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PubMed2003

Ductus venosus flow velocities in relation to the cardiac defects in first-trimester fetuses with enlarged nuchal translucency.

OBJECTIVE: Our aim is to study first-trimester ductus venosus (DV) velocities in relation to cardiac abnormalities. STUDY DESIGN: Ultrasound examination was performed in 85 normal fetuses and 45 fetuses with a nuchal translucency (NT) >95th percentile. Pulsatility index for veins (PIV) and velocity during late diastole (a-V) of the DV were measured and compared with the use of multilevel analysis, between fetuses with a heart defect and those without. RESULTS: Compared with 85 normal fetuses, the a-V and PIV of the fetuses with NT>95th percentile and normal hearts were decreased and increased, respectively. The a-V and PIV of 11 fetuses with NT>95th percentile and cardiac defects were decreased and increased compared with the 25 fetuses with normal hearts, irrespective of the karyotype. The most common cardiac malformations were septal defects. CONCLUSION: Fetuses with NT >95th percentile and cardiac defects show markedly changed DV velocities. Because the type of cardiac defects cannot always explain the hemodynamic changes found in these fetuses, some other mechanisms seem to be involved.

Adult↗
PubMed1999

Recovery versus retest effects in attention after closed head injury.

Recovery in 60 patients with a closed-head injury (CHI) in the first year posttrauma was assessed repeatedly with a series of attention tests. A matched group of healthy subjects was tested at the same intervals to allow us to control for practice effects. The results of a multilevel analysis for longitudinal data show retest effects in all but one of the tests. Patients performed more poorly on all tests, but their results on each test appeared to show recovery over time. The indicator of recovery was an improvement in test performance that was greater than the retest effect shown by the controls. On most tests, the performance of the more severely injured patients was initially worse, but showed more recovery over time. Test results differed with respect to changes over time, sensitivity to severity of injury, and subject specific characteristics like age and vocational level. Recovery rate was not related to age or vocational status. Despite their recovery, the patient group was still impaired 1 year posttrauma on all tests sensitive to mental slowness. Outcome after 1 year, scored on a modified Glasgow Outcome Scale, was predicted to a small extent by PTA duration and initial performance on the RT-Distraction task. Return to work 2 to 5 years posttrauma was predicted by initial performance and improvement over time on the Stroop Color Word Test.

Adolescent↗
PubMed2003

Sampling procedure, participation rates and representativeness in the Swedish part of the European Youth Heart Study (EYHS).

OBJECTIVE: The European Youth Heart Study (EYHS) is a cross-sectional, school-based population study on risk factors for future cardiovascular disease in children, with an overall participation rate in Sweden of about 50%. To study the representativeness of the participants in the Swedish part of EYHS, a comprehensive non-participant follow-up study was carried out. DESIGN: A structured multilevel analysis model was developed, addressing each level in the sampling procedure. The income, educational and occupational categories of the geographical regions of the study (level I), school catchment areas (level II) and parents (level III) were compared with official data. Participating and non-participating pupils (level IV) were compared through a questionnaire. SETTING: Thirty-seven state schools in two regions of Central Sweden (Orebro and southern Stockholm) were visited during the school year 1998/1999. SUBJECTS: Boys and girls aged 9 and 15 years were randomly sampled through a multiphase sampling procedure. RESULTS: Data for socio-economic status for levels I and II corresponded well to national and regional official data. At level III, non-manually working parents were slightly over-represented among parents of participating children. At level IV, non-participating subjects corresponded in most respects to participants with a few exceptions--mainly more interest in physical exercise among participants. CONCLUSIONS: Based on the knowledge from the non-participant study, we do not foresee problems regarding interpretation of the outcomes in the EYHS, despite the low participation rate.

Adolescent↗
PubMed2001

Effect of teachers' stereotyping on students' stereotyping of mathematics as a male domain.

This multilevel analysis used data from a representative sample from Grades 6, 7, and 8 in public schools in Switzerland. The data included information on (a) 6,602 students (3,307 girls, 3,295 boys) nested within 338 classes and (b) 321 mathematics teachers of these classes. The teachers and the students tended to stereotype mathematics as a male domain, and the teachers' stereotypes significantly affected the students' stereotypes after the author controlled for achievement, interest, and self-confidence in mathematics and for school grade and schooling track.

Achievement↗
PubMed2004

Maternal prenatal stress and 4-6 year old children's salivary cortisol concentrations pre- and post-vaccination.

In this study influences of maternal prenatal stress on the cortisol reactions of children to a vaccination were determined. Prenatal stress at around 16 weeks of gestation was measured through questionnaires and a cortisol day curve. Cortisol reactions were determined preceding and following the vaccination. A total of 24 children (age between 3.11 and 5.9 years, mean age 4.9 years) and their mothers participated in this study. Multilevel analysis (hierarchical linear modelling) was used to analyze the data. Children of mothers who had higher concentrations of morning cortisol during pregnancy had higher concentrations of cortisol as compared to children of mothers who had lower concentrations of morning cortisol. Furthermore, more daily hassles and a higher level of fear of bearing a handicapped child during pregnancy were associated with higher concentrations of cortisol in the children.

Adult↗
PubMed2006

Health behaviour among adolescents in Denmark: influence of school class and individual risk factors.

AIMS: The aim of this study was to assess the relative influence of school class on health behaviour among adolescents versus that of the family's socioeconomic status and individual factors among adolescents. METHODS: The material comprised 3,458 students in grades 8 and 9 in 244 school classes. Data were collected through questionnaires completed by the students and by their class teacher and information from the school physician. Multilevel analysis was used to indicate the relative significance of individual and school class characteristics. RESULTS: We find no consistent pattern between the mother's socioeconomic status and the included health behaviour measurements; however, adolescents from the lower socioeconomic groups had a higher risk of unhealthy dietary habits and adolescents whose mothers were unemployed had a significantly lower risk of drinking alcohol weekly versus all other adolescents. Not living with both biological parents, focusing on friends, and not being very academically proficient were associated with an increased risk of harmful health behaviour. Health behaviour varied substantially between school classes, especially for daily smoking, weekly alcohol consumption, and use of hashish and other euphoriants. Circumstances in the school class more profoundly influenced risk behaviour among adolescents (smoking, alcohol consumption, and use of hashish or other euphoriants) than their dietary habits (eating breakfast, frequent intake of fruit and vegetables, and frequent intake of soft drinks). CONCLUSIONS: The school class had the relatively strongest influence on adolescents' risk behaviour (smoking, alcohol intake, and use of hashish or other euphoriants), whereas family circumstances comprised the strongest influence on dietary habits.

Adolescent↗
PubMed2003

Changes of plasma lipoprotein(a) during and after normal pregnancy in Caucasians.

OBJECTIVE: Elevated plasma concentrations of lipoprotein(a) are associated with an increased risk for development of atherosclerosis. High lipoprotein(a) concentrations may also be associated with pregnancy-induced hypertension and pre-eclampsia, but reference data on the course of lipoprotein(a) during uneventful pregnancies are limited and questionable. METHODS: We studied plasma lipoprotein(a) concentrations in 19 healthy nulliparous Caucasian women during and after uncomplicated pregnancy. Blood was sampled every 4 weeks during pregnancy from 9 weeks onwards, during labor and at 2-4 weeks and 3-5 months after delivery. An apolipoprotein(a) (apo(a)) isoform-independent enzyme-linked immunosorbent assay (ELISA) was used to measure lipoprotein(a). Multilevel analysis was used to describe the data. RESULTS: Lipoprotein(a) increased until 35 weeks, subsequently decreased slightly until delivery, and fell to values below early pregnancy concentrations thereafter. The curve is defined by the formula lipoprotein(a) (mg/l) = exp [4.789 + (0.05215 x GA) + (-0.0007371 x GA2)] where GA = gestational age in weeks. CONCLUSIONS: We constructed a curve for plasma lipoprotein(a) which may serve as the standard reference for changes in pregnancy. Its formula is helpful in predicting changes of gestational age-dependent changes of lipoprotein(a) in normal pregnancy.

Adult↗
PubMed1991

Vertical facial growth: a longitudinal study from 7 to 14 years of age.

Multilevel analysis is used to describe the changes in vertical facial dimensions and their relationships in Dutch girls between 7 and 14 years of age. For the anterior face height (nasion-gnathion) and the posterior face height (sella-gonion) a fourth degree polynomial was fitted. The mandibular plane angle (sella nasion-gonion gnathion) could be described with a second degree polynomial. Low correlations were found between the growth parameters (intercept and age coefficient) of the anterior and posterior face height, which points to independent growth and development of the anterior and posterior face height. The individual length and growth velocity (at age 10.8) of the anterior face height and the mandibular plane angle showed substantial correlations. It was concluded that changes during growth with regard to the mandibular plane angle are more strongly related to the anterior than to the posterior face height.

Adolescent↗
PubMed2003

Giving while in need: support provided by disabled older adults.

OBJECTIVES: This paper focuses on predictors and patterns of support provision over time among disabled older adults. The ability to provide support to others may become an especially critical issue for persons who are dealing with a progressive, chronic impairment that typically results in increased functional disability and thus places them in greater need for support. METHODS: This multilevel analysis examined change in support provision over time, as well as the degree to which sociodemographics, health, functional disability, use of rehabilitation services, and the receipt of support predicted support provision. Participants, 449 older adults with a progressive, chronic visual impairment, were interviewed three times over an 18-month period. RESULTS: Affective and instrumental support provided to family and friends each showed a decrease over time. Age, gender, and education emerged as predictors of support provided at baseline. Receipt of support was positively related to support provision at all three time points, both within and across support types. DISCUSSION: Findings indicated that there may be feasible ways of providing support, even by older adults who are in need of support themselves.

Aged↗
PubMed2006

Outpatient care utilization in urban Kerala, India.

CONTEXT: Kerala is characterized by a high density of public and private health infrastructure. While less inequality in access has been reported in this Indian state, few studies have looked at problems found within cities. Escalation of costs of private services and reduced public investments could generate some inequalities in access for the poor. OBJECTIVE: To assess factors associated with utilization and source of outpatient care in urban Kerala, and to discuss policy implications with regards to access to care. METHODS: A multilevel analysis of individual and urban characteristics associated with utilization and source of outpatient care was conducted using data from a 1995-96 survey by the National Sample Survey Organisation on health care in urban Kerala. RESULTS: There is a high level of utilization (83.6%) of allopathic medical services. Controlling for illness severity and age, utilization thereof was lower for the very poor (OR 0.13 [0.03; 0.49]), inhabitants of medium towns (OR 0.20 [0.05; 0.70]), and inhabitants of cities with a lower proportion of permanent material (pucca) houses (0.21 [0.06; 0.72]). Among all users, 77% resorted to a private source of care. Utilization of a private provider was less likely for the very poor (OR 0.13 [0.03; 0.51]) and individuals from casual worker households (OR 0.54 [0.30; 0.97]), while it was more likely for inhabitants of cities from both low public bed density districts (OR 4.08 [1.05; 15.95]) and high private bed density districts (OR 5.83 [2.34; 14.53]). Problems of quality and accessibility of the public sector were invoked to justify utilization of private clinics. A marked heterogeneity in utilization of outpatient care was found between cities of various sizes and characteristics. CONCLUSION: This study confirms high utilization of private outpatient care in Kerala and suggests problems of access for the poorest. Even in a context of high public availability and considering the health transition factor, relying on the development of the private sector to respond to increasing health care needs could create inequalities in access. Investing in the public urban primary care system and ensuring access to quality health care for the poorest is warranted.

Adolescent↗
PubMed2000

Epidemiological models and related simulation results for understanding of contraceptive adoption in India.

BACKGROUND: For the first time, models using multilevel analysis of Indian data and related simulation results are reported. They take hierarchical structure into account and incorporate variables from all levels to get correct analysis and proper interpretation of data on current contraceptive use (including sterilization and modern methods). METHODS: The data from an Indian State, Uttar Pradesh (UP), collected by the National Family Health Survey (NFHS) conducted during 10 October 1992 to 22 February 1993 was used. For model I, 7851 currently married women who were neither pregnant nor had continuing post-partum amenorrhoea (PPA) were considered. For model II, these women with at least one child (n = 6748) were used. Two-level logistic regression analysis was carried out for which women's level (level 1) and PSU (Primary Sampling Unit) level (level 2) variables were considered. The results were considered significant at the 5% level of significance. Simulation analysis using each model was also carried out. RESULTS: Model I reveals that those more likely to adopt contraception were women exposed to a TV message (odds ratio [OR] = 1.3; 95% CI: 1.1-1.6); whose houses were pucca (bricks and mortar) (OR = 1.3; 95% CI: 1.1-1.5); who were educated to high school level and above (OR = 2.9; 95% CI: 2.2-3.7); whose husbands were literate with schooling of > or =11 years (OR = 1.7; 95% CI: 1.4-2.1); and who had > or =2 living sons (OR = 2.2; 95% CI: 1.1-4.4). Muslim and other religious women were less likely than Hindu women to adopt contraception (OR = 0.5; 95% CI: 0.4-0.6). Also, the PSU level availability of all weather road was positively associated with contraceptive adoption (OR = 1.4; 95% CI: 1.1-1.7). The PSU level variance, which is the unexplained PSU level variation after controlling for the considered characteristics, was significantly higher. The simulation results revealed that public health education (a TV message) was found to be more effective among less educated women. The PSU level availability of all weather road was as effective as public health education. Similar results were evident from the analysis of second data set (model II) with the noticeable finding that those whose last child is surviving are most likely to adopt contraception (OR = 8.82; 95% CI: 1.01-77.38). CONCLUSIONS: These results reveal that the survival status of the last child has a marked effect on the adoption of contraception in UP. They further support the idea that public health education (a TV message) is more effective among less educated women. Also, the PSU level presence of all weather road is equally effective. Consideration of higher level variables provides not only more accurate results but also important public health clues to help the policy planners.

Adolescent↗
PubMed1999

How do we compare with our colleagues? Quality of general practitioner performance in consultations for non-acute abdominal complaints.

OBJECTIVE: To investigate what factors influence the quality of general practitioner performance in consultations for non-acute abdominal complaints and to establish the extent to which performance quality differs between general practitioners (GPs). DESIGN: Explorative study in two parts: (i) detection of variables influencing quality scores of consultations; and (ii) comparison of mean quality scores of the consultations, selected by each GP. SETTING: Sixty-two family practices across The Netherlands. SUBJECTS: Eight-hundred and forty consultations concerning non-acute abdominal complaints, first encounters; 62 GPs. METHOD: Multilevel analysis was carried out to detect factors that influence quality. After correction for the effect of significant factors the mean quality scores of individual GPs were calculated and compared. RESULTS: Eighty-eight per cent of the total variance in quality scores was located at the consultation/patient level, and 12% at the GP level. One consultation characteristic had significant influence on quality: quality scores were higher in consultations of longer than average duration (>15 minutes). Several patient characteristics were of significant influence. Consultation quality scores were higher in consultations for patients with upper abdominal or non-specific abdominal complaints. Quality scores were lower in consultations with female patients and with patients aged >40 years. Together these characteristics explained 20% of the variance at the GP level. None of the GP characteristics investigated in this study appeared to have significant influence on the quality of their performance. After correction of the scores for the effect of significant factors the differences in performance quality between GPs remained significant. CONCLUSIONS: Quality of performance is far more influenced by consultation and patient characteristics than by GP characteristics. After correction for influencing factors, the mean quality scores of GPs still differed considerably and significantly. For many GPs the quality scores varied substantially between different consultations; to a large extent this variation remained unexplained. Consultation quality can be improved by booking more time per patient and by giving more medical/technical attention to female and older patients.

Adolescent↗
PubMed2004

Factors influencing bruises and mortality of broilers during catching, transport, and lairage.

A multilevel analysis was performed to identify and quantify risk factors associated with mortality and bruises occurring between catching and slaughter of broiler flocks. The effect of each factor in the final model was expressed as an odds ratio (OR). Data included 1,907 Dutch and German broiler flocks slaughtered in 2000 and 2001 at a Dutch processing plant. The mean dead on arrival (DOA) percentage was 0.46. Percentage of bruises was corrected for economic value. The mean corrected bruises percentage was 2.20. Factors associated with corrected bruises percentage were season, moment of transport, and ambient temperature. Unfortunately, these factors are quite difficult to manipulate. Factors associated with DOA percentage were ambient temperature, moment of transport, catching company, breed, flock size, mean BW, mean compartment stocking density, transport time, lairage time, and the interaction term transport time x ambient temperature. The most important factors that influence DOA percentage, and which can be reduced relatively easily, were compartment stocking density (OR = 1.09 for each additional bird in a compartment), transport time (OR = 1.06 for each additional 15 min), and lairage time (OR = 1.03 for each additional 15 min). In particular, reduction of transport and lairage times might have a major influence due to their large variations. Reducing or removing these factors will reduce DOA percentage. Consequently, profitability and animal welfare will increase.

Animal Welfare↗
PubMed1998

Mixed messages about primary care in the culture of U.S. medical schools.

PURPOSE: To examine the contributions of school-level variables associated with primary care career choice to students' enthusiasm for and perceived encouragement toward primary care. METHOD: Multilevel analysis of 264 fourth-year students and 500 clinical faculty members at 59 medical schools using data obtained in 1993 to 1994 from telephone interviews of a national stratified probability sample of students (response rate 90%) and faculty (response rate 81%). RESULTS: On average, students reported slightly positive regard for primary care and felt neither supported nor unsupported in their interests in primary care. Students' reports of encouragement toward primary care showed some consistency within schools (intraclass correlation = .08); their regard for primary care did not (intraclass correlation = .02). Regard for primary care was associated with students' intended specialty choices (p < .001), with students who planned to enter primary care careers reporting more positive attitudes. Students' perceptions of encouragement toward primary care careers were unrelated to their intended specialty choices, but significantly related to their schools' historical primary care production (p < .0001), federal research funding (p < .01), and school ownership (p < .01). CONCLUSION: Schools that have primary care missions and have historically produced more generalists transmit higher levels of encouragement to their students about primary care. However, even at schools with strong primary care missions, students hold unenthusiastic attitudes about primary care practice.

Attitude of Health Personnel↗
PubMed2000

Gender-related differences in the organization and provision of services among general practitioners in Europe: a signal to health care planners.

BACKGROUND: The number of women entering general practice is rising in many countries. Thus, gender differences in work situation preferences and practice activities are important for future planning. OBJECTIVES: This article describes the differences between male and female general practitioners (GPs) in 32 European countries. It examines gender differences in curative and preventive services and relates these to features of the health care system and the practice. METHODS: The data were collected in 1993 and 1994 in the European Study of Task Profiles of General Practitioners. In 32 countries, 8,183 GPs answered standardized questionnaires written in their own languages on their self-reported involvement in curative and preventive services, as well as how their practice was organized and managed. Because the independent variables in this study were on both the national 1 and individual practice levels, the data were subjected to multilevel analysis. RESULTS: Regardless of the type of health care system, the female GPs were younger than the male GPs and more often worked part time in groups or partnerships and in cities, although not in deprived areas. They made fewer house calls and did less work outside office hours. Differences between men and women regarding workload diminished considerably after controlling for part-time work. When other characteristics of the person and the practice were taken into account, female GPs proved to be less involved in several curative services, except as the first contact for gynecological problems, but more involved in health education. Some differences were found in only certain types of health care systems. CONCLUSIONS: The results may have important implications for working arrangements, training, education, and planning of resources for general practice in the future.

Adult↗
PubMedDate not supplied

The effects of nurse staffing on adverse events, morbidity, mortality, and medical costs.

BACKGROUND: Nurse staffing levels are an important working condition issue for nurses and believed to be a determinant of the quality of nursing care and patient outcomes. OBJECTIVES: To examine the effects of nurse staffing on adverse events, morbidity, mortality, and medical costs. METHODS: Using two existing databases, the study sample included 232 acute care California hospitals and 124,204 patients in 20 surgical diagnosis-related groups. The adverse events included patient fall/injury, pressure ulcer, adverse drug event, pneumonia, urinary tract infection, wound infection, and sepsis. Multilevel analysis was employed to examine, simultaneously, the effects of nurse staffing and patient and hospital characteristics on patient outcomes. RESULTS: Three statistically significant relationships were found between nurse staffing and adverse events. An increase of 1 hour worked by registered nurses (RN) per patient day was associated with an 8.9% decrease in the odds of pneumonia. Similarly, a 10% increase in RN Proportion was associated with a 9.5% decrease in the odds of pneumonia. Providing a greater number of nursing hours per patient day was associated with a higher probability of pressure ulcers. The occurrence of each adverse event was associated with a significantly prolonged length of stay and increased medical costs. Patients who had pneumonia, wound infection or sepsis had a greater probability of death during hospitalization. CONCLUSION: Patients are experiencing adverse events during hospitalization. Care systems to reduce adverse events and their consequences are needed. Having appropriate nurse staffing is a significant consideration in some cases.

California↗
PubMedDate not supplied

The effects of perceived stress, traits, mood states, and stressful daily events on salivary cortisol.

This study examined the effects of perceived stress and related individual characteristics, mood states, and stressful daily events on salivary cortisol levels. Forty-one "high stress" and 46 "low stress" subjects were selected on the basis of Perceived Stress Scale scores from a sample of male, white collar workers. Subjects completed Experience Sampling self-reports and collected saliva samples 10 times a day over 5 consecutive days. Multilevel analysis revealed that trait anxiety and depression, but not perceived stress, were associated with small but statistically significant cortisol elevation. No effects on cortisol were found for recent life events, chronic difficulties, trait anger, or psychosomatic symptoms. Distress, as reflected by the mood states Negative Affect and Agitation, was associated with higher cortisol levels, whereas Positive Affect had no statistically significant effect. Stressful daily events were associated with increased cortisol secretion, the magnitude of the effect depending on whether the event was still ongoing and on how frequently a similar kind of event had occurred previously. Although perceived stress, anxiety, and depression did not increase cortisol reactivity to daily events, we found evidence for reduced habituation to recurrent events in subjects scoring high on these traits. Mood appeared to play a mediating role in the relationship between stressful events and cortisol secretion. These results suggest that negative affectivity is not just a confounder but is related to elevated cortisol secretion during normal daily activities. The finding that even minor events and fluctuations in mood states were associated with increased adrenocortical activity points to a possible mechanism linking subjective experience to health outcomes.

Adult↗
PubMedDate not supplied

The effect of fear of movement on muscle activation in posttraumatic neck pain disability.

Studies using surface electromyography have demonstrated a reorganization of muscle activation patterns of the neck and shoulder muscles in patients with posttraumatic neck pain disability. The neurophysiologically oriented "pain adaptation" model explains this reorganization as a useful adaptation to prevent further pain and injury. The cognitive-behavioral-oriented "fear avoidance" model suggests that fear of movement, in addition to the effects of pain, modulates the muscle activation level. We analyzed the extent to which pain and fear of movement influenced the activation patterns of the upper trapezius muscle during the transition from acute to chronic posttraumatic neck pain. Ninety-two people with an acute traumatic neck injury after a motor vehicle accident were followed up for 24 weeks. Visual analog scale ratings of pain intensity, response on the Tampa Scale of Kinesophobia--fear of movement, and surface electromyography of the upper trapezius muscles during a submaximal isometric physical task were obtained at 1, 4, 8, 12, and 24 weeks after the motor vehicle accident. Multilevel analysis revealed that an increased level of both fear of movement (t value=-2.19, P=0.030) and pain intensity (t value=-2.94, P=0.004) were independently associated with a decreased level of muscle activation. Moreover, the results suggest that the association between fear of movement and lower muscle activity level is stronger in patients reporting high pain intensity (t value=2.15, P=0.033). The contribution of pain intensity to the muscle activation level appeared to decrease over time after the trauma (t value=2.58, P=0.011). The results support both the "pain adaptation" and the "fear avoidance" models. It is likely that the decrease in muscle activation level is aimed at "avoiding" the use of painful muscles.

Accidents, Traffic↗