Clinical outcomes with unfractionated heparin or low-molecular-weight heparin as bridging therapy in patients on long-term oral anticoagulants: the REGIMEN registry.

BACKGROUND: Patients who receive long-term oral anticoagulant (OAC) therapy often require interruption of OAC for an elective surgical or an invasive procedure. Heparin bridging therapy has been used in these situations, although the optimal method has not been established. No large prospective studies have compared unfractionated heparin (UFH) with low-molecular-weight heparin (LMWH) for the perioperative management of patients at risk of thromboembolism requiring temporary interruption of long-term OAC therapy. PATIENTS/METHODS: This multicenter, observational, prospective registry conducted in North America enrolled 901 eligible patients on long-term OAC who required heparin bridging therapy for an elective surgical or invasive procedure. Practice patterns and clinical outcomes were compared between patients who received either UFH alone (n = 180) or LMWH alone (n = 721). RESULTS: Overall, the majority of patients (74.5%) requiring heparin bridging therapy had arterial indications for OAC. LMWH, in mostly twice-daily treatment doses, represented approximately 80% of the study population. LMWH-bridged patients had significantly fewer arterial indications for OAC, a lower mean Charlson comorbidity score, and were less likely to undergo major or cardiothoracic surgery, receive intraprocedural anticoagulants or thrombolytics, or receive general anesthesia than UFH-bridged patients (all P < 0.05). The LMWH group had significantly more bridging therapy completed in an outpatient setting or with a < 24-h hospital stay vs. the UFH group (63.6% vs. 6.1%, P < 0.001). In the LMWH and UFH groups, similar rates of overall adverse events (16.2% vs. 17.1%, respectively, P = 0.81), major composite adverse events (arterial/venous thromboembolism, major bleed, and death; 4.2% vs. 7.9%, respectively, P = 0.07) and major bleeds (3.3% vs. 5.5%, respectively, P = 0.25) were observed. The thromboembolic event rates were 2.4% for UFH and 0.9% for LMWH. Logistic regression analysis revealed that for postoperative heparin use a Charlson comorbidity score > 1 was an independent predictor of a major bleed and that vascular, general, and major surgery were associated with non-significant trends towards an increased risk of major bleed. CONCLUSIONS: Treatment-dose LMWH, mostly in the outpatient setting, is used substantially more often than UFH as bridging therapy in patients with predominately arterial indications for OAC. Overall adverse events, including thromboembolism and bleeding, are similar for patients treated with LMWH or UFH. Postoperative heparin bridging should be used with caution in patients with multiple comorbidities and those undergoing vascular, general, and major surgery. These findings need to be confirmed using large randomized trials for specific patient groups undergoing specific procedures.

Health care utilization in chronic obstructive pulmonary disease. A case-control study in a health maintenance organization.

BACKGROUND: Information about health care utilization and costs among patients with chronic obstructive pulmonary disease (COPD) is needed to improve care and for appropriate allocation of resources for patients with COPD (COPD patients or cases) in managed care organizations. METHODS: Analysis of all inpatient, outpatient, and pharmacy utilization of 1522 COPD patients continuously enrolled during 1997 in a 172,484-member health maintenance organization. Each COPD case was matched with 3 controls (n = 4566) by age (+/-5 years) and sex. Information on tobacco use and comorbidities was obtained by chart review of 200 patients from each group. RESULTS: Patients with COPD were 2.3 times more likely to be admitted to the hospital at least once during the year, and those admitted had longer average lengths of stay (4.7 vs 3.9 days; P<.001). Mean costs per case and control were $5093 vs $2026 for inpatient services, $5042 vs $3050 for outpatient services, and $1545 vs $739 for outpatient pharmacy services, respectively (P<.001 for all differences). Patients with COPD had a longer smoking history (49.5 vs 34.9 pack-years; P =.002) and a higher prevalence of smoking-related comorbid conditions and were more likely to use cigarettes during the study period (46.0% vs 13.5%; P<.001). CONCLUSIONS: Health care utilization among COPD patients is approximately twice that of age- and sex-matched controls, with much of the difference attributable to smoking-related diseases. In this health maintenance organization, inpatient costs were similar to and outpatient costs were much higher than national averages for COPD patients covered by Medicare.

Mammography screening and breast cancer tumor size in female members of a managed care organization.

A study of temporal trends in mammography screening and changes in stage of disease at diagnosis was conducted among Hispanic and non-Hispanic white female members of the Lovelace Health Plan, Flexcare Plan, and Lovelace Senior Plan/Senior Options (LHP), a managed care organization. Two-year screening rates for female members ages 50-74 years were calculated for 1989-1996. From 1989-1996, mammography screening rates for non-Hispanic white female members increased from 65.5 to 71.6%, although this was not a statistically significant increase. Screening rates for Hispanic female members also increased from 50.6 to 62.7%, but they were significantly lower than for non-Hispanic white women. All breast cancers occurring among LHP female members ages 40-74 years were also identified for this same time period. A logistic regression model adjusting for age, year of diagnosis, ethnicity, and duration of enrollment prior to diagnosis found that statistically significant predictors of more advanced stage of disease at diagnosis included young age, diagnosis after 1991 for non-Hispanic white women, and diagnosis prior to 1992 for Hispanic women. Longer duration of enrollment prior to diagnosis was predictive of lower stage of disease, but the odds ratio was not statistically significant. For the time period 1992-1996, Hispanic women with breast cancer were more than twice as likely to have advanced stage of breast cancer compared with non-Hispanic white women (odds ratio, 2.12).

Utilization in COPD: patient characteristics and diagnostic evaluation.

STUDY OBJECTIVES: Information on current practices of COPD diagnosis and treatment is needed to identify opportunities for improving care. This study describes the clinical characteristics and diagnostic evaluations of COPD patients in a health maintenance organization (HMO) and a university-affiliated county medical center (UMC). DESIGN: Cross-sectional survey performed in a 174,484-member regional HMO and in The University of New Mexico Hospitals and Clinics (UNMH). PATIENTS: Two hundred COPD patients from each system randomly selected from administrative databases based on discharge diagnoses. RESULTS: COPD patients in the UMC, compared to those in the HMO, were younger (mean age, 59.3 vs 66.9 years, respectively), were more likely to be using home oxygen (33% vs 20%, respectively), and had fewer chronic medical conditions (mean number of conditions, 3.1 vs 3.7, respectively) (p < 0.01 for all differences). Approximately half of the COPD patients in both groups continued to smoke cigarettes during the study year. Only 38% of patients in the HMO and 42% in the UNMH system had spirometry results documented in their medical records. CONCLUSIONS: The demographic and clinical characteristics of the COPD patients in these two health-care systems were very different, but smoking status and utilization of diagnostic tests were similar. The diagnosis of COPD in most patients was based only on a history of chronic respiratory symptoms and smoking; spirometry often was not used to confirm the diagnosis. An increased emphasis on smoking cessation and more effective utilization of spirometry are needed to improve the management of COPD in these health-care systems.

Serological analysis of a cryptosporidiosis epidemic.

BACKGROUND: A cryptosporidiosis epidemic occurred among residents and visitors to Collingwood, Ontario, during March 1996. Fifty-five per cent of 36 confirmed cases were Collingwood visitors and 57% of Collingwood resident cases were under 10 years of age. The low level of reported diarrhoeal illness among adult Collingwood residents caused government officials and physicians to question whether an epidemic had occurred in Collingwood. METHODS: To better evaluate the extent of the epidemic, anonymous surplus sera from 89 adult Collingwood residents, collected for routine tests prior to, during and after the epidemic, and from 80 adult Toronto residents were tested using a Western blot assay for IgG antibody response to two Cryptosporidium antigen groups (15/17-kDa and 27-kDa). RESULTS: For sera collected from 1 January 1996 to 17 June 1996, a higher fraction of Collingwood residents had a detectable serological response (P < 0.002) and the mean intensity of serological responses was higher for Collingwood than Toronto residents (P < 0.001). The mean intensity of serological responses for Collingwood residents was higher in specimens drawn during the 8 weeks following the initial case reports compared to those drawn before or after this period (15/17-kDa, P < 0.02; 27-kDa, P < 0.10). CONCLUSIONS: These elevated serological responses indicate that Cryptosporidium infections among Collingwood residents likely occurred more commonly than illness reports suggested, consistent with a community-wide cryptosporidiosis epidemic. Similar studies should be considered in future suspected cryptosporidiosis epidemic investigations.

Smoking prevalence of pregnant women compared to women in the general population of Washington State.

We used two readily available sources of information to identify subgroups of pregnant Washington State women with high smoking rates. We compared smoking rates in pregnant women and women in general using information from the Washington State birth certificate collection system and the Washington State Behavioral Risk Factor Surveillance System. Smoking rates are substantially higher in young mothers 18-24 years of age than in comparable age cohorts in the general population of women in the state. In contrast, mothers 25 years of age and older smoke at lower rates than their age cohort in the general population. For multiparous women of all ages, smoking prevalence is related to age at first birth. Married women, whether pregnant or not, smoked less than unmarried women.

Smoking prevalence during pregnancy for women who are and women who are not Medicaid-funded.

Maternal smoking has been related to a number of adverse pregnancy outcomes. Although maternal smoking prevalence has decreased over time, certain populations have retained a high smoking prevalence and remain at high risk for adverse pregnancy outcomes. This study used the Washington State First Steps Program Database to estimate the difference in maternal smoking prevalence between mothers whose prenatal or delivery care was Medicaid-funded and mothers whose care was not Medicaid-funded. We evaluated differences in maternal smoking prevalence between these two groups by marital status, race, adequacy of prenatal care, and age. Among the Medicaid-funded mothers, the age-adjusted maternal smoking prevalence was 44.4% versus 16.3% for those not Medicaid-funded. Among married Medicaid-funded mothers, the smoking prevalence was 2.6 times higher in whites, 1.4 times higher in blacks, and 1.8 times higher in American Indians than for married mothers not funded by Medicaid. Among single Medicaid-funded mothers, the rate was 1.4 times higher in whites and 1.7 times higher in blacks. Differences in smoking prevalence were most apparent among older mothers. For single white and single black mothers, the smoking prevalence increased with increasing maternal age among both Medicaid-funded and other women. Adequacy of prenatal care also influences smoking prevalence. For white and black mothers, the maternal smoking prevalence was lower for those receiving adequate prenatal care than for mothers of the same race who received inadequate prenatal care. The increased maternal smoking prevalence in older single mothers and the higher maternal smoking prevalence in women with Medicaid-funded deliveries suggest that infants born to these mothers may be particularly susceptible to smoking-related health effects.

Impact of poorly controlled hypertension on healthcare resource utilization and cost.

OBJECTIVE: To examine the relation between blood pressure (BP) control and utilization and cost of healthcare resources. STUDY DESIGN: A retrospective database study of managed care patients in New Mexico from January 1, 1996, to December 31, 1997. PATIENTS AND METHODS: We stratified 1000 hypertensive patients into categories based on average and maximum BP. Antihypertensive medication use and cost, number of physician visits, and interval between hypertension-related physician visits were determined. RESULTS: Medication costs increased progressively across all BP categories from lowest to highest, and higher average systolic BP (SBP) was significantly correlated with increased cost (P < .001). There were significant correlations between higher maximum BP and greater number of hypertension-related physician visits (P < .001). Mean number of visits for BP groups was 5.5 for patients with a maximum diastolic BP (DBP) < 85 mm Hg and 10.0 for those with a maximum DBP > or = 100 mm Hg (P < .001). Patients with a maximum SBP > or = 180 mm Hg averaged 9.7 visits, whereas those with a maximum SBP < 120 mm Hg averaged 4.1 visits (P < .001). Both SBP and DBP were significantly correlated with time to next visit (P < .001). Mean visit intervals ranged from 44 days for patients with an SBP < 85 mm Hg to 25 days for those with an SBP > or = 180 mm Hg (P < .001). A similar association was found between DBP and visit interval. CONCLUSIONS: Poor control of hypertension is associated with higher drug costs and more physician visits. Aggressive treatment might help reduce managed care costs and resource utilization.

Dientamoeba fragilis detection methods and prevalence: a survey of state public health laboratories.

Dientamoeba fragilis is a pathogenic protozoan parasite that has no cyst stage. Because of the lack of a cyst stage, the laboratory detection of D. fragilis in stool specimens is dependent on the stool processing and examination methods employed. Failure to use recommended stool fixation and permanent staining techniques almost precludes identification of D. fragilis, which is associated with gastrointestinal illness in humans. In this survey, questionnaires were mailed to all State and territorial public health laboratories requesting information on the number of ova and parasite examinations, methods of processing and examining stools, and the number of D. fragilis positive stools for 1985. Forty-three of 54 (80 percent) laboratories responded. Results showed that those laboratories which reported D. fragilis detection examined more stools using recommended stool fixation methods and were more likely to stain permanently all stools examined. Permanent staining of all stools, as compared to loose and watery stools only, resulted in a fivefold greater detection of D. fragilis. More State and territorial public health laboratories reported finding D. fragilis infections in 1985 than in a 1978 survey performed by the Centers for Disease Control. However, in 1985 only six laboratories reported 82 percent of all D. fragilis detections. To increase the probability of detecting D. fragilis in stool specimens, the findings suggest that all stools should be submitted fixed in polyvinyl alcohol fixative, sodium acetate-acetic acid-formalin fixative, or Schaudinn's fixative. Further, all specimens, regardless of consistency, should be permanently stained prior to microscopic examination.

Possible information bias in a waterborne outbreak investigation.

Although an investigation of a cryptosporidiosis outbreak in 1994 in Clark County, Nevada, concluded that illness was associated with consumption of municipal water, no water treatment deficiencies or breakdowns and no water quality changes were discovered during the investigation. We evaluated the strength of the evidence for waterborne transmission and conducted a sensitivity analysis to define the limitations of the epidemiological data. Our analyses suggest a spurious inference of waterborne transmission might be due to differential misclassification bias. If exposure and disease status were incorrectly classified for a relatively small number of study participants, findings of the investigation would be interpreted differently. We offer this example to illustrate the importance of assessing the stability of a relative risk estimate and effect of possible biases during an outbreak investigation.

Descriptive features of Dientamoeba fragilis infections.

A total of 237 cases of Dientamoeba fragilis were identified by a state public health laboratory in 1985 and 1986. Dientamoeba fragilis was the only parasite found in about two-thirds of the cases. Compared to Giardia cases diagnosed in a similar time period, D. fragilis occurred more frequently in females and in children 5-9 years old; it was also more likely to be detected in spring and summer months. Giardia occurred more frequently in children 0-4 years old. Seventy-nine per cent of 70 interviewed D. fragilis cases reported symptoms associated with infection; nearly 80% had diarrhoea or loose stools. Interviewed cases reported more household and non-household exposure to children 5-9 years old than children of other ages. The difference in age and sex distribution of D. fragilis and Giardia cases may be related to the life cycle and mode of transmission of the two protozoans.

A comparison of two methods for estimating the health care costs of epilepsy.

PURPOSE: Previous studies have estimated medical care costs of epilepsy by applying unit costs to estimated utilization or by summing costs for (a) ambulatory care and hospitalizations coded as epilepsy and (b) procedures and drugs specifically associated with the diagnosis or treatment of epilepsy. These methods may underestimate the cost of medical care for epilepsy. Two methods for estimating the medical care costs of epilepsy ("epilepsy-attributable cost method" and "case-control cost method") were compared. METHODS: The study population was 655 individuals with an epilepsy diagnosis enrolled in a managed care plan in the southwestern United States. The epilepsy-attributable costs were determined by summing costs for inpatient and outpatient encounters coded as epilepsy, procedures for the diagnosis or treatment of epilepsy, and drugs used to treat epilepsy. The case-control method determined costs by calculating the difference in total costs between cases and 1,965 age- and gender-matched controls. RESULTS: The case-control epilepsy costs were $2,923 per case compared with epilepsy-attributable costs of $1,335 per case. The case-control method found statistically significant differences in costs between cases and controls for inpatient care, prescription drugs, and 8 of 11 categories of outpatient care. The largest contributors to the discrepancy between estimates were inpatient care, emergency department care, laboratory tests, and "other specialist" care. CONCLUSIONS: Epilepsy-attributable costs accounted for only 46% of the total difference in costs between epilepsy cases and controls. Persons with epilepsy use more medical services than controls, but a substantial portion of this care is not coded to epilepsy.

Paired city cryptosporidium serosurvey in the southwest USA.

In 1996, serological responses to two Cryptosporidium antigens were determined for 200 Las Vegas (LV), Nevada, and 200 Albuquerque, New Mexico, blood donors to evaluate associations between endemic infections, water exposures, and other risk factors. LV uses chlorinated filtered drinking water from Lake Mead while Albuquerque uses chlorinated ground water. The intensity of serological response to both markers was higher for older donors (P < 0.05). donors who washed food with bottled water (P < 0.05) and donors from LV (P < 0.05). A decreased serological response was not associated with bottled water consumption, nor was an increased response associated with self-reported cryptosporidiosis-like illness or residence in LV at the time of a cryptosporidiosis outbreak 2 years earlier. Although these findings suggest the serological response may be associated with type of tap water and certain foods, additional research is needed to clarifythe role of both food and drinking water in endemic Cryptosporidium infection.

A serological survey of college students for antibody to Cryptosporidium before and after the introduction of a new water filtration plant.

In April 1997, a large city in the northeastern United States changed their drinking water treatment practices. The city, which previously provided only chlorination for their surface water sources added filtration in addition to chlorination. To assess whether Cryptosporidium infections rates declined following filtration, we tested serological responses to 15/17-kDa and 27-kDa Cryptosporidium antigens among 107 community college students 1 month before and 225 students 5 months after filtration. Results suggest that levels of Cryptosporidium infections did not decline following water filtration. However, seasonal changes in other exposures may have confounded the findings. Swimming in a lake, stream or public pool and drinking untreated water from a lake or stream predicted a more intense response to one or both markers. Residence in the city, not drinking city tap water or drinking bottled water, gender, travel or exposure to pets, young pets, diapers or a household child in day care were not found to be predictive of more or less intense serological responses for either the 15/17-kDa and 27-kDa antigen.

Serological evidence of Cryptosporidium infections in southern Europe.

Although cryptosporidiosis outbreaks have been frequently reported in the United States, Canada and the United Kingdom, few outbreaks have been reported on the European continent. The reasons for this are unclear. To ascertain whether a European population has been previously exposed to Cryptosporidium, we conducted a survey of 100 resident blood donors in a northern Italian city for IgG serological response to two oocyst antigen groups. A serological response to the 15/17-kDa antigen group was detected in 83% of blood donors and response to the 27-kDa antigen group in 62%. Donors who traveled outside of Italy during the prior 12 months were less likely to have had a response to the 15/17-kDa antigen group (p < 0.04) and to have a less intense response (p < 0.05). Older age was predictive of a more intense response to each antigen group (p < 0.01). The fraction of Italian blood donors with a serological response to either antigen group was higher than in four United States blood donor populations, with differences more pronounced for response to the 15/17-kDa antigen group (p < 0.01). A lower fraction of Italian donors had a serological response to either antigen group than persons tested at the time of a cryptosporidiosis outbreak in the United States or blood donors tested six months after that outbreak (p < 0.05). Since the presence of serological responses to these antigen groups predicts a reduced risk of cryptosporidiosis, the high prevalence of serological responses in these Italian blood donors may explain the infrequent occurrences of clinically detectable cryptosporidiosis in this city.

Health indicators and intimate partner violence among women who are members of a managed care organization.

BACKGROUND: There have been no population-based studies estimating the prevalence of intimate partner violence (IPV) in an insured population. There is also little information on how well routinely collected health status information predicts IPV risk. Many women now obtain health care from providers who are members of a managed care organization (MCO). To justify efforts to routinely screen for IPV, it is essential to know the prevalence of IPV in this growing population and to identify correlates of IPV among female MCO members. METHODS: A telephone survey with questions on health status, behavioral risk factors, preventive services use, and the Conflict Tactics Scale was completed by 2,415 female members of a New Mexico MCO. RESULTS: Overall, 13.5% of respondents reported experiencing major verbal aggression and 6.7% reported experiencing physical aggression. Younger age, degree of sadness, and inability to handle stress, and a perception of a poorer general health status were significantly associated with major verbal aggression. Race/ethnicity, degree of sadness, and average number of drinks consumed at one sitting were significantly associated with physical aggression. CONCLUSIONS: There is a low but important annual prevalence of IPV among female members of a MCO that occurs across all variables studied. This information is needed to develop appropriate screening protocols and interventions in this population.

The excess costs of breast cancer health care in Hispanic and non-Hispanic female members of a managed care organization.

The differences in costs for health care services between women with breast cancer and those without were estimated for Hispanic and non-Hispanic members of a managed care organization. A total of 317 cases of breast cancer and 949 controls were selected using a comprehensive patient database. All health care costs for the 4-12 months prior to the case's diagnosis and for the 12 months following the case's diagnosis were obtained. Costs were defined as charges to the health plan. Mean differences in total health care costs between cases and controls were predicted using Tobit models for 4-12 months prior to diagnosis and the year after diagnosis by age group. Compared to controls, women diagnosed with in situ breast cancers in all age groups had significantly higher health care costs 4-12 months prior to diagnosis. For women under 50 years of age, the difference in costs for cases compared to controls 12 months after diagnosis was almost three times greater for women with regional/distant disease ($17,093 +/- $1,559) compared to in situ disease ($5,089 +/- $1,050). For women in the two other age groups (50-70 years and over 70 years), the difference was over twice as great for those with regional/distant disease compared to those with in situ disease. Mean differences between cases and controls in health care costs 12 months after diagnosis were similar for Hispanic and non-Hispanic women for all stages of disease.

Comparisons of ELISA and Western blot assays for detection of Cryptosporidium antibody.

A seroprevalence survey was conducted using ELISA and Western blot (WB) assays for antibody to three Cryptosporidium antigens on 380 blood donors in Jackson County, Oregon. The purpose was to determine if either assay could detect serological evidence of an outbreak which occurred in Talent, Oregon 6 months earlier. The ELISA, which tested for combined IgG, IgA and IgM, and the WB, which tested separately for IgG and IgA, detected an almost twofold increase in serological response for persons who consumed Talent drinking water during the previous 11 months. The increases, however, were statistically significant (P < 0.05) only for the WB. The identification of serological evidence of infection, using sera collected 6 months after the end of the outbreak in a population not selected because of cryptosporidiosis-like illness, suggests that assays of Cryptosporidium-specific IgG and IgA may assist in estimating the magnitude of asymptomatic infections in the population.

Serological responses to Cryptosporidium antigens among users of surface- vs. ground-water sources.

Cryptosporidium oocysts are commonly detected in surface-derived drinking water. However, the public health significance of these findings is unclear. This study compared serological responses to two Cryptosporidium antigen groups for blood donors and college students using chlorinated and filtered river water vs. ground-water sources. The surface water received agricultural and domestic sewage discharges upstream. Participants from the surface-water city had a higher relative prevalence (RP) of a serological response to the 15/17-kDa antigen group (72.3 vs. 52.4%, RP = 1.36, P < 0.001) and to the 27-kDa antigen group (82.6 vs. 72.5%, RP = 1.14, P < 0.02). Multivariate logistic regression analysis found that the people with a shorter duration of residence or drinking bottled water also had a lower seropositivity for each marker. Use of private wells was associated with a higher prevalence of response to the 15/17-kDa markers. Seroconversion to the 15/17-kDa antigen group was more common in the residents of the city using surface water. These findings are consistent with an increased risk of Cryptosporidium infection for users of surface-derived drinking water compared with users of municipal ground-water-derived drinking water. Users of private well water may also have an increased risk of infection.

A two-year follow-up survey of antibody to Cryptosporidium in Jackson County, Oregon following an outbreak of waterborne disease.

To estimate the duration of Cryptosporidium-specific antibody, a Western blot assay measured antibody in paired sera from 124 residents of Jackson County, Oregon collected 0.5 and 2.5 years after the end of an outbreak in Talent, Jackson County. The outcome measure was the intensity of antibody responses, (which may approximate to a titre), to 27-kDa and 15/17-kDa antigens. Intensity of response to the 27-kDa antigen(s) declined to 54% of the 1992 value while responses to a 15/17-kDa antigen(s) remained close to the initial values. Increasing age of the donor predicted higher intensity of antibody to the 15/17-kDa antigen(s) in both the initial (P = 0.004) and follow-up (P = 0.038) surveys. No relationship was observed between age and antibody intensity for the 27-kDa antigen(s) during either survey (P > 0.10). Both the initial and follow-up surveys showed significant elevations in antibody intensity for Talent residents, possibly indicating a high endemic rate of infection/re-infection or high levels of chronic infection.