The impact of prenatal dog keeping on infant gut microbiota development.

INTRODUCTION: Prenatal and early-life dog exposure has been linked to reduced childhood allergy and asthma. A potential mechanism includes altered early immune development in response to changes in the gut microbiome among dog-exposed infants. We thus sought to determine whether infants born into homes with indoor dog(s) exhibit altered gut microbiome development. METHODS: Pregnant women living in homes with dogs or in pet-free homes were recruited in southeast Michigan. Infant stool samples were collected at intervals between 1 week and 18 months after birth and microbiome was assessed using 16S ribosomal sequencing. Perinatal maternal vaginal/rectal swabs and stool samples were sequenced from a limited number of mothers. Mixed effect adjusted models were used to assess stool microbial community trajectories comparing infants from dog-keeping versus pet-free homes with adjustment for relevant covariates. RESULTS: Infant gut microbial composition among vaginally born babies became less similar to the maternal vaginal/rectal microbiota and more similar to the maternal gut microbiota with age-related accumulation of bacterial species with advancing age. Stool samples from dog-exposed infants were microbially more diverse (p = .041) through age 18 months with enhanced diversity most apparent between 3 and 6 months of age. Statistically significant effects of dog exposure on ß-diversity metrics were restricted to formula-fed children. Across the sample collection period, dog exposure was associated with Fusobacterium genera enrichment, as well as enrichment of Collinsella, Ruminococcus, Clostridaceae and Lachnospiraceae OTUs. CONCLUSION: Prenatal/early-life dog exposure is associated with an altered gut microbiome during infancy and supports a potential mechanism explaining lessened atopy and asthma risk. Further research directly linking specific dog-attributable changes in the infant gut microbiome to the risk of allergic disorders is needed.

Pediatric asthma incidence rates in the United States from 1980 to 2017.

BACKGROUND: Few studies have examined longitudinal asthma incidence rates (IRs) from a public health surveillance perspective. OBJECTIVE: Our aim was to calculate descriptive asthma IRs in children over time with consideration for demographics and parental asthma history. METHODS: Data from 9 US birth cohorts were pooled into 1 population covering the period from 1980 to 2017. The outcome was earliest parental report of a doctor diagnosis of asthma. IRs per 1,000 person-years were calculated. RESULTS: The racial/ethnic backgrounds of the 6,283 children studied were as follows: 55% European American (EA), 25.5% African American (AA), 9.5% Mexican-Hispanic American (MA) and 8.5% Caribbean-Hispanic American (CA). The average follow-up was 10.4 years (SD = 8.5 years; median = 8.4 years), totaling 65,291 person-years, with 1789 asthma diagnoses yielding a crude IR of 27.5 per 1,000 person-years (95% CI = 26.3-28.8). Age-specific rates were highest among children aged 0 to 4 years, notably from 1995 to 1999, with a decline in EA and MA children in 2000 to 2004 followed by a decline in AA and CA children in 2010 to 2014. Parental asthma history was associated with statistically significantly increased rates. IRs were similar and higher in AA and CA children versus lower but similar in EA and MA children. The differential rates by sex from birth through adolescence principally resulted from a decline in rates among males but relatively stable rates among females. CONCLUSIONS: US childhood asthma IRs varied dramatically by age, sex, parental asthma history, race/ethnicity, and calendar year. Higher rates in the 0- to 4-year-olds group, particularly among AA/CA males with a parental history of asthma, as well as changes in rates over time and by demographic factors, suggest that asthma is driven by complex interactions between genetic susceptibility and variation in time-dependent environmental and social factors.

Increased risk of asthma at age 10 years for children sensitized to multiple allergens.

BACKGROUND: Childhood sensitization patterns have been previously found to be related to variable risk of early life allergic disease in several birth cohorts. OBJECTIVE: To determine whether these risks persist into later childhood. METHODS: In the birth cohort of the Wayne County Health, Environment, Allergy and Asthma Longitudinal Study, previous latent class analysis based on sensitization to 10 allergens found the following 4 early life sensitization patterns at age 2 years: "highly sensitized," "milk/egg dominated," "peanut and inhalant(s)," and "low to no sensitization." At an age 10 study-specific visit, children were evaluated by an allergist for current asthma and atopic dermatitis through a physical examination and interviews with the child and parent or guardian. Total and specific immunoglobulin E (IgE), spirometry, and methacholine challenge were also completed. RESULTS: Compared with children sensitized to none or 1 allergen, children sensitized to 4 or more food and inhalant allergens at age 2 had the highest risk of current asthma (relative risk [RR], 4.42; 95% confidence interval [CI], 2.58-7.59; P < .001) and bronchial hyperresponsiveness (RR, 1.77; 95% CI, 1.29-2.42; P < .001). In addition, they had the highest levels of total IgE (geometric mean, 800 IU/mL; 95% CI, 416-1536) among the 4 groups. Risk of current atopic dermatitis did not depend on pattern of sensitization but remained increased for children with any sensitization (RR, 2.23; 95% CI, 1.40-3.55; P < .001). No differences in spirometry (forced expiratory volume in 1 second, forced expiratory flow between 25% and 75%, and forced expiratory volume in 1 second/forced vital capacity) were identified. CONCLUSION: The previously reported importance of a specific pattern of sensitization in early life (sensitization to ≥4 inhalant and food allergens) continues to be associated with an increased risk of asthma, bronchial hyperresponsiveness, and high total IgE at age 10 years.

Association between cesarean delivery types and obesity in preadolescence.

BACKGROUND/OBJECTIVES: The association between mode of delivery and childhood obesity remains inconclusive. Because few studies have separated C-section types (planned or unplanned C-section), our objective was to assess how these subtypes relate to preadolescent obesity. SUBJECTS/METHODS: The study consisted of 570 maternal-child pairs drawn from the WHEALS birth cohort based in Detroit, Michigan. Children were followed-up at 10 years of age where a variety of anthropometric measurements were collected. Obesity was defined based on BMI percentile (≥95th percentile), as well as through Gaussian finite mixture modeling on the anthropometric measurements. Risk ratios (RRs) and 95% confidence intervals (CIs) for obesity comparing planned and unplanned C-sections to vaginal deliveries were computed, which utilized inverse probability weights to account for loss to follow-up and multiple imputation for covariate missingness. Mediation models were fit to examine the mediation role of breastfeeding. RESULTS: After adjusting for marital status, maternal race, prenatal tobacco smoke exposure, maternal age, maternal BMI, any hypertensive disorders during pregnancy, gestational diabetes, prenatal antibiotic use, child sex, parity, and birthweight z-score, children born via planned C-section had 1.77 times higher risk of obesity (≥95th percentile), relative to those delivered vaginally ((95% CI) = (1.16, 2.72); p = 0.009). No association was found comparing unplanned C-section to vaginal delivery (RR (95% CI) = 0.75 (0.45, 1.23); p = 0.25). The results were similar but slightly stronger when obesity was defined by anthropometric class (RR (95% CI) = 2.78 (1.47, 5.26); p = 0.002). Breastfeeding did not mediate the association between mode of delivery and obesity. CONCLUSIONS: These findings indicate that children delivered via planned C-section-but not unplanned C-section-have a higher risk of preadolescent obesity, suggesting that partial labor or membrane rupture (typically experienced during unplanned C-section delivery) may offer protection. Additional research is needed to understand the biological mechanisms behind this effect, including whether microbiological differences fully or partially account for the association.

Breast Milk Transforming Growth Factor ß Is Associated With Neonatal Gut Microbial Composition.

BACKGROUND AND OBJECTIVES: Breast milk is a complex bioactive fluid that varies across numerous maternal and environmental conditions. Although breast-feeding is known to affect neonatal gut microbiome, the milk components responsible for this effect are not well-characterized. Given the wide range of immunological activity breast milk cytokines engage in, we investigated 3 essential breast milk cytokines and their association with early life gut microbiota. METHODS: A total of 52 maternal-child pairs were drawn from a racially diverse birth cohort based in Detroit, Michigan. Breast milk and neonatal stool specimens were collected at 1-month postpartum. Breast milk transforming growth factor (TGF)ß1, TGFß2, and IL-10 were assayed using enzyme-linked immunosorbent assays, whereas neonatal gut microbiome was profiled using 16S rRNA sequencing. RESULTS: Individually, immunomodulators TGFß1 and TGFß2 were significantly associated with neonatal gut microbial composition (R = 0.024, P = 0.041; R = 0.026, P = 0.012, respectively) and increased richness, evenness, and diversity, but IL-10 was not. The effects of TGFß1 and TGFß2, however, were not independent of one another, and the effect of TGFß2 was stronger than that of TGFß1. Higher levels of TGFß2 were associated with the increased relative abundance of several bacteria, including members of Streptococcaceae and Ruminococcaceae, and lower relative abundance of distinct Staphylococcaceae taxa. CONCLUSIONS: Breast milk TGFß concentration explains a portion of variability in gut bacterial microbiota composition among breast-fed neonates. Whether TGFß acts in isolation or jointly with other bioactive components to alter bacterial composition requires further investigation. These findings contribute to an increased understanding of how breast-feeding affects the gut microbiome-and potentially immune development-in early life.

Effect of depressive symptoms on asthma intervention in urban teens.

BACKGROUND: The literature suggests that depression is an important comorbidity in asthma that can significantly influence disease management and quality of life (QOL). OBJECTIVE: To study the effect of coexisting depressive symptoms on the effectiveness of self-management interventions in urban teens with asthma. METHODS: We analyzed data from a randomized controlled trial of Puff City, a web-based, tailored asthma management intervention for urban teens, to determine whether depression modulated intervention effectiveness for asthma control and QOL outcomes. Teens and caregivers were classified as depressed based on responses collected from baseline questionnaires. RESULT: Using logistic regression analysis, we found that a lower percentage of treatment students had indicators of uncontrolled asthma compared with controls (adjusted odds ratios <1). However, for teens depressed at baseline, QOL scores at follow-up were significantly higher in the treatment group compared with the control group for the emotions domain (adjusted relative risk, 2.08; 95% confidence interval, 1.2-3.63; P = .01; interpreted as emotional QOL for treatment students increased by a factor of 2.08 above controls). Estimates for overall QOL and symptoms QOL were borderline significant (adjusted relative risk, 1.57; 95% confidence interval, 0.93-2.63; P = .09; and adjusted relative risk, 1.72; 95% confidence interval, 0.94-3.15; P = .08; respectively). Among teens not depressed at baseline, no significant differences were observed between treatment and control groups in QOL domains at follow-up. CONCLUSION: Our results suggest that depression modified the relationship between the effectiveness of an asthma intervention and emotional QOL in urban teens. Further assessment of self-management behavioral interventions for asthma should explore the mechanism by which depression may alter the intervention effect.

Tobacco smoke exposure and allergic sensitization in children: a propensity score analysis.

BACKGROUND AND OBJECTIVE: There is conflicting evidence of the effect of environmental tobacco smoke (ETS) on the development of allergic diseases in children. Studies have shown that this relationship differs depending on maternal history of the disease. We employed the rigour of propensity score methods to assess this relationship using data from a birth cohort. METHODS: Using n = 662 children from the Wayne County Health, Environment, Allergy and Asthma Longitudinal Study, we assessed the relationship between early-life ETS and subsequent allergic sensitization via a positive skin prick test (SPT+) or at least one specific immunoglobulin E (IgE) ≥ 0.35 (sIgE+) in children aged 2-3 years. Propensity score estimation followed by full and nearest neighbour matching was compared with standard multivariable regression models. RESULTS: Among children without a maternal history of allergic disease, ETS was positively associated with allergic sensitization in children with an adjusted odds ratio (aOR) for SPT+ of 2.32 (95% confidence interval (CI): 1.28-4.22) and the aOR for sIgE+ was 2.53 (95% CI: 1.43-4.48). Contrarily, for children with a positive maternal history, the aOR for SPT+ and sIgE+ was 0.56 (95% CI: 0.24-1.32) and 0.43 (95% CI: 0.20-0.91), respectively. CONCLUSIONS: Using propensity score methods to rigorously control for confounding factors, ETS exposure was found to reduce the risk of allergic sensitization in children with a positive maternal history. There is a strong association between early-life ETS and the development of allergic sensitization for children aged 2-3 years without maternal history.

Early complementary feeding and risk of food sensitization in a birth cohort.

BACKGROUND: Exposure to solid food or cow's milk (complementary food) before age 4 months may confer immune protection (tolerance) or detriment (allergy). OBJECTIVE: We explored the relationship between introduction of complementary food <4 months and IgE to egg, milk, and peanut allergen at 2 years in the Wayne County Health, Environment, Allergy and Asthma Longitudinal Study birth cohort of Detroit, Mich. METHODS: At infant ages 1, 6, and 12 months, mothers were interviewed about feeding practices. Blood samples were collected at age 2 to 3 years to assess sensitization (IgE ≥ 0.35 IU/mL) to egg, milk, or peanut. RESULTS: For the 594 maternal-infant pairs analyzed, maternal mean age was 29.7 years, and 60.6% self-reported as African American or black. Infant exposure to complementary food <4 months was reported by 39.7% of mothers. IgE ≥0.35 IU/mL for egg, milk, or peanut allergen at age 2 years was observed in 23.9% (95% CI, 20.5% to 27.6%), 30.6% (26.9% to 34.5%), and 11.4% (8.9% to 14.3%) of children, respectively. The association between early feeding and sensitization was modified by parental history of asthma or allergy. In multivariable analysis, early feeding reduced the risk of peanut sensitization among children with a parental history (adjusted odds ratio, 0.2 [95% CI, 0.1-0.7]; P = .007). The relationship also became significant for egg when a cutoff for IgE of ≥0.70 IU/mL was used (adjusted odds ratio, 0.5 [95% CI, 0.3-0.9]; P = .022). CONCLUSION: In this cohort, complementary food introduced <4 months was associated with a reduced risk of peanut (and perhaps egg) sensitization by age 2 to 3 years, but only for children with a parental history of asthma or allergy.

Infant Feeding Practices and Subsequent Dietary Patterns of School-Aged Children in a US Birth Cohort.

BACKGROUND: Infant feeding practices are thought to shape food acceptance and preferences. However, few studies have evaluated whether these affect child diet later in life. OBJECTIVE: The study objective was to examine the association between infant feeding practices and dietary patterns (DPs) in school-aged children. DESIGN: A secondary analysis of data from a diverse prospective birth cohort with 10 years of follow-up (WHEALS [Wayne County Health Environment Allergy and Asthma Longitudinal Study]) was conducted. PARTICIPANTS/SETTING: Children from the WHEALS (Detroit, MI, born 2003 through 2007) who completed a food screener at age 10 years were included (471 of 1,258 original participants). MAIN OUTCOME MEASURES: The main outcome was DPs at age 10 years, identified using the Block Kids Food Screener. STATISTICAL ANALYSIS PERFORMED: Latent class analysis was applied for DP identification. Breastfeeding and age at solid food introduction were associated with DPs using a 3-step approach for latent class modeling based on multinomial logistic regression models. RESULTS: The following childhood DPs were identified: processed/energy-dense food (35%), variety plus high intake (41%), and healthy (24%). After weighting for loss to follow-up and covariate adjustment, compared with formula-fed children at 1 month, breastfed children had 0.41 times lower odds of the processed/energy-dense food DP vs the healthy DP (95% CI 0.14 to 1.25) and 0.53 times lower odds of the variety plus high intake DP (95% CI 0.17 to 1.61), neither of which were statistically significant. Results were similar, but more imprecise, for breastfeeding at 6 months. In addition, the association between age at solid food introduction and DP was nonsignificant, with each 1-month increase in age at solid food introduction associated with 0.81 times lower odds of the processed/energy-dense food DP relative to the healthy DP (95% CI 0.64 to 1.02). CONCLUSIONS: A significant association between early life feeding practices and dietary patterns at school age was not detected. Large studies with follow-up beyond early childhood that can also adjust for the multitude of potential confounders associated with breastfeeding are needed.

Relationship between thiazolidinedione use and cardiovascular outcomes and all-cause mortality among patients with diabetes: a time-updated propensity analysis.

PURPOSE: To investigate the association of the thiazolidinediones (TZDs), rosiglitazone, and pioglitazone, together and individually on the risk of cardiovascular outcomes and all-cause mortality, using time-updated propensity score adjusted analysis. METHODS: We conducted a retrospective cohort study in a large vertically integrated health system in southeast Michigan. Cohort inclusion criteria included adult patients with diabetes treated with oral medications and followed longitudinally within the health system between 1 January 2000 and 1 December 2006. The primary outcome was fatal and non-fatal acute myocardial infarction (AMI). Secondary outcomes included hospitalizations for congestive heart failure (CHF), fatal, and non-fatal cerebrovascular accidents (CVA) and transient ischemic attacks (TIA), combined coronary heart disease (CHD) events, and all-cause mortality. RESULTS: 19,171 patients were included in this study. Use of TZDs (adjusted hazard ratio (aHR) with propensity adjustment (PA), 0.92; 95% confidence interval (CI) 0.73-1.17), rosiglitazone (aHR with PA, 1.06; 95%CI 0.66-1.70), and pioglitazone (aHR with PA, 0.91; 95%CI 0.69-1.21) was not associated with a higher risk of AMI. However, pioglitazone use was associated with a reduction in all-cause mortality (aHR with PA, 0.60; 95%CI 0.42-0.96). Compared with rosiglitazone, pioglitazone use was associated with a lower risk of all outcomes assessed, particularly CHF (p = 0.013) and combined CHD events (p = 0.048). CONCLUSIONS: Our findings suggest that pioglitazone may have a more favorable risk profile when compared to rosiglitazone, arguing against a singular effect for TZDs on cardiovascular outcomes.

Differences in allergic sensitization by self-reported race and genetic ancestry.

BACKGROUND: Many allergic conditions occur more frequently in African American patients when compared with white patients; however, it is not known whether this represents genetic predisposition or disparate environmental exposures. OBJECTIVE: We sought to assess the relationship of self-reported race and genetic ancestry to allergic sensitization. METHODS: We included 601 women enrolled in a population-based cohort study whose self-reported race was African American or white. Genetic ancestry was estimated by using markers that differentiate West African and European ancestry. We assessed the relationship between allergic sensitization (defined as > or =1 allergen-specific IgE results) and both self-reported race and genetic ancestry. Regression models adjusted for sociodemographic variables, environmental exposures, and location of residence. RESULTS: The average proportion of West African ancestry in African American participants was 0.69, whereas the mean proportion of European ancestry in white participants was 0.79. Self-reported African American race was associated with allergic sensitization when compared with those who reported being white (adjusted odds ratio, 2.19; 95% CI, 1.22-3.93), even after adjusting for other variables. Genetic ancestry was not significantly associated with allergic sensitization after accounting for location of residence (adjusted odds ratio, 2.09 for urban vs suburban residence; 95% CI, 1.32-3.31). CONCLUSION: Self-reported race and location of residence appeared to be more important predictors of allergic sensitization when compared with genetic ancestry, suggesting that the disparity in allergic sensitization by race might be primarily a result of environmental factors rather than genetic differences.

Effects of baseline comorbidities on cancer screening trial adherence among older African American men.

BACKGROUND: The purpose of this study was to examine the effects of baseline comorbidities on screening adherence in a sample of older African American men (ages >or=55 years) enrolled in a case management intervention in a cancer screening trial. METHODS: Baseline comorbidity data were obtained from 683 African American men who were randomly assigned to a case management intervention group (n = 344) or to a case management control group (n = 339). The effects of comorbidities on the screening adherence rates of each group were then assessed. RESULTS: No statistically significant interactions were found between each health history characteristic and the intervention. Therefore, analyses were not stratified by intervention status. In general, participants with comorbidities were no less likely to adhere to trial screening than participants without comorbidities. Exceptions were current smokers and participants with chronic bronchitis. Current smokers were less likely than others to adhere to the prostate-specific antigen test (P = 0.02) and the digital rectal examination for prostate cancer screening (P = 0.01), to the chest X-ray for lung cancer screening (P < 0.01), and to the flexible sigmoidoscopy for colorectal cancer screening (P = 0.04). Participants with chronic bronchitis had lower rates of adherence to the chest X-ray (P = 0.06). Having a relative with cancer positively influenced adherence to the digital rectal examination (P = 0.05). CONCLUSIONS: Overall, older African American men with comorbidities appear to be very good candidates for participation in longitudinal cancer screening trials. However, smoking had a statistically significant and deleterious effect on adherence to all types of screening.

Factors influencing behavioral intention regarding prostate cancer screening among older African-American men.

PURPOSE: To assess factors associated with perceptions of prostate cancer screening among African-American men aged > or = 55 years based upon items developed using the Preventive Health model (PHM). RESEARCH APPROACH: Focus group research and thematic coding using content analysis. SETTING: A large midwestern, private, nonprofit health system. PARTICIPANTS: African-American men aged > or = 55 years. Focus group 1 included 10 men who ranged in age from 55-87 years, with a mean age of 73.4 years. The 11 participants in focus group 2 ranged in age from 55-81 years, with a mean age of 68.7 years. METHODOLOGICAL APPROACH: Focus group questions were developed based on the conceptual framework of the PHM. African-American men aged > or = 55 years were randomly selected from the patient population of the healthcare system to participate in one of two focus groups. Content analysis was used to code the focus group transcripts. MAIN RESEARCH VARIABLES: Self-reported perceptions of prostate cancer screening. FINDINGS: Major themes emerging from the focus groups related to prostate cancer screening include: lack of knowledge regarding cancer, fear of cancer, confusion between prostate cancer screening and prostate cancer diagnostic tests, encouragement by others as motivation for cancer screening, intergenerational transfer of health information, lack of health insurance coverage as a barrier to prostate cancer screening and treatment, and limited availability of screening clinic hours during nonworking hours. INTERPRETATION: The information gained from this study could be used to develop interventions promoting informed and shared decision-making by patients and their providers regarding prostate cancer screening.

Joint effects of pregnancy, sociocultural, and environmental factors on early life gut microbiome structure and diversity.

The joint impact of pregnancy, environmental, and sociocultural exposures on early life gut microbiome is not yet well-characterized, especially in racially and socioeconomically diverse populations. Gut microbiota of 298 children from a Detroit-based birth cohort were profiled using 16S rRNA sequencing: 130 neonates (median age = 1.2 months) and 168 infants (median age = 6.6 months). Multiple factors were associated with neonatal gut microbiome composition in both single- and multi-factor models, with independent contributions of maternal race-ethnicity, breastfeeding, mode of delivery, marital status, exposure to environmental tobacco smoke, and indoor pets. These findings were consistent in the infants, and networks demonstrating the shared impact of factors on gut microbial composition also showed notable topological similarity between neonates and infants. Further, latent groups defined by these factors explained additional variation, highlighting the importance of combinatorial effects. Our findings also have implications for studies investigating the impact of the early life gut microbiota on disease.

Effects of false-positive prostate cancer screening results on subsequent prostate cancer screening behavior.

OBJECTIVES: Little is known about screening behavior following a false-positive prostate cancer screening result, which we have defined as a screening result with "abnormal/suspicious" labeling that did not result in a prostate cancer diagnosis within 14 months. The purpose of this analysis was to examine whether age, race, education, or previous false-positive prostate cancer screening results via prostate-specific antigen or digital rectal exam predict decision to obtain subsequent prostate cancer screening. METHODS: Data were drawn from the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial. The study sample consisted of 2,290 older men (mean age, 62.8 years; range, 55-75 years) who had false-positive (n = 318) or negative (n = 1,972) prostate-specific antigen or digital rectal exam baseline prostate cancer screening results. Multivariable logistic regression was used to assess the effect of false-positive results on subsequent prostate cancer screening behavior, adjusting for all covariates. RESULTS: The multivariable model showed that being African American (P = 0.016), and having a high school education or less (P = 0.007), having a previous false-positive prostate cancer screening result (P < 0.001), were predictive of not returning for prostate cancer screening in the following screening trial year. CONCLUSION: The study results highlight the importance of shared decision making between patients and their providers regarding the risks and benefits of prostate cancer screening, and follow-up options for abnormal prostate cancer screening results. Shared decision making may be especially important for African American men, whom prostate cancer disproportionately affects.

Airway hyperresponsiveness to methacholine at age 6 to 8 years in nonasthmatic patients is not related to increased health-care utilization for asthma in the ensuing 5 years: a longitudinal study of a birth cohort.

BACKGROUND: Children with heightened airway responsiveness have a greater tendency to develop asthma symptoms. Many existing studies describing this relationship have relied on self-reported symptoms that may be prone to recall bias. In addition, few studies have examined the relationship of airway hyperresponsiveness (AHR) to indicators of asthma severity such as health-care utilization. OBJECTIVE: To determine whether a positive response to methacholine challenge in children without current or physician-diagnosed asthma at age 6 to 8 years is predictive of the subsequent onset of asthma requiring medical evaluation or treatment in the ensuing 5 years. METHODS: Data were obtained from subjects in a population-based birth cohort (n = 835) enrolled from 1987 to 1989, who were members of a large medical group practice component of a health maintenance organization (HMO). We analyzed a subset of subjects (n = 245) who had completed a methacholine challenge at age 6 to 8 years, had no current or physician-diagnosed asthma, and were still served by the same medical group. These children were followed up from the time of methacholine challenge until HMO disenrollment or through June 2001 (ages 11 to 13 years), whichever came first. Pharmacy claims data and diagnostic codes from physician-patient encounters were evaluated for incident asthma. Incident cases of clinical asthma were defined as any child with two outpatient visits or one hospitalization, one emergency department encounter associated with an asthma diagnostic code (ie, 493.XX), or any child filling prescriptions for two bronchodilators or one antiinflammatory asthma medicine. Methacholine responsiveness was interpreted using American Thoracic Society criteria. RESULTS: Asthma incidence did not differ based on methacholine challenge results for children with normal, borderline, and mild AHR. No child in the study demonstrated moderate-to-severe AHR. CONCLUSION: Our data suggest that AHR with a borderline or weakly positive result in a methacholine challenge in children 6 to 8 years old without current or physician-diagnosed asthma is not related to increased health-care utilization for asthma in the ensuing 5 years.

Usefulness of a home affluence scale administered to urban adolescents with asthma to estimate the family's socioeconomic status.

PURPOSE: Measurement of socioeconomic status (SES) is traditionally based on education, income, and occupation. This information may not be readily available from adolescents participating in research. METHODS: Using data from school-based randomized trial of an asthma intervention targeting urban adolescents, we compared percent poverty in zip code of residence (% poverty), median housing value, and parental income and education, to teen responses on the Home Affluence Scale for Children (HASC), which included home, car, and computer ownership for the family and eligibility for free school lunch. The association of HASC with measures of asthma control was also assessed. RESULTS: Of 422 adolescents, 390 (92%) responded to HASC items (mean HASC = 2.5). HASC was associated with mother's education and household income (both P < .001), and significantly correlated with % poverty (P < .0001) and median home value (P = .003). The association of HASC <2.0 to indicators of uncontrolled asthma was in the direction hypothesized, especially for nighttime symptoms, odds ratio (95% confidence interval) = 1.59 (0.95-2.66) and restricted activity, odds ratio = 1.87 (1.12-3.12). CONCLUSIONS: HASC correlates well with more traditional measures of SES, and the risk estimates for HASC less than 2.0 and indicators of uncontrolled asthma were mostly in the hypothesized direction. Methods of obtaining SES indicators from youth are needed for research studies.

Examining the effects of false positive lung cancer screening results on subsequent lung cancer screening adherence.

OBJECTIVE: The study goal was to examine the effects of an initial false positive chest X-ray screening result on subsequent lung cancer screening adherence. METHODS: Adherence rates among 4705 individuals in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial at the Henry Ford Health System site with an abnormal/suspicious chest X-ray screening result in the first study year that was subsequently determined to be noncancerous (false positive result, n = 1137 exams) were compared with adherence rates among individuals with an initial negative chest X-ray screening result (n = 3568 exams). RESULTS: Univariate results showed a >50% increase in subsequent nonadherence among individuals with false positive screening results compared with those with negative screening results (17.2% versus 10.3% nonadherence rate, respectively; P < 0.001). Multivariable results showed that statistically significant predictors of nonadherence were false positive cases with current smoking status (P < 0.001) and false positive cases with past smoking status (P < 0.001). Additional predictors of subsequent nonadherence were being African-American (P < 0.01), being female (P < 0.001), and having a high school education or less (P < 0.01). CONCLUSION: Our results demonstrate that the impact of previous screening results, smoking status, race, gender, and education on subsequent screening adherence needs to be weighed carefully, particularly for smokers, an at-risk group, when conducting lung cancer screening intervention studies and perhaps should be considered in clinical practice as well.

The role of test accuracy in predicting acceptance of genetic susceptibility testing for Alzheimer's disease.

A survey questionnaire regarding perceptions of risk and genetic susceptibility to Alzheimer's disease (AD) was completed by 518 offspring of AD cases from families with multiple affected, ascertained as part of a genetic linkage study of late onset AD. The questionnaire focused on respondents' perceptions of their own risk for AD as well as on the properties of real and hypothetical susceptibility tests, including error rates for false-positive and false-negative test results. Our findings showed that about 20% of the sample would refuse a susceptibility test with zero error rates, about 40% would accept tests with very high error rates in both directions, and the remainder would exercise some discrimination. Acceptance of high test error rates was significantly associated with male gender, low education, and high perceived lifetime risk of AD. In a previous paper related to this work, we showed that physicians caring for these families exercised much more discrimination in judging the acceptability of genetic tests they would offer to these same respondents. The findings show that there is a pressing need to educate the public, particularly those with relatives affected by a complex disease, to expect standards of accuracy for genetic tests comparable to those that prevail in other diagnostic and prognostic testing efforts in the broad field of clinical medicine.