Dichotomous Measure (dichotomous + measure)

Distribution by Scientific Domains


Selected Abstracts


Multilevel generalized linear models for modelling age-related gender difference in violent behaviour and associated factors in the general household population

INTERNATIONAL JOURNAL OF METHODS IN PSYCHIATRIC RESEARCH, Issue 3 2005
Min Yang Senior Statistician
Abstract It is preferable to use longitudinal data when studying patterns of violence and antisocial behaviour over the lifespan together with the associated risk factors in the general population. From the statistical modelling perspective, random samples of cross-sectional data, representative of the population, can be a reliable alternative. Sampling, weighting, and possible geographical clustering of the behaviour must be considered in the analysis together with correct choice of model as a function of age, although cohort effects and age effects are not separated from the analysis. This paper demonstrates the use of multilevel generalized linear models in the British National Survey of Psychiatric Morbidity in 2000. A multilevel logistic model as a special case of a generalized linear model with individual weightings was adapted for a dichotomous measure of violence and extended to Poisson and negative binomial outcomes. Three types of age function, discrete age effects, continuous age effects, and piecewise polynomial function of age intervals were evaluated for goodness of fit, and for their practical advantages and disadvantages. Models were developed for possible risk factors in relation to specific age groups of interest. Copyright © 2005 John Wiley & Sons, Ltd. Copyright © 2005 John Wiley & Sons, Ltd. [source]


Satisfaction and Use of Prenatal Care: Their Relationship Among African-American Women in a Large Managed Care Organization

BIRTH, Issue 1 2003
Arden Handler DrPH
ABSTRACT:Background: Although many more mothers of almost all ethnic groups began prenatal care in the first trimester during the last decade, a significant number of low-income and minority women still fail to obtain adequate care in the United States,a failure that may be related to their dissatisfaction with the prenatal care experience. This study sought to examine the relationship between satisfaction with care and subsequent prenatal care utilization among African-American women using prospective methods. Methods: A sample of 125 Medicaid and 275 non-Medicaid African-American adult women seeking care through a large Midwest managed care organization were interviewed before or at 28 weeks' gestation at one of two prenatal care sites. Women were interviewed about personal characteristics, prenatal care experience, and ratings of care (satisfaction). Information about subsequent use of prenatal care was obtained through retrospective medical record review after delivery. Univariate and multivariable analyses examining the relationship between women's satisfaction and prenatal care use were conducted using a dichotomous measure of satisfaction and a continuous measure of utilization. Results: Women were highly satisfied with prenatal care, with an overall mean satisfaction score of 80.3. Non-Medicaid women were significantly (p < 0.05) less satisfied with their prenatal care (mean score, 79.1) than Medicaid women (mean score, 82.8), and the latter had significantly fewer visits on average than the former subsequent to the interview. Analyses showed no significant difference in subsequent utilization according to whether a woman had a high versus low level of satisfaction at the prenatal care interview. Conclusions: This study challenges the assumption that improving a woman's satisfaction with care will lead to an increase in the adequacy of her prenatal care utilization. Since this study was limited to African-American women and is the first prospective study of women's satisfaction with care and prenatal care utilization, the negative findings do not yet settle this area of inquiry. Monitoring women's satisfaction with prenatal care in both managed care and fee-for-service settings and working to improve those aspects of care associated with decreased satisfaction is warranted. (BIRTH 30:1 March 2003) [source]


Heart Rate-Defined Phases of Attention, Look Duration, and Infant Performance in the Paired-Comparison Paradigm

CHILD DEVELOPMENT, Issue 6 2001
John Colombo
Four-month-old infants (N= 68) were tested in a paired-comparison familiarization , novelty recognition task in which the length of choice trials was systematically manipulated. Peak look duration during pretest and familiarization periods significantly predicted a dichotomous measure of recognition performance, but recognition was unaffected by choice-trial length. Heart rate (HR) was simultaneously assessed during the task, and the amount of time infants spent in various HR-defined phases of attention was assessed. Longer durations of looking during pretest and familiarization were significantly associated with more time spent in both sustained attention (SA) and attention termination (AT). Of these two variables, only individual differences in AT accounted for significant variance in recognition memory performance. A final analysis addressed the possibility that individual differences in AT mediated the relation between look duration and recognition performance. These findings provide support for the hypothesis that individual differences in the disengagement of attention underlie the relation between look duration and cognitive performance in early to midinfancy. [source]


Assessing the Validity of Insurance Coverage Data in Hospital Discharge Records: California OSHPD Data

HEALTH SERVICES RESEARCH, Issue 5 2003
Thomas C. Buchmueller
Objective. To assess the accuracy of data on "expected source of payment" in the patient discharge database compiled by the California Office of Statewide Health Planning and Development (OSHPD). Data Sources. The OSHPD discharge data for the years 1993 to 1996 linked with administrative data from the University of California (UC) health benefits program for the same years. The linked dataset contains records for all stays in California hospitals by UC employees, retirees, and spouses. Study Design. The accuracy of the OSHPD data is assessed using cross-tabulations of insurance type as coded in the two data sources. The UC administrative data is assumed to be accurate, implying that differences between the two sources represent measurement error in the OSHPD data. We cross-tabulate insurance categories and analyze the concordance of dichotomous measures of health maintenance organization (HMO) enrollment derived from the two sources. Principal Findings. There are significant coding errors in the OSHPD data on expected source of payment. A nontrivial percentage of patients with preferred provider organization (PPO) coverage are erroneously coded as being in HMOs, and vice versa. The prevalence of such errors increased after OSHPD introduced a new expected source of payment category for PPOs. Measurement problems are especially pronounced for older patients. Many patients over age 65 who are still covered by a commercial insurance plan are erroneously coded as having Medicare coverage. This, combined with the fact that during the period we analyzed, Medicare HMO enrollees and beneficiaries in the fee-for-service (FFS) program are combined in a single payment category, means that the OSHPD data provides essentially no information on insurance coverage for older patients. Conclusions. Researchers should exercise caution in using the expected source of payment in the OSHPD data. While measures of HMO coverage are reasonably accurate, it is not possible in these data to clearly identify PPOs as a distinct insurance category. For patients over age 65, it is not possible at all to distinguish among alternative insurance arrangements. [source]


Microbial composition of supra- and subgingival plaque in subjects with adult periodontitis

JOURNAL OF CLINICAL PERIODONTOLOGY, Issue 10 2000
Laurie Ann Ximénez-Fyvie
Abstract Background, aims: The purpose of the present study was to compare and relate the microbial composition of supra and subgingival plaque in 23 adult periodontitis subjects (mean age 51±14 years). Methods: A total of 1,170 samples of supra and subgingival plaque were collected from the mesial aspect of every tooth (up to 28 supra and 28 subgingival samples) from each subject and evaluated for the presence and levels of 40 bacterial taxa using whole genomic DNA probes and checkerboard DNA-DNA hybridization. Clinical assessments including dichotomous measures of gingival redness, bleeding on probing, plaque accumulation and suppuration, as well as duplicate measures of pocket depth and attachment level, were made at 6 sites per tooth. The counts (levels), % DNA probe count (proportion) and % of sites colonized (prevalence) of each species in supra and separately in subgingival plaque were computed for each subject. Significance of differences between supra and subgingival plaque for each species was sought using the Wilcoxon signed ranks test and adjusted for multiple comparisons. Results: All 40 taxa were detected in both supra and subgingival plaque. Actinomyces species were the most prevalent taxa in both habitats. 75 to 100% of supra and 62 to 100% of subgingival sites were colonized by at least one of the 5 Actinomyces species. Supragingival samples exhibited significantly higher counts of Actinomyces naeslundii genospecies 1, Actinomyces israelii, Actinomyces odontolyticus, Neisseria mucosa, Streptococcus gordonii, Capnocytophaga ochracea and Capnocytophaga sputigena when compared with mean counts in subgingival samples taken from the same tooth surfaces. Subgingival plaque samples presented significantly higher counts of Prevotella nigrescens, Prevotella intermedia, Bacteroides forsythus and Porphyromonas gingivalis. Subgingival samples exhibited a significantly higher proportion of "red" and "orange complex" species, while supragingival plaque exhibited higher proportions of "green" and "purple" complex species as well as Actinomyces species. Suspected periodontal pathogens could be detected in supragingival plaque from sites where subgingival samples were negative for the same species. Conclusions: The data indicate that supragingival plaque can harbor putative periodontal pathogens, suggesting a possible rôle of this environment as a reservoir of such species for the spread or reinfection of subgingival sites. [source]