted, 0.35 to 0.37). In this model, social assistance recipients were more likely to use greater amounts of SA beta-agonist (odds ratio [OR], 3.4; 95% confidence interval [CI], 1.7 to 6.5). An inverse relationship between SA beta-agonist use and both annual household income (> $50,000; OR, 0.28; 95% CI, 0.13 to 0.60; and $20,000 to $50,000; OR, 0.44; 95% CI, 0.21 to 0.96; relative to <$20,000) and education (completing a bachelor's degree vs no formal education; OR, 0.25; 95% CI, 0.14 to 0.71). Participants living in a neighborhood with higher median household income (OR, 0.91; 95% CI, 0.84 to 0.98 per $1,000 increase) or a higher prevalence of having attained a bachelor's degree (OR, 0.96; 95% CI, 0.84 to 0.98 per 1% increase) were also less likely use greater amounts of SA beta-agonist. Results were consistent for neighborhood unemployment rate. The social gradient in asthma-related outcomes may be at least partially attributable to poorer asthma control in lower-SES asthmatics.

Using commercial telephone directories to obtain a population‐based sample for mail survey of women of reproductive age

In the United States, sampling women of reproductive age from the general population for research purposes is a challenge. Even more difficult is conducting a population-based study of couples attempting pregnancy to assess fecundity and fertility or related impairments. To address the problem of obtaining representative samples from the population in order to study such health-related issues, a commercially and readily available CD-ROM telephone directory was used and tested as a sampling framework for studies aimed at enrolling gravid women aged 18-44 years. A self-administered questionnaire (SAQ) was mailed to a stratified random sample of 10 005 (3%) households in Erie County, NY, USA. Overall, 17% of the questionnaires were undeliverable despite updating all addresses with residential software before mailing. Thirteen per cent (n = 1089) of the households returned completed questionnaires, of which 35% (n = 377) were completed by women aged 18-44 years. Using 1990 census information for zip code, respondents were more likely to be white and to have higher median household incomes than non-respondents. Of the 377 women who completed the questionnaire, 79% had been pregnant at least once, 5% reported being unable to become pregnant, and 16% reporting never trying to become pregnant. Despite the overall low response to the SAQ, the sampling framework captured a diverse group of women of reproductive age who reported various fecundity and fertility outcomes. The use of low-cost commercially available software linked to census data for selecting samples of women or couples for reproductive and perinatal research may be possible; however, oversampling of households, use of incentives and follow-up of non-respondents is needed to ensure adequate sample sizes.

Neighborhood Socioeconomic Status, Maternal Race and Preterm Delivery: A Case-Control Study

PURPOSE: To explore associations between neighborhood socioeconomic context and preterm delivery, independent of maternal and family socioeconomic status, in African-American and white women. METHODS: A case-control study of African-American ( n = 417) and white ( n = 1244) women delivering infants at the University of California, San Francisco's Moffitt Hospital, between 1980 and 1990. RESULTS: Neighborhood socioeconomic contexts were associated with preterm delivery but associations were non-linear and varied with race/ethnicity. For African-American women, living in a neighborhood with either high or low median household income was associated with an increased risk of spontaneous preterm delivery, as was living in a neighborhood with large increases or decreases in the proportion of African-American residents during the study decade. Residence in neighborhoods with high and low rates of male unemployment was associated with a decreased risk of preterm delivery. Among white women only large positive and negative changes in neighborhood male unemployment were associated with risk of preterm delivery. CONCLUSIONS: Neighborhood factors and changes in neighborhoods over time are related to preterm delivery, although the mechanisms linking local environments to maternal risk remain to be specified.

The epidemiology of pediatric traumatic brain injury in Minnesota.

To determine the epidemiology of pediatric traumatic brain injury (TBI) in a midwestern state and to examine differences between metropolitan and nonmetropolitan residents. Population-based case series. Patients aged 0-19 years sustaining TBI in 1993 that resulted in hospitalization or death. None. Incidence, mortality and case-fatality rates, length of hospital stay, discharge status, and Glasgow Outcome Scale score. Nine hundred seventy-seven patients met inclusion criteria. Incidence, mortality, and case-fatality rates were 73.5 per 100 000, 9.3 per 100 000, and 12.8 per 100, respectively. Higher median household incomes and percentages of adult high-school graduates in a patient's census block group correlated with lower incidence. Median length of stay was 2 days. Of those included in the study, 720 patients (74%) were discharged home with self-care. Three hundred fifty-seven patients met criteria for severe TBI; 346 (97%) were assigned Glasgow Outcome Scale scores, of which 161 (47%) had disabilities or died. Severe TBI was associated with nonmetropolitan residence, higher median household income, and certain injury mechanisms. Incidence was similar for metropolitan and nonmetropolitan residents. Median head-region Abbreviated Injury Score, Injury Severity Score, and mortality and case-fatality rates were higher for nonmetropolitan residents. This study reports the lowest incidence of pediatric TBI that results in death or hospitalization to date. One half of severely injured patients suffered poor outcomes. A greater proportion of nonmetropolitan than metropolitan residents suffered severe TBI and had higher mortality and case-fatality rates.

Geocoding and linking data from population-based surveillance and the US Census to evaluate the impact of median household income on the epidemiology of invasive Streptococcus pneumoniae infections.

The emergence of drug-resistant Streptococcus pneumoniae poses new clinical challenges and may also reflect a change in the epidemiology of S. pneumoniae infections. A variety of studies have shown that drug-resistant S. pneumoniae infections are linked to antimicrobial use. It has been hypothesized that persons of high socioeconomic status are at increased risk for a drug-resistant infection because of greater access to antimicrobial drugs. To assess whether median household income is associated with increased risk of penicillin-nonsusceptible S. pneumoniae infections, the authors geocoded and linked data from population-based surveillance for invasive pneumococcal disease with data from the 1990 US Census. Among invasive pneumococcal isolates from Atlanta, Georgia, in 1994, increasing proportions of penicillin-nonsusceptible isolates were associated with higher median household incomes (chi2 for trend, 15.17; p=0.002). Despite higher rates of invasive pneumococcal disease among blacks and persons who resided within lower median household income areas, white patients in areas with higher median household income had a higher risk of being infected with strains that were not susceptible to penicillin (Wilcoxon rank sum, Z=2.66, p=0.008). These findings demonstrated the utility of geocoding and US Census data in describing the epidemiology of drug-resistant S. pneumoniae and also provided more evidence that socioeconomic factors may influence the development of drug resistance.

Making a place in the metropolis: Locational attainment in cities and suburbs

What accounts for the differences in the kinds of communities within the metropolis in which members of different racial and ethnic groups live? Do socioeconomic advancement and acculturation provide greater integration with whites or access to more desirable locations for minority-group members? Are these effects the same for Asians or Hispanics as for blacks? Does suburbanization offer a step toward greater equality in the housing market, or do minorities find greater discrimination in the suburban housing market? Data from 1980 for five large metropolitan regions are used to estimate "locational-attainment models," which evaluate the effects of group members' individual attributes on two measures of the character of their living environment: the socioeconomic standing (median household income) and racial composition (proportion non-Hispanic white) of the census tract where they reside. Separate models predict these outcomes for whites, blacks, Hispanics, and Asians. Net of the effects of individuals' background characteristics, whites live in census tracts with the highest average proportion of white residents and the highest median household income. They are followed by Asians and Hispanics, and-at substantially lower levels-blacks. Large overall differences exist between city and suburban locations; yet the gap between whites and others is consistently lower in the suburbs than in the cities of these five metropolitan regions.