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In Britain, mandatory continuing dental education is on its way. In California, we have had mandatory continuing dental education for some twenty-five years. Maybe it would help to see some of the good and bad sides of this, learn from some of our mistakes and see what does work and what does not work--at least in California.
Although studies suggest that air pollution is linked to perinatal outcomes, the geographic characterization of exposure to pollution differs between the studies. We compared neighborhood- and county-level measures of air pollution exposure, while examining the association between particulate matter less than 2.5 microm in aerodynamic diameter (PM(2.5)) and birth weight among full-term births in California in 2000. To reduce the effects of demographic variability, our analysis was limited to two populations of 8579 non-Hispanic white and 8114 Hispanic mothers who were married, between 20 and 30 years of age, completed at least a high school education, and gave birth for the first time. Measurements from the nearest monitor, and average and distance-weighted average of monitors within a 5-mile radius from each mother's residence (constituting neighborhood metrics) and the mean of monitors within each mother's county of residence were considered. PM(2.5) measurements, provided by the California Air Resources Board, were calculated to correspond to each mother's 9-month gestation period. Although metrics within the 5-mile radii and the county were highly correlated (r(2)=0.78), the county-level metric provided a stronger association between PM(2.5) and birth weight (beta=-4.04, 95% confidence interval =-6.71, -1.37) than the metric for the average of all monitors within 5-miles (beta=-1.38, 95% confidence interval =-3.36, 0.60) among non-Hispanic white mothers; similar results were observed among the Hispanic sample of mothers. Consequently, inferences from studies using different definitions of air pollution exposure may not be comparable.
Continuous measurements of particle number (PN), particle mass (PM(10)) and gaseous copollutants (NO(x), CO and O3) were obtained at eight sites (urban, suburban and remote) in Southern California during years 2002 and 2003 in support of University of Southern California Children's Health Study. We report the spatial and temporal variation of PNs and size distributions within these sites. Higher average total PN concentrations are found in winter (November to February), compared to summer (July to September) and spring (March to June) in all urban sites. Contribution of local vehicular emissions is most evident in cooler months, whereas effects of long-range transport of particles are enhanced during warmer periods. The particle size profile is most represented by a combination of the spatial effects, for example, sources, atmospheric processes and meteorological conditions prevalent at each location. Afternoon periods in the warmer months are characterized by elevated number concentrations that either coincide or follow a peak in ozone concentrations, suggesting the formation of new particles by photochemistry. Results show no meaningful correlation between PN and mass, indicating that mass based standards may not be effective in controlling ultrafine particles. The study of the impact of the Union worker's strike at port of Long Beach in October 2002 revealed statistically significant increase in PN concentrations in the 60-200 nm range (P<0.001), which are indicative of contributions of emissions from the idling ships at the port.
AIMS: To examine the effects of gender and acculturation on illicit drug use among the Mexican-origin population in California. DESIGN: The 3012 subjects between 18 and 59 years of age were selected under a stratified, multi-stage cluster sampling method. SETTING: Fresno County in California is primarily agricultural, with only one metropolitan area. Over 30% of the total population of 764,800, are Hispanics, of Mexican origin. MEASUREMENTS: A modified version of the World Health Organization's Composite International Diagnostic Instrument (WHO-CIDI) was used to ascertain drug use. Respondents were considered drug users if they had ever used marijuana, cocaine, hallucinogens, heroin or inhalants. Acculturation was measured with a Likert scale, assessing English vs. Spanish language preference. Other covariates of interest were nativity and place of residence. FINDINGS: Men had higher rates of use than women for every drug (men = 46.3%, women = 23.2%). Urban rates were higher than rural rates, for both women (urban = 32.8% vs. rural = 16.6%) and men (urban = 57.0% vs. rural = 36.8%). In logistic regression models, men were more likely than women to have ever used illicit drugs or inhalants (adjusted OR = 4.8), cocaine (adjusted OR = 5.3) or marijuana (OR = 4.3). However, the combined effect of United States nativity and acculturation, on drug use, was greater among women (adjusted OR = 29.3) than among men (adjusted OR = 7.4). The effect of acculturation was stronger among urban, than among town or rural residents. CONCLUSIONS: Acculturation and United States nativity are risk factors for illicit drug use among Mexican origin men and women. However, women have increased vulnerability compared with men. Findings reinforce the need for culturally based public health interventions.
The fragmented populations and reduced population densities that result from human disturbance are issues of growing importance in evolutionary and conservation biology. A key issue is whether remnant individuals become reproductively isolated. California Valley oak (Quercus lobata) is a widely distributed, endemic species in California, increasingly jeopardized by anthropogenic changes in biota and land use. We studied pollen movement in a savannah population of Valley oak at Sedgwick Reserve, Santa Barbara County, to estimate effective number of pollen donors (Nep) and average distance of effective pollen movement (delta). Using twogener, our recently developed hybrid model of paternity and genetic structure treatments that analyses maternal and progeny multilocus genotypes, we found that current Nep = 3.68 individuals. Based on an average adult density of d= 1.19 stems/ha, we assumed a bivariate normal distribution to model current average pollen dispersal distance (delta) and estimated delta= 64.8 m. We then deployed our parameter estimates in spatially explicit models of the Sedgwick population to evaluate the extent to which Nep may have changed, as a consequence of progressive stand thinning between 1944 and 1999. Assuming that pollen dispersal distance has not changed, we estimate Nep was 4.57 individuals in 1944, when stand density was 1.48. Both estimates indicate fewer effective fathers than one might expect for wind-pollinated species and fewer than observed elsewhere. The results presented here provide a basis for further refinements on modelling pollen movement. If the trends continue, then ongoing demographic attrition could further reduce neighbourhood size in Valley oak resulting in increased risk of reproductive failure and genetic isolation.
The California Floristic Province harbours more endemic plant and animal taxa and more identifiable subspecies than any other area of comparable size in North America. We present evidence that physical historical processes have resulted in congruent patterns of genetic diversity over the past 2-10 million years. Using a molecular clock approach we show that diversification and establishment of spatial genetic structure across six taxonomic groups coincide with the putative age of California's mountain ranges and aridification in the region. Our results demonstrate the importance of geographical barriers and climatological events to species diversification and the overall geographical structure of biodiversity. These results should facilitate conservation efforts in this biodiversity hotspot for taxa whose population genetic structure is still unknown and may suggest the potential utility of this approach in regional conservation planning efforts.
OBJECTIVE: To determine the population-based prevalence of migraine in a cross-sectional random sample of Mexican Americans aged at least 45 years in San Diego County, California. BACKGROUND: The prevalence of migraine has been assessed in various populations in the United States and Mexico, but no study of migraine prevalence in Mexican Americans has been reported in the literature to date. DESIGN/METHODS: Using an epidemiological cross-sectional research design, the population-based prevalence and associated descriptive epidemiology of self-reported migraine was estimated in Mexican Americans aged at least 45 years in San Diego County, California from a random sample of size 657. RESULTS: The lifetime migraine prevalence was 9.2% (95% confidence interval, 6.8 to 11.6) and current prevalence was 7.4% (95% confidence interval, 5.3 to 9.5). The prevalence of migraine was higher in women than in men, higher in low income groups than in high income groups, and decreased with increasing age. Prevalence among Mexican Americans born in Mexico was twice that of American-born Mexican Americans. CONCLUSIONS: These population-based data on migraine prevalence in Mexican Americans aged 45 and over contribute substantially to the understanding of this disease. A second study addressing migraine prevalence in Mexican Americans younger than 45 years in San Diego County will be reported.
The growth of investor-owned hospital-management companies represents the most dramatic change in the hospital industry in recent years. Whereas supporters of investor-owned chains suggest that their growth is attributable to operating efficiencies, critics suggest that it has resulted from pricing and marketing strategies. Using data supplied by the California Health Facilities Commission, we compared the economic performance of investor-owned and not-for-profit hospitals in California. There were three principal findings. First, during the study period both costs and charges were higher in for-profit than in not-for-profit hospitals, measured on the basis of either patient-days or admissions. Second, the for-profit chains have used aggressive marketing and pricing strategies to generate high rates of profitability and growth. Finally, the payer class of patients did not differ specifically according to the hospital-ownership category. We conclude that the recent dramatic growth of investor-owned hospital chains is attributable to the employment of managerial strategies that were well suited to the reimbursement system in effect during the period studied. As a result of recent changes in federal and state reimbursement, many of these reimbursement-maximization strategies have become obsolete. Whether the investor-owned chains will be able to adapt rapidly to this new reimbursement environment remains to be seen.
BACKGROUND: Perinatal substance exposure has been linked to many neonatal and obstetrical complications. There have been few population-based epidemiologic studies to identify the prevalence and demographic profiles associated with drugs, alcohol, and smoking during pregnancy. METHODS: We studied a fully probabilistic stratified-cluster sample to estimate the prevalence of perinatal substance exposures in California in 1992. Urine samples from 29,494 women presenting for delivery in 202 hospitals were coded and screened for toxins; the results of toxicology screening were later linked by code number to the subjects' demographic variables and their reported use of tobacco and prescribed drugs. Urinary toxicologic tests provide conservative estimates because they can detect only very recent substance use. RESULTS: The weighted prevalence for perinatal substance exposure was 5.16 percent for the use of one or more drugs, 6.72 percent for alcohol (analyzed independently), and 8.82 percent for self-reported smoking. The percentage of women testing positive for any drug, including alcohol, was 11.35 percent. Estimates for racial and ethnic groups varied widely. Black women had the highest prevalence of total drug use (14.22 percent), alcohol use (11.58 percent), cocaine use (7.79 percent), and tobacco use (20.12 percent). Most drug exposures occurred among white non-Hispanic and Hispanic women. White non-Hispanic women had the second highest prevalence rate for the use of one or more drugs (6.79 percent) and self-reported tobacco use (14.82 percent). Hispanic women had the second highest prevalence rate for alcohol (6.87 percent). CONCLUSIONS: In California in 1992, there were 67,361 estimated perinatal exposures to one or more drugs, including alcohol, and 52,346 self-reported exposures to tobacco. These findings have clinical and public health implications.
BACKGROUND: Lower rates of use of resources have been reported for the treatment of hospitalized patients covered by Medicaid than for privately insured patients. Cost-containment policies may exacerbate such differences in the use of hospital resources. We studied patients with ischemic heart disease who received care at nonfederal hospitals in California in 1983 (the year a Medicaid cost-containment program was implemented), in 1985, or in 1988. Within this sample of patients, we compared the rates of coronary revascularization (coronary-artery bypass surgery or coronary angioplasty) among patients covered by Medicaid, patients with private insurance covering fee-for-service care, and patients enrolled in a health maintenance organization (HMO). METHODS: Logistic-regression models were used to determine adjusted odds ratios for the use of coronary revascularization procedures in patients with different types of insurance, with control for demographic, clinical, and hospital characteristics. The study samples were made up of 49,167 patients in 1983, 47,809 in 1985, and 44,631 in 1988. RESULTS: The frequency of revascularization increased in all three insurance groups from 1983 to 1988, but it did so much faster in the fee-for-service and HMO groups than in the Medicaid group. Patients with private fee-for-service insurance were 1.66 times as likely as Medicaid patients to undergo revascularization in 1983 (P < 0.01), 2.01 times as likely in 1985 (P < 0.01) and 2.33 times as likely in 1988 (P < 0.01). Patients enrolled in HMOs were 0.96 times as likely as Medicaid patients to undergo revascularization in 1983 (P < 0.05), 1.23 times as likely in 1985 (P < 0.01), and 1.53 times as likely in 1988 (P < 0.01). CONCLUSIONS: The frequency of coronary revascularization in California in 1983 was nearly twice as high for patients with private fee-for-service insurance as for patients enrolled in HMOs or for Medicaid recipients. The implementation that year of stringent cost-control measures by Medicaid may explain the slower increase in the frequency of revascularization over five year among Medicaid recipients as compared with patients in the fee-for-service and HMO groups. Different incentives in fee-for-service and HMO practice may explain the lower frequency of revascularization among patients enrolled in HMOs, although the rates of increase for these two groups were about the same from 1983 to 1988.
BACKGROUND: Human babesiosis is a tick-transmitted zoonosis associated with two protozoa of the family Piroplasmorida: Babesia microti (in the United States) and B. divergens (in Europe). Recently, infection with an unusual babesia-like piroplasm (designated WA1) was described in a patient from Washington State. We studied four patients in California who were identified as being infected with a similar protozoal parasite. All four patients had undergone splenectomy, three because of trauma and one because of Hodgkin's disease. Two of the patients had complicated courses, and one died. METHODS: Piroplasm-specific nuclear small-subunit ribosomal DNA was recovered from the blood of the four patients by amplification with the polymerase chain reaction. The genetic sequences were compared with those of other known piroplasm species. Indirect immunofluorescent-antibody testing of serum from the four patients and from other potentially exposed persons was performed with WA1 and babesia antigens. RESULTS: Genetic sequence analysis showed that the organisms from all four patients were nearly identical. Phylogenic analysis showed that this strain is more closely related to a known canine pathogen (B. gibsoni) and to theileria species than to some members of the genus babesia. Serum from three of the patients was reactive to WA1 but not to B. microti antigen. Serologic testing showed WA1-antibody seroprevalence rates of 16 percent (8 of 51 persons at risk) and 3.5 percent (4 of 115) in two geographically distinct areas of northern California. CONCLUSIONS: A newly identified babesia-like organism causes infections in humans in the western United States. The clinical spectrum associated with infection with this protozoan ranges from asymptomatic infection or influenza-like illness to fulminant, fatal disease.
BACKGROUND: On January 17, 1994, an earthquake with a moment magnitude (total energy release) of 6.7 occurred in Northridge, California, leading to the evacuation of patients from several hospitals. We examined the reasons for and methods of evacuation and the emergency-management strategies used. The experience in California may have implications for hospital strategies for responding to any major disaster, including an act of terrorism. METHODS: From September 1995 to September 1996, we surveyed all acute care hospitals in Los Angeles County that reported having evacuated patients after the Northridge earthquake. Physicians, nurses, hospital administrators, and staff on duty at the hospitals during the evacuation responded to a 58-item structured questionnaire. RESULTS: Eight of 91 acute care hospitals (9 percent) were evacuated. Six hospitals evacuated patients within 24 hours (the immediate-evacuation group), four completely and two partially. All six cited nonstructural damage such as water damage and loss of electrical power as a major reason for evacuation. Five hospitals evacuated the most seriously ill patients first, and one hospital evacuated the healthiest patients first. All hospitals used available equipment to transport patients (blankets, backboards, and gurneys) rather than specialized devices. No deaths resulted from evacuation. One hospital evacuated patients after 3 days and another after 14 days because of structural damage, even though initial inspections had shown no damage (the delayed-evacuation group). Both hospitals required demolition. Some hospitals identified destinations for their evacuated patients independently, whereas others sought the assistance of the Los Angeles County Emergency Operations Center; the two strategies were equally effective. CONCLUSIONS: After even a moderate earthquake, hospitals are at risk for both immediate nonstructural damage that may force them to evacuate patients and the delayed discovery of structural damage resulting in permanent closure. Evacuation of large numbers of inpatients from multiple hospitals can be accomplished quickly and safely with the use of available resources and personnel.
BACKGROUND: Several states have developed prescription-drug discount programs for Medicare beneficiaries. In California, Senate Bill 393, enacted in 1999, requires pharmacies participating in the state Medicaid program (Medi-Cal) to charge customers who present a Medicare card amounts based on Medi-Cal rates. Because Medicare beneficiaries may not be accustomed to presenting their Medicare cards at pharmacies, we assessed the compliance of pharmacies with Senate Bill 393. METHODS: Fifteen Medicare beneficiaries who received special training and acted as "standardized patients" visited a random sample of pharmacies in the San Francisco Bay area and Los Angeles County in April and May 2001. According to a script, they asked for the prices of three commonly prescribed drugs: rofecoxib, sertraline, and atorvastatin. The script enabled us to determine whether and when, during their interactions with pharmacists or salespeople, the discounts specified in Senate Bill 393 were offered. Pharmacies at which the appropriate discounts were offered were considered compliant. RESULTS: The patients completed visits to 494 pharmacies. Seventy-five percent of the pharmacies complied with the prescription-drug discount program; at only 45 percent, however, was the discount offered before it was specifically requested. The discount was offered at 91 percent of pharmacies that were part of a chain, as compared with 58 percent of independent pharmacies (P<0.001). Compliance was higher in the San Francisco Bay area than in Los Angeles County (84 percent vs. 72 percent, P=0.004) and was higher in high-income than low-income neighborhoods (81 percent vs. 69 percent, P=0.002). A Medicare beneficiary taking all three drugs would have saved an average of $55.70 per month as compared with retail prices (a savings of 20 percent). CONCLUSIONS: Discounts required under California's prescription-drug discount program for Medicare beneficiaries offer substantial savings. Many patients, however, especially those who use independent pharmacies or who live in low-income neighborhoods, may not receive the discounts.
INTRODUCTION: Health care workers have long been recognized as having a high risk of work-related assault. In response to a growing threat of violence in hospitals, California implemented the Hospital Security Act (AB508) in 1993. This study compares surveys of emergency nurses before and after implementation of AB508. METHODS: In 1990, the CAL/ENA surveyed emergency departments in California to enumerate violent events and describe security programs. Using the CAL/ENA membership directory, hospitals were resurveyed in 2000 to identify changes from the original survey. Surveys were mailed to the ED nurse manager or equivalent. Survey responses were anonymous. RESULTS: Most hospitals reported fewer violent episodes after the implementation of AB508. However, 32% of hospitals reported that 5 or more verbal threats occurred monthly, and 5% reported that 5 or more violent injuries occurred monthly. Overall, hospitals reported improvements in security programs. The most notable increase was in employee training, which rose from 34% to 95.6% of reporting hospitals. However, almost a quarter of hospitals reported not having general violence prevention policies, and many believed that security personnel were inadequate. DISCUSSION: Although results reported here cannot be directly attributed to AB508, the increase in security program components suggests that hospitals are responding positively to reduce violence. The high prevalence of threats and violent events reported indicates a persistent risk of violence against health care workers.
OBJECTIVE: This study provides revised population-based measurements for the occurrence rates of cancer associated with obstetric delivery and examines perinatal and cancer-related outcomes within the group of women with 4,846,505 obstetric deliveries in California, inclusive of the years 1991 through 1999. STUDY DESIGN: This observational study used a population-based retrospective review of cases identified as a result of computer linkage of maternal/neonatal hospital discharge and birth/death records with case files in the California Cancer Registry (CCR). The effect of timing of cancer diagnosis on clinical outcomes was studied by dividing the cases into three groups as follows: "prenatal" for cancer diagnosis within 9 months before delivery, "at delivery" for cancer diagnosis during delivery hospitalization, and "post partum" for cancer diagnosis within 12 months after delivery. Computerized records for 4,846,505 obstetric patients and 4,906,920 newborn infants comprising the linked vital statistics birth/patient discharge database (VS/PDD) were used to identity-match cases within the CCR case files. Cases of malignant disease were categorized into 22 anatomic or histologic subgroups. Perinatal clinical outcomes including preterm delivery, prolonged neonatal hospital stay, stillbirth, neonatal death, frequency of first trimester prenatal care, and cesarean delivery were analyzed by use of International Classification of Diseases, 9th Revision, Clinical Modification codes from the VS/PDD. Clinical cancer outcomes including cancer stage and vital status on follow-up were drawn from CCR records. Statistical comparisons for trends were performed with the Cochran-Armitage test, outcomes comparisons with the Fisher exact test, and survival comparisons were performed with the Cox proportional hazard model. RESULTS: Among 4,846,505 obstetric deliveries, 4,539 cases of invasive malignancy were identified for an observed occurrence rate of 0.94 per 1000 births. Sixty-four percent of the cases occurred post partum; cancers of the breast, thyroid, cervix, along with malignant melanoma, and Hodgkin's disease accounted for 64% of the cases. The timing of cancer diagnosis affected clinical outcomes: for all cancer cases as a group, the most favorable perinatal and cancer outcomes occurred in women whose cancer diagnosis was made 6 to 9 months before delivery (6% of cases). The most unfavorable perinatal and cancer outcomes were associated with cancer diagnosis made 0 to 3 months before delivery (14% of cases). For women whose cancer was diagnosed post partum, perinatal outcomes were minimally affected by the presumed existence of occult cancer at the time of obstetric delivery. CONCLUSION: The use of computer-linkage to the CCR files enhanced identification of cases of maternal malignancy associated with obstetric delivery. Cancer diagnosis was associated with approximately 1 in 1000 deliveries. Most cases were diagnosed after delivery and were comprised predominantly of cancers of the breast, thyroid, cervix, malignant melanoma, and Hodgkin's disease. A small group of women (approximately 1 per 5000 deliveries) are seen within a few months before delivery or at delivery with malignant disease, many of whom have rapidly progressing disease and may require high-risk perinatal and oncology services.
The magnitude of future climate change depends substantially on the greenhouse gas emission pathways we choose. Here we explore the implications of the highest and lowest Intergovernmental Panel on Climate Change emissions pathways for climate change and associated impacts in California. Based on climate projections from two state-of-the-art climate models with low and medium sensitivity (Parallel Climate Model and Hadley Centre Climate Model, version 3, respectively), we find that annual temperature increases nearly double from the lower B1 to the higher A1fi emissions scenario before 2100. Three of four simulations also show greater increases in summer temperatures as compared with winter. Extreme heat and the associated impacts on a range of temperature-sensitive sectors are substantially greater under the higher emissions scenario, with some interscenario differences apparent before midcentury. By the end of the century under the B1 scenario, heatwaves and extreme heat in Los Angeles quadruple in frequency while heat-related mortality increases two to three times; alpine/subalpine forests are reduced by 50-75%; and Sierra snowpack is reduced 30-70%. Under A1fi, heatwaves in Los Angeles are six to eight times more frequent, with heat-related excess mortality increasing five to seven times; alpine/subalpine forests are reduced by 75-90%; and snowpack declines 73-90%, with cascading impacts on runoff and streamflow that, combined with projected modest declines in winter precipitation, could fundamentally disrupt California's water rights system. Although interscenario differences in climate impacts and costs of adaptation emerge mainly in the second half of the century, they are strongly dependent on emissions from preceding decades.
The Rancho La Brea tar pit fossil collection includes Juniperus (C3) wood specimens that 14C date between 7.7 and 55 thousand years (kyr) B.P., providing a constrained record of plant response for southern California during the last glacial period. Atmospheric CO2 concentration ([CO2]) ranged between 180 and 220 ppm during glacial periods, rose to approximately 280 ppm before the industrial period, and is currently approaching 380 ppm in the modern atmosphere. Here we report on delta13C of Juniperus wood cellulose, and show that glacial and modern trees were operating at similar leaf-intercellular [CO2](ci)/atmospheric [CO2](ca) values. As a result, glacial trees were operating at ci values much closer to the CO2-compensation point for C3 photosynthesis than modern trees, indicating that glacial trees were undergoing carbon starvation. In addition, we modeled relative humidity by using delta18O of cellulose from the same Juniperus specimens and found that glacial humidity was approximately 10% higher than that in modern times, indicating that differences in vapor-pressure deficits did not impose additional constrictions on ci/ca in the past. By scaling ancient ci values to plant growth by using modern relationships, we found evidence that C3 primary productivity was greatly diminished in southern California during the last glacial period.
For the first 150 years following their introduction, eucalypts planted in the California landscape were free of both insect pests and diseases. In the last 15 years, numerous herbivorous insect species have been introduced accidentally into the State and have caused significant damage to the trees. Several of these species, e.g. Phoracantha semipunctata (Fabricius), Phoracantha recurva Newman (Coleoptera: Cerambycidae) and Gonipterus scutellatus Gyllenhal (Coleoptera: Curculionidae), have also been introduced into other parts of the world where eucalypts are grown, whereas others, e.g. Glycaspsis brimblecombei Moore (Hemiptera: Spondyliaspidae) and Eucalyptolyma maideni Froggatt (Hemiptera: Spondyliaspidae), are currently restricted to California and Australia. Research programmes have provided management solutions to individual pest problems, but as more pest species are introduced, these solutions must be integrated across broad geographic, horticultural, and economic scales, in a systems approach.