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R S Thompson

Publications and source records attributed to R S Thompson.

At least 37 records · Page 2Linked to original sources

Impact of the change in polio vaccination schedule on immunization coverage rates: a study in two large health maintenance organizations.

OBJECTIVE: In January 1997, one of the most significant changes to United States vaccine policy occurred when polio immunization guidelines changed to recommend a schedule containing inactivated polio vaccine (IPV). There were concerns that parent or physician reluctance to accept IPV into the routine childhood immunization schedule would lead to lowered coverage. We determined whether adoption of an IPV schedule had a negative impact on immunization coverage. DESIGN: A cohort study of 2 large health maintenance organizations (HMOs), Group Health Cooperative and Kaiser Permanente Northern California, was conducted. For analysis at 12 months of age, children who were born between October 1, 1996, and December 31, 1997, and were commercially insured and covered by Medicaid were continuously enrolled; for analysis at 24 months of age, children who were born between October 1, 1996, and June 30, 1997, and were commercially insured and covered by Medicaid were continuously enrolled. The 3 measures of immunization status at 12 and 24 months of age were up-to-date status, cumulative time spent up-to-date, and the number of missed opportunity visits. RESULTS: At both HMOs, children who received IPV were as likely to be up to date at 12 months as were children who received oral poliovirus vaccine (OPV), whereas at Group Health, children who received IPV were slightly more likely to be up to date at 24 months (relative risk: 1.12; 95% confidence interval [CI]: 1.05, 1.19). These findings were consistent for children who were covered by Medicaid. At Kaiser Permanente, children who received IPV spent ~3 fewer days up to date in the first year of life, but this difference did not persist at 2 years of age. At Group Health, children who received IPV were no different from those who received OPV in terms of days spent up to date by 1 or 2 years of age. At Group Health, children who received IPV were less likely to have a missed opportunity by 12 months old (odds ratio [OR] 0.46; 95% CI: 0.31, 0.70), but this finding did not persist at 24 months of age. At Kaiser Permanente, children who received IPV were more likely to have a missed opportunity by 12 months (OR 2.06; 95% CI: 1.84, 2.30), and 24 months of age (OR 1.50; 95% CI: 1.36, 1.67). CONCLUSIONS: The changeover from an all-OPV schedule to one containing IPV had little if any negative impact on vaccine coverage. Use of IPV was associated with a small increase in the likelihood of being up to date at 2 years of age at one of the HMOs and conversely was associated with a small increase in the likelihood of having a missed-opportunity visit in the other HMO.polio, poliomyelitis, vaccination, immunization coverage.

California↗

Variation in clinician recommendations for multiple injections during adoption of inactivated polio vaccine.

OBJECTIVES: To describe variation in clinician recommendations for multiple injections during the adoption of inactivated poliovirus vaccine (IPV) in 2 large health maintenance organizations (HMOs), and to test the hypothesis that variation in recommendations would be associated with variation in immunization coverage rates. DESIGN: Cross-sectional study based on a survey of clinician practices 1 year after IPV was recommended and computerized immunization data from these clinicians' patients. STUDY SETTINGS: Two large West Coast HMOs: Kaiser Permanente in Northern California and Group Health Cooperative of Puget Sound. OUTCOME MEASURES: Immunization status of 8-month-olds and 24-month-olds cared for by the clinicians during the study. RESULTS: More clinicians at Group Health (82%), where a central guideline was issued, had adopted the IPV/oral poliovirus vaccine (OPV) sequential schedule than at Kaiser (65%), where no central guideline was issued. Clinicians at both HMOs said that if multiple injections fell due at a visit and they elected to defer some vaccines, they would be most likely to defer the hepatitis B vaccine (HBV) for infants (40%). At Kaiser, IPV users were more likely than OPV users to recommend the first HBV at birth (64% vs 28%) or if they did not, to defer the third HBV to 8 months or later (62% vs 39%). In multivariate analyses, patients whose clinicians used IPV were as likely to be fully immunized at 8 months old as those whose clinicians used all OPV. At Kaiser, where there was variability in the maximum number of injections clinicians recommended at infant visits, providers who routinely recommended 3 or 4 injections at a visit had similar immunization coverage rates as those who recommended 1 or 2. At both HMOs, clinicians who strongly recommended all possible injections at a visit had higher immunization coverage rates at 8 months than those who offered parents the choice of deferring some vaccines to a subsequent visit (at Kaiser, odds ratio [OR]: 1.2; 95% confidence interval [CI]: 1.0-1.5; at Group Health, OR: 1.8; 95% CI: 1.1-2.8). CONCLUSIONS: Neither IPV adoption nor the use of multiple injections at infant visits were associated with reductions in immunization coverage. However, at the HMO without centralized immunization guidelines, IPV adoption was associated with changes in the timing of the first and third HBV. Clinical policymakers should continue to monitor practice variation as future vaccines are added to the infant immunization schedule.

Child, Preschool↗

Selective transmission of a focused Doppler ultrasound beam through a plastic layer.

Laboratory test objects are widely used in Doppler ultrasound (US). Although the acoustic properties of in vitro materials are usually known, they are unlikely to match each other, or their in vivo counterparts, exactly. We conducted theoretical and experimental studies of a focused ultrasound beam as it passes from one fluid, through an intervening plastic layer at an oblique angle, and then into a different fluid. Dual mode propagation may occur (i.e., both longitudinal and shear waves can propagate in the plastic layer). Our calculations show that the power transmitted by either mode drops very rapidly to zero at certain critical angles. A range of angles of incidence exists within a focused beam and this, combined with the highly angle-dependent power transmission behaviour, can produce major distortions of Doppler data. These may persist even when the beam axis is not oriented exactly at the critical angle. The total power transmitted depends on all the wave speeds, may involve mode conversion, and is a very complicated function of the angle of incidence. This study reports a practical method for the calculation of power transmission though a plastic layer, and shows how the resulting power vs. angle graph can be used to avoid artefacts in in vitro Doppler studies.

Phantoms, Imaging↗

Development of a health care provider survey for domestic violence: psychometric properties.

BACKGROUND: Despite rapid proliferation of descriptive studies of health care providers (HCPs) and protocols for identification and management of domestic violence (DV), few reliable instruments exist for assessing HCPs' attitudes, beliefs, and behaviors regarding this practice. This study describes the development and psychometric properties of a measure of attitudes, beliefs, and self-reported behaviors related to the identification and management of DV. METHODS: We used a multiphase study design to develop items across eight content domains. We administered an initial pool of 104 items to a pilot sample of 129 primary care providers (physicians, physician assistants, nurse practitioners, and medical assistants) in a large, urban health maintenance organization. Descriptive statistics, principal components, and reliability analyses were performed on each of the eight content domains. The analyses guided the deletion of items and development of additional items, yielding a 56-item pool. The items were then administered and re-analyzed with an independent sample of 246 HCPs. RESULTS: Six separate and reliable domains were identified: Perceived Self-Efficacy, System Support, Blame Victim, Professional Role Resistance/Fear of Offending Patient, Victim/Provider Safety, and Frequency of DV Inquiry. We found item domain Cronbach alpha to be acceptable, ranging from 0.73 to 0.91. The final overall measure had 39 items and an alpha of 0.88. Data are reviewed that support the measure's sensitivity to change in response to a training intervention. CONCLUSION: The measure provides a reliable method for assessing provider characteristics and training needs. It may also serve to evaluate training and policy interventions in DV.

Attitude of Health Personnel↗

Identification and management of domestic violence: a randomized trial.

BACKGROUND: Diagnosis of domestic violence (DV) in primary care is low compared to its prevalence. Care for patients is deficient. Over a 1-year period, we tested the effectiveness of an intensive intervention to improve asking about DV, case finding, and management in primary care. The intervention included skill training for providers, environmental orchestration (posters in clinical areas, DV questions on health questionnaires), and measurement and feedback. METHODS: We conducted a group-randomized controlled trial in five primary care clinics of a large health maintenance organization (HMO). Outcomes were assessed at baseline and follow-up by survey, medical record review, and qualitative means. RESULTS: Improved provider self-efficacy, decreased fear of offense and safety concerns, and increased perceived asking about DV were documented at 9 months, and also at 21 months (except for perceived asking) after intervention initiation. Documented asking about DV was increased by 14.3% with a 3.9-fold relative increase at 9 months in intervention clinics compared to controls. Case finding increased 1.3-fold (95%, confidence interval 0.67-2.7). CONCLUSIONS: The intervention improved documented asking about DV in practice up to 9 months later. This was mainly because of the routine use of health questionnaires containing DV questions at physical examination visits and the placement of DV posters in clinical areas. A small increase in case finding also resulted. System changes appear to be a cost-effective method to increase DV asking and identification.

Adult↗

Developing an evidence-based Guide to Community Preventive Services--methods. The Task Force on Community Preventive Services.

Systematic reviews and evidence-based recommendations are increasingly important for decision making in health and medicine. Over the past 20 years, information on the science of synthesizing research results has exploded. However, some approaches to systematic reviews of the effectiveness of clinical preventive services and medical care may be less appropriate for evaluating population-based interventions. Furthermore, methods for linking evidence to recommendations are less well developed than methods for synthesizing evidence. The Guide to Community Preventive Services: Systematic Reviews and Evidence-Based Recommendations (the Guide) will evaluate and make recommendations on population-based and public health interventions. This paper provides an overview of the Guide's process to systematically review evidence and translate that evidence into recommendations. The Guide reviews evidence on effectiveness, the applicability of effectiveness data, (i.e., the extent to which available effectiveness data is thought to apply to additional populations and settings), the intervention's other effects (i.e., important side effects), economic impact, and barriers to implementation of interventions. The steps for obtaining and evaluating evidence into recommendations involve: (1) forming multidisciplinary chapter development teams, (2) developing a conceptual approach to organizing, grouping, selecting and evaluating the interventions in each chapter; (3) selecting interventions to be evaluated; (4) searching for and retrieving evidence; (5) assessing the quality of and summarizing the body of evidence of effectiveness; (6) translating the body of evidence of effectiveness into recommendations; (7) considering information on evidence other than effectiveness; and (8) identifying and summarizing research gaps. Systematic reviews of and evidence-based recommendations for population-health interventions are challenging and methods will continue to evolve. However, using an evidence-based approach to identify and recommend effective interventions directed at specific public health goals may reduce errors in how information is collected and interpreted, identify important gaps in current knowledge thus guiding further research, and enhance the Guide users' ability to assess whether recommendations are valid and prudent from their own perspectives. Over time, all of these advantages could help to increase agreement regarding appropriate community health strategies and help to increase their implementation.

Decision Making↗

The incidence of Kawasaki syndrome in West Coast health maintenance organizations.

BACKGROUND: Kawasaki syndrome (KS) causes an acute vasculitis of unknown etiology. It is a leading cause of acquired heart disease of children in Japan and the United States. METHODS: We examined the incidence of KS in a well-defined population group of children < or =6 years of age, using data collected through the Vaccine Safety Datalink (VSD) project. The VSD database contains information on >1 million children enrolled in four West Coast health maintenance organizations (HMOs). RESULTS: During 1993 through 1996 a total of 234 physician-diagnosed KS patients were reported in the 4 HMOs; 152 (65.0%) were boys and 195 (83.3%) were <5 years of age. The incidence of KS among children <5 years of age in the HMOs ranged from 9.0 to 19.1 per 100,000 person years. KS incidence was higher among boys in 3 of the sites. In the 2 sites with the highest number of KS patients, a seasonal occurrence of KS in winter and early spring was observed. Overall 226 (96.6%) of the KS patients were reported to have been hospitalized; hospitalization rates for children <5 years of age ranged from 9.0 to 16.8 per 100,000 person years. CONCLUSIONS: The incidence of KS in the HMOs was similar to that reported in other population-based studies in the United States and higher than estimates for Australia and several European countries.

Age Factors↗

Firearm safety counseling in primary care pediatrics: a randomized, controlled trial.

CONTEXT: Physicians have been encouraged to counsel families about risks associated with gun ownership, but the effectiveness of physician counseling regarding gun safety is unknown. OBJECTIVE: To determine the effectiveness of gun safety counseling during well-child care visits. DESIGN: Group randomized, controlled trial. Physicians, nurse practitioners, and physician assistants were randomized to either the intervention group or a control group. SETTING: Group Health Cooperative, a staff-model health maintenance organization. Patients. Consecutive sample of families (n = 1295) seen for a scheduled appointment for well-child care for a child <18 years of age. Of the families originally scheduled for a visit, 80. 3% were seen and completed the outcomes surveys. INTERVENTION: Each family in the intervention group was given a 60-second message by their practitioner that depended on the presence of guns in the home. Families without guns were informed of the health risks associated with gun ownership and given a standard information pamphlet. Families with guns were given the same information about risks and were told that if they chose to keep a gun, they should store it locked and unloaded. They were given instructions on storage and a folder with material, including the same pamphlet, a letter from the police department, written storage guidelines, and discount coupons for gun storage devices. MAIN OUTCOME MEASURE: Changes in the following self-reported events: 1) acquisition of a safe storage device; 2) removal of firearms from the home; and 3) acquisition of firearms. Results. There were no important differences between intervention and control groups in the rate of acquisition of new guns (intervention: 1.3% vs control:.9%) after the intervention. Among households with guns at baseline, there were also no differences between groups in the removal of guns (intervention: 6.7% vs control: 5.7%), but there was a fairly large nonsignificant difference in the proportion who purchased trigger locks (intervention: 8.0% vs control: 2.5%). CONCLUSIONS: A single firearm safety-counseling session during well-child care, combined with economic incentives to purchase safe storage devices, did not lead to changes in household gun ownership and did not lead to statistically significant overall changes in storage patterns.

Adolescent↗

The Vaccine Safety Datalink: immunization research in health maintenance organizations in the USA.

The Vaccine Safety Datalink is a collaborative project involving the National Immunization Program of the Centers for Disease Control and Prevention and several large health maintenance organizations in the USA. The project began in 1990 with the primary purpose of rigorously evaluating concerns about the safety of vaccines. Computerized data on vaccination, medical outcome (e.g. outpatient visits, emergency room visits, hospitalizations, and deaths) and covariates (e.g. birth certificates, census data) are prospectively collected and linked under joint protocol at multiple health maintenance organizations for analysis. Approximately 6 million persons (2% of the population of the USA) are now members of health maintenance organizations participating in the Vaccine Safety Datalink, which has proved to be a valuable resource providing important information on a number of vaccine safety issues. The databases and infrastructure created for the Vaccine Safety Datalink have also provided opportunities to address vaccination coverage, cost-effectiveness and other matters connected with immunization as well as matters outside this field.

Centers for Disease Control and Prevention, U.S.↗

Immunization levels among premature and low-birth-weight infants and risk factors for delayed up-to-date immunization status. Centers for Disease Control and Prevention Vaccine Safety Datalink Group.

CONTEXT: Studies have noted that health care professionals may not conform to proper immunization schedules for premature and low-birth-weight infants in the United States. Little is known about the success of current efforts to immunize these high-risk infants. OBJECTIVE: To describe current immunization practices for premature and low-birth-weight infants and ascertain risk factors for poor immunization status, using large population-based data sources. DESIGN AND SETTING: Cohort and case-control analyses of immunization data tracked from March 1991 through March 1997 for 3 large health maintenance organizations (HMOs) participating in the Centers for Disease Control and Prevention's Vaccine Safety Datalink project. PARTICIPANTS: A total of 11580 low-birth-weight and premature infants were enrolled from birth to age 2 months; 6832 of these were continuously enrolled from birth to age 24 months. At age 2 months, there were 173373 full-term, normal-birth-weight infants enrolled as controls; at age 24 months, there were 103 324. MAIN OUTCOME MEASURES: Age-specific immunization status by prematurity and birth weight (<1500 g, 1500-2500 g, born at <38 weeks' gestation with birth weight of >2500 g, or full-term with normal birth weight) and patient characteristics associated with up-to-date status. RESULTS: At each age, infants weighing less than 1500 g at birth had lower up-to-date immunization levels than other infants. At age 6 months, 52% to 65% of infants weighing less than 1500 g were up-to-date at each of the 3 HMOs compared with 69% to 73% of those weighing 1500 to 2500 g, 66% to 80% of premature infants weighing more than 2500 g, and 65% to 76% of full-term, normal-birth-weight infants. By age 24 months, 78% to 86% of infants weighing less than 1500 g were up-to-date, significantly less than heavier infants, who had levels of 84% to 89%. Well-child preventive care strongly predicted immunization status, while concomitant pulmonary disease did not. CONCLUSIONS: Our data suggest that infants born prematurely are vaccinated at levels approaching that of the general population, but levels of vaccination for very low-birth-weight infants lag slightly behind.

Health Maintenance Organizations↗

Safety of revaccination with pneumococcal polysaccharide vaccine.

CONTEXT: Revaccination of healthy adults with pneumococcal polysaccharide vaccine (PPV) within several years of first vaccination has been associated with a higher than expected frequency and severity of local injection site reactions. The risk of adverse events associated with revaccination of elderly and chronically ill persons 5 or more years after first vaccination, as is currently recommended, has not been well defined. OBJECTIVE: To determine whether revaccination with PPV at least 5 years after first vaccination is associated with more frequent or more serious adverse events than those following first vaccination. DESIGN: Comparative intervention study conducted between April 1996 and August 1997. PARTICIPANTS: Persons aged 50 to 74 years either who had never been vaccinated with PPV (n = 901) or who had been vaccinated once at least 5 years prior to enrollment (n = 513). INTERVENTION: PPV vaccination. MAIN OUTCOME MEASURES: Postvaccination local injection site reactions and prevaccination concentrations of type-specific antibodies. RESULTS: Those who were revaccinated were more likely than those who received their first vaccinations to report a local injection site reaction of at least 10.2 cm (4 in) in diameter within 2 days of vaccination: 11% (55/513) vs 3% (29/901) (relative risk [RR], 3.3; 95% confidence interval [CI], 2.1-5.1). These reactions resolved by a median of 3 days following vaccination. The highest rate was among revaccinated patients who were immunocompetent and did not have chronic illness: 15% (33/228) compared with 3% (10/337) among comparable patients receiving their first vaccinations (RR, 4.9; 95% CI, 2.4-9.7). The risk of these local reactions was significantly correlated with prevaccination geometric mean antibody concentrations. CONCLUSIONS: Physicians and patients should be aware that self-limited local injection site reactions occur more frequently following revaccination compared with first vaccination; however, this risk does not represent a contraindication to revaccination with PPV for recommended groups.

Aged↗

Biodegradation and ecotoxicity of HFCs and HCFCs.

Hydrofluorocarbons (HFCs) and hydrochlorofluorocarbons (HCFCs) are used or developed as substitutes for fully halogenated chlorofluorocarbons. Based on the results of closed-bottle tests, the biodegradation of HFC-32, HCFC-123, HCFC-124, HFC-125, HFC-134a, HCFC-141b, HCFC-225ca, and HCFC-225cb was less than 60% after 28 days and therefore these compounds are considered not readily biodegradable. Standard acute toxicity tests with HCFC-123, HCFC-141b, and HCFC-225ca using algae, water fleas, and fish revealed EC50 values in the range of 17-126 mg/L. EC50 values of HFC-134a ranged between 450-980 mg/L. Fish studies with HCFC-141b and HCFC-225ca revealed bioaccumulation factors of <3 and 15-64, respectively. A study with plants revealed no effect of HCFC-141b on seed germination and growth of wheat (Triticum aestivum), radish (Raphanus sativus), and cress (Lepidium sativum). In conclusion, HFCs and HCFCs are not very toxic to aquatic organisms and terrestrial plants. No evidence for any aerobic biodegradation for most of the HFCs and HCFCs was found.

Animals↗

Transformation of a non-oestrogenic steroid metabolite to an oestrogenically active substance by minimal bacterial activity.

The majority of oestrogenic material excreted from humans and wildlife, and therefore released into sewers, is in a conjugated form. However, the finding of "free" oestrogens in sewage effluent suggests that these metabolites are somehow converted back into an active form, before or during passage through a sewage treatment process. When male fathead minnows (Pimephales promelas) were continuously exposed to oestradiol-3-glucuronide, in a continuous-flow system, it demonstrated no inherent oestrogenic activity. However, when fish were exposed to effluent generated from laboratory simulations of sewage treatment processes, to which had been added oestradiol-3-glucuronide, oestrogenic activity was observed, suggesting microbial activity was capable of degrading the steroid metabolite into a more potent oestrogen. Oestrogenic potency was determined by measuring changes in plasma vitellogenin (egg yolk precursor) concentrations and gonadosomatic index. The results suggest that inactive metabolites of steroids are very readily biotransformed into biologically active oestrogens.

Animals↗

Fit of bicycle safety helmets and risk of head injuries in children.

BACKGROUND: Although bicycle helmets are effective in preventing head and brain injury, some helmeted individuals nevertheless sustain head injury. One of the possible reasons may be poor fit of the helmet on the head. This study was undertaken to examine the relationship between helmet fit and risk of injury. METHODS: 1718 individuals who were helmeted riders in a crash were queried on helmet fit and position. A sample of 28 children 2-14 years of age who sustained a head injury while wearing a bicycle helmet and 98 helmeted individuals of the same age treated in the same hospital emergency departments for injuries other than to the head, underwent anthropometric measurements of helmet fit. Measurements were made of the child's head, the helmet, and on a cast made of the child's head. RESULTS: Individuals whose helmets were reported to fit poorly had a 1.96-fold increased risk of head injury compared with those whose helmets fit well. Children with head injuries had helmets which were significantly wider than their heads compared with children without head injuries. Helmet fit was poorer among males and among younger children. CONCLUSIONS: Poor fit of helmets may be associated with an increased risk of head injury in children, especially in males. Helmets may not be designed to provide optimal protection.

Adolescent↗

Hospitalization and mortality rates for nursing home-acquired pneumonia.

BACKGROUND: The effect of hospitalization on nursing home patients with pneumonia is not known. We hoped to learn more about the effect of hospitalization on outcome by comparing patients with pneumonia from 2 nursing homes. METHODS: Using a retrospective chart review, we compared a total of 129 patients with pneumonia from 2 community nursing homes in upstate New York over a 2-year study period. The main intervention measures were treatment in the hospital or treatment in the nursing home. The main outcome measures were resolution or mortality at 6 weeks. RESULTS: Nursing home B had a hospital admission rate for pneumonia (38.8%) that was double that of nursing home A (19.4%). The patient populations were judged to be similar, and the overall mortality outcome for both (weighted average = 24.8%) was essentially identical. CONCLUSIONS: Doubling the hospital admission rate in 1 of 2 similar groups of nursing home patients with pneumonia was not associated with an improved mortality outcome at 6 weeks.

Activities of Daily Living↗