Longitudinal Predictors of Pain in Pediatric Sickle Cell Disease.

OBJECTIVE: Despite the identified pathophysiology of vaso-occlusive pain in sickle cell disease (SCD), predictors of pain in youth with SCD remain elusive. In this study, we measured changes in pain frequency, intensity, and interference over 1 year and examined biopsychosocial risk factors (SCD disease severity, age, female, depression, and sleep quality) as possible longitudinal predictors. METHODS: Medical history was obtained from retrospective chart review for 79 children with SCD (ages 2-18 years; 48.1% female; 100% Black/African American; 83.5% SCD, SS genotype). As part of a clinical screening protocol, caregivers (n = 79) and youth 8-18 years (n = 43) completed psychosocial questionnaires approximately 1 year apart (M = 15.52 months, SD = 5.69). Zero-order correlations, paired t-tests, and hierarchical linear models examined longitudinal predictors of pain. The longitudinal bidirectional relationship between pain and sleep was also examined. RESULTS: The rate of severe SCD disease increased from 41.8% to 55.7% across the year, while most hematologic medical parameters remained stable. Increased depression and pain interference at survey 1 significantly predicted increased pain interference at survey 2. Poor sleep quality and increased pain frequency at survey 1 predicted increased pain frequency at survey 2. Finally, increased pain interference at survey 1 predicted poor sleep quality at survey 2. DISCUSSION: History of pain, depression, and sleep quality were longitudinal predictors of pain over 1 year in youth with SCD. Identifying longitudinal predictors of pain may lead to earlier identification of patients with a high-risk SCD pain phenotype and earlier medical, psychological, and behavioral interventions.

The Effect of Pediatric Early Warning Score Use on Emergency Response Calls After Admission From the Pediatric Emergency Department.

OBJECTIVES: Pediatric Early Warning Scores (PEWS) are an easy-to-use diagnostic tool for patient evaluation. The goal of this study was to determine if using PEWS in our pediatric emergency department (PED) at the time of admission to the hospital was associated with a decrease in the number of emergency response calls within 6 hours of admission. METHODS: A retrospective chart review of 6 months before (May 2013-October 2013) and after (December 2013-May 2014) initiation of PEWS upon inpatient admission from our urban, tertiary care PED was conducted to determine the number of patients who had emergency response calls within 6 hours of admission. RESULTS: The percentage of patients admitted from the PED who required an emergency response call within 6 hours of admission dropped from 1.77% in the 6 months before assigning PEWS to 0.79% in the 6 months after, a 55% reduction (P = 0.0070). CONCLUSIONS: Assigning PEWS to patients being admitted to our hospital from the PED was associated with a reduced number of emergency response calls in the period immediately after admission.

Recruitment and enrollment of African Americans into health promoting programs: the effects of health promoting programs on cardiovascular disease risk study.

Objectives: Randomized controlled trials (RCT) often employ multiple recruitment methods to attract participants, however, special care must be taken to be inclusive of under-represented populations. We examine how recruiting from an existing observational study affected the recruitment of African Americans into a RCT that included yoga-based interventions. In particular, we report the recruitment success of The Effects of Health Promoting Programs (HPP) on Cardiovascular Disease Risk (NCT02019953), the first yoga-based clinical trial to focus only on African Americans. Design: To recruit participants, a multifaceted recruitment strategy was implemented exclusively in the Jackson Heart Study (JHS) cohort. The HPP recruited from the JHS cohort using direct mailings, signs and flyers placed around JHS study facilities, and through JHS annual follow-up interviews. Results: Enrollment into HPP was open to all active JHS participants that were eligible to return for the third clinic exam (n = 4644). The target sample size was 375 JHS participants over a 24 month recruitment and enrollment period. From the active members of the JHS cohort, 503 were pre-screened for eligibility in HPP. More than 90% of those pre-screened were provisionally eligible for the study. The enrollment goal of 375 was completed after a 16-month enrollment period with over 25% (n = 97) of the required sample size enrolling during the second month of recruitment. Conclusions: The findings show that participants in observational studies can be successfully recruited into RCT. Observational studies provide researchers with a well-defined population that may be of interest when designing clinical trials. This is particularly useful in the recruitment of a high-risk, traditionally underrepresented populations for non-pharmacological clinical trials where traditional recruitment methods may prolong enrollment periods and extend study budgets.

Adherence and retention of African Americans in a randomized controlled trial with a yoga-based intervention: the effects of health promoting programs on cardiovascular disease risk study.

Objectives: Sedentary lifestyle is a risk factor for cardiovascular disease (CVD). Few alternative lifestyle interventions, such as yoga practice, focus on African Americans (AA), the population most vulnerable to CVD. Our objective is to compare the retention and adherence rates between yoga, walking, and health education interventions while providing information about the acceptance of various yoga regimens. Design: Three hundred seventy-five AA participants were recruited exclusively from an active cohort study and randomized into a 48-week study (24 weeks intervention, 24 weeks follow-up) with 5 health promotion interventions: high frequency yoga, moderate frequency yoga, low frequency yoga, guided walking, and health education. In addition to examining the separate yoga interventions, a pooled yoga intervention is considered for comparison to guided walking and health education. Participant retention, adherence, and vitals were monitored at each intervention session. Participants were also scheduled for four clinic visits throughout the study where blood panels, health behavior, and medication surveys were administered. Results: Of the 375 participants recruited, 31.7% did not complete the study. At baseline, in both the guided walking group and the high frequency yoga group, there were significant differences between those who completed the study and those who did not. Although intervention retention in the pooled yoga program (78.3%) was higher compared to the walking (60%) and education programs (74.3%) (p = 0.007), differences in post-intervention retention was not significant. Median adherence rates for the pooled yoga program exceeded rates for guided walking and education with moderate frequency yoga out performing high and low frequency yoga. Conclusion: Study-defined retention success rates were not reached by all health promotion programs. However, retention and adherence rates for the pooled yoga program show that older African Americans are receptive to participating in yoga-based health promotion practices.

Physical Activity and Pain in Youth With Sickle Cell Disease.

Study objectives were to examine the relationships between physical activity, pain, and psychological distress in youth 8 to 17 years of age with sickle cell disease. Participants were 206 youth with sickle cell disease (M = 11.73 years, 54.9% female, 99.5% African American). Caregivers and youth completed a clinical psychosocial screening battery. Results revealed frequent pain (37.6%), moderate median pain intensity, and elevated median pain interference in youth. Lower caregiver-reported physical activity was associated with worse pain outcomes. Increased anxiety was also associated with worse pain outcomes. A better understanding of the relationship between physical activity/inactivity and pain will guide multifactorial treatment interventions.

Impact of Race and Socioeconomic Status on Psychologic Outcomes in Childhood Cancer Patients and Caregivers.

Complex relationships between race and socioeconomic status have a poorly understood influence on psychologic outcomes in pediatric oncology. The Family Symptom Inventory was used to assess symptoms of depression and anxiety in pediatric patients with cancer and their caregivers. Separate hierarchical linear regression models examined the relationship between demographic variables, cancer characteristics, socioeconomic status, and access to care and patient or caregiver depression/anxiety. Participants included 196 pediatric patients with cancer (mean age, 11.21 y; 49% African American) and their caregivers. On average, caregivers reported low levels of depression/anxiety. Symptoms of depression and anxiety in patients were correlated with poorer mental health in caregivers (r=0.62; P<0.01). Self-reported financial difficulty (ß=0.49; P<0.001) and brain cancer diagnosis for their child (ß=0.42; P=0.008) were significantly associated with depression and anxiety in caregivers. Analysis did not reveal significant associations between race, household income, or access to care and patient or caregiver depression/anxiety. Perception of financial hardship can adversely impact mental health in caregivers of children with cancer. Psychosocial assessment and interventions may be especially important for caregivers of patients with brain tumors and caregivers who report feeling financial difficulty.

Does intravenous acetaminophen reduce perioperative opioid use in pediatric tonsillectomy?

OBJECTIVE: Postoperative pain control is of significant interest in pediatric otolaryngology given the safety concerns with opioid use. We sought to determine if addition of intraoperative intravenous acetaminophen decreases perioperative morphine use in pediatric tonsillectomy. METHODS: This study is a retrospective cohort study performed at a tertiary care academic children's hospital. 166 pediatric patients (aged 1-16 years) who underwent tonsillectomy with or without adenoidectomy were for review. Seventy-four patients received intraoperative intravenous acetaminophen (intervention cohort), while ninety-two patients served as our control and did not receive any intraoperative intravenous acetaminophen. Perioperative (intraoperative and postoperative) morphine use was our primary outcome measure. Rate of adverse events in the post anesthesia care unit and time for discharge readiness were secondary outcome measures. Wilcoxon two-sample t-test approximation and Fisher's exact test were used for data analyses. RESULTS: Patients in the intravenous acetaminophen cohort received less morphine (mg/kg) intraoperatively (0.058 versus 0.070, p = 0.089) and in the post anesthesia care unit (0.034 versus 0.051, p = 0.034) than the control cohort. The median time to discharge readiness for the intravenous acetaminophen and control groups was 108.5 versus 105 min (p = 0.018). There was no adverse respiratory event (oxygen desaturation <92% lasting more than a minute, requiring bag mask ventilation or reintubation) in either group in the post anesthesia care unit. There were 5 (7%) episodes of postoperative vomiting in the IV APAP, while 2 (2%) were recorded in the control cohort (p = 0.244). CONCLUSION: Our findings suggest intraoperative intravenous acetaminophen use in pediatric tonsillectomy can decrease the perioperative use of opioid for optimal pain management.

Incident Cardiovascular Disease Among Adults With Blood Pressure <140/90 mm Hg.

BACKGROUND: Data from before the 2000s indicate that the majority of incident cardiovascular disease (CVD) events occur among US adults with systolic and diastolic blood pressure (SBP/DBP) ≥140/90 mm Hg. Over the past several decades, BP has declined and hypertension control has improved. METHODS: We estimated the percentage of incident CVD events that occur at SBP/DBP <140/90 mm Hg in a pooled analysis of 3 contemporary US cohorts: the REGARDS study (Reasons for Geographic and Racial Differences in Stroke), the MESA (Multi-Ethnic Study of Atherosclerosis), and the JHS (Jackson Heart Study) (n=31 856; REGARDS=21 208; MESA=6779; JHS=3869). Baseline study visits were conducted in 2003 to 2007 for REGARDS, 2000 to 2002 for MESA, and 2000 to 2004 for JHS. BP was measured by trained staff using standardized methods. Antihypertensive medication use was self-reported. The primary outcome was incident CVD, defined by the first occurrence of fatal or nonfatal stroke, nonfatal myocardial infarction, fatal coronary heart disease, or heart failure. Events were adjudicated in each study. RESULTS: Over a mean follow-up of 7.7 years, 2584 participants had incident CVD events. Overall, 63.0% (95% confidence interval [CI], 54.9-71.1) of events occurred in participants with SBP/DBP <140/90 mm Hg; 58.4% (95% CI, 47.7-69.2) and 68.1% (95% CI, 60.1-76.0) among those taking and not taking antihypertensive medication, respectively. The majority of events occurred in participants with SBP/DBP <140/90 mm Hg among those <65 years of age (66.7%; 95% CI, 60.5-73.0) and ≥65 years of age (60.3%; 95% CI, 51.0-69.5), women (61.4%; 95% CI, 49.9-72.9) and men (63.8%; 95% CI, 58.4-69.1), and for whites (68.7%; 95% CI, 66.1-71.3), blacks (59.0%; 95% CI, 49.5-68.6), Hispanics (52.7%; 95% CI, 45.1-60.4), and Chinese-Americans (58.5%; 95% CI, 45.2-71.8). Among participants taking antihypertensive medication with SBP/DBP <140/90 mm Hg, 76.6% (95% CI, 75.8-77.5) were eligible for statin treatment, but only 33.2% (95% CI, 32.1-34.3) were taking one, and 19.5% (95% CI, 18.5-20.5) met the SPRINT (Systolic Blood Pressure Intervention Trial) eligibility criteria and may benefit from a SBP target goal of 120 mm Hg. CONCLUSIONS: Although higher BP levels are associated with increased CVD risk, in the modern era, the majority of incident CVD events occur in US adults with SBP/DBP <140/90 mm Hg. While absolute risk and cost-effectiveness should be considered, additional CVD risk-reduction measures for adults with SBP/DBP <140/90 mm Hg at high risk for CVD may be warranted.

Recurrent Acute Chest Syndrome in Pediatric Sickle Cell Disease: Clinical Features and Risk Factors.

Acute chest syndrome (ACS) is a common and serious lung complication in sickle cell disease. A retrospective medical chart review was performed over a 6-year period in all pediatric ACS patients to investigate whether factors during the initial hospitalization were associated with recurrent ACS episodes. There were 386 episodes of ACS: 149 had only 1 episode of ACS, and 76 had >1 episode of ACS; 172 (76.4%) had hemoglobin SS, and 39 (17.3%) had hemoglobin SC. The most common presenting features were fever (83%), pain (70%), and cough (61%), which changed with the number of ACS episodes. Children <4 years old were at greatest risk of recurrent ACS (P=0.018). In addition, history of asthma (adjusted incident rate ratio [IRR]=1.52; 95% confidence interval [CI], 1.22-1.98; P<0.0001), shortness of breath (IRR, 1.29; 95% CI, 1.02-1.62; P=0.033), and length of hospital stay (IRR, 1.04; 95% CI, 1.01-1.08; P=0.017) were significantly associated with prospective ACS events. Multiple episodes of ACS are common in sickle cell disease, and certain risk factors during the initial hospitalization are associated with recurrent ACS.

Surgical Interventions in Infants Born Preterm with Congenital Heart Defects: An Analysis of the Kids' Inpatient Database.

OBJECTIVE: To evaluate short-term outcomes in infants born preterm with congenital heart defects (CHDs) and the factors associated with surgery, survival, and length of hospitalization in this population. STUDY DESIGN: We analyzed data from infants born preterm (gestational age <37 weeks) enrolled in the multicenter Kids' Inpatient Database of the Healthcare Cost and Utilization Project who were admitted to the hospital within 30 days after birth. Infants with atrial septal defects were excluded. RESULTS: Of 1 429 762 enrolled infants born preterm, 27 434 (2.0%) with CHDs were included. Overall survival to discharge was 90.5%; 74.0% among infants with critical CHDs and 45.7% among infants with hypoplastic left heart syndrome. Cardiac surgeries were performed in 12.2% of all infants born preterm. Rates of surgical intervention for infants with critical CHDs were lower for very low birth weight (≤1.5 kg) vs larger infants >1.5 kg (27% vs 44%), and only 6.3% of infants born with very low birth weight underwent surgeries in Risk-adjustment for Congenital Heart Surgery categories 4 or greater. Greater birth weight, left-sided lesions, care at children's hospitals, and absence of trisomies were associated with a greater likelihood of surgery. Birth weight <2 kg, nonwhite race, trisomy syndromes, prematurity-related morbidities, and Risk-adjustment for Congenital Heart Surgery category 4 or greater were independent predictors of mortality. Birth weight <2 kg, Risk-adjustment for Congenital Heart Surgery category, morbidities, and sidedness of lesion predicted length of stay. CONCLUSIONS: The high survival rates of infants born preterm with CHDs suggests that a cautiously optimistic approach to surgery may be warranted in all but the most immature infants with the greatest-risk conditions.

Relational Intimacy Mediates Sexual Outcomes Associated With Impaired Sexual Function: Examination in a Clinical Sample.

BACKGROUND: Relational intimacy is hypothesized to underlie the association between female sexual functioning and various sexual outcomes, and married women and women with sexual dysfunction have been generally absent from prior studies investigating these associations, thus restricting generalizability. AIM: To investigate whether relational intimacy mediates sexual outcomes (sexual satisfaction, coital frequency, and sexual distress) in a sample of married women with and without impaired sexual functioning presenting in clinical settings. METHODS: Using a cross-sectional design, 64 heterosexual married women with (n = 44) and without (n = 20) impaired sexual functioning completed a battery of validated measurements assessing relational intimacy, sexual dysfunction, sexual frequency, satisfaction, and distress. Intimacy measurements were combined using latent factor scores before analysis. Bias-corrected mediation models of the indirect effect were used to test mediation effects. Moderated mediation models examined whether indirect effects were influenced by age and marital duration. OUTCOMES: Patients completed the Female Sexual Function Index, the Couple's Satisfaction Index, the Sexual Satisfaction Scale for Women, the Inclusion of the Other in the Self Scale, and the Miller Social Intimacy Test. RESULTS: Mediation models showed that impaired sexual functioning is associated with all sexual outcomes directly and indirectly through relational intimacy. Results were predominantly independent of age and marital duration. CLINICAL IMPLICATIONS: Findings have important treatment implications for modifying interventions to focus on enhancing relational intimacy to improve the sexual functioning of women with impaired sexual functioning. STRENGTHS AND LIMITATIONS: The importance of the role relational intimacy plays in broad sexual outcomes of women with impaired sexual functioning is supported in clinically referred and married women. Latent factor scores to improve estimation of study constructs and the use of contemporary mediation analysis also are strengths. The cross-sectional design precludes any causal conclusions and it is unknown whether the results generalize to male partners, partners within other relationship structures, and non-heterosexual couples. CONCLUSION: Greater relational intimacy mitigates the adverse impact of impaired sexual functioning on sexual behavior and satisfaction in women. Witherow MP, Chandraiah S, Seals SR, et al. Relational Intimacy Mediates Sexual Outcomes Associated With Impaired Sexual Function: Examination in a Clinical Sample. J Sex Med 2017;14:843-851.

Correlation of frontal sinus recess anatomy with ethnicity, gender, and pathology.

PURPOSE: Research on frontal sinus cells has been conflicting regarding relationship between frontal sinus cells and frontal sinus disease. There are no published studies regarding gender differences in frontal sinus disease. No comparisons between African Americans and Caucasians and frontal sinus disease have been published. This study attempts to define the above relationships as well as the relationship between number and types of cells and disease. METHODS: A retrospective chart review was performed on sinus CT scans done from 2003 to 2011 at an academic medical center. Exclusion criteria included previous frontal sinus surgery, sinus malignancy, obvious trauma, congenital anomalies, and poor quality of scan. Number and type of frontal cells were recorded for 602 scans. Statistical analysis performed demographic comparisons and compared number and types of cells to evidence of disease. RESULTS: Males were more likely than females to have frontal sinus disease. Patients with Type 3 and Type 4 cells were more likely to have disease. No significant ethnic related differences in disease were found using a multivariate logistic regression model. Total number of cells did not significantly affect likelihood of disease. CONCLUSIONS: This is one of the largest collections of data on frontal sinus cells as predictors of frontal sinus disease. These results suggest that gender and certain types of cells affect likelihood of disease. This study is the first to demonstrate a lack of difference in disease in African Americans and Caucasians. These results are significant regarding gender, race, number and type of cells as predictors of disease.

Microcirculatory Effects of Botulinum Toxin A in the Rat: Acute and Chronic Vasodilation.

BACKGROUND: Botulinum toxin-A (BTX) has numerous cosmetic and therapeutic applications. Our previous studies have found that BTX augments pedicled flap survival through both vasodilatory effects and attenuation of the inflammatory response to ischemia in the rat. This study examines the effect of chronic BTX on microcirculatory vascular tone and its response to acute topical vasodilators in muscle flaps. METHODS: The spinotrapezius muscle of Sprague-Dawley rats underwent a single 2-week pretreatment of 0.2 mL saline either with (n = 5) or without (n = 5) 2u BTX. After surgical elevation, an arcade arteriole was observed using a video caliper device. Vessel diameter was measured at 30-second intervals after sequential superfusion of nitroglycerin (100 and 200 µg/mL), multiple concentrations of lidocaine, and a combination of adenosine (10 µM) and nitroprusside (10 µM) to induce maximum dilation. RESULTS: Baseline and dilation diameters were expressed as ratios of pharmacologically induced maximum dilation, whereas percent dilation was defined as the change in diameter over baseline diameter. We found a significant increase in resting diameter with BTX pretreatment (P = 0.0028). Compared with the control group, mean baseline diameter was 15% greater, and percent dilation was 25% less in BTX-pretreated flaps. There was no significant relationship between BTX pretreatment and dilation diameter (P = 0.2895) after adjusting for the effect of acute vasodilators. CONCLUSIONS: Pretreatment with BTX may induce the arteriolar resting diameter to be closer to their maximum potential diameter. Additionally, BTX does not display a synergistic effect with topical vasodilators on vasodilation.

Sedentary behavior and subclinical atherosclerosis in African Americans: cross-sectional analysis of the Jackson heart study.

BACKGROUND: Previous studies have reported conflicting results as to whether an association exists between sedentary time and cardiovascular disease (CVD) risk among African Americans. These studies, however, were limited by lack of consideration of sedentary behavior in leisure versus non-leisure settings. To elucidate this relation, we investigated the associations of television (TV) viewing time and occupational sitting with carotid intima-media thickness (CIMT), a subclinical atherosclerosis measure, in a community-based sample of African Americans. METHODS: We studied 3410 participants from the Jackson Heart Study, a single-site, community-based study of African Americans residing in Jackson, MS. CIMT was assessed by ultrasonography and represented mean far-wall thickness across right and left sides of the common carotid artery. TV viewing time, a measure of leisure sedentary behavior, and occupational sitting, a measure of non-leisure sedentary behavior, were assessed by questionnaire. RESULTS: In a multivariable regression model that included physical activity and CVD risk factors, longer TV viewing time (2-4 h/day and >4 h/day) was associated with greater CIMT (adjusted mean ± SE difference from referent [<2 h/day] of 0.009 ± 0.008 mm for 2-4 h/day, and 0.028 ± 0.009 mm for >4 h/day; P-trend =0.001). In contrast, more frequent occupational sitting ('sometimes' and 'often/always') was associated with lower CIMT (adjusted mean ± SE difference from referent ['never/seldom']:-0.021 ± 0.009 mm for 'sometimes', and-0.018 ± 0.008 mm for 'often/always'; P-trend = 0.042). CONCLUSIONS: Longer TV viewing time was associated with greater CIMT, while occupational sitting was associated with lower CIMT. These findings suggest the role of sedentary behaviors in the pathogenesis of CVD among African Americans may vary by whether individuals engage in leisure versus non-leisure sedentary behaviors.

Relational Intimacy and Sexual Frequency: A Correlation or a Cause? A Clinical Study of Heterosexual Married Women.

Researchers and practitioners have noted the importance of using clinical samples in sex therapy research. This study investigated the relationship between perceived levels of marital intimacy, sexual frequency, and sexual functioning among heterosexual married women. A clinical sample of 67 women completed the Couples Satisfaction Index (CSI), the Miller Social Intimacy Test (MSI), the Sexual Satisfaction Scale for Women (SSS-W), the Inclusion of the Other in the Self Scale (IOS), and the Female Sexual Functioning Index (FSFI-6). Data analyses revealed that marital intimacy acted as a predictor in univariate relationships on sexual frequency and sexual functioning but did not act as a mediator on sexual frequency and sexual functioning. Overall, these findings may further the discussion in the treatment of relational intimacy, sexual desire discrepancy, and female sexual dysfunction.

Alternative strategies in newborns and infants with major co-morbidities to improve congenital heart surgery outcomes at an emerging programme.

INTRODUCTION: Debilitating patient-related non-cardiac co-morbidity cumulatively increases risk for congenital heart surgery. At our emerging programme, flexible surgical strategies were used in high-risk neonates and infants generally considered in-operable, in an attempt to make them surgical candidates and achieve excellent outcomes. MATERIALS AND METHODS: Between April, 2010 and November, 2013, all referred neonates (142) and infants (300) (average scores: RACHS 2.8 and STAT 3.0) underwent 442 primary cardiac operations: patients with bi-ventricular lesions underwent standard (n=294) or alternative (n=19) repair/staging strategies, such as pulmonary artery banding(s), ductal stenting, right outflow patching, etc. Patients with uni-ventricular hearts followed standard (n=96) or alternative hybrid (n=34) staging. The impact of major pre-operative risk factors (37%), standard or alternative surgical strategy, prematurity (50%), gestational age, low birth weight, genetic syndromes (23%), and major non-cardiac co-morbidity requiring same admission surgery (27%) was analysed on the need for extracorporeal membrane oxygenation, mortality, length of intubation, as well as ICU and hospital length of stays. RESULTS: The need for extracorporeal membrane oxygenation (8%) and hospital survival (94%) varied significantly between surgical strategy groups (p=0.0083 and 0.028, respectively). In high-risk patients, alternative bi- and uni-ventricular strategies minimised mortality, but were associated with prolonged intubation and ICU stay. Major pre-operative risk factors and lower weight at surgery significantly correlated with prolonged intubation, hospital length of stay, and mortality. DISCUSSION: In our emerging programme, flexible surgical strategies were offered to 53/442 high-risk neonates and infants with complex CHDs and significant non-cardiac co-morbidity, in order to buffer risk and achieve patient survival, although at the cost of increased resource utilisation.

Survival analysis and regression models.

Time-to-event outcomes are common in medical research as they offer more information than simply whether or not an event occurred. To handle these outcomes, as well as censored observations where the event was not observed during follow-up, survival analysis methods should be used. Kaplan-Meier estimation can be used to create graphs of the observed survival curves, while the log-rank test can be used to compare curves from different groups. If it is desired to test continuous predictors or to test multiple covariates at once, survival regression models such as the Cox model or the accelerated failure time model (AFT) should be used. The choice of model should depend on whether or not the assumption of the model (proportional hazards for the Cox model, a parametric distribution of the event times for the AFT model) is met. The goal of this paper is to review basic concepts of survival analysis. Discussions relating the Cox model and the AFT model will be provided. The use and interpretation of the survival methods model are illustrated using an artificially simulated dataset.

Changing demographics at a comprehensive stroke center amidst the rise in primary stroke centers.

BACKGROUND: The creation of The Joint Commission primary stroke centers (PSCs) has increased access to acute stroke care in metropolitan areas. We hypothesized that the rise in PSCs in the Houston area was associated with demographic changes and decreased trial enrollment at our comprehensive stroke center. METHODS: Consecutive admissions to the UT Houston stroke team from January 2005 to June 2011 were reviewed for demographic and clinical information. Patient characteristics were compared across years. Logistic regression was performed to assess the odds of admission per year. RESULTS: During the 6.5-year study period, there were 6623 admissions. Admissions increased each year. The proportion of patients transferred from other hospitals to our Comprehensive Stroke Center increased from 24.6% in 2005 to 45.5% in 2011. The number of The Joint Commission PSCs in the greater Houston area increased from 2 to 15. The percentage of large artery occlusions fell from 32.9% in 2005 to a low of 16.4% in 2010, whereas minor strokes (National Institutes of Health Stroke Scale, 0-5) increased from 37.4% in 2005 to 48.6% in 2011. Among stroke patients presenting within 3 hours, study enrollment fell from 45.8% in 2005 to 19.3% in 2011. CONCLUSIONS: We observed a temporal association between the changes in our patient demographics and the number of The Joint Commission PSCs in Houston. The number of large artery occlusions decreased over time, whereas the number of mild strokes increased. In addition, the number of patients enrolled into clinical trials substantially decreased. Increased access to stroke care at PSCs may be associated with changes in patient demographics and clinical trial enrollment at our center.

Risk factors for uterine atony/postpartum hemorrhage requiring treatment after vaginal delivery.

OBJECTIVE: We sought to identify risk factors for uterine atony or hemorrhage. STUDY DESIGN: We conducted a secondary analysis of a 3-arm double-blind randomized trial of different dose regimens of oxytocin to prevent uterine atony after vaginal delivery. The primary outcome was uterine atony or hemorrhage requiring treatment. In all, 21 potential risk factors were evaluated. Logistic regression was used to identify independent risk factors using 2 complementary predefined model selection strategies. RESULTS: Among 1798 women randomized to 10, 40, or 80 U of prophylactic oxytocin after vaginal delivery, treated uterine atony occurred in 7%. Hispanic (odds ratio [OR], 2.1; 95% confidence interval [CI], 1.3-3.4), non-Hispanic white (OR, 1.6; 95% CI, 1.0-2.5), preeclampsia (OR, 3.2; 95% CI, 2.0-4.9), and chorioamnionitis (OR, 2.8; 95% CI, 1.6-5.0) were consistent independent risk factors. Other risk factors based on the specified selection strategies were obesity, induction/augmentation of labor, twins, hydramnios, anemia, and arrest of descent. Amnioinfusion appeared to be protective against uterine atony (OR, 0.53; 95% CI, 0.29-0.98). CONCLUSION: Independent risk factors for uterine atony requiring treatment include Hispanic and non-Hispanic white ethnicity, preeclampsia, and chorioamnionitis.