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Biomedical subjects

John Adams

Publications and source records attributed to John Adams.

At least 37 records · Page 2Linked to original sources

Managing potential health risks from electric powerlines: a decision analysis caught in controversy.

Over the past 20 years, several epidemiological studies have found an association between exposure to electromagnetic fields (EMFs) and health effects, including childhood leukemia and adult brain cancer. However, experts strongly disagree about whether this association is causal and, if so, how strong it is. In this article, we examine several alternatives to reduce EMFs from sources of the California power grid, including undergrounding distribution and transmission lines and reconfiguring or rephasing lines. The alternatives were evaluated in terms of the potential health risk reduction, cost, impacts on service reliability, property values, and many other consequences. Because of the uncertainty about an EMF-health link, the main effort was to determine the sensitivity of the decisions to the probability and seriousness of an EMF hazard. User-friendly computer models were developed to allow stakeholders to change the model assumptions and parameters to analyze the impacts of their own assumptions and estimates on the decision. The analysis clearly demonstrated that only four of the many concerns raised by the stakeholders could make a difference in the decision: health risks, costs, service reliability, and property values. Whether undergrounding, moderate alternatives for EMF reduction, or no change was the best decision depended on a few key factors, including the probability that EMF exposure is a hazard, the severity of this hazard, how the EMF reduction measures are financed, and the impacts on property values. While the analysis did not resolve the EMF issues, it showed that even in the most controversial settings, a little analysis goes a long way to clarifying the issues and to focus the debate.

Accidents↗

Socioeconomic disparities in the use of home health services in a medicare managed care population.

OBJECTIVE: To investigate socioeconomic disparities in access to home health visits and durable medical equipment by persons enrolled in two Medicare managed care health plans. DATA SOURCES: A telephone survey of 4,613 Medicare managed care enrollees conducted between April and October of 2000 and linked to administrative claims for a subsequent 12-month period. STUDY DESIGN: We estimated a series of logistic regression models to determine which socioeconomic factors were related to home health visits and the use of durable medical equipment (DME) among Medicare managed care enrollees. PRINCIPAL FINDINGS: Controlling for health and demographic differences, Medicare managed care enrollees in the lowest tertile for nonhousing assets had 50 percent greater odds than those in the highest tertile of having one or more home health visits. All else equal, enrollees with less than a high school education had 30 percent lower odds than those who had graduated from high school of using durable medical equipment. CONCLUSIONS: Medicare managed care enrollees of low socioeconomic status do not appear to have reduced access to home health visits; however, use of durable medical equipment is considerably lower for enrollees with less than a high school education. Physicians and therapists working with Medicare managed care enrollees may want to actively target DME prescriptions to those with educational disadvantages.

Aged↗

Specificity and sensitivity of claims-based algorithms for identifying members of Medicare+Choice health plans that have chronic medical conditions.

OBJECTIVE: To examine the effects of varying diagnostic and pharmaceutical criteria on the performance of claims-based algorithms for identifying beneficiaries with hypertension, heart failure, chronic lung disease, arthritis, glaucoma, and diabetes. STUDY SETTING: Secondary 1999-2000 data from two Medicare+Choice health plans. STUDY DESIGN: Retrospective analysis of algorithm specificity and sensitivity. DATA COLLECTION: Physician, facility, and pharmacy claims data were extracted from electronic records for a sample of 3,633 continuously enrolled beneficiaries who responded to an independent survey that included questions about chronic diseases. PRINCIPAL FINDINGS: Compared to an algorithm that required a single medical claim in a one-year period that listed the diagnosis, either requiring that the diagnosis be listed on two separate claims or that the diagnosis to be listed on one claim for a face-to-face encounter with a health care provider significantly increased specificity for the conditions studied by 0.03 to 0.11. Specificity of algorithms was significantly improved by 0.03 to 0.17 when both a medical claim with a diagnosis and a pharmacy claim for a medication commonly used to treat the condition were required. Sensitivity improved significantly by 0.01 to 0.20 when the algorithm relied on a medical claim with a diagnosis or a pharmacy claim, and by 0.05 to 0.17 when two years rather than one year of claims data were analyzed. Algorithms that had specificity more than 0.95 were found for all six conditions. Sensitivity above 0.90 was not achieved all conditions. CONCLUSIONS: Varying claims criteria improved the performance of case-finding algorithms for six chronic conditions. Highly specific, and sometimes sensitive, algorithms for identifying members of health plans with several chronic conditions can be developed using claims data.

Algorithms↗

The quality of medical care provided to vulnerable community-dwelling older patients.

BACKGROUND: Many people 65 years of age and older are at risk for functional decline and death. However, the resource-intensive medical care provided to this group has received little evaluation. Previous studies have focused on general medical conditions aimed at prolonging life, not on geriatric issues important for quality of life. OBJECTIVE: To measure the quality of medical care provided to vulnerable elders by evaluating the process of care using Assessing Care of Vulnerable Elders quality indicators (QIs). DESIGN: Observational cohort study. SETTING: Managed care organizations in the northeastern and southwestern United States. PATIENTS: Vulnerable older patients identified by a brief interview from a random sample of community-dwelling adults 65 years of age or older who were enrolled in 2 managed care organizations and received care between July 1998 and July 1999. MEASUREMENTS: Percentage of 207 QIs passed, overall and for 22 target conditions; by domain of care (prevention, diagnosis, treatment, and follow-up); and by general medical condition (for example, diabetes and heart failure) or geriatric condition (for example, falls and incontinence). RESULTS: Patients were eligible for 10 711 QIs, of which 55% were passed. There was no overall difference between managed care organizations. Wide variation in adherence was found among conditions, ranging from 9% for end-of-life care to 82% for stroke care. More treatment QIs were completed (81%) compared with other domains (follow-up, 63%; diagnosis, 46%; and prevention, 43%). Adherence to QIs was lower for geriatric conditions than for general medical conditions (31% vs. 52%; P < 0.001). CONCLUSIONS: Care for vulnerable elders falls short of acceptable levels for a wide variety of conditions. Care for geriatric conditions is much less optimal than care for general medical conditions.

Aged↗

The quality of health care delivered to adults in the United States.

BACKGROUND: We have little systematic information about the extent to which standard processes involved in health care--a key element of quality--are delivered in the United States. METHODS: We telephoned a random sample of adults living in 12 metropolitan areas in the United States and asked them about selected health care experiences. We also received written consent to copy their medical records for the most recent two-year period and used this information to evaluate performance on 439 indicators of quality of care for 30 acute and chronic conditions as well as preventive care. We then constructed aggregate scores. RESULTS: Participants received 54.9 percent (95 percent confidence interval, 54.3 to 55.5) of recommended care. We found little difference among the proportion of recommended preventive care provided (54.9 percent), the proportion of recommended acute care provided (53.5 percent), and the proportion of recommended care provided for chronic conditions (56.1 percent). Among different medical functions, adherence to the processes involved in care ranged from 52.2 percent for screening to 58.5 percent for follow-up care. Quality varied substantially according to the particular medical condition, ranging from 78.7 percent of recommended care (95 percent confidence interval, 73.3 to 84.2) for senile cataract to 10.5 percent of recommended care (95 percent confidence interval, 6.8 to 14.6) for alcohol dependence. CONCLUSIONS: The deficits we have identified in adherence to recommended processes for basic care pose serious threats to the health of the American public. Strategies to reduce these deficits in care are warranted.

Adult↗

Quality-of-care indicators for early-stage prostate cancer.

PURPOSE: Decisions regarding treatment for early-stage prostate cancer are frustrated not only by inadequate evidence favoring one treatment modality but also by the absence of data comparing quality among providers. In fact, the choice of provider may be as important as the choice of treatment. We undertook this study to develop an infrastructure to evaluate variations in quality of care for men with early-stage prostate cancer. METHODS: We enlisted several sources to develop a list of proposed quality-of-care indicators and covariates. After an extensive structured literature review and a series of focus groups with patients and their spouses, we conducted structured interviews with national academic leaders in prostate cancer treatment. We then convened an expert panel using the RAND consensus method to discuss and rate the validity and feasibility of the proposed quality indicators and covariates. RESULTS: The panel endorsed 49 quality-of-care indicators and 14 covariates, which make up our final list of candidate measures. Several domains of quality are represented in the selected indicators, including patient volume, pretreatment referrals, preoperative testing, interpretation of pathology specimens, and 10-year disease-free survival. Covariates include measures of case-mix, such as patient age and comorbidity. CONCLUSION: This study establishes a foundation on which to build quality-of-care assessment tools to evaluate the treatment of early-stage prostate cancer. The next step is to field-test the indicators for feasibility, reliability, validity, and clinical utility in a population-based sample. This work will begin to inform medical decision-making for patients and their physicians.

Adenocarcinoma↗

Use of ambulance dispatch data as an early warning system for communitywide influenzalike illness, New York City.

In 1998, the New York City Department of Health and the Mayor's Office of Emergency Management began monitoring the volume of ambulance dispatch calls as a surveillance tool for biologic terrorism. We adapted statistical techniques designed to measure excess influenza mortality and applied them to outbreak detection using ambulance dispatch data. Since 1999, we have been performing serial daily regressions to determine the alarm threshold for the current day. In this article, we evaluate this approach by simulating a series of 2,200 daily regressions. In the influenza detection implementation of this model, there were 71 (3.2%) alarms at the 99% level. Of these alarms, 64 (90%) occurred shortly before or during a period of peak influenza in each of six influenza seasons. In the bioterrorism detection implementation of this methodology, after accounting for current influenza activity, there were 24 (1.1%) alarms at the 99% level. Two occurred during a large snowstorm, 1 is unexplained, and 21 occurred shortly before or during a period of peak influenza activity in each of six influenza seasons. Our findings suggest that this surveillance system is sensitive to communitywide respiratory outbreaks with relatively few false alarms. More work needs to be done to evaluate the sensitivity of this approach for detecting nonrespiratory illness and more localized outbreaks.

Ambulances↗

Quality of health care for women: a demonstration of the quality assessment tools system.

BACKGROUND: Consumers, purchasers, and regulators are seeking information on quality for a variety of purposes. To address these demands, methods are required that are flexible in meeting the information needs of different audiences. OBJECTIVES: To test a new clinically detailed, comprehensive approach to quality measurement called Quality Assessment (QA) Tools. DESIGN: Quality measures were developed for women ages 18 to 50 years for preventive care and 17 clinical areas that included chronic and acute health problems. A stratified random sample of women enrolled in 1 of 2 health plans in 1996 to 1997 was drawn and data abstracted from the medical records of all their providers for a 2-year period. FINDINGS: We evaluated quality for 758 women in 2 managed care plans. Quality of care varied substantially depending on the dimension being examined. For example, acute care was significantly better than chronic or preventive care. Quality was highest for follow-up care and lowest for treatment in both plans. Quality by modality ranged from approximately 90% for referral or admission to 16% for education and counseling. We found significant differences between the plans in the quality of care for 7 of the 17 conditions studied. CONCLUSION: The QA Tools system offers an alternative approach to evaluating health system performance. Potential advantages include the richness of the information produced by the system, the ability to create summary scores for consumers and purchasers, and the system-level performance information for use in quality improvement activities.

Acute Disease↗

Pharmacokinetics of ritonavir and delavirdine in human immunodeficiency virus-infected patients.

To evaluate the pharmacokinetic effect of adding delavirdine mesylate to the antiretroviral regimens of human immunodeficiency virus (HIV)-infected patients stabilized on a full dosage of ritonavir (600 mg every 12 h), 12 HIV-1-infected subjects had delavirdine mesylate (400 mg every 8 h) added to their current antiretroviral regimens for 21 days. Ritonavir pharmacokinetics were evaluated before (day 7) and after (day 28) the addition of delavirdine, and delavirdine pharmacokinetics were evaluated on day 28. The mean values (+/- standard deviations) for the maximum concentration in serum (C(max)) of ritonavir, the area under the concentration-time curve from 0 to 12 h (AUC(0-12)), and the minimum concentration in serum (C(min)) of ritonavir before the addition of delavirdine were 14.8 +/- 6.7 micro M, 94 +/- 36 micro M. h, and 3.6 +/- 2.1 micro M, respectively. These same parameters were increased to 24.6 +/- 13.9 micro M, 154 +/- 83 micro M. h, and 6.52 +/- 4.85 micro M, respectively, after the addition of delavirdine (P is <0.05 for all comparisons). Delavirdine pharmacokinetic parameters in the presence of ritonavir included a C(max) of 23 +/- 16 micro M, an AUC(0-8) of 114 +/- 75 micro M. h, and a C(min) of 9.1 +/- 7.5 micro M. Therefore, delavirdine increases systemic exposure to ritonavir by 50 to 80% when the drugs are coadministered.

Adult↗

The case identification challenge in measuring quality of cancer care.

PURPOSE: The delivery of quality care to all patients with cancer has been named as a national priority within the American health care system. This article addresses the issues critical to case identification in cancer quality measurement and recommends possible strategies for accurately identifying a population of cancer patients. METHODS: We present the measurement issues associated with the basic challenges of case identification strategies for quality measurement. We discuss two basic challenges: (1) accurately identifying all patients with the defining characteristics (eg, a diagnosis of breast cancer), and (2) identifying only patients with these characteristics. RESULTS: Possible options for identifying newly diagnosed patients include using claims or other administrative data, cancer registries, cancer registry rapid case ascertainment, pathology laboratories, and physicians' offices. In the published literature, the sensitivity of claims varies from 75% to 95%, whereas central registries must have a 90% completeness rate to be certified. Most of these approaches, however, involve limitations to obtaining valid and comparable data across multiple settings. CONCLUSION: Using an existing data collection system staffed by skilled data collectors and managers should result in substantially more accurate and timely data. Registry officials and the government agencies that provide their support should be encouraged to adopt quality-of-care analyses as an important purpose of the registry system and to enhance their capacity to rapidly ascertain cases, collect the appropriate identifying information needed for patient contact, and verify stage at diagnosis. In order to meet the growing demand for timely, accurate information about quality of care, registries are likely to require additional support so they can enhance their capacity to rapidly ascertain cases, collect the appropriate identifying information needed for patient contact, and verify stage at diagnosis.

Breast Neoplasms↗

Validity of cancer registry data for measuring the quality of breast cancer care.

BACKGROUND: Various groups have called for a national system to monitor the quality of cancer care. The validity of cancer registry data for quality of cancer care has not been well studied. We investigated the validity of such information in the California Cancer Registry. METHODS: We compared registry data associated with care with data abstracted from the medical records of patients diagnosed with breast cancer. We also calculated a quality score for each subject by determining the proportion of four evidence-based quality indicators that were met and then compared overall quality scores obtained from registry and medical record data. All statistical tests were two-sided. RESULTS: Records of 304 patients were studied. Compared with the medical record data gold standard, the accuracy of registry data was higher for hospital-based services (sensitivity = 95.0% for mastectomy, 94.9% for lumpectomy, and 95.9% for lymph node dissection) than for ambulatory services (sensitivity = 9.8% for biopsy, 72.2% for radiation therapy, 55.6% for chemotherapy, and 36.2% for hormone therapy). On average, quality scores calculated from registry data were 11 percentage points (95% confidence interval [CI] = 9 to 13 percentage points, P<.001) lower than those calculated from medical record data. Quality scores calculated from registry data were 5 percentage points (95% CI = 3 to 7 percentage points) lower for patients with stage I breast cancer, 16 percentage points (95% CI = 12 to 20 percentage points) lower for patients with stage II breast cancer, and 20 percentage points (95% CI = 8 to 32 percentage points) lower for patients with stage III breast cancer than were corresponding scores calculated from medical record data (all P<.001). The greater difference in quality scores for stage II and III patients revealed that disease severity and setting of care affected the validity of registry data. CONCLUSIONS: Cancer registry data for quality measurement may not be valid for all care settings, but registries could provide the infrastructure for collecting data on the quality of cancer care. We urge that funding be increased to augment data collection by cancer registries.

Age Factors↗

Phoneme awareness is a better predictor of early reading skill than onset-rime awareness.

We present the results of a short-term longitudinal study. Children in the early stages of learning to read (5 and 6 year olds) were administered three different tasks (deletion, oddity, and detection) tapping awareness of four phonological units (initial phoneme, final phoneme, onset, and rime). Measures of phoneme awareness were the best concurrent and longitudinal predictors of reading skill with onset-rime skills making no additional predictive contribution once phonemic skills were accounted for. The findings are related to recent controversy over the role of large versus small phonological units as predictors of children's reading skills.

Awareness↗

Developing a reliable, valid, and feasible plan for quality-of-care measurement for cancer: how should we measure?

BACKGROUND: Recent changes in the US health care delivery system have raised expectations that the medical marketplace will compete on quality and cost of care. This effort will require a systematic evaluation of the measurement of quality of care as it applies to cancer and other critical conditions. OBJECTIVES: To articulate the components of the design of quality-of-care measurement systems that must be considered and optimally manipulated to generate feasible, reliable, and valid data pertinent to patients with cancer. RESEARCH DESIGN: A synthesis of information obtained from literature reviews and experience. MEASURES: Four key areas of design that influence quality-of-care measurement scores are discussed: case identification, data source, data-collection strategies, and the quality of the care-measurement model. RESULTS: Challenges associated with these design and measurement strategies are defined and discussed. CONCLUSIONS: Policy analyses vary as a function of measurement domains. The design of a quality-of-care measurement system should consider trade-offs between validity and burden by considering the intricate relations between domains of measurement.

Data Collection↗