Effects of the composition of standard reference material on the accuracy of determinations of 210Pb and 137Cs in soils with gamma spectrometry.

The effect of the composition of the used standard reference material (SRM) on results of determination of fallout radionuclides in soil samples was studied. Using five soil types as SRMs, we measured the specific activity of (210)Pb and (137)Cs in six target samples of Chestnut soil. It was observed that the determination of the (210)Pb activity in the samples depended on the chemical composition of SRMs used to create the efficiency curves. Thus, using SRMs similar in chemical composition to the target samples should improve accuracy in the determination of (210)Pb in environmental samples.

The risks and costs of multiple-generic substitution of topiramate.

OBJECTIVE: To investigate clinical and economic consequences following generic substitution of one vs multiple generics of topiramate (Topamax; Ortho-McNeil Neurologics, Titusville, NJ). METHODS: Medical and pharmacy claims data of Régie de l'Assurance-Maladie du Québec from January 2006 to October 2007 were used. Patients with epilepsy treated with topiramate were selected. An open-cohort design was used to classify the observation period into periods of brand, single-generic, and multiple-generic use. One-year generic-switch and switchback-to-brand rates were estimated using Kaplan-Meier methodology. Medical resource utilization and costs were compared among the three periods using multivariate regression analysis. RESULTS: In total, 948 patients were observed during 1,105 person-years of brand use, 233 person-years of single-generic use, and 92 person-years of multiple-generic use. A total of 23% of generic users received at least two different generic versions. Compared to brand use, multiple-generic use was associated with higher utilization of other prescription drugs (incidence rate ratio [IRR] = 1.27, 95% confidence interval [CI] = 1.24-1.31), higher hospitalization rates (0.48 vs 0.83 visit/person-year, IRR = 1.65, 95% CI = 1.28-2.13), and longer hospital stays (2.6 vs 3.9 days/person-year, IRR = 1.43, 95% CI = 1.27-1.60), but the effect was less pronounced in single-generic use (hospitalization: IRR = 1.08, 95% CI = 0.88-1.34, length of stay: IRR = 1.12, 95% CI = 1.03-1.23). The risk of head injury or fracture was nearly three times higher (hazard ratio = 2.84, 95% CI = 1.24-6.48) following a generic-to-generic switch compared to brand use. The total annualized health care cost per patient was higher in the multiple-generic than brand periods by C$1,716 (cost ratio = 1.21, p = 0.0420). CONCLUSION: Multiple-generic substitution of topiramate was significantly associated with negative outcomes, such as hospitalizations and injuries, and increased health care costs.

Healthcare expenditure in patients treated with venlafaxine or selective serotonin reuptake inhibitors for depression and anxiety.

We compared healthcare expenditure over a six-month period following initiation of therapy with either venlafaxine (immediate and extended-release) or a selective serotonin reuptake inhibitor (SSRI) in depressed patients with or without anxiety. Patients beginning treatment for a new depressive episode were identified retrospectively using the administrative data of the MEDSTAT MarketScan database for the period 1994-1999. Before beginning therapy, patients prescribed venlafaxine had more non-mental illnesses (0.85 vs 0.76; p<0.01) and hospitalisations for mental illness (0.53 vs 0.29; p<0.05) than patients prescribed SSRIs. In the six months after initiating treatment, venlafaxine was associated with lower hospitalisation expenditure for non-mental illness ($177 vs $526; p<0.01) than SSRIs, although total healthcare expenditure was not significantly different. Venlafaxine was associated with a 50% decrease in the odds of hospitalisation for non-mental illness compared with SSRIs, with significantly lower inpatient expenditure.

Improved cholesterol management in coronary heart disease patients enrolled in an HMO.

The purpose of the study was to describe the effect of physician reminders on the measurement of low-density lipoprotein cholesterol (LDL-C) levels and treatment to achieve an LDL-C goal of < or = 100 mg/dL in coronary heart disease (CHD) patients. After reminders were initiated, the number of CHD patients without a documented LDL-C was reduced from 30% to 18%, between January 1997 and July 1998, and the percentage of CHD patients achieving the LDL-C goal improved from 10% to 27%. Thus, reminders can be an effective tool in improving cholesterol management of CHD patients. In contrast, a cholesterol-lowering clinic made available to some physicians, in addition to the reminders, was rarely used.

Use of simvastatin treatment in patients with combined hyperlipidemia in clinical practice. For the Simvastatin Combined Hyperlipidemia Registry Group.

OBJECTIVE: To describe and understand current care of simvastatin-treated patients with combined hyperlipidemia in routine clinical practice. DESIGN: A 6-month prospective observational study. Demographics, simvastatin dosage, cardiac risk factors, and lipid profile were collected from August 1997 to December 1998 at 20 sites (230 patients) across the United States. RESULTS: Overall mean percentage of reduction in total cholesterol levels was 27% (P<.001), low-density lipoprotein cholesterol (LDL-C) was 35% (P<.001), and triglyceride values was 28% (P<.001). Among those patients with low baseline high-density lipoprotein cholesterol (HDL-C) values (<0.91 mmol/L [<35 mg/dL]) (N = 49), there was a 17% increase in HDL-C (P< or =.001); 35% of these patients achieved National Cholesterol Education Program HDL-C goal (ie, < or =0.91 mmol/L [> or =35 mg/dL]). Coronary heart disease (CHD) patients were given significantly higher initial doses (mean, 15.1 mg) compared with non-CHD patients (mean, 11.5 mg) (P< or =.001). Overall, 74% of patients achieved LDL-C goal (52% on starting dose, 22% after 1 titration). Among those patients who were not at goal and had a follow-up lipid profile result available, only 1 patient (2%) was at the maximum dose (80 mg); 69% were receiving 20 mg or less. Approximately 63% of patients with CHD, 80% of patients with 2 or more risk factors, and 91% of patients with fewer than 2 risk factors achieved LDL-C goal. CONCLUSIONS: Multiple factors contribute to LDL-C goal achievement in a usual care setting. A significant opportunity exists to increase the number of patients who achieve LDL-C goal by appropriate dose titration and/or give patients a higher initial dose of simvastatin.

The impact of socio-cultural and clinical factors on health-related quality of life reports among Hispanic and African-American cancer patients.

A hierarchical multiple linear regression approach (N = 761) was used to identify pertinent factors which influence health-related quality of life (HRQL) reports among Hispanic and African-American cancer patients. The independent variables include: performance status, disease site, disease stage, mode of administration, socio-economic status (SES), gender, age, living arrangement, race/ethnicity, religious affiliation, insurance status, and spiritual beliefs. The outcome measures, five subscales of HRQL (physical well-being, social well-being, satisfaction with treatment, emotional well-being, functional well-being) and overall HRQL (sum of the five subscales), were estimated using the Functional Assessment of Cancer Therapy (FACT) Scales. This study identified performance status and spiritual beliefs as consistent predictors of overall HRQL. This study also found no significant effects of SES, mode of administration, gender age, living arrangement and insurance status on the reporting of overall HRQL. Spiritual beliefs and performance status are important determinants of HRQL across a diverse group of cancer patients.

An analysis of the impact of demographic, clinical, and social factors on health-related quality of life.

This study investigated the impact of demographic, social, and clinical factors on cancer patients' self-ratings of health-related quality of life (HRQL). The sample consisted of 1342 ethnically diverse individuals in treatment at four member institutions of the Eastern Cooperative Oncology Group (ECOG). Multivariable regression analyses were employed to determine the relationship between demographic variables (age, gender, race/ethnicity, socio-economic status (SES), living arrangement), clinical factors (performance status rating (PSR), disease type, disease stage), and social characteristics (spiritual beliefs, religious affiliation, relationship with physician) and five outcome measures of HRQL. The dependent variables, four dimensions of HRQL and overall HRQL, were measured by the Functional Assessment of Cancer Therapy-General (FACT-G) Quality of Life Measurement System. The results indicated that the full set of predictor variables accounted for 45% of the variance in patients' reporting of overall HRQL, 25% of the variance in physical well-being, 27% of the variance in social well-being, 30% of the variance in emotional well-being, and 41% of the variance in the area of functional well-being. The findings suggest that there are multiple factors that influence an individual's assessment of their HRQL and that these factors need to be considered in the management and treatment of culturally diverse cancer patients.

Changes in the SF-36 in 12 months in a clinical sample of disadvantaged older adults.

OBJECTIVES: The present study assessed changes in the Medical Outcomes Study 36-item short-form health survey (SF-36) during a 12-month period and examined the relation of those changes to selected baseline characteristics. METHODS: The study was a 12-month follow-up evaluation of 786 disadvantaged adults aged 50 to 99 years old who had participated in a randomized controlled clinical trial in the general medicine outpatient clinics of a major academic medical center. Descriptive and psychometric analyses of changes in the SF-36 scale scores during a 12-month period were performed, and two series of multivariable logistic regressions of increases or decreases greater than one standard error of measurement (SEM) versus stability on selected baseline characteristics were done. Measures were the eight SF-36 scales. RESULTS: Mean baseline scores on the SF-36 scales were substantially below age-specific national norms. Problematic floor and/or ceiling effects were found for the bodily pain, social function, role--physical, and role--emotional scales, consistent with age-specific national norms. Internal consistency was unacceptable for the general health perceptions scale, adequate for the social function scale, and good for all the other SF-36 scales. Improvements greater than one standard error of measurement were found for between one fifth and one third of the patients, and declines greater than one standard error of measurement were found for between one fifth and one third of the patients. Selected baseline characteristics generally were unrelated to either improvements or declines on the SF-36 scales. CONCLUSIONS: The SF-36 scales appear to be sufficiently sensitive for measuring changes in health outcomes during a 1-year period in older patients with debilitating disease. Little of the measured change, however, was predictable.

The sequelae of hospitalization for ischemic stroke among older adults.

OBJECTIVES: To estimate the independent effect of hospitalization for ischemic stroke on change in functional status, subsequent hospitalization, and mortality. DESIGN: Secondary analysis of the nationally representative Longitudinal Study on Aging. Baseline (1984) interview data were linked to Medicare hospitalization and death records for 1984-1991 and to functional status reports at three biennial follow-ups. SETTING: In-person and telephone interviews were conducted. PARTICIPANTS: A total of 6071 noninstitutionalized respondents 70 years old or older at baseline. MEASUREMENTS: Hospitalization for ischemic stroke was defined as having one or more episodes with primary discharge ICD9-CM codes of 433.0-434.9, 436, and 437.0-437.1. Two reference groups were used: those who were hospitalized for something other than stroke, and those who were not hospitalized at all. The statistical methods employed were multivariable proportional hazards, logistic, and linear regression. RESULTS: The adjusted hazards ratio for having a primary hospital discharge diagnosis of ischemic stroke on mortality was 7.57 (CI95% = 6.47 to 8.85) versus 3.67 (CI95% = 3.28 to 4.10) for having been hospitalized for something other than stroke (both compared with the reference category of those not hospitalized at all). The adjusted odds ratio for having any subsequent hospitalization associated with having a primary hospital discharge diagnosis of ischemic stroke (compared with having been hospitalized for something other than stroke) was not significantly elevated (AOR = 1.16; CI95% = .94 to 1.42). However, the percent increases in the subsequent number of hospital episodes, total charges, and total length of stay for those who were hospitalized for ischemic stroke relative to those hospitalized for something other than stroke were significant (P < .001), and ranged from 16.3 to 39.0%. Hospitalization for ischemic stroke was also related significantly to greater increases in the regression-adjusted mean number of instrumental activities of daily living and lower body function limitations at follow-up. CONCLUSION: Hospitalization for ischemic stroke among older adults substantially increases the risk of subsequent mortality, the volume of hospital resource consumption, and greater functional decline, even when compared with hospitalization for something other than stroke. Therefore, greater attention to the prevention and management of ischemic stroke is needed.

Organizational and market determinants of HMOs' performance of preventive practices.

This study validates the measurements of performance of preventive practices and identifies organizational and market factors that affect variations in the preventive care practices of health maintenance organizations (HMOs). Confirmatory factor analysis was used to assess HMO performance, reflecting the rates of five preventive practice services. A structural equation model of the preventive practice performance of HMOs was evaluated. It was discovered that HMOs that employ more board-certified primary care practitioners have a higher rate of preventive care practices and that market competition and market forces do not influence the variation in HMO preventive care practices.

The risk of hospitalization for ischemic stroke among older adults.

OBJECTIVES: The purpose of this study was to identify risk factors for stroke and to estimate their relative importance in a large, nationally representative sample of very old men and women. METHODS: The study was designed as a secondary analysis of the Longitudinal Study on Aging. Baseline (1984) in-person interview data were linked to Medicare hospitalization records for 1984 to 1991. Participants were 6,071 noninstitutionalized adults 70 years old or older at baseline. Hospitalization for ischemic stroke was defined as having one or more episodes with a primary discharge diagnosis containing ICD-9-CM codes of 433.0-434.9, 436, and 437.0-437.1. Multivariable proportional hazards regression was used to estimate the risks associated with previously identified epidemiologic factors. RESULTS: Five hundred and three persons (8.3%) had at least one primary discharge diagnosis of ischemic stroke. In descending order of importance-based on the partial r statistics associated with their adjusted hazards ratios (AHRs), the salient risk factors were having a previous history of stroke (AHR = 2.86), age (AHR = 1.04 per year), diabetes (AHR = 1.78), male gender (AHR = 1.42), lower body limitations (AHR = 1.09 per limitation), arthritis (AHR = 0.74), hypertension (AHR = 1.29), and poverty (AHR = 1.33). CONCLUSION: Patients presenting with the high risk factors identified in this study should be considered for further evaluation and monitoring. Current protocols for the therapeutic management of these higher risk patients should be considered, and compliance should be encouraged.

The influence of personal expectations on cancer patients' reports of health-related quality of life.

The role of personal expectations on reports of health-related quality of life (HRQL) in the context of a set of other variables commonly thought to affect patient report of HRQL was examined. The complete set of predictor variables included: (1) patient factors including age, gender, race, education, income, insurance type, living arrangement and expectations; and (2) clinical factors namely performance status rating (PSR), diagnosis and disease stage. The outcome measures included five dimensions of HRQL (relationship with physician, physical, social, emotional and functional well being) and an overall measure of HRQL. Five variables (PSR, expectation rating, age, living arrangement and managed care enrollment) exerted significant effects on the summated rating of HRQL. Older cancer patients, those living with others, those enrolled in managed care organizations and those who report better-than-expected experience are more likely to have a higher overall HRQL. In addition to treating the disease itself, quality of life can possibly be enhanced by narrowing the disparities between individuals' expectations and what actually occurs. Patients would likely therefore benefit from being encouraged to set and maintain realistic goals concerning their cancer prognosis and treatment process.

The impact of demographics, injury severity, and trauma type on the likelihood of survival in child and adolescent trauma patients.

OBJECTIVE: The purpose of this study was to examine the influence of demographics, clinical factors, and injury types on the likelihood of survival. DESIGN: This cross-sectional analysis was restricted to persons younger than 18 years, treated in trauma centers in 1990. MATERIALS: A total of 3,540 individuals from the 1990 Virginia Statewide Trauma Registry was included in the analysis. METHODS AND MEASUREMENTS: The outcome variable was the patient's survival likelihood after injury. The independent variables included Injury Severity Score (ISS), demographics (age, gender, and race), and injury types -- motor vehicle collision (MVC) or gunshot wound (GSW). Correlation coefficients were obtained from the study variables. Logistic regression evaluated the effect of injury severity, controlling for demographics and type of injury. MAIN RESULTS: Three variables (ISS, GSW, and MVC) exerted significant effects of survival. Individuals with more severe injuries were more likely to die than their counterparts. Patients with gunshot wounds and motor vehicle injuries were more likely to die than those who had other injuries. After adjusting for demographics and injury type, injury severity (beta = -0.323) was found to be the most influential predictor of survival. CONCLUSIONS: The overall findings suggest a need for hospitals to collect data routinely for calculating injury severity for the management and treatment of injured patients.

Infections related to venous access devices in patients with AIDS.

The use of implanted venous access devices (VADs) for long-term administration of medications and fluids in HIV/AIDS patients has become common. This retrospective study compared infection rates in implanted external catheters and totally implanted ports. The study also investigated possible relationships between infection, type of VAD, frequency of use, compliance, home care, frequency of clinic visits, and number of inpatient hospital days. The sample consisted fo 48 AIDS patients with a total of 54 VADs. The external catheters had an infection rate of 36.5%, while the ports had an infection rate of 30.8%. A significant relationship was found between lack of compliance with care of the VAD and infection rates.