A Study Comparing Gait and Lower Limb Muscle Activity During Aquatic Treadmill Running with Different Water Depth and Land Treadmill Running.

Aquatic treadmill running is a partial weight-bearing exercise for rehabilitation. The purpose of this study was to investigate the surface electromyography activities of the rectus femoris, tibialis anterior, biceps femoris and medial head of gastrocnemius, and gait kinematics during aquatic treadmill running in water levels at waist, mid-thigh and mid-shin and on land. Seventeen healthy subjects (9 males and 8 females) were recruited by convenience sampling. Participants performed 2-min aquatic treadmill running at a specific speed for each water depth. The test speed was selected based upon the speed that elicited 110 steps per min. The surface electromyography data of lower limb muscles and the joint angles at three different water depths and on land were collected to evaluate the muscle activity and gait kinematics using a waterproofed surface electromyography system and inertial measurement unit for each muscle. Results showed that rectus femoris electromyography was different between depths during the swing and stance phases. Likewise, biceps femoris and tibialis anterior electromyography were different between depths for the swing phase. However, it was not the case for gastrocnemius electromyography. Peak flexion angles in both left and right hips were different between depths. A significant increase in a stance/swing ratio was observed with rising water depths. Water depth influenced muscle activity as well as kinematics. Aquatic treadmill running in the mid-thigh level should be further evaluated for its effectiveness, training value and applicability.

Effect of age on the risk of Fever and seizures following immunization with measles-containing vaccines in children.

IMPORTANCE The first dose of live attenuated measles-containing vaccines is associated with an increased risk of febrile seizures 7 to 10 days following immunization among 12- to 23-month-old children. The combination measles, mumps, rubella, and varicella vaccine is associated with a 2-fold increased risk of febrile seizures 7 to 10 days following immunization compared with the separately administered measles, mumps, and rubella and varicella vaccines. It is unknown whether the magnitude of these increased risks depends on age at immunization. OBJECTIVE To examine the potential modifying effect of age on the risk of fever and seizures following immunization with measles-containing vaccines. DESIGN, SETTING, AND PARTICIPANTS Retrospective cohort study at 8 Vaccine Safety Datalink sites of a total of 840,348 children 12 to 23 months of age who had received a measles-containing vaccine from 2001 through 2011. EXPOSURES Any measles-containing vaccines and measles-containing vaccines by type. MAIN OUTCOMES AND MEASURES Fever and seizure events occurring during a 42-day postimmunization observation period. RESULTS In the analysis of any measles-containing vaccines, the increased risk of seizures during the 7- to 10-day risk interval, using the remainder of the observation period as the control interval, was significantly greater among older children (relative risk, 6.5; 95% CI, 5.3-8.1; attributable risk, 9.5 excess cases per 10,000 doses; 95% CI, 7.6-11.5) than among younger children (relative risk, 3.4; 95% CI, 3.0-3.9; attributable risk = 4.0 excess cases per 10,000 doses; 95% CI, 3.4-4.6). The relative risk of postimmunization fever was significantly greater among older children than among younger children; however, its attributable risk was not. In the analysis of vaccine type, measles, mumps, rubella, and varicella vaccine was associated with a 1.4-fold increase in the risk of fever and 2-fold increase in the risk of seizures compared with measles, mumps, and rubella vaccine administered with or without varicella vaccine in both younger and older children. CONCLUSIONS AND RELEVANCE Measles-containing vaccines are associated with a lower increased risk of seizures when administered at 12 to 15 months of age. Findings of this study that focused on safety outcomes highlight the importance of timely immunization of children with the first dose of measles-containing vaccines.

Effect of nonpayment for preventable infections in U.S. hospitals.

BACKGROUND: In October 2008, the Centers for Medicare and Medicaid Services (CMS) discontinued additional payments for certain hospital-acquired conditions that were deemed preventable. The effect of this policy on rates of health care-associated infections is unknown. METHODS: Using a quasi-experimental design with interrupted time series with comparison series, we examined changes in trends of two health care-associated infections that were targeted by the CMS policy (central catheter-associated bloodstream infections and catheter-associated urinary tract infections) as compared with an outcome that was not targeted by the policy (ventilator-associated pneumonia). Hospitals participating in the National Healthcare Safety Network and reporting data on at least one health care-associated infection before the onset of the policy were eligible to participate. Data from January 2006 through March 2011 were included. We used regression models to measure the effect of the policy on changes in infection rates, adjusting for baseline trends. RESULTS: A total of 398 hospitals or health systems contributed 14,817 to 28,339 hospital unit-months, depending on the type of infection. We observed decreasing secular trends for both targeted and nontargeted infections long before the policy was implemented. There were no significant changes in quarterly rates of central catheter-associated bloodstream infections (incidence-rate ratio in the postimplementation vs. preimplementation period, 1.00; P=0.97), catheter-associated urinary tract infections (incidence-rate ratio, 1.03; P=0.08), or ventilator-associated pneumonia (incidence-rate ratio, 0.99; P=0.52) after the policy implementation. Our findings did not differ for hospitals in states without mandatory reporting, nor did it differ according to the quartile of percentage of Medicare admissions or hospital size, type of ownership, or teaching status. CONCLUSIONS: We found no evidence that the 2008 CMS policy to reduce payments for central catheter-associated bloodstream infections and catheter-associated urinary tract infections had any measurable effect on infection rates in U.S. hospitals. (Funded by the Agency for Healthcare Research and Quality.).

Signal identification and evaluation for risk of febrile seizures in children following trivalent inactivated influenza vaccine in the Vaccine Safety Datalink Project, 2010-2011.

In fall 2010 in the southern hemisphere, an increased risk of febrile seizures was noted in young children in Australia in the 24 h after receipt of trivalent inactivated influenza vaccine (TIV) manufactured by CSL Biotherapies. Although the CSL TIV vaccine was not recommended for use in young children in the US, during the 2010-2011 influenza season near real-time surveillance was conducted for febrile seizures in the 0-1 days following first dose TIV in a cohort of 206,174 vaccinated children ages 6 through 59 months in the Vaccine Safety Datalink Project. On a weekly basis, surveillance was conducted with the primary approach of a self-controlled risk interval design and the secondary approach of a current vs. historical vaccinee design. Sequential statistical methods were employed to account for repeated analyses of accumulating data. Signals for seizures based on computerized data were identified in mid November 2010 using a current vs. historical design and in late December 2010 using a self-controlled risk interval design. Further signal evaluation was conducted with chart-confirmed febrile seizure cases using only data from the primary approach (i.e. self-controlled risk interval design). The magnitude of the incidence rate ratio and risk difference comparing risk of seizures in the 0-1 days vs. 14-20 days following TIV differed by receipt of concomitant 13-valent pneumococcal conjugate vaccine (PCV13). Among children 6-59 months of age, the incidence rate ratio (IRR) for TIV adjusted for concomitant PCV13 was 2.4 (95% CI 1.2, 4.7) while the IRR for PCV13 adjusted for concomitant TIV was 2.5 (95% CI 1.3, 4.7). The IRR for concomitant TIV and PCV13 was 5.9 (95% CI 3.1, 11.3). Risk difference estimates varied by age due to the varying baseline risk for seizures in young children, with the highest estimates occurring at 16 months (12.5 per 100,000 doses for TIV without concomitant PCV13, 13.7 per 100,000 doses for PCV13 without concomitant TIV, and 44.9 per 100,000 doses for concomitant TIV and PCV13) and the lowest estimates occurring at 59 months (1.1 per 100,000 doses for TIV without concomitant PCV13, 1.2 per 100,000 doses for PCV13 without concomitant TIV, and 4.0 per 100,000 doses for concomitant TIV and PCV13). Incidence rate ratio and risk difference estimates were lower for children receiving TIV without concomitant PCV13 or PCV13 without concomitant TIV. Because of the importance of preventing influenza and pneumococcal infections and associated complications, our findings should be placed in a benefit-risk framework to ensure that population health benefits are maximized.

Cumulative stress and maternal prenatal corticotropin-releasing hormone in an urban U.S. cohort.

BACKGROUND: To date, there have been conflicting reports of the association of psychosocial stressors with prenatal corticotropin-releasing hormone (CRH) levels. METHODS: We examined whether racial discrimination, community violence, interpersonal violence (IPV), negative life events, considered independently, and as a composite measure of cumulative stress, were associated with prenatal CRH levels in the Asthma Coalition on Community, Environment, and Social Stress (ACCESS) project, a multiethnic pre-birth cohort in urban Boston. Blood was collected between 20 and 37 weeks gestation (Mean=28.1, SD=4.6 weeks gestation). During pregnancy, women were administered the Conflict Tactics Scale survey to assess IPV, the Crisis in Family Systems-Revised survey to assess negative life events, the My Exposure to Violence survey to assess community violence, and the Experiences of Discrimination survey. A cumulative stress measure was derived from these instruments to characterize exposure to high levels of multiple stressors. RESULTS: None of the individual stressors or cumulative stress was associated with CRH in combined analyses including Whites (n=20), Blacks (n=46), and Hispanics (n=110). In separate analyses of Blacks and Hispanics, racial discrimination, community violence, and cumulative stress were associated with CRH in Blacks, but were not associated with CRH in Hispanics. CONCLUSIONS: Though these results require replication, they suggest that the effects of stress on prenatal CRH levels may be mediated by factors that differ between racial/ethnic groups. Further studies in larger samples are warranted to clarify whether associations of chronic stressors and prenatal CRH levels differ by race/ethnicity and to better understand underlying mechanisms.

Association of maternal prenatal depressive symptoms with child cognition at age 3 years.

We examined the association of prenatal depressive symptoms at mid-pregnancy with child cognition at age 3 years in Project Viva, a pre-birth cohort study of 1030 mother-child pairs in eastern Massachusetts. We measured maternal depressive symptoms using the Edinburgh Postnatal Depression Scale (EPDS), a self-report measure validated for use during pregnancy. Measures of child cognition included the Peabody Picture Vocabulary Test (PPVT) and the Wide Range Achievement of Visual Motor Abilities (WRAVMA). At mid-pregnancy, 81 mothers (7.9%) scored 13 or above on the EPDS, indicating probable depression. In the unadjusted model, children born to mothers with prenatal depressive symptoms had PPVT scores that were 3.8 points lower [95% confidence interval (CI) -7.1, -0.5]. With adjustment for sociodemographic variables, the association substantially attenuated [adjusted regression coefficient b for PPVT score = -0.7 (95% CI -3.6, 2.3)]. In both unadjusted and multivariable models, prenatal depressive symptoms were not associated with WRAVMA scores [adjusted b for total WRAVMA score = -0.5 (95% CI -3.0, 2.1)]. We found no evidence to suggest that maternal prenatal depression is independently associated with early child cognition.