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K Swartz

Publications and source records attributed to K Swartz.

At least 19 recordsLinked to original sources
PubMed1999

Wavelet analysis of neuroelectric waveforms: a conceptual tutorial.

This paper presents a nontechnical, conceptually oriented introduction to wavelet analysis and its application to neuroelectric waveforms such as the EEG and event related potentials (ERP). Wavelet analysis refers to a growing class of signal processing techniques and transforms that use wavelets and wavelet packets to decompose and manipulate time-varying, nonstationary signals. Neuroelectric waveforms fall into this category of signals because they typically have frequency content that varies as a function of time and recording site. Wavelet techniques can optimize the analysis of such signals by providing excellent joint time-frequency resolution. The ability of wavelet analysis to accurately resolve neuroelectric waveforms into specific time and frequency components leads to several analysis applications. Some of these applications are time-varying filtering for denoising single trial ERPs, EEG spike and spindle detection, ERP component separation and measurement, hearing-threshold estimation via auditory brainstem evoked response measurements, isolation of specific EEG and ERP rhythms, scale-specific topographic analysis, and dense-sensor array data compression. The present tutorial describes the basic concepts of wavelet analysis that underlie these and other applications. In addition, the application of a recently developed method of custom designing Meyer wavelets to match the waveshapes of particular neuroelectric waveforms is illustrated. Matched wavelets are physiologically sensible pattern analyzers for EEG and ERP waveforms and their superior performance is illustrated with real data examples.

Brain↗
PubMed1999

Can adverse selection be avoided in a market for individual health insurance?

Adverse selection is a potentially significant problem in the individual (nongroup) health insurance markets if states use regulations to restrict insurance companies' ability to select whom they will insure. In 1993, New Jersey implemented the Individual Health Coverage Program (IHCP), presenting an opportunity to test for adverse selection when insurers' ability to select enrollees is severely restricted. The authors collected socioeconomic, demographic, and health status data from a sample of 2,211 adults covered by IHCP policies and compared the IHCP enrollee characteristics with those of two control groups of New Jersey residents (uninsured adults and adults with employer group insurance). Adverse selection does not appear to have occurred against the IHCP. However, the IHCP premiums were not cheap, and the findings suggest that people who can afford to purchase individual insurance and do so are, on average, healthier than those who do not choose to enroll, probably because the latter cannot afford insurance.

Adult↗
PubMed1999

Meeting information needs: lessons learned from New Jersey's Individual Health Insurance Reform Program.

At national and state levels, there have been significant changes in the regulations governing individual and small group health insurance markets. Reforms to the individual health insurance market in New Jersey exemplify the challenges of informing consumers about changes in the regulation of insurers, where the changes are intended to simplify and broaden access to health insurance. To best take advantage of expanded access to coverage under new regulations governing the individual health insurance market, individuals need to understand the changed rules under which carriers determine eligibility and premiums. Survey results from New Jersey indicate, however, that a significant proportion of people who purchased policies under the restructured individual health insurance market did not fully understand how the new market operates.

Adult↗
PubMed1998

Insurance or a regular physician: which is the most powerful predictor of health care?

OBJECTIVES: This study compared the relative effects on access to health care of relationship with a regular physician and insurance status. METHODS: The subjects were 1952 nonretired, non-Medicare patients aged 18 to 64 years who presented with 1 of 6 chief complaints to 5 academic hospital emergency departments in Boston and Cambridge, Mass, during a 1-month study period in 1995. Access to care was evaluated by 3 measures: delay in seeking care for the current complaint, no physician visit in the previous year, and no emergency department visit in the previous year. RESULTS: After clinical and socioeconomic characteristics were controlled, lacking a regular physician was a stronger, more consistent predictor than insurance status of delay in seeking care (odds ratio [OR] = 1.6, 95% confidence interval [CI] = 1.2, 2.1), no physician visit [OR] = 4.5%, 95% CI = 3.3, 6.1), and no emergency department visit (OR = 1.8, 95% CI = 1.4, 2.4). For patients with a regular physician, access was no different between the uninsured and the privately insured. For privately insured patients, those with no regular physician had worse access than those with a regular physician. CONCLUSIONS: Among patients presenting to emergency departments, relationship with a regular physician is a stronger predictor than insurance status of access to care.

Adolescent↗
PubMed1997

Changes in the 1995 Current Population Survey and estimates of health insurance coverage.

This analysis compares the March 1994 and March 1995 Current Population Survey (CPS) counts of the numbers of people with different types of health insurance and without any health insurance coverage. The findings contain some surprises: there were no changes in the numbers of nonelderly people with Medicaid coverage and without any health insurance, and there were increases in the numbers of nonelderly people with employer-sponsored health insurance and with CHAMPUS/VA/military health care. Four changes were introduced in the CPS in 1995 and were likely, by themselves, to both raise and lower the estimates of the numbers of people with specific types of health insurance coverage. Three of the changes relate to questions about health insurance coverage; they coincide with the traditional mid-decade shift in the sample framework for the CPS.

Adult↗
PubMed1996

Integrated health care, capitated payment, and quality: the role of regulation.

Concerns about the effect of managed care techniques on the quality of medical care have been raised in many quarters. Physicians have advocated the reiteration of professional ethics or even the prohibition of market incentives in health care as solutions to the problem of cost-quality tradeoffs in managed care systems. However, few recognize the existing systems for the regulation of managed care or consider how additional regulation could alleviate some of the potential problems posed by market-based competition. We review the evolution and growth of managed care organizations and the payment techniques that could cause a conflict between patient welfare and physician income. We then discuss the existing types of federal and state regulation of managed care and suggest some new incentives that could buttress the ethical practice of medicine in the medical marketplace.

Capitation Fee↗