A New Method for Diaphragmatic Maximum Relaxation Rate Ultrasonographic Measurement in the Assessment of Patients With Diaphragmatic Dysfunction.

Measurements of ultrasound diaphragmatic motion, amplitude, force, and velocity of contraction may provide important and essential information about diaphragmatic fatigue, weakness, or paralysis. In this paper, we propose and evaluate a semi-automated analysis system for measuring the diaphragmatic motion and estimating the maximum relaxation rate (MRR_SAUS) from ultrasound M-mode images of the diaphragmatic muscle. The system was evaluated on 27 M-mode ultrasound images of the diaphragmatic muscle [20 with no resistance (NRES) and 7 with resistance (RES)]. We computed semi-automated ultrasound MRR measurements on all NRES/RES images, using the proposed system (MRR_SAUS = 3.94 ± 0.91/4.98 ± 1.98 [1/s]), and compared them with the manual measurements made by a clinical expert (MRR_MUS = 2.36 ± 1.19/5.8 ± 2.1 [1/s],) and those made by a reference manual method (MRR_MB = 3.93 ± 0.89/3.73 ± 0.52 [1/sec], performed manually with the Biopac system. MRR_SAUS and MRR_MB measurements were not statistically significantly different for NRES and RES subjects but were significantly different with the MRR-MUS measurements made by the clinical expert. It is anticipated that the proposed system might be used in the future in the clinical practice in the assessment and follow up of patients with diaphragmatic weakness or paralysis. It may thus potentially help to understand post-operative pulmonary dysfunction or weaning failure from mechanical ventilation. Further validation and additional experimentation in a larger sample of images and different patient groups is required for further validating the proposed system.

Demographic and dietary risk factors in relation to urinary metabolites of organophosphate flame retardants in toddlers.

Organophosphate flame retardants (OPFRs), including Tris (1,3-dichloro-isopropyl) phosphate (TDCPP), triphenyl phosphate (TPP), and isopropylated triphenyl phosphate (ITP), are increasingly used in consumer products because of the recent phase out of polybrominated diphenyl ether (PBDE) flame retardants. OPFRs have been widely detected in adults and have been linked to reproductive and endocrine changes in adult males. Carcinogenicity and damage to immunologic, neurologic and developmental systems have been observed in human cell lines. Young children are especially vulnerable to OPFR exposure, but little is known about exposure levels or exposure risk factors in this population. We examined parent-reported demographic and dietary survey data in relation to OPFR urinary metabolite concentrations in 15- to 18-month old toddlers (n = 41). OPFR metabolites were detected in 100% of subjects. The metabolite of TPP, diphenyl phosphate (DPP) was detected most commonly (100%), with TDCPP metabolite, bis(1,3-dichloro-2-propyl) phosphate (BDCPP), detected in 85-95% of samples, and ITP metabolite, monoisopropylphenyl phenyl phosphate (ip-DPP), detected in 81% of samples (n = 21). Toddlers of mothers earning <$10,000 annually had geometric mean DPP concentrations 66% higher (p = 0.05) than toddlers of mothers earning >$10,000/year (7.8 ng/mL, 95% CI 5.03, 12.11 and 4.69 ng/mL, 95% CI 3.65-6.04, respectively). While no dietary factors were significantly associated with OPFR metabolite concentrations, results suggested meat and fish consumption may be associated with higher DPP and BDCPP levels while increased dairy and fresh food consumption may be associated with lower DPP, BDCPP, and ip-DPP levels. Research with larger sample sizes and more detailed dietary data is required to confirm these preliminary findings.

Parental optimism about childhood obesity-related disease risks.

OBJECTIVES: Most parents believe childhood obesity is a problem for society, but not for their own children. We sought to understand whether parents' risk assessment was skewed by optimism, the tendency to overestimate one's chances of experiencing positive events. METHODS: We administered a national web-based survey to 502 parents of 5-12-year-old children. Parents reported the chances that (a) their child and (b) 'a typical child in their community' would be overweight or obese, and develop hypertension, heart disease, type 2 diabetes and depression in adulthood. Respondents self-reported demographic and health information, and we obtained demographic and health information about the typical child using zip code-level census and lifestyle data. We used regression models with fixed effects to evaluate whether optimism bias was present in parent predictions of children's future health outcomes. RESULTS: Parents had 40 times lower adjusted odds (OR=0.025, P<0.001, 99% CI: 0.006, 0.100) of predicting that their child (versus a typical child) would be overweight or obese in adulthood. Of the 20% of parents who predicted their child would be overweight in adulthood, 93% predicted the typical child would also be overweight in adulthood. Controlling for health and demographic characteristics, parents estimated that their children's chances of developing obesity-related comorbidities would be 12-14 percentage points lower those that of a typical child. CONCLUSIONS: Parent risk assessment is skewed by optimism, among other characteristics. More accurate risk perception could motivate parents to engage in behavior change.

Overstimulation of newborn mice leads to behavioral differences and deficits in cognitive performance.

Observational studies in humans have found associations between overstimulation in infancy via excessive television viewing and subsequent deficits in cognition and attention. We developed and tested a mouse model of overstimulation whereby p10 mice were subjected to audio (70 db) and visual stimulation (flashing lights) for six hours per day for a total of 42 days. 10 days later cognition and behavior were tested using the following tests: Light Dark Latency, Elevated Plus Maze, Novel Object Recognition, and Barnes Maze. In all tests, overstimulated mice performed significantly worse compared to controls suggesting increased activity and risk taking, diminished short term memory, and decreased cognitive function. These findings suggest that excessive non-normative stimulation during critical periods of brain development can have demonstrable untoward effects on subsequent neurocognitive function.

Gait variability measurements in lumbar spinal stenosis patients: part A. Comparison with healthy subjects.

The objective of this study is to compare the gait variability of patients with lumbar spinal stenosis (experimental group) with healthy individuals (control group). The hypothesis is that the preoperative gait variability of the experimental group is higher than the control group. The experimental group consisted of 35 adults (18 males, 17 females). The subjects of the experimental group suffered exclusively from spinal stenosis. The patients were determined by MRI scans. A tri-axial accelerometer sensor was used for the gait measurement, and differential entropy algorithm was used to quantify the gait acceleration signal. The Oswestry Low Back Pain Questionnaire was used to determine the condition on the day of the measurement. Receiver operating characteristic (ROC) was utilized to assess the diagnostic value of the method and determine a cut-off value. There is a statistically significant difference between gait variability in the control group and the experimental group. ROC analysis determines a cut-off differential entropy value. The cut-off value has a 97.6% probability of separating patients with spinal stenosis from healthy subjects. The Oswestry Low Back Questionnaire is well correlated with the spectral differential entropy values.

Gait variability measurements in lumbar spinal stenosis patients: part B. Preoperative versus postoperative gait variability.

The objective of this study was to assess the gait variability of lumbar spinal stenosis (LSS) patients and to evaluate its postoperative progression. The hypothesis was that LSS patients' preoperative gait variability in the frequency domain was higher than the corresponding postoperative. A tri-axial accelerometer sensor was used for the gait measurement and a spectral differential entropy algorithm was used to measure the gait variability. Twelve subjects with LSS were measured before and after surgery. Preoperative measurements were performed 2 days before surgery. Postoperative measurements were performed 6 and 12 months after surgery. Preoperative gait variability was higher than the corresponding postoperative. Also, in most cases, gait variability appeared to decrease throughout the year.

The influence of types of decision support on physicians' decision making.

OBJECTIVE: To determine whether physicians' post-test probability estimates are influenced by receiving test characteristics and impact their subsequent clinical decisions. DESIGN: Questionnaire based randomised controlled trial. SETTING: Mailed survey with a vignette describing an infant whose pretest likelihood of pertussis was 30% and direct fluorescent-antibody (DFA) test was negative for pertussis. SUBJECTS: Nationally representative sample of US paediatricians (n = 1502). INTERVENTIONS: Random receipt of no additional information (controls), the DFA's sensitivity and specificity (TC group) or the test's sensitivity and specificity with their definitions (TCD group). MAIN OUTCOME MEASURES: Estimated post-test probability (PTP) of pertussis, PTP of 0.50, "nearly correct" PTP (+/-5%), intended erythromycin management and intended hospital disposition. ANALYSES: Chi2 and t tests. RESULTS: Despite the negative DFA result, 67% of the 635 (49.7%) participants who responded estimated a PTP higher than the pretest probability of 30%; the overall mean estimated PTP was 0.41 (SD 0.26) (correct answer: 0.18). The TCD group's mean PTP was significantly higher than controls' mean PTP (0.45 vs 0.38, p<0.001), while the TC and control groups' mean PTP did not differ significantly (0.41 vs 0.38, p = 0.16). With decision support significantly more TC and TCD participants compared to controls estimated the PTP as 0.50 (38% vs 17%, p<0.001; 41% vs 17%, p<0.001, respectively) and also estimated a nearly correct PTP more often (20% vs 13%, p = 0.06; 19% vs 13%, p = 0.08, respectively). The mean PTP of participants intending to discontinue erythromycin therapy or discharge the patient home was significantly lower than that of participants who intended continuing erythromycin or hospitalisation (0.20 vs 0.43, p<0.001; 0.40 vs 0.49, p = 0.005, respectively). CONCLUSIONS: Paediatricians differed in their response to information about test characteristics. For many, it increased errors in estimating post-test probability; for others, it reduced errors. Estimated post-test probability was logically associated with intended clinical management.

Accelerometry for evaluation of gait pattern in healthy soccer athletes.

An accelerometer system was used to measure the characteristics of the motion of 133 healthy male soccer athletes in a 30-s walking test and the data obtained were analysed using the gait evaluation differential entropy method (GEDEM). GEDEM processes gait acceleration data and calculates an index that provides a quantitative evaluation of a subject's gait, at low cost and with negligible effect on the subject. The GEDEM index was not significantly correlated with age, body weight, body mass index, or the number of years of active training. The GEDEM value for the anterior-posterior axis showed a small negative statistically significant correlation with height and the vertical axis was moderately and statistically significantly positively correlated with the time spent training per week. The triaxial accelerometry system described here is easy for subjects and testers to use, and enables measurements to be made on the sports field to evaluate an athlete's musculoskeletal condition with respect to gait stability.

Validation of parent self reported home safety practices.

OBJECTIVES: To evaluate the validity of parents' self reported home safety practices concerning smoke detectors, bike helmets, car seats, and water heater temperature. SETTING: Parents of children 12 years old and under whose child had made at least one visit to a study clinic in the years 2000-2003. METHODS: As part of a randomized controlled trial to improve patient provider communication and preventive practices, parents' responses to telephone interview were compared with observations of safety practices during a home visit. Home visits were completed within nine weeks of the telephone interview. Parents were not told that the visit was part of a validation study and home visit observers were unaware of the interview responses. The authors calculated sensitivities, specificities, positive and negative predictive values, and their corresponding confidence intervals. RESULTS: Sensitivity (0.78 to 0.98) and positive predictive values (0.75 to 1.00) were high for all items. Specificities and negative predictive values were more variable and the highest estimates (specificity 0.95 to 1.00, negative predictive value 0.95 to 0.97) were for car seat types. CONCLUSIONS: The results suggest that parent self report practice of certain injury prevention behaviors (owning a car seat, hot water temperatures) is reliable, whereas self reports on other practices (working smoke detectors, properly fitting bike helmets) may be overstated.

The risk of seizures after receipt of whole-cell pertussis or measles, mumps, and rubella vaccine.

BACKGROUND: The administration of the diphtheria and tetanus toxoids and whole-cell pertussis (DTP) vaccine and measles, mumps, and rubella (MMR) vaccine has been associated with adverse neurologic events, including seizures. We studied the relation between these vaccinations and the risk of a first seizure, subsequent seizures, and neurodevelopmental disability in children. METHODS: This cohort study was conducted at four large health maintenance organizations and included reviews of the medical records of children with seizures. We calculated the relative risks of febrile and nonfebrile seizures among 679,942 children after 340,386 vaccinations with DTP vaccine, 137,457 vaccinations with MMR vaccine, or no recent vaccination. Children who had febrile seizures after vaccination were followed to identify the risk of subsequent seizures and other neurologic disabilities. RESULTS: Receipt of DTP vaccine was associated with an increased risk of febrile seizures only on the day of vaccination (adjusted relative risk, 5.70; 95 percent confidence interval, 1.98 to 16.42). Receipt of MMR vaccine was associated with an increased risk of febrile seizures 8 to 14 days after vaccination (relative risk, 2.83; 95 percent confidence interval, 1.44 to 5.55). Neither vaccination was associated with an increased risk of nonfebrile seizures. Analyses of automated data alone gave results similar to the analyses of the data from medical-record reviews. The number of febrile seizures attributable to the administration of DTP and MMR vaccines was estimated to be 6 to 9 and 25 to 34 per 100,000 children, respectively. As compared with other children with febrile seizures that were not associated with vaccination, the children who had febrile seizures after vaccination were not found to be at higher risk for subsequent seizures or neurodevelopmental disabilities. CONCLUSIONS: There are significantly elevated risks of febrile seizures on the day of receipt of DTP vaccine and 8 to 14 days after the receipt of MMR vaccine, but these risks do not appear to be associated with any long-term, adverse consequences.

Association of lower continuity of care with greater risk of emergency department use and hospitalization in children.

CONTEXT: The benefits of continuity of pediatric care remain controversial. OBJECTIVE: To determine whether there is an association between having a continuous relationship with a primary care pediatric provider and decreased risk of emergency department (ED) visitation and hospitalization. DESIGN: Retrospective cohort study. Setting and Population. We used claims data from 46 097 pediatric patients enrolled at Group Health Cooperative, a large staff-model health maintenance organization, between January 1, 1993, and December 31, 1998, for our analysis. To be eligible, patients had to have been continuously enrolled for at least a 2-year period or since birth and to have made at least 4 visits to one of the Group Health Cooperative clinics. MAIN EXPOSURE VARIABLE: A continuity of care (COC) index that quantifies the degree to which a patient has experienced continuous care with a provider. MAIN OUTCOME MEASURES: ED utilization and hospitalization. RESULTS: Compared with children with the highest COC, children with medium continuity were more likely to have visited the ED (hazard ratio [HR]: 1.28 [1.20-1.36]) and more likely to be hospitalized (HR: 1.22 [1.09-1.38]). Children with the lowest COC were even more likely to have visited the ED (HR: 1.58 [1.49-1.66]) and to be hospitalized (HR: 1.54 [1.33-1.75]). These risks were even greater for children on Medicaid and those with asthma. CONCLUSIONS: Lower continuity of primary care is associated with higher risk of ED utilization and hospitalization. Efforts to improve and maintain continuity may be warranted.

A randomized controlled trial of point-of-care evidence to improve the antibiotic prescribing practices for otitis media in children.

CONTEXT: Prescribing practices for otitis media are not consistent with current evidence-based recommendations. OBJECTIVE: To determine whether point-of-care evidence delivery regarding the use and duration of antibiotics for otitis media decreases the duration of therapy from 10 days and decreases the frequency of prescriptions written. DESIGN: Randomized, controlled trial. SETTING: Primary care pediatric clinic affiliated with university training program. Intervention. A point-of-care evidence-based message system presenting real time evidence to providers based on their prescribing practice for otitis media. MAIN OUTCOME MEASURES: Proportion of prescriptions for otitis media that were for <10 days and frequency with which antibiotics were prescribed. RESULTS: Intervention providers had a 34% greater reduction in the proportion of time they prescribed antibiotics for <10 days. Intervention providers were less likely to prescribe antibiotics than were control providers. CONCLUSIONS: A point-of-care information system integrated into outpatient pediatric care can significantly influence provider behavior for a common condition.

Methodologic issues in pediatric outcomes research.

Clinicians, health services researchers, and third-party payers, among others, are justifiably interested in the outcomes of pediatric medical care and are, therefore, supportive of research in this area. Pediatric populations pose some unique methodologic challenges for health services researchers. To date, however, many of the approaches, models, and techniques used in pediatric outcomes research have been imported uncritically from experience with adult populations. As a result, some of the most interesting and salient aspects of pediatric outcomes research have yet to be fully developed. These include the following: 1) the problems posed by the dynamics of childhood development, 2) an emphasis on health supervision, 3) the need to see children within the context of a family system and to appreciate the interrelatedness of child health domains, 4) the measurement of the effects of interventions that span sectors, and 5) the paucity of available data sources. This article reviews these problematic areas and argues for a broad conceptual definition of pediatric health, a systems approach to assessing outcomes, and increased interdisciplinary collaboration.

Continuity and quality of care for children with diabetes who are covered by medicaid.

BACKGROUND: Poor and minority children with Type 1 diabetes mellitus are at increased risk of severe adverse outcomes as a result of their disease. However, little is known about the quality of care that these children receive and which factors are associated with better quality of care. OBJECTIVES: Our objectives were as follows: 1) to describe the utilization of services associated with quality of care for children with Type 1 diabetes mellitus who are covered by Medicaid and 2) to test the hypothesis that increased continuity of primary care is associated with better care for these children. DESIGN: Retrospective cohort study. METHODS: Washington State Medicaid claims data for 1997 were used to determine what proportion of children with diabetes had 1) an inpatient or outpatient diagnosis of diabetic ketoacidosis (DKA), 2) a glycosylated hemoglobin (HgA1c) level that had been checked, 3) a retinal examination, and 4) thyroid function studies. Continuity of care was quantified using a pre-established index. RESULTS: Two hundred fifty-two eligible patients were identified. During the observation year, 20% had an outpatient diagnosis of DKA, 6% were admitted with DKA, 43% visited an ophthalmologist, 54% had their HgA1c checked, and 21% had their thyroid function assessed. Children with high continuity of care were less likely to have DKA as an outpatient (0.30 [0.13-0.71]). Children with medium continuity of care and high continuity of care were less likely to be hospitalized for DKA (0.22 [0.05-0.87] and 0.14 [0.03-0.67], respectively). For preventive services utilization, high continuity of care was associated only with an increased likelihood of visiting an ophthalmologist (2.80 [1.08-3.88]). CONCLUSIONS: The quality of care for Medicaid children with diabetes can be substantially improved. Low continuity of primary care is an identifiable risk factor for DKA.