Can Asymmetry in Total Knee Arthroplasty Design Lead to More Normal-Like Postoperative Kinematics? A Multi-Implant Evaluation.

BACKGROUND: Few studies have evaluated the effects of symmetrical versus asymmetrical implant designs, more specifically the femoral condyles, trochlear groove, joint line, and bearing surfaces. The objective of this study was to investigate multiple posterior cruciate-retaining (PCR) total knee arthroplasty (TKA) designs influencing factors related to TKA asymmetry, and to investigate whether asymmetry can improve postoperative knee kinematics. METHODS: In vivo tibio-femoral kinematics for 99 subjects was evaluated in this retrospective study. Overall, 10 subjects had a nonimplanted, normal knee, and 89 subjects had 1 of 3 PCR TKAs with varying degrees of asymmetry within their femoral and tibial components (PCR #1 = 30, PCR #2 = 29, PCR #3 = 30). All TKAs were implanted by the same surgeon and were analyzed using fluoroscopy during a deep knee bend. RESULTS: At full extension, all 3 PCR TKAs experienced a more posteriorized position of the femoral condyles compared to the normal knee, with the 2 asymmetrical PCR TKAs experiencing more anteriorization compared to the third, symmetrical PCR TKA. Both the normal knee and the PCR TKA with greatest amount of asymmetry experienced statistically more posterior femoral rollback of the lateral condyle than the other 2 PCR TKAs. The PCR TKA with greater asymmetry also experienced statistically greater range of motion than the other 2 PCR TKAs. CONCLUSIONS: With increasing flexion, the design with the most asymmetry also experienced the most posterior femoral rollback, axial rotation, and greatest range of motion. The results in this study seem to suggest that the inclusion of asymmetry in a TKA could be beneficial for achieving more normal-like kinematics and greater weight-bearing knee flexion.

Inducible Nitric Oxide Synthase Embedded in Alginate/Polyethyleneimine Hydrogel as a New Platform to Explore NO-Driven Modulation of Biological Function.

Nitric oxide (NO), a small free radical molecule, turned out to be pervasive in biology and was shown to have a substantial influence on a range of biological activities, including cell growth and apoptosis. This molecule is involved in signaling and affects a number of physiologic functions. In recent decades, several processes related to cancer, such as angiogenesis, programmed cell death, infiltration, cell cycle progression, and metastasis, have been linked with nitric oxide. In addition, other parallel work showed that NO also has the potential to operate as an anti-cancer agent. As a result, it has gained attention in cancer-related therapeutics. The nitric oxide synthase enzyme family (NOS) is required for the biosynthesis of nitric oxide. It is becoming increasingly popular to develop NO-releasing materials as strong tumoricidal therapies that can deliver sustained high concentrations of nitric oxide to tumor sites. In this paper, we developed NO-releasing materials based on sodium alginate hydrogel. In this regard, alginate hydrogel discs were modified by adsorbing layers of polyethyleneimine and iNOS-oxygenase. These NO-releasing hydrogel discs were prepared using the layer-by-layer film building technique. The iNOS-oxygenase is adsorbed on the positively charged polyethyleneimine (PEI) matrix layer, which was formed on a negatively charged sodium alginate hydrogel. We show that nitric oxide is produced by enzymes contained within the hydrogel material when it is exposed to a solution containing all the components necessary for the NOS reaction. The electrostatic chemical adsorption of the layer-by-layer process was confirmed by FTIR measurements as well as scanning electron microscopy. We then tested the biocompatibility of the resulting modified sodium alginate hydrogel discs. We showed that this NOS-PEI-modified hydrogel is overall compatible with cell growth. We characterized the NOS/hydrogel films and examined their functional features in terms of NO release profiles. However, during the first 24 h of activity, these films show an increase in NO release flux, followed by a gradual drop and then a period of stable NO release. These findings show the inherent potential of using this system as a platform for NO-driven modulation of biological functions, including carcinogenesis.

Anatomic vs Dome Patella: Is There a Difference Between Fixed- vs Mobile-Bearing Posterior-Stabilized Total Knee Arthroplasties?

BACKGROUND: It has been hypothesized that the patella, working in conjunction with both medial and lateral femoral condyles, can influence kinematic parameters such as posterior femoral rollback and axial rotation. The objective of this study is to determine the in vivo kinematics of subjects implanted with a fixed-bearing (FB) or mobile-bearing (MB) posterior-stabilized (PS) total knee arthroplasty (TKA), with a specific focus on evaluating the impact that Anatomic and Medialized Dome patellar components have on tibiofemoral kinematic patterns. METHODS: Tibiofemoral kinematics were assessed for 40 subjects; 20 with an anatomic patella and 20 with a dome patella. Within these groups, 10 subjects received an FB PS TKA and 10 subjects received an MB PS TKA. All subjects were analyzed using fluoroscopy while performing a deep knee bend activity. Kinematics were collected during specific intervals to determine similarities and differences in regard to patella and bearing type. RESULTS: The greatest variation in kinematics was detected between the 2 Anatomic patellar groups. Specifically, the MB-Anatomic subjects experienced greater translation of the lateral condyle, the highest magnitude of axial rotation, and the highest range of motion compared to the FB-Anatomic subjects. Subjects with a Dome Patella displayed much variability among the average kinematics, with all parameters between FB and MB cohorts being similar. CONCLUSION: The findings in this study suggest that subjects with an Anatomic patellar component could have more normal kinematic patterns with an MB PS TKA as opposed to an FB PS TKA, while subjects with a Dome patella could achieve similar kinematics regardless of TKA type.

In Vivo Knee Kinematics: How Important Are the Roles of Femoral Geometry and the Cruciate Ligaments?

BACKGROUND: While posterior cruciate-retaining (PCR) implants are a more common total knee arthroplasty (TKA) design, newer bicruciate-retaining (BCR) TKAs are now being considered as an option for many patients, especially those that are younger. While PCR TKAs remove the ACL, the BCR TKA designs keep both cruciate ligaments intact, as it is believed that the resection of the ACL greatly affects the overall kinematic patterns of TKA designs. The objectives of this study are to assess the in vivo kinematics for subjects implanted with either a PCR or BCR TKA and to compare the in vivo kinematic patterns to the normal knee during flexion. These objectives were achieved with an emphasis on understanding the roles of the cruciate ligaments, as well as the role of changes in femoral geometry of nonimplanted anatomical femurs vs implanted subjects having a metal femoral component. METHODS: Tibiofemoral kinematics of 50 subjects having a PCR (40 subjects) or BCR (10 subjects) TKA were analyzed using fluoroscopy while performing a deep knee bend activity. The kinematics were compared to previously published normal knee data (10 subjects). Kinematics were determined during specific intervals of flexion where the ACL or PCL was most dominant. RESULTS: In early flexion, subjects having a BCR TKA experienced more normal-like kinematic patterns, possibly attributed to the ACL. In mid-flexion, both TKA groups exhibited variable kinematic patterns, which could be due to the transitional cruciate ligament function period. In deeper flexion, both TKA functioned more similar to the normal knee, leading to the assumption that the PCL was properly balanced and functioning in the TKA groups. Interestingly, during late flexion (after 90°), the kinematic patterns for all three groups appeared to be statistically similar. CONCLUSION: Subjects having a PCR TKA experienced greater weight-bearing flexion than the BCR TKA group. Subjects having a BCR TKA exhibited a more normal-like kinematic pattern in early and late flexion. The normal knee subjects achieved greater lateral condyle rollback and axial rotation compared to the TKA groups.

Risk factors and prevalence of symptoms of sexually transmitted infections in Rural Mayan Villages in Guatemala.

In this study, we identify and describe the risk factors and symptoms that are suggestive of sexually transmitted infections (STIs) in rural Mayan villages of Guatemala. We used the World Health Organization's syndromic guidelines for diagnosis and management of STIs to design questionnaires and to identify STI symptoms among indigenous Mayans who presented to mobile clinics in villages served by Guatemala Village Health (GVH). Symptoms that include abdominal pain or pain on urination, genital discharge, itching and sores were highest among younger participants. Lack of male participation in sexual health matters constitutes an important determinant of risk of exposure.

Rosacea fulminans with extrafacial lesions in an elderly man: successful treatment with subantimicrobial-dose doxycycline.

Rosacea fulminans, previously known as pyoderma faciale, is a rare disease occurring almost exclusively in young women characterized by the sudden eruption of coalescing papules and pustules, and large cystic nodules limited to the face. Patients generally respond well to standard therapy consisting of systemic isotretinoin in combination with topical and systemic corticosteroids. Lesions usually resolve with minimal scarring with appropriate management. We describe an elderly male patient with extrafacial rosacea fulminans successfully treated with daily subantimicrobial (40mg) dose doxycycline (SDD). To our knowledge, this is the first report of rosacea fulminans with extrafacial lesions in an elderly male. We suggest that SDD may be a safe and effective alternative, particularly for those unable to tolerate standard therapy.

Adults' Understandings and Experiences of the Capacity to Consent to Substance-Involved Sexual Activity.

Most research on capacity to consent to substance-involved sex has focused exclusively on the implications of alcohol with little attention given to other or additional psychoactive drugs. This study aimed to explore people's understanding and experiences of the capacity to consent to alcohol- and/or drug-involved sexual activity. UK adults (N = 354) completed an online mixed-methods survey on sexual consent during sober, alcohol- and/or drug-involved sex. Qualitative data were analyzed using thematic analysis. Themes for capacity to consent were: (1) "There is no normative understanding of substance-involved sexual consent," (2) "Moving beyond the binary of consciousness versus incapacitation" and (3) "Substance-involved sexual decisions are viewed as irresponsible." The findings illustrated that capacity to consent is nuanced and multidimensional, and that people's understandings and experiences of capacity to consent to substance-involved sex are not solely individual, but rather, they are also shaped by their environment. We call for a multidimensional view of capacity to consent, where a standard of "unimpaired," rather than sober, is used and modeled by academics, legislators, and educators.

Mohs surgeons' use of topical emollients in postoperative wound care.

BACKGROUND: Although there is no universally accepted topical emollient recommended for wound care, there has been a trend toward minimizing exposure to common culprits of allergic contact dermatitis. OBJECTIVE: To assess the current practices of postoperative emollient use of dermatologic surgeons. METHODS AND MATERIALS: An anonymous 10-question survey on postoperative emollient use for clean surgical wounds was e-mailed to 857 members of the American College of Mohs Surgery. RESULTS: Two hundred ninety-four members (34.3%) responded. After routine closure, the most commonly used topical emollient placed immediately postoperatively was petroleum jelly (53.1%), followed by Aquaphor (Beiersdorf Inc., Wilton, CT) (19.4%) and bacitracin (8.2%) (p < .001). Respondents recommended that patients use the following topical emollients at home to keep the wound moist: petroleum jelly (69.4%), Aquaphor (38.4%), bacitracin (10.0%), mupirocin (9.2%), polymyxin (8.8%), neomycin (2.0%), and gentamicin (1.0%) (p < .001). The three most common topical emollients that were requested not to be used were neomycin (92.8%), polymyxin (44.3%), and bacitracin (44.3%) (p < .001). CONCLUSION: Although emollients with low risk for contact allergy such as petroleum jelly are used more frequently, topical antimicrobials with known sensitizing potential are being applied and recommended for clean surgical wounds. A change in practice is needed to avoid these allergens.

The use of the 300 microsecond 1064 nm Nd:YAG laser in the treatment of keloids.

BACKGROUND: Keloids can be quite resistant to conventional methods of treatment. A wide range of treatment modalities exists, often with suboptimal results, recurrences, and adverse events occurring. Laser therapy with the carbon dioxide, erbium:YAG, Q switched frequency doubled neodymium-doped yttrium aluminium garnet (Nd:YAG), and 585/595 nm pulsed dye lasers have all be purported as potential treatment modalities however with limited efficacy and data especially in the skin of color population is limited. We report the successful use of the 300 microsecond 1064 nm Nd:YAG laser in treating keloids in patients with skin types ranging from Fitzpatrick I through VI with special attention in treating skin of color patients. OBJECTIVE: We examined the use of the 300 microsecond 1064 nanometer (nm) Nd:YAG laser for the treatment keloids in patients with skin types ranging from Fitzpatrick I through VI. METHODS & MATERIALS: A retrospective analysis of treatment efficacy was conducted on 44 patients with keloids. Three separate treatment groups were compared. The groups consisted of: a "control group" in which the whole keloid was only treated with intralesional corticosteroid (triamcinolone 10 mg/cc) (16 patients); a "laser only" group in which the patient's keloid was only treated with the 1064 nm Nd:YAG laser at a fluency of 13 to 18 Joules / centimeter2 (J/cm2), a fixed pulse duration of 300 microseconds, 5 mm spot size, and a total of 2000 pulses (14 patients); and a "combination group" that received both the aforementioned laser therapy and adjuvant intralesional triamcinolone (14 patients). RESULTS: Patients in the "combination group" treated with the 300 microsecond 1064 nm Nd:YAG laser therapy plus intralesional corticosteroid and the "laser only" group both were observed to have durable clinical reduction in the thickness and erythema of the keloids. These results were shown to be superior to the "control group" whom were only treated with intralesional corticosteroids. Only mild and transient post treatment erythema was noted as an adverse effect. STATISTICAL ANALYSIS: Data analysis was performed using IBM SPSS Statistics 19.0.0 (Armonk, NY). In order to assess the statistical significance of differences in keloid improvement among the three treatment groups, The Kruskal-Wallis test (non-parametric ANOVA test) was applied. The level of statistical significance was set at P< 0.05. A statistically significant difference in keloid improvement was appreciated between treatment groups (P<0.0001). LIMITATIONS: A small sample size and the retrospective nature of the analysis are limitations to the study.
CONCLUSION: The 300 microsecond 1064 nm Nd:YAG laser proved effective in improving the clinical appearance of keloids. We recommended this laser protocol in conjunction with intralesional corticosteroids as a treatment option for patients with keloids, especially in the skin of color population. The 1064 nm Nd:YAG laser did not show post inflammatory hyperpigmentation nor hypopigmenatation, which are concerns for skin types IV to VI, and therefore is a suitable option for such patients.

1894 revisited: Cross-education of skilled muscular control in women and the importance of representation.

In 1894 foundational work showed that training one limb for "muscular power" (i.e. strength) or "muscular control" (i.e. skill) improves performance in both limbs. Despite that the original data were exclusively from two female participants ("Miss Smith" and "Miss Brown"), in the decades that followed, such "cross-education" training interventions have focused predominantly on improving strength in men. Here, in a female cohort, we revisit that early research to underscore that training a task that requires precise movements in a timely fashion (i.e. "muscular control") on one side of the body is transferred to the contralateral untrained limb. With unilateral practice, women reduced time to completion and the number of errors committed during the commercially available game of Operation® Iron Man 2 with both limbs. Modest reductions in bilateral Hoffmann (H-) reflex excitability evoked in the wrist flexors suggest that alterations in the spinal cord circuitry may be related to improvements in performance of a fine motor task. These findings provide a long overdue follow-up to the efforts of Miss Theodate L. Smith from more than 125 years ago, highlight the need to focus on female participants, and advocate more study of cross-education of skilled tasks.

The Impact of Maternal Worry on Infant Care Practices.

OBJECTIVES: Examine the 1) prevalence of worries among US mothers of infants; 2) association between worries and American Academy of Pediatrics recommended infant care practices (breastfeeding, supine sleep, roomsharing without bedsharing); 3) association of maternal and household characteristics with worries. METHODS: We analyzed a nationally representative sample of 3165 mothers who were surveyed regarding safe sleep and breastfeeding when infants were 2 to 6 months of age in 2011-2014. We examined the prevalence of 8 maternal worries (housing, job, income, neighborhood, family relationships, health, baby's health, family member health). We used multivariable logistic regression to examine associations of A) both overall number of worries and individual worries with each infant care practice; and B) maternal and household characteristics with worries. RESULTS: Twenty-six percent of mothers reported 0 worries, 26% reported 1-2 worries, 23% reported 3-4 worries, and 25% reported 5-8 worries. Compared to those with 0 worries, mothers with 5-8 worries had increased odds of bedsharing (adjusted odds ratio = 1.60 [1.19-2.14]) and non-supine sleep (aOR = 1.37 [1.07-1.74]). Specific worries associated with increased odds of bedsharing included: housing (aOR = 1.39 [1.09-1.78]), income (aOR = 1.35 [1.09-1.67]), neighborhood (aOR = 1.37 [1.05-1.78]), family relationships (aOR = 1.43 [1.10-1.86]), and health of a family member (aOR = 1.24 [1.06-1.46]). Maternal worries were not associated with infant feeding practices. CONCLUSIONS: We found a high prevalence of worries regarding basic needs, family relationships, and health among US mothers. Greater total worries and several individual worries were associated with higher odds of bedsharing. The "cognitive load" of maternal worries may impact adherence to safe sleep practices and requires further investigation.

Colourful parrot feathers resist bacterial degradation.

The brilliant red, orange and yellow colours of parrot feathers are the product of psittacofulvins, which are synthetic pigments known only from parrots. Recent evidence suggests that some pigments in bird feathers function not just as colour generators, but also preserve plumage integrity by increasing the resistance of feather keratin to bacterial degradation. We exposed a variety of colourful parrot feathers to feather-degrading Bacillus licheniformis and found that feathers with red psittacofulvins degraded at about the same rate as those with melanin and more slowly than white feathers, which lack pigments. Blue feathers, in which colour is based on the microstructural arrangement of keratin, air and melanin granules, and green feathers, which combine structural blue with yellow psittacofulvins, degraded at a rate similar to that of red and black feathers. These differences in resistance to bacterial degradation of differently coloured feathers suggest that colour patterns within the Psittaciformes may have evolved to resist bacterial degradation, in addition to their role in communication and camouflage.

Making and Communicating Decisions About Sexual Consent During Drug-Involved Sex: A Thematic Synthesis.

Sexual consent is a central component in the primary prevention of sexual violence. There is growing evidence of the impact that alcohol consumption has on sexual consent. However, there has been no review examining sexual consent in the context of other drug-taking. Published literature was sought using searches of: PsycINFO, PsycARTICLES, Scopus, Web of Science, CINAHL, MEDLINE and Open Dissertations. Unpublished literature, such as unpublished government or charity reports, were identified through Google search engine. All 21 eligible studies employed qualitative or mixed methods; therefore, a thematic synthesis was deemed an appropriate method of analysis. Three themes were constructed: "Drug-taking changes sexual norms", "Drug-taking diminishes the capacity to make sexual decisions" and "Drug-taking reduces verbal and non-verbal ability to communicate consent". The findings demonstrated that prevailing models of sexual consent may not account for circumstances relevant to drug-involved sex, such as how drug-taking impacts freedom and capacity to consent to sex. We propose the use of the medical model of capacity to consent as a broader framework through which capacity to consent to sex in drug-taking contexts can be assessed. The importance of both the social and situational context for sexual decision-making following drug-taking is discussed.

Recommendations from a Dialogue on Evolving National Cancer Institute-Designated Comprehensive Cancer Center Community Outreach and Engagement Requirements: A Path Forward.

While cancer mortality is declining in the United States, significant racial, ethnic, economic and geographic inequities persist. To help address inequities in cancer treatment, care, support and research, the National Cancer Institute (NCI) instituted the community outreach and engagement (COE) mandate for NCI-designated comprehensive cancer centers (CCCs). The Bristol Myers Squibb Foundation designed a convening and listening session on COE with NCI leaders and staff gathering representatives from CCCs and the broader cancer community. This paper captures recommendations from the listening session for the NCI and CCCs to further evolve the implementation and impact of the COE mandate on cancer control and outcomes.

Special Convening and Listening Session on Health Equity and Community Outreach and Engagement at National Cancer Institute-Designated Comprehensive Cancer Centers.

In recent years, the cancer research and care community has been more attuned to health equity, increasingly pursuing coordinated and comprehensive action to achieve equitable health outcomes. In addition to its support of a joint research agenda for health disparities in 2017, the National Cancer Institute (NCI) has demonstrated its commitment to addressing health inequities with its 2012 requirement for cancer centers to define and address the needs of a local "catchment area" and the 2016 mandate for Community Outreach and Engagement (COE). With several years of experience with the COE requirements, there is an opportunity to reflect on the experience to-date and identify opportunities to bolster the impact of COE on equitable cancer outcomes for the future. To do so, the Bristol Myers Squibb Foundation (BMSF) hosted a special convening and listening session in April 2019. The session agenda was cocreated by BMSF and NCI leaders and staff. It brought together 41 individuals, including representatives from the NCI Cancer Centers Program, Division of Cancer Control and Population Health and Center to Reduce Cancer Health Disparities, 22 NCI-designated, emerging or affiliated comprehensive cancer centers, and the broader cancer community. This article captures key themes from that meeting, including an overview of current COE efforts, with a deeper look at how four cancer centers are embedding health equity and COE efforts into their institutions and work, and the successes and challenges they have encountered.

Patterns of concordance and non-concordance with clinician recommendations and parents' explanatory models in children with asthma.

OBJECTIVE: Many children with asthma do not take medications as prescribed. We studied parents of children with asthma to define patterns of non-concordance between families' use of asthma controller medications and clinicians' recommendations, examine parents' explanatory models (EMs) of asthma, and describe relationships between patterns of non-concordance and EM. METHODS: Qualitative study using semi-structured interviews with parents of children with persistent asthma. Grounded theory analysis identified recurrent themes and relationships between reported medication use, EMs, and other factors. RESULTS: Twelve of the 37 parents reported non-concordance with providers' recommendations. Three types of non-concordance were identified: unintentional--parents believed they were following recommendations; unplanned--parents reported intending to give controller medications but could not; and intentional--parents stated giving medication was the wrong course of action. Analysis revealed two EMs of asthma: chronic--parents believed their child always has asthma; and intermittent--parents believed asthma was a problem their child sometimes developed. CONCLUSIONS: Concordance or non-concordance with recommended use of medications were related to EM's and family context and took on three different patterns associated with medication underuse. PRACTICE IMPLICATIONS: Efforts to reduce medication underuse in children with asthma may be optimized by identifying different types of non-concordance and tailoring interventions accordingly.

Infant Sleep Location and Breastfeeding Practices in the United States, 2011-2014.

OBJECTIVE: To describe the prevalence of breastfeeding and sleep location practices among US mothers and the factors associated with these behaviors, including advice received regarding these practices. METHODS: A nationally representative sample of 3218 mothers who spoke English or Spanish were enrolled at a sample of 32 US birth hospitals between January 2011 and March 2014. RESULTS: Exclusive breastfeeding was reported by 30.5% of mothers, while an additional 29.5% reported partial breastfeeding. The majority of mothers, 65.5%, reported usually room sharing without bed sharing, while 20.7% reported bed sharing. Compared to mothers who room shared without bed sharing, mothers who bed shared were more likely to report exclusive breastfeeding (adjusted odds ratio 2.46, 95% confidence interval 1.76, 3.45) or partial breastfeeding (adjusted odds ratio 1.75, 95% confidence interval 1.33, 2.31). The majority of mothers reported usually room sharing without bed sharing regardless of feeding practices, including 58.2% of exclusively breastfeeding mothers and 70.0% of nonbreastfeeding mothers. Receiving advice regarding sleep location or breastfeeding increased adherence to recommendations in a dose response manner (the adjusted odds of room sharing without bed sharing and exclusive breastfeeding increased as the relevant advice score increased); however, receiving advice regarding sleep location did not affect feeding practices. CONCLUSIONS: Many mothers have not adopted the recommended infant sleep location or feeding practices. Receiving advice from multiple sources appears to promote adherence in a dose response manner. Many women are able to both breastfeed and room share without bed sharing, and advice to adhere to both of these recommendations did not decrease breastfeeding rates.

Rethinking race/ethnicity, income, and childhood asthma: racial/ethnic disparities concentrated among the very poor.

OBJECTIVE: Past studies of the prevalence of childhood asthma have yielded conflicting findings as to whether racial/ethnic disparities remain after other factors, such as income, are taken into account. The objective of this study was to examine the association of race/ethnicity and family income with the prevalence of childhood asthma and to assess whether racial/ethnic disparities vary by income strata. METHODS: Cross-sectional data on 14,244 children aged <18 years old in the 1997 National Health Interview Survey were examined. The authors used logistic regression to analyze the independent and joint effects of race/ethnicity and income-to-federal poverty level (FPL) ratio, adjusting for demographic covariates. The main outcome measure was parental report of the child having ever been diagnosed with asthma. RESULTS: Bivariate analyses, based on weighted percentages, revealed that asthma was more prevalent among non-Hispanic black children (13.6%) than among non-Hispanic white children (11.2%; p<0.01), but the prevalence of asthma did not differ significantly between Hispanic children (10.1%) and non-Hispanic white children (11.2%; p=0.13). Overall, non-Hispanic black children were at higher risk for asthma than non-Hispanic white children (adjusted odds ratio [OR]=1.20; 95% confidence interval [CI] 1.03, 1.40), after adjustment for sociodemographic variables, including the ratio of annual family income to the FPL. Asthma prevalence did not differ between Hispanic children and non-Hispanic white children in adjusted analyses (adjusted OR=0.85; 95% CI 0.71, 1.02). Analyses stratified by income revealed that only among children from families with incomes less than half the FPL did non-Hispanic black children have a higher risk of asthma than non-Hispanic white children (adjusted OR=1.99; 95% CI 1.09, 3.64). No black vs. white differences existed at other income levels. Subsequent analyses of these very poor children that took into account additional potentially explanatory variables did not attenuate the higher asthma risk for very poor non-Hispanic black children relative to very poor non-Hispanic white children. CONCLUSIONS: Non-Hispanic black children were at substantially higher risk of asthma than non-Hispanic white children only among the very poor. The concentration of racial/ethnic differences only among the very poor suggests that patterns of social and environmental exposures must overshadow any hypothetical genetic risk.

Hospital differences in cesarean deliveries in Massachusetts (US) 2004-2006: the case against case-mix artifact.

OBJECTIVE: We examined the extent to which differences in hospital-level cesarean delivery rates in Massachusetts were attributable to hospital-level, rather than maternal, characteristics. METHODS: Birth certificate and maternal in-patient hospital discharge records for 2004-06 in Massachusetts were linked. The study population was nulliparous, term, singleton, and vertex births (NTSV) (n = 80,371) in 49 hospitals. Covariates included mother's age, race/ethnicity, education, infant birth weight, gestational age, labor induction (yes/no), hospital shift at time of birth, and preexisting health conditions. We estimated multilevel logistic regression models to assess the likelihood of a cesarean delivery. RESULTS: Overall, among women with NTSV births, 26.5% births were cesarean, with a range of 14% to 38.3% across hospitals. In unadjusted models, the between-hospital variance was 0.103 (SE 0.022); adjusting for demographic, socioeconomic and preexisting medical conditions did not reduce any hospital-level variation 0.108 (SE 0.023). CONCLUSION: Even after adjusting for both socio-demographic and clinical factors, the chance of a cesarean delivery for NTSV pregnancies varied according to hospital, suggesting the importance of hospital practices and culture in determining a hospital's cesarean rate.