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Estimating Equation Models (estimating + equation_models)
Kinds of Estimating Equation Models Selected AbstractsDaily computer usage correlated with undergraduate students' musculoskeletal symptoms,AMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 6 2007Che-hsu (Joe) Chang PT Abstract Background A pilot prospective study was performed to examine the relationships between daily computer usage time and musculoskeletal symptoms on undergraduate students. Methods For three separate 1-week study periods distributed over a semester, 27 students reported body part-specific musculoskeletal symptoms three to five times daily. Daily computer usage time for the 24-hr period preceding each symptom report was calculated from computer input device activities measured directly by software loaded on each participant's primary computer. General Estimating Equation models tested the relationships between daily computer usage and symptom reporting. Results Daily computer usage longer than 3 hr was significantly associated with an odds ratio 1.50 (1.01,2.25) of reporting symptoms. Odds of reporting symptoms also increased with quartiles of daily exposure. Conclusions These data suggest a potential dose,response relationship between daily computer usage time and musculoskeletal symptoms. Am. J. Ind. Med. 50:481,488, 2007. © 2007 Wiley-Liss, Inc. [source] Outcomes for 236 patients from a 2-year early intervention in psychosis serviceACTA PSYCHIATRICA SCANDINAVICA, Issue 2 2009M. A. Turner Objective:, To examine: i) changes in key outcome measures over time in treatment in a representative first-episode psychosis treatment cohort and ii) baseline predictors of service disengagement. Method:, Baseline characteristics of 236 patients were examined for associations with outcomes over time using generalized estimating equation models. The data on disengagement were analysed using logistic regression. Results:, After controlling for admission scores, patients showed consistently improved outcomes while in treatment on functional recovery (unemployment, P < 0.01; HoNOS, P < 0.001; the Quality of Life Scale, P < 0.001; GAF, P < 0.05) but not symptomatology (as assessed by the PANSS and substance abuse). The 64 (33%) who disengaged were more likely to be unemployed (P < 0.01) and have higher HoNOS (P < 0.01) and GAF (P < 0.05) scores at baseline. Conclusion:, This evaluation has shown significant improvements in psychosocial functioning but not psychopathology during treatment at an Early Intervention for Psychosis Service. Despite attempts to retain patients, there is a high rate of treatment discontinuation. [source] Cessation of periodontal care during pregnancy: effect on infant birthweightEUROPEAN JOURNAL OF ORAL SCIENCES, Issue 1 2006Philippe P. Hujoel The goal of this study was to assess whether interruption of care for chronic periodontitis during pregnancy increased the risk of low-birthweight infants. A population-based case-control study was designed with 793 cases (infants <,2,500 g) and a random sample of 3,172 controls (infants ,,2,500 g). Generalized estimating equation models were used to relate periodontal treatment history to low birthweight risk and to common risk factors. The results indicate that periodontal care utilization was associated with a 2.35-fold increased odds of self-reported smoking during pregnancy (95% confidence interval: 1.48,3.71), a 2.19-fold increased odds for diabetes (95% confidence interval: 1.21,3.98), a 3.90-fold increased odds for black race (95% confidence interval: 2.31,6.61), and higher maternal age. After adjustment for these factors, interruption of periodontal care during pregnancy did not lead to an increased risk for a low-birthweight infant when compared to women with no history of periodontal care (odds ratio, 0.96; 95% confidence interval, 0.60,1.52). In conclusion, women receiving periodontal care had genetic and environmental characteristics, such as smoking, diabetes and race, that were associated with an increased risk for low-birthweight infants. Periodontal care patterns, in and of themselves, were unrelated to low-birthweight risk. [source] Provider Characteristics Related to Antidepressant Use in Older PeopleJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 6 2006Gerda G. Fillenbaum PhD OBJECTIVES: To determine whether the characteristics of the usual medical care providers of older antidepressant users changed between 1986 and 1997 with the introduction of selective serotonin reuptake inhibitors. DESIGN: Longitudinal study. SETTING: Five-county Piedmont area of North Carolina. PARTICIPANTS: Stratified random sample of African-American (n=2,261) and white (n=1,875) community residents aged 65 to 105. MEASUREMENTS: Sample members provided information on prescription medications, demographic and health status, and usual medical care provider (matched to North Carolina Health Professions Data Systems files to ascertain provider characteristics) in 1986/87, 1989/90, 1992/93, and 1996/97. Most (77.5%) named a provider (name unmatchable for 4.1%). Sample member characteristics were aggregated into probability (propensity) scores summarizing predisposing (demographic), enabling (medical care access), and need (health status) categories. Along with wave of study and whether a provider was named, these were entered as control variables in generalized estimating equation models that examined the association between provider race (white vs nonwhite), sex, age, location of practice, and primary versus specialist care and antidepressant use. RESULTS: The characteristics of the usual medical care providers remained stable over the decade, although prevalence of antidepressant use increased. Two provider characteristics,race and area of practice (but not the interaction between them),were significantly associated with patients' use of antidepressants. Patients of white physicians and of physicians with urban practices were more likely to use antidepressants. CONCLUSION: Although use of antidepressants has increased over time, there has been little change in the characteristics of users' usual medical care providers. [source] Maternal smoking increases risk of allergic sensitization and wheezing only in children with allergic predisposition: longitudinal analysis from birth to 10 yearsALLERGY, Issue 3 2009T. Keil Background:, The role of passive smoking for allergies and asthma in children above the age of 3 years remains unclear and possible interactive effects with parental allergies have not been formally evaluated in long-term studies. To examine the interaction of passive smoking and an allergic predisposition regarding allergic sensitization, allergic airway symptoms and respiratory infections during the first 10 years of life. Methods:, In a prospective multicenter birth cohort study with 1314 recruited children in Germany, we assessed serum immunoglobulin E against common allergens at seven time points, and parental smoking and respiratory symptoms annually by using questionnaires. Longitudinal analyses were performed using generalized estimating equation models (stratified by parental allergy status). Results:, During the first 10 years, 18% of the children were exposed to regular maternal smoking since pregnancy, 43% to irregular maternal or only paternal smoking. Among children with two allergic parents, a mother who smoked regularly significantly increased the odds for allergic sensitization (adjusted OR 4.8, 95% CI 1.3,18.2) and wheezing (adjusted OR 5.7, 95% CI 1.7,19.0) in her child compared with children who were never exposed. For those with only one allergic parent, the odds were doubled and also statistically significant, whereas in children without allergic parents maternal smoking had no effects. There was no association of maternal smoking with allergic rhinitis or respiratory infections. Conclusions:, Our results suggest that regular maternal smoking is a strong risk factor for allergic sensitization and asthma symptoms during the first 10 years of life, but only in children with allergic parents. [source] Attenuation of Racial Differences in Health Service Utilization Patterns for Previously Uninsured Children in the DeltaTHE JOURNAL OF RURAL HEALTH, Issue 4 2005Zola K. Moon MA ABSTRACT: Context: A school-based health insurance program for children of the working poor was conducted in 2 isolated, rural communities in the Lower Mississippi Delta region. The larger of the 2 communities had an array of locally available health care providers, whereas the smaller community did not. In response to this lack of available care, the project designed and delivered outreach programs, including transportation to providers. Purpose: The purpose of this paper is to examine the role of race, age, and gender in the relationships between the utilization of care and the impact of outreach programs. Method: General estimating equation models are used to examine the response of utilization variables to race, age, gender, and community. Four years of insurance claims data are analyzed. Findings: Race is seen to be an important component of utilization. The majority of participants were African American; however, children receiving prescription services, emergency room care, routine physician visits, and hospital outpatient services were more likely to be white. Outreach programs in vision and dental services were found to eliminate racial differences and increase utilization. A relatively strong gender effect was found in prescription, wellness, vision, and dental services. Conclusions: Previous research has shown differences by race in utilization of care. Our findings show that targeted outreach programs can significantly diminish these differences. Findings also suggest that barriers to health care for poor rural children are closely linked to transportation and availability of providers, not merely to cost of care or insurance. [source] Indocyanine green,enhanced imaging of antigen-induced arthritis with an integrated optical imaging/radiography system,ARTHRITIS & RHEUMATISM, Issue 8 2010Reinhard Meier Objective To evaluate a combined indocyanine green,enhanced optical imaging/radiography system for the detection of arthritic joints in a rat model of antigen-induced arthritis. Methods Arthritis of the knee and ankle joints was induced in 6 Harlan rats, using peptidoglycan,polysaccharide polymers. Three rats served as untreated controls. Optical imaging of the knee and ankle joints was done with an integrated optical imaging/radiography system before and up to 24 hours following intravenous injection of 10 mg/kg indocyanine green. The fluorescence signal intensities of arthritic and normal joints were compared for significant differences, using generalized estimating equation models. Specimens of knee and ankle joints were further processed and evaluated by histology. Results Immediately after administration, indocyanine green provided a significant increase in the fluorescence signal of arthritic joints compared with baseline values (P < 0.05). The fluorescence signal of arthritic joints was significantly higher compared with that of nonarthritic control joints at 1,720 minutes after intravenous injection (P < 0.05). Fusion of indocyanine green,enhanced optical imaging and radiography allowed for anatomic coregistration of the inflamed tissue with the associated joint. Hematoxylin and eosin staining confirmed marked synovial inflammation of arthritic joints and the absence of inflammation in control joints. Conclusion Indocyanine green,enhanced optical imaging is a clinically applicable tool for detection of arthritic tissue. Using relatively high doses of indocyanine green, long-term enhanced fluorescence of arthritic joints can be achieved. This may facilitate simultaneous evaluations of multiple joints in a clinical setting. Fusion of indocyanine green,enhanced optical imaging scans with radiography increases anatomic resolution. [source] | ||||||||||