Note: multiplexed multiple-tau auto- and cross-correlators on a single field programmable gate array.

We introduce a new multiple-tau hardware correlator design for computing fluorescence correlation functions (CFs) in real time. Use of hardware resources is minimized by scheduling the computation of different segments of the CFs on a single correlator block. Simultaneous calculation of two multiple-tau autocorrelation (ACFs) and two cross-correlation functions (CCFs) is implemented in LabVIEW on a National Instruments field programmable gate array (FPGA) card with a minimal sampling time of 400 ns. Raw data are stored with a time resolution of 50 ns. The design can be easily adapted to other FPGA cards and extended to more inputs.

Researcher and researched--community perspectives: toward bridging the gap.

In the process of initiating a new community-based research project, the authors wanted to understand the experiences of community members and researchers in community-based research projects and to develop guidelines to improve future projects. They conducted qualitative, key informant interviews with 41 people involved at all levels of community-based research projects in Seattle. Respondents were identified using a snowball sampling technique. More problems than successes were discussed by informants, including dissatisfaction with the focus of research, which some said is marked by a lack of cultural appropriateness and relevance. Power imbalances, lack of trust, and communication difficulties impeded collaboration. According to respondents, many problems could be avoided if the community were involved from the beginning in setting research priorities and developing and implementing interventions. Meaningful collaboration between communities and researchers is characterized by early involvement of communities, power sharing, mutual respect, community benefit, and cultural sensitivity.

Accessing population health information through interactive systems: lessons learned and future directions.

In the mid-1990s, several state and county public health departments implemented interactive software systems that provided easy access to public health-related data for local boards of health, other public health agencies, health care providers, community groups, and other interested members of the public. Based on their experiences with two well-established state interactive systems and one well-established county system, the authors summarize lessons that could prove useful to state and local public health agencies interested in developing new interactive systems or adapting existing ones. The article addresses issues such as: basing interactive systems on a broad definition of health, designing systems to incorporate user preferences, moving from data warehouses to information warehouses, and fostering prevention communities. Finally, the article provides recommendations to assist federal, state, and local public health agencies in developing the next generation of interactive data access systems.

Improving collaboration between researchers and communities.

Active collaboration between communities and researchers is critical to developing appropriate public health research strategies that address community concerns. To capture the perspectives of inner-city Seattle communities about issues in community-researcher partnerships, Seattle Partners for Healthy Communities conducted interviews with community members from the ethnically diverse neighborhoods of Central and Southeast Seattle. The results suggest that effective community-researcher collaborations require a paradigm shift from traditional practices to an approach that involves: acknowledging community contributions, recruiting and training minority people to participate in research teams, improving communication, sharing power, and valuing respect and diversity.

Asthma and the home environment of low-income urban children: preliminary findings from the Seattle-King County healthy homes project.

OBJECTIVES: Childhood asthma is a growing public health concern in low-income urban communities. Indoor exposure to asthma triggers has emerged as an important cause of asthma exacerbations. We describe indoor environmental conditions related to asthma triggers among a low-income urban population in Seattle/King County, Washington, as well as caregiver knowledge and resources related to control of these triggers. METHODS: Data are obtained from in-person, structured, closed-end interviews with the caretakers of children aged 4-12 years with persistent asthma living in households with incomes less than 200% of poverty. Additional information is collected during a home inspection. The children and their caregivers are participants in the ongoing Seattle-King County Healthy Homes Project, a randomized controlled trial of an intervention to empower low-income families to reduce exposure to indoor asthma triggers. We report findings on the conditions of the homes prior to this intervention among the first 112 enrolled households. RESULTS: A smoker was present in 37.5% of homes. Mold was visible in 26.8% of homes, water damage was present in 18.6% of homes, and damp conditions occurred in 64.8% of households, while 39.6% of caregivers were aware that excessive moisture can increase exposures to allergens. Dust-trapping reservoirs were common; 76.8% of children's bedrooms had carpeting. Cockroach infestation in the past 3 months was reported by 23.4% of caregivers, while 57.1% were unaware of the association of roaches and asthma. Only 19.8% of the children had allergy-control mattress covers. CONCLUSIONS: Many low-income urban children with asthma in King County live in indoor environments that place them at substantial risk of ongoing exposure to asthma triggers. Substandard housing and lack of resources often underlie these exposures. Initiatives involving health educators, outreach workers, medical providers, health care insurers, housing agencies, and elected officials are needed to reduce these exposures.

Increasing influenza and pneumococcal immunization rates: a randomized controlled study of a senior center-based intervention.

BACKGROUND: Immunizations decrease morbidity from influenza and pneumococcal infections. Immunization levels remain below desired levels despite clinic-based and public education efforts. This paper describes a randomized, controlled trial of a senior center-based program, which used peer-to-peer outreach to increase pneumococcal and influenza immunization rates among an urban senior population. METHODS: Seniors were randomized to intervention or control groups. The intervention group received educational brochures mailed with reply cards to report immunization status, telephone calls from senior volunteers to unimmunized participants, and computerized immunization tracking. Immunization rates were obtained before and after the intervention by self-report. RESULTS: Among participants without prior pneumococcal immunization, the pneumococcal immunization rate among the intervention group (52.0%; 95% CI = 46.6%-57.4%) was significantly higher than that of the control group (30.9%; 95% CI = 26.6%-35.2%) (rate ratio = 1.68; 95% CI = 1.40-2.03). Among those without influenza immunization in the prior year, significantly more (50.0%; 95% CI = 40.0%-60.0%) were immunized against influenza in the intervention group than in the control group (23.0%; 95% CI = 15.2%-33.3%) (rate ratio = 2.17; 95% CI = 1.42-3.31). Among those with influenza immunization in the prior year, the rate ratio was 1.04 (95% CI = 1.01-1.07). CONCLUSIONS: The intervention increased both influenza and pneumococcal immunization rates to high levels, suggesting that further progress in increasing adult immunization coverage is possible.

A baseline detection method for analyzing transient electrophysiological events.

A baseline detection method has been developed that identifies and defines event transitions for whole-cell voltage or current ('transient') events that are produced by the activity of ion channel ensembles. The method utilizes a variety of iterative techniques that independently determine, for each event, several output parameters that are ultimately referrable to the mean and variance of each pre-event baseline. Examination of miniature endplate potentials using the baseline detection method provided the following output parameters for each transient event: pre-event mean and variance; rise time; peak amplitude and duration; a determination of whether the decay phase was best fit by a one- or two-component negative exponential function; time constants for the slow and/or fast decay components; percent contribution of the slow component to the decay phase; and the predicted peak amplitude determined by extrapolation of the least squares fit to the decay phase. Joint probability density representations involving the rise time and peak amplitudes of miniature endplate potentials indicated the power of this multivariate approach in identifying and isolating specific event classes. The baseline detection method is particularly advantageous for analyzing records containing multiple classes of event amplitudes, and provides a reproducible statistical standard for the analyses of transient events that are characteristic of whole-cell electrophysiological recordings.

Prone sleep position and the sudden infant death syndrome in King County, Washington: a case-control study.

OBJECTIVE: To determine whether the prone sleep position was associated with an increased risk of the sudden infant death syndrome (SIDS). STUDY DESIGN: Population-based case-control study. PARTICIPANTS: Case subjects were infants who died of SIDS in King County, Washington. Control subjects were randomly selected infants born in King County. Up to four control subjects were matched on date of birth to each case subject. METHODS: During the study period, November 1992 through October 1994, sleep-position data were collected on infants who died of SIDS by the King Count Medical Examiner's Office during their investigation of the deaths. Parents of infants chosen as control subjects were contacted by telephone, and sleep position information was obtained. Infants who usually slept on their abdomen were classified as sleeping prone; those who usually slept on the side or back were categorized as sleeping nonprone. The adjusted odds ratio for prone sleep position as a risk factor for SIDS was calculated with conditional logistic regression after control for race, birth weight, maternal age, maternal marital status, household income, and maternal cigarette smoking during pregnancy. RESULTS: Sleep position data were collected on 47 infants with SIDS (77% of eligible infants) and 142 matched control subjects; 57.4% of infants who died of SIDS usually slept prone versus 24.6% of control subjects (p < 0.00001). The unadjusted odds ratio for prone sleep position as a risk factor for SIDS was 4.69 (95% confidence interval: 2.17, 10.17). After control for potentially confounding variables, the adjusted odds ratio for prone sleep position was 3.12 (95% confidence interval: 1.08, 9.03). CONCLUSION: Prone sleep position was significantly associated with an increased risk of SIDS among a group of American infants.

Attitudes of Washington State physicians toward health care reform.

Attitudes of Washington State physicians about health care reform and about specific elements of managed competition and single-payer proposals were evaluated. Opinions about President Clinton's reform plan were also assessed. Washington physicians (n = 1,000) were surveyed from October to November 1993, and responses were collected through January 1994; responses were anonymous. The response rate was 80%. Practice characteristics of respondents did not differ from other physicians in the state. Of physicians responding, 80% favored substantial change in the current system, 43% favored managed competition, and 40% preferred a single-payer system. Of physicians responding, 64% thought President Clinton's proposal would not adequately address current problems. Reduced administrative burden, a central element of single-payer plans, was identified by 89% of respondents as likely to improve the current system. Other elements of reform plans enjoyed less support. More procedure-oriented specialists than primary care physicians favored leaving the current system unchanged (28% versus 8%, P < .001). While physicians favor health care reform, there is no consensus on any single plan. It seems unlikely that physicians will be able to speak with a single voice during the current debates on health care reform.

Health status of urban American Indians and Alaska Natives. A population-based study.

OBJECTIVE: To use vital statistics and communicable disease reports to characterize the health status of an urban American Indian and Alaska Native (AI/AN) population and compare it with urban whites and African Americans and with AI/ANs living on or near rural reservations. DESIGN: Descriptive analysis of routinely reported data. SETTING: One metropolitan county and seven rural counties with reservation land in Washington State. SUBJECTS: All reported births, deaths, and cases of selected communicable diseases occurring in the eight counties from 1981 through 1990. MAIN OUTCOME MEASURES: Low birth weight, infant mortality, and prevalence of risk factors for poor birth outcomes; age-specific and cause-specific mortality; rates of reported hepatitis A and hepatitis B, tuberculosis, and sexually transmitted diseases. RESULTS: Urban AI/ANs had a much higher rate of low birth weight compared with urban whites and rural AI/ANs and had a higher rate of infant mortality than urban whites. During the 10 years, urban AI/AN infant mortality rates increased from 9.6 per 1000 live births to 18.6 per 1000 live births compared with no trend among the other populations. Compared with rural AI/AN mothers, urban AI/AN mothers were 50% more likely to receive late or no prenatal care during pregnancy. Relative to urban whites, urban AI/AN risk factors for poor birth outcomes (delayed prenatal care, adolescent age, and use of tobacco and alcohol) were more common and closely resembled the prevalence among the African-American population except for a higher rate of alcohol use among AI/ANs. Compared with urban whites, urban AI/AN mortality rates were higher in every age group except the elderly. Differences between urban whites and AI/ANs were largest for injury- and alcohol-related deaths. All-cause mortality was lower among urban AI/ANs compared with rural AI/ANs and urban African Americans, although injury- and alcohol-related deaths were higher for AI/ANs. All communicable diseases studied were significantly (P < .05) more common among urban AI/ANs compared with whites. Tuberculosis rates were highest in the urban AI/AN group, but rates of sexually transmitted diseases were intermediate between urban whites and African Americans. CONCLUSIONS: In this urban area, great disparities exist between the health of AI/ANs and whites across almost every health dimension we measured. No consistent pattern was found in the comparison of health indicators between urban and rural AI/ANs, though rural AI/ANs had lower rates of low birth weight and higher rates of timely prenatal care use. The poor health status of urban AI/AN people requires greater attention from federal, state, and local health authorities.

Medicaid prenatal care: a comparison of use and outcomes in fee-for-service and managed care.

BACKGROUND: To control rising costs, state Medicaid agencies are enrolling recipients in managed care health plans (MCPs). We performed this study to assess this policy's impact on accessibility and outcomes of Medicaid-funded prenatal care. METHODS: We performed a retrospective, controlled study with three cohorts: a study group of 1106 Medicaid recipients enrolled in three MCPs, a matched comparison group of 4830 recipients receiving care in the fee-for-service (FFS) system, and a second matched comparison group of 4434 non-Medicaid enrollees of the same MCPs. Data on prenatal care use and birth outcomes were obtained through linkage of claims and discharge files with birth certificate files. RESULTS: Medicaid recipients enrolled in MCPs used prenatal care similarly to those in the FFS system and showed equal or modestly improved birth-weight distributions. However, Medicaid MCP enrollees showed poorer use of prenatal care and birth outcomes compared with non-Medicaid enrollees of the same plans. CONCLUSIONS: Enrollment in MCPs has a neutral or small beneficial effect on the prenatal care received by the Medicaid population. However, providing financial access and modifying the system of care for this population did not result in parity with the general population.