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PubMed1977

[Isocount scanning in brain tumors-a quantitative investigation of the tracer activity (author's transl)].

In the previous reports, the theoretical background [corrected] and technical details of the Isocount scanning were described. Based on clinical experiences of various brain diseases, the newly developed scanning method was confirmed to be more useful than the conventional scintiscanning. Besides the new scanning method, a new display system was also developed for the sake of more precise analysis of the Isocount scanned data. This display method is called MULTILEVEL ANALYSIS or MULTILEVEL SLICING. In the present investigation, this method was applied to fortysix cases of brain tumors, including forty cases of supratentorial tumors and six cases of infratentorial tumors, positive rates being 95% and 67% respectively. Furthermore, as a measure of the quantitative investigation of the radioactive tracer uptake of the target area, the maximum uptake rate of the target area (RTmax.=Tmax./NTmean), and the deviation index (DI=DT/DNT) were introduced; Tmax., NTmean, DT and DNT are respectively defined as a maximum uptake of the target area, a mean uptake of the non-target area, a deviation rate of the target area and a deviation rate of the non-target area. They can be obtained from analysing the television figures of MULTILEVEL ANALYSIS. By this method, thirty-four cases of supratentorial tumors were studied. In cases of glioma (12 scans), meningioma (9 scans), and metastatic tumor (7 scans), the mean values of RTmax. were 1.26, 1.37, and 1.24 and the mean values of DI were 0.81, 0.68 and 0.60 respectively. In gliomas, the RTmax. and the DI were correlated with the degree of malignancy of the tumors. This quantitative analysis could be considered to be useful to foresee the nature of the brain tumor from the scintiscanning findings.

Adolescent↗
PubMed2005

An illustration of multilevel factor analysis.

The factor analysis of repeated measures psychiatric data presents interesting challenges for researchers in terms of identifying the latent structure of an assessment instrument. Specifically, repeated measures contain both within and between individual sources of variance. Although a number of techniques exist for separating out these 2 sources of variance, all are problematic. Recently, researchers have proposed that exploratory multilevel factor analysis (MFA) be used to appropriately analyze the latent structure of repeated measures data. The chief objective of this report is to provide a didactic step-by-step guide on how MFA may be applied to psychiatric data. In the discussion, we describe difficulties associated with MFA and consider challenges in factor analyzing life event appraisals in psychiatric samples.

Adolescent↗
PubMed2003

Factors associated with the difference in score between women's and doctors' decisional conflict about hormone therapy: a multilevel regression analysis.

OBJECTIVE: To explore factors associated with the difference in score between women's and doctors' decisional conflict about hormone therapy (HT). DESIGN: Secondary analysis. SETTING AND PARTICIPANTS: family doctors were randomized to prepare women for counselling about HT using either a decision aid or a pamphlet. MAIN VARIABLES STUDIED: After each counselling session, decisional conflict was assessed in women and doctors using the Decisional Conflict Scale (DCS) and the Provider Decision Process Assessment Instrument (PDPAI), respectively. The difference in score between the DCS and PDPAI was computed and entered as the dependent variable in a multilevel regression analysis. MAIN OUTCOME RESULTS: A total of 40 doctors and 167 women were included in the analysis. The intra-doctor correlation coefficient was 0.25. Factors associated with women experiencing higher decisional conflict than their doctor were: age of doctor >45 years, women who were undecided about the best choice after the counselling session, women with a university degree and women who said that their doctor usually does not give them control over treatment decision. Factors associated with doctors experiencing more decisional conflict than women were: doctors who were undecided about the quality of the decision, length of visit <30 min and women who thought that the decision was shared with their doctor. CONCLUSION: In order to reduce the disparities between women's and doctors' decisional conflict about HT, interventions aimed at raising awareness of doctors about shared decision-making should be encouraged.

Canada↗
PubMed2002

The dimensionality of speaking and writing: a multilevel factor analysis of situational, task and school effects.

BACKGROUND: This article addresses the question whether communication apprehension (CA) should be regarded as a unidimensional or alternatively as a multidimensional construct. The answer is not only interesting from a theoretical point of view. There might also be practical implications for the treatment of CA. If CA were to appear to be unidimensional and a student's level of CA were to be the same across situations and tasks, there would be no need to tailor the treatment to particular speaking situations or specific writing problems. If, however, CA appeared to be multi-dimensional and a student might have a variety of different levels and types of CA, one type of treatment might be more effective for one student than for another one. AIM: To examine the effects of situational, task and school effects on speaking and writing apprehension. SAMPLE: Use was made of the dataset of the 1987-1988 National Assessment of Language Performance in the Netherlands. The nationally representative sample consisted of 1448 students from 184 secondary schools; 52% of the students were boys and 48% were girls; the mean age of the students was 15 years 6 months. METHOD: Speaking and writing apprehension were measured by means of self-report measures in grade 9. Multilevel factor analysis (MLFA) was used to determine the dimensionality of the measurement of speaking and writing apprehension. RESULTS AND CONCLUSIONS: First, all seven speaking situations and three out of four writing problems could be distinguished empirically. Speaking and writing apprehension are clearly multidimensional constructs that depend on the speaking situation and the writing task. Second, correlations between speaking and writing apprehension were rather low. Speaking and writing apprehension seem to represent skill-specific constructs, which cannot be considered as equivalent forms of communication apprehension. Third, differences between schools in the level of speaking and writing apprehension were very small compared to measurements of speaking and writing performance.

Adolescent↗
PubMed2005

Role of socioeconomic markers and state prohibition policy in predicting alcohol consumption among men and women in India: a multilevel statistical analysis.

OBJECTIVE: To investigate the independent contribution of individual socioeconomic markers and state prohibition policy on alcohol consumption among men and women in India. METHODS: The study used a multilevel cross-sectional analysis of alcohol consumption from the 1998-1999 Indian national family health survey of 301 984 adult individuals in 92 447 households in 3215 villages in 440 districts in 26 states, stratified by sex. FINDINGS: Men with no education were more likely to consume alcohol that those with a post graduate education (OR, 2.28; 95% CI, 2.08-2.50). Unlike men, women showed a U-shaped association between education and alcohol consumption. Men and women living in households at the lowest standard-of-living quintile were more likely to consume alcohol (OR, 1.92; 95% CI, 1.81-2.03, and OR, 2.72, 95% CI, 2.18-3.39), respectively, than those classified as living in the top quintile. Members of scheduled tribes and castes and other backward classes were more likely to consume alcohol than members of other caste groups. There was no difference in alcohol consumption between men from states that were not under prohibition (OR, 1.36; 95% CI 0.69-2.03) and those that were. By contrast, states not under prohibition has higher alcohol use by women (OR, 3.04, 95% CI, 1.59-4.48) than those under partial or complete prohibition. CONCLUSION: Caste, education and standard of living independently influence alcohol use in India. Prohibition policies appear to have little effect on alcohol use by men, but may reduce the proportion of women who consume alcohol. The socioeconomic patterning of health behaviours is likely to feed substantially into inequalities in health outcomes. Further investigation is required to understand how social and cultural factors in more localized contexts (e.g. districts) influence alcohol consumption.

Alcohol Drinking↗
PubMed1999

Accidents to preschool children: comparing family and neighbourhood risk factors.

Accidental injury in young children is more common among poorer families and in deprived areas but little is known about how these factors interact. This paper describes a study to measure the contribution of individual family factors and area characteristics in determining risk of accidental injury among preschool children. We conducted a population based study of preschool accident and emergency attendances over two years in and around the city of Norwich, UK. Information on individual families was extracted from the district child health information system while "social areas" were constructed from adjacent census enumeration districts with homogeneous social and demographic characteristics. Statistical analysis was by multilevel modelling. Accidental injury rates were much higher in deprived urban neighbourhoods than in affluent areas but the multilevel analysis showed that, for all accidents, much of the variation in rates was accounted for by factors at the individual level i.e. male sex, young maternal age, number of elder siblings and distance from hospital, with a smaller, but independent, influence of living in a deprived neighbourhood. The model for more severe injuries was similar except single parenthood was now significant at the level of individuals and the effect of area deprivation was stronger. We conclude that preschool accidental injuries are influenced by factors operating at both the level of individual families and between areas. This evidence suggests that both social policy changes to improve child care among unsupported young families and targeting accident prevention measures at a local level towards deprived neighbourhoods would reduce accidents.

Accidents↗
PubMed2000

Doctor-patient communication in different European health care systems: relevance and performance from the patients' perspective.

Our aim is to investigate differences between European health care systems in the importance attached by patients to different aspects of doctor-patient communication and the GPs' performance of these aspects, both being from the patients' perspective. 3658 patients of 190 GPs in six European countries (Netherlands, Spain, United Kingdom, Belgium, Germany, Switzerland) completed pre- and post-visit questionnaires about relevance and performance of doctor-patient communication. Data were analyzed by variance analysis and by multilevel analysis. In the non-gatekeeping countries, patients considered both biomedical and psychosocial communication aspects to be more important than the patients in the gatekeeping countries. Similarly, in the patients' perception, the non-gatekeeping GPs dealt with these aspects more often. Patient characteristics (gender, age, education, psychosocial problems, bad health, depressive feelings, GPs' assessment of psychosocial background) showed many relationships. Of the GP characteristics, only the GPs' psychosocial diagnosis was associated with patient-reported psychosocial relevance and performance. Talking about biomedical issues was more important for the patients than talking about psychosocial issues, unless the patients presented psychosocial problems to the GP. Discrepancies between relevance and performance were apparent, especially with respect to biomedical aspects. The implications for health policy and for general practitioners are discussed.

Adolescent↗
PubMed2005

[Effectiveness of advanced group and individual interventions in tackling tobacco dependency in primary care].

OBJECTIVES: To compare the effectiveness of group advanced intervention and individual advanced intervention for smoking management in primary health care; b) to know if in group intervention exists an added positive effect due of the group and, if this is true, to characterize it; and c) to know the advantages and inconvenients that the participants attribute to each intervention. DESIGN: Control clinic trial randomized in individual scale. SETTING: Mallorca primary health centers, Spain. PARTICIPANTS: Smokers >5 packet-year or monoxid carbon levels >15 ppm prepared for give up smoking. People younger than 18 years, people with terminal illness, and mental problems will be excluded. INTERVENTIONS: Candidates will be assigned to: a) group intervention; b) individual intervention; or c) short intervention or control group. Interventions will be done by a nurse and a general practitioner. Depth interview will be done for qualitative study. PRINCIPAL MEASUREMENT: Maintained cessation during 12 months confirmed by expired-air carbon monoxide measurement. SECONDARY MEASUREMENTS: Self-declared cessation and confirmed by expired-air carbon monoxide measurement months 1, 2, 3, 6, and 9, and tobacco reduction if there isn't abandonment. ANALYSIS: Intention treatment. Multilevel analysis will be done to determinate the positive effect added of the group if it's proved that exists. Content analysis for qualitative study. DISCUSSION: Randomization will prevent participants will be treated by their general practitioner o their nurse, this can mean worse results than results obtained in practice.

Female↗
PubMed2006

[Multilevel model analysis on the influence of smoking among university students in Tianjin].

OBJECTIVE: To study the influencing factors of smoking among university students on individual and classes level by multilevel model and to identify high risk groups in order to develop pertinent prevention measures which can decrease smoking behavior among university students. METHODS: Self-reported data on knowledge, attitude and behavior on smoking coming from a randomly clustered sampling of 24 classes in students from 12 universities in Tianjin. RESULTS: Through analyses of 743 questionnaires from university students, we learned that the occasional smoking rate was 10.0% , the regular smoking rate was 7.4% and 5.9% had given up smoking. The influencing factors for students who smoked occasionally and regularily were gender (OR values were 0.243 and 0. 186), moods (OR values were 0.071 and 0.078) and environment (OR values were 2.722 and 19.075). Gender (OR value was 0. 180), age (OR value was 1.567), moods (OR value was 0.221) and environment (OR value was 2.776) had positive influences on students in giving up their smoking behavior. CONCLUSION: According to the different status of university students, different measures should be taken to prevent smoking and to change thier smoking behavior.

China↗
PubMed2000

A novel model of retinopathy of prematurity simulating preterm oxygen variability in the rat.

PURPOSE: To examine changes in the retinal vasculature of rat pups after 14 days of minute-by-minute small variations in oxygen. METHODS: Arterial oxygen data from a preterm infant who developed severe retinopathy of prematurity (ROP) was translated to equivalent values for the rat. Newborn rat pups were raised for 14 days in a cage in which a computer controlled the atmosphere to mimic the fluctuating oxygen profile (group V). Positive controls (P) of 12-hour cycles of 80% and 21% were run concurrently, as were room air controls (C). All were killed at day 14. RESULTS: Groups V and P had significantly larger avascular retinal areas than C [median, interquartile range (IQR) 1.7%, 0-7.9%; 10%, 8.1-13%; 0%, 0-0%, respectively; each group n = 30]. Group P had a higher capillary branch count than C (median, IQR: 310/mm(2); 253-311 mm(2); versus 277/mm(2), 272-364/mm(2), respectively), but this was not significant using a multilevel analysis. Group V had significantly reduced capillary counts compared with C (median, 261/mm(2); IQR, 215-290/mm(2); P < 0.05 multilevel analysis). No neovascularization was seen in any group, though abnormal terminal vessels were seen at the avascular/vascular retina interface in 73% of rats in group P and 21% of rats in group V. In situ hybridization on serial sections demonstrated VEGF in the inner nuclear layer of the retina in P and V, whereas C showed trace levels only. CONCLUSIONS: The vaso-obliterative stage of ROP can be induced in rats using clinically relevant oxygen levels.

Animals↗
PubMed2005

Relative contribution of patient-, tooth-, and site-associated variability on the clinical outcomes of subgingival debridement. I. Probing depths.

BACKGROUND: The objective of this clinical trial was to assess the relative contribution of patient-, tooth-, and site-associated variables on changes in probing depths (PD) following delivery of a standard non-surgical phase of periodontal therapy. METHODS: Ninety-four (94) systemically healthy subjects with severe generalized periodontitis were included in this 6-month prospective longitudinal study. Medical, periodontal, and microbiological parameters were collected at baseline and 2 and 6 months after completion of oral hygiene instructions, motivation, and subgingival debridement using a piezoelectric instrument. The relative contribution of patient-, tooth-, and site-associated variables was evaluated with a hierarchical multilevel analysis. RESULTS: Eighty percent (80%) of variability in PD reductions was attributed to site level parameters, while 12% was at the tooth level and 8% at the patient level. The multilevel analysis associated PD reductions with patient factors (cigarette smoking status and carriage of the rare allele of a specific polymorphism for the interleukin-6 [IL-6] gene), tooth factors (tooth mobility and tooth type), and site factors (mesial and distal location). Cigarette smoking and carriage of the rare allele of the IL- 6-174 G/C polymorphism were associated with less PD reduction. Incisors and canines responded better than premolars and molars. A dose-dependent effect of mobility was observed: teeth with higher baseline mobility resulted in significantly greater decreases in PD. At the site level, greater reductions were observed at interdental sites (compared to facial or oral), and at deeper sites (1.2 mm for 4 to 5 mm pockets and 2.4 mm for pockets > or =6 mm). CONCLUSION: These data provided an estimation of the relative contribution of site-, tooth-, and patient-associated variables in terms of PD reductions following a standard course of machine-driven subgingival debridement.

Cytosine↗
PubMed2002

Consultation length in general practice: cross sectional study in six European countries.

OBJECTIVES: To compare determinants of consultation length discussed in the literature with those found in consultations with general practitioners from different European countries; to explore the determinants of consultation length, particularly the effect of doctors' and patients' perceptions of psychosocial aspects. DESIGN: Analysis of videotaped consultations of general practitioners from the Eurocommunication study and of questionnaires completed by doctors and by patients. SETTING: General practices in six European countries. PARTICIPANTS: 190 general practitioners and 3674 patients. RESULTS: In a multilevel analysis with three levels (country, general practitioner, and patient), country and doctor variables contributed a similar amount to the total variance in consultation length (23% and 22%, respectively) and patient variables accounted for 55% of the variance. The variables used in the multilevel analysis explained 25% of the total variation. The country in which the doctor practised, combined with the doctors' variables, was as important for the variance in consultation length as the variation between patients. Consultations in which psychosocial problems were considered important by the doctor and the patient lasted longer than consultations about biomedical problems only. The doctor's perception had more influence in this situation than the patient's. Consultation length is influenced by the patients' sex (women got longer consultations), whether the practice was urban or rural, the number of new problems discussed in the consultation (the more problems the longer the consultation), and the patient's age (the older the patient the longer the consultation). As a doctor's workload increased, the length of consultations decreased. The general practitioner's sex or age and patient's level of education were not related to the length of consultation. CONCLUSION: Consultation length is determined by variables related to the doctor and the doctor's country as well as by those related to patients. Women consulting in an urban practice with problems perceived as psychosocial have longer consultations than other patients.

Adult↗
PubMedDate not supplied

Saving future lives. A comparison of three discounting models.

This paper compares three models of intertemporal choice concerning saving future lives: the constant discounting model, the proportional discounting model and the hyperbolic discounting model. The three models were investigated using data collected from the general public. Since these data have a multilevel structure, ordinary least-squares (OLS) estimates were supplemented by multilevel analysis. There is evidence in favour of the proportional (and to a lesser extent) the hyperbolic model over the constant discounting model. There is clear evidence for this data set that multilevel analysis is more appropriate than OLS.

Adult↗
PubMedDate not supplied

Are patients' ratings of their physicians related to health outcomes?

PURPOSE: Observational studies using patient reports suggest associations between physician interpersonal styles and patient outcomes. Possible confounding of these associations has not been carefully examined. METHODS: Approximately 4,700 patients of 96 physicians completed a survey instrument that included reported health status changes during the previous year, perceptions of their physician (satisfaction, trust, knowledge of patient, and autonomy support), and sociodemographic and clinical covariates. We examined the adjusted relationship between patient perceptions of their physicians and reported health status changes. Using multilevel analyses, we then explored differences among physicians in patient perceptions of their physicians and whether these differences were explained by the relationship between patient perceptions and reported health status changes. RESULTS: There were significant adjusted relationships between patient perceptions of their physician and reported health status changes: better perceptions were associated with a smaller risk of health status decline (adjusted odds ratio = 1.14; 95% confidence interval [CI], 1.05-1.24; P <.01). Multilevel analysis showed significant differences between physicians in patient perceptions of their physicians (rho = 0.10; 95% CI, 0.07-0.13; P <.01), but these physician differences were unrelated to reported health status decline (rho = 0; P >.99). CONCLUSIONS: Using methods similar to those of previous studies, we found a relationship between patient perceptions of their physicians and reported health status declines. Multilevel analysis, however, suggested that this relationship is not a physician effect; it may reflect unmeasured patient confounding. Multilevel analyses may help to examine the relationships between physician styles and outcomes.

Adult↗
PubMed2005

Changing analytical approaches in European epidemiology -- a short comment on a recent article.

Multilevel analysis is today considered a more appropriate way to monitor health care performance, as it allows a less biased estimation of uncertainty, and can also separate and quantify contextual (as opposed to individual) effects. Multilevel analysis should be applied as the standard methodology for hospital comparisons. A greater awareness of this question in future Journal articles may be in order.

Adult↗
PubMed2003

[Use of multilevel models in health research].

OBJECTIVE: The aim of this study was to analyze the use of multilevel methodology in health sciences. DESIGN: A literature search was performed in Medline for articles published between 1995 and 2001. Fifteen search words were used, some of which were "multilevel model", "multilevel analysis", "hierarchical linear model", "mixed model", and "random effects model". A total of 1288 abstracts were retrieved. Two hundred twenty-two of the articles on theoretical and/or applied issues related to multilevel methods were examined to determine their current use, the type of model, the number of levels, the units of analysis and the outcome variables related to health sciences. RESULTS: 66.7% of the articles studied was found with the keywords: "multilevel analysis", "multilevel modelling" and "multilevel model". Fifty-six percent of the articles were multilevel applications in different health sciences. However, in 10% of the articles, the main objective was to present and disseminate the methodology in a language comprehensible to non-specialists. CONCLUSIONS: The use of multilevel modelling in health has increased with time and is being applied in different health areas and specialties. However, it is still not considered a commonly used technique.

Biomedical Research↗
PubMed2004

Family caregiver satisfaction with the nursing home after placement of a relative with dementia.

OBJECTIVE: This article examines family caregiver satisfaction after nursing home placement of a relative with Alzheimer disease or a related dementia. Determining what contributes to family caregiver satisfaction is a critical step toward implementing effective quality improvement strategies. METHODS: A stress process model is used to study caregiver satisfaction among 285 family caregivers in relation to primary objective stressors (stage of dementia, length of stay, length of time in caregiving role, visitation frequency, involvement in nursing home, and involvement in hands-on care), subjective stressors (expectations for care), caregiver characteristics (education, marital status, familial relationship, workforce participation, distance from nursing home, and age), and organizational resources (rural/urban location, profit/nonprofit ownership, special care unit [SCU] designation, and custodial unit designation). SAS PROC MIXED is used in a multilevel analysis. RESULTS: Higher satisfaction is associated with earlier stage of dementia, greater length of time involved in caregiving prior to institutionalization, higher visitation frequency, less involvement in hands-on care, greater expectations for care, and less workforce participation. DISCUSSION: Multilevel analysis showed that primary stressors are the strongest predictors of satisfaction. Only one caregiver characteristic (work participation) and one organizational resource (rural/urban location) predict satisfaction. SCU designation was unrelated to satisfaction, perhaps because SCUs have less to offer residents in more advanced as opposed to earlier stages of Alzheimer disease. If family satisfaction is to be achieved, family presence in a nursing home needs to give caregivers a sense of positive involvement and influence over the care of their relative.

Aged↗
PubMed1998

Patient satisfaction with the general practitioner: a two-level analysis.

OBJECTIVES: The authors examine how patient satisfaction with health care providers relates to either the individual characteristics of respondents or the characteristics of health care providers and the structural setting in which they work. METHODS: Measures of three dimensions of patient satisfaction with the general practitioner (GP)--accessibility, interpersonal relationship, information given--were derived from an existing data set. Patients were nested with GPs. Multilevel analysis was used as the analyzing technique. RESULTS: Between 90% and 95% of the variance in patient satisfaction scores is at the patient level, whereas the remaining 5% to 10% is at the GP or practice level. At the patient level, in addition to the usual predictor variables such as age and morbidity, which explain approximately 5% of the variance at this level, previous experiences with the general practitioner in the form of misunderstandings or incidents may play an important role in the emergence of dissatisfaction among patients. CONCLUSIONS: This study demonstrated the usefulness of multilevel analysis in studying patient satisfaction scores. Findings indicate that the effectiveness of strategies directed at health care providers or services and aiming to improve the quality of care through the patient's eyes can be questioned when these strategies are based on general satisfaction scores only. More attention should be paid to the interaction process between patient and GP.

Adult↗