High serological response to Cryptosporidium-specific antigens in the Czech Republic and its association with water supply.

A survey was conducted in the Czech Republic to determine whether serological responses to the 15/17-kDa and 27-kDa Cryptosporidium antigens had changed since the end of the communist era and if these responses were associated with drinking water sources. Sera from 301 blood donors residing in six areas served by various sources of drinking water were analysed by Western Blot (mini-immunoblots) to measure the IgG response. The intensity of response and percentage of persons with a strong response to the 27-kDa, but not the 15/17-kDa, antigen were higher than found 20 years earlier. A strong response to both the 15/17- and 27-kDa-antigens was higher than reported in other countries, and the probability of persons having a strong response was greater in areas with surface water sources than river-bank infiltration. Few cases of cryptosporidiosis were reported in spite of these high responses to Cryptosporidium antigens. These responses suggest a chronic low-level exposure from several sources that may be affording protection against symptoms and illness. Although strong serological responses were associated with surface water sources, drinking water is not likely to be the most important exposure for Cryptosporidium in the Czech Republic.

Cryptosporidium infection, onsite wastewater systems and private wells in the arid Southwest.

Few prior studies have examined the potential health risks from transmission of enteric parasites via aquifers contaminated by wastewater from onsite systems. A cross-sectional study of 600 residents in households served with either onsite wastewater systems and private wells or city sewer/water systems in three different sites in central New Mexico compared serological responses to Cryptosporidium, a common waterborne infections agent. Study participants completed a short self-administered questionnaire with questions on demographic characteristics, characteristics of the onsite wastewater system and private well, and common risk factors associated with cryptosporidiosis. A sample of household tap water was collected, as well as a blood sample from each study participant to measure IgG responses to antigen groups for Cryptosporidium. Logistic regression analysis showed a significant association between having an onsite wastewater system and private well and the 27-kDa marker for Cryptosporidium in the River Valley site after adjusting for covariates (OR = 1.98; 95% CI = 1.11-3.55). This study, together with one prior study, suggests that the presence of onsite wastewater systems and private wells might be associated with an increased risk of Cryptosporidium infection.

Enteric illness risks before and after water treatment improvements.

This study evaluated whether occurrence of acute gastrointestinal illnesses declined after filtration and ozonation were added to a previously unfiltered, chlorinated high-quality surface water source in a northwest United States city. Enteric and other illnesses were recorded for two 6-month periods for control and intervention sites in the same city. During phase 1, chlorinated, unfiltered drinking water for both sites was obtained from protected watersheds. During phase 2, the intervention site received chlorinated, filtered and ozonated drinking water. The water was not altered in the control site. No overall differences were found in the risk of any of the illnesses after the new water treatment plant was completed. There was a significantly increased risk of diarrhoea and highly credible gastrointestinal illness in participants with three or more episodes of the same type of illness during phase 1.

Under utilization of surveillance mammography among older breast cancer survivors.

BACKGROUND: Annual surveillance mammography is recommended for follow-up of women with a history of breast cancer. We examined surveillance mammography among breast cancer survivors who were enrolled in integrated healthcare systems. METHODS: Women in this study were 65 or older when diagnosed with early stage invasive breast cancer (N = 1,762). We assessed mammography use during 4 years of follow-up, using generalized estimating equations to account for repeated measurements. RESULTS: Eighty-two percent had mammograms during the first year after treatment; the percentage declined to 68.5% in the fourth year of follow-up. Controlling for age and comorbidity, women who were at higher risk of recurrence by being diagnosed at stage II or receiving breast-conserving surgery (BCS) without radiation therapy were less likely to have yearly mammograms (compared to stage I, odds ratio [OR] for stage IIA 0.72, confidence interval [CI] 0.59, 0.87, OR for stage IIB 0.75, CI 0.57, 1.0; compared to BCS with radiation, OR 0.58, CI 0.43, 0.77). Women with visits to a breast cancer surgeon or oncologist were more likely to receive mammograms (OR for breast cancer surgeon 6.0, CI 4.9, 7.4, OR for oncologist 7.4, CI 6.1, 9.0). CONCLUSIONS: Breast cancer survivors who are at greater risk of recurrence are less likely to receive surveillance mammograms. Women without a visit to an oncologist or breast cancer surgeon during a year have particularly low rates of mammography. Improvements to surveillance care for breast cancer survivors may require active participation by primary care physicians and improvements in cancer survivorship programs by healthcare systems.

Influenza and COPD mortality protection as pleiotropic, dose-dependent effects of statins.

BACKGROUND: Published data on antiinflammatory and immunomodulatory effects of statins suggest they may reduce mortality risks associated with an unchecked immune response to selected infections, including influenza and COPD. We assessed whether statin users had reduced mortality risks from these conditions. METHODS: We conducted a matched cohort study (n = 76,232) and two separate case-control studies (397 influenza and 207 COPD deaths) to evaluate whether statin therapy is associated with increased or decreased mortality risk and survival time using health-care encounter data for members of health maintenance organizations. For the cohort study, baseline illness risks from all causes prior to initiation of statin therapy were used to statistically adjust for the occurrence of outcomes after initiation of treatment. RESULTS: For moderate-dose (>/= 4 mg/d) statin users, this cohort study found statistically significant reduced odds ratios (ORs) of influenza/pneumonia death (OR, 0.60; 95% confidence interval [CI], 0.44 to 0.81) and COPD death (OR, 0.17; 95% CI, 0.07 to 0.42) and similarly reduced survival hazard ratios. Findings were confirmed with the case-control studies. Confounding factors not considered may explain some of the effects observed. CONCLUSIONS: This study found a dramatically reduced risk of COPD death and a significantly reduced risks of influenza death among moderate-dose statin users.

Survival of COPD patients using inhaled corticosteroids and long-acting beta agonists.

We conducted a historical cohort study to examine the relationship between survival and use of inhaled corticosteroids (ICS) and/or long-acting beta agonists (LABA) in patients with chronic obstructive pulmonary disease (COPD). All COPD patients aged 40 years who were enrolled in one of two regional managed care organizations during 1995-2000, and who had 90 days use of an ICS and/or LABA (N=1288) or of a short-acting bronchodilator (N=397), were identified. Of patients treated with ICS and/or LABA, 14.4% died during the follow-up period, as compared to 28.2% of comparison patients (P<0.01). In a Cox proportional hazards model that controlled for age, sex, comorbidities, COPD severity, and asthma status, a reduced risk of death was found for ICS treatment (HR 0.59 [95% CI 0.46-0.78]), LABA (HR 0.55 [0.34-0.89]), and ICS plus LABA treatment (HR 0.34 [0.21-0.56]). A second model that excluded any patient who also had an ICD-9 code for asthma (N=840) still found improved survival among those using the combination of ICS plus LABA (HR 0.35 [CI 0.17-0.71]). Additional analyses that varied the exposure criteria also found a consistent treatment benefit. Inclusion of ICS or bronchodilator treatment during the follow-up period as a time-dependent function appears to negate the survival benefit; however, the underlying assumptions for valid time-dependent modeling are clearly violated in this situation. In conclusion, we found that COPD patients who used ICS alone or in combination with LABA had substantially improved survival even after adjustment for asthma and other confounding factors.

An algorithm for the identification of undiagnosed COPD cases using administrative claims data.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a major cause of death in the United States, but most persons who have airflow obstruction have never been diagnosed with lung disease. This undiagnosed COPD negatively affects health status, and COPD patients may have increased health care utilization several years before the initial diagnosis of COPD is made. OBJECTIVE: To investigate whether utilization patterns derived from analysis of administrative claims data using a discriminant function algorithm could be used to identify undiagnosed COPD patients. METHODS: Each patient who had a new diagnosis of COPD during the study period (N = 2,129) was matched to as many as 3 control subjects by age and gender. Controls were assigned an index date that was identical to that of the corresponding case, and then all health care utilization for cases and controls for the 24 months prior to the initial COPD diagnosis was compared using logistic regression models. Factors that were significantly associated with COPD were then entered into a discriminant function algorithm. This algorithm was then validated using a separate patient population. RESULTS: In the main model, 19 utilization characteristics were significantly associated with preclinical COPD, although most of the power of the discriminant function algorithm was concentrated in a few of these factors. The main model was able to identify COPD patients in the validation population of adult subjects aged 40 years and older (N = 41,428), with a sensitivity of 60.5% and specificity of 82.1%, even without having information on the history of tobacco use for the majority of the group. Models developed and tested on only 12 months of utilization data performed similarly. CONCLUSION: Discriminant function algorithms based on health care utilization data can be developed that have sufficient positive predictive value to be used as screening tools to identify individuals at risk for having undiagnosed COPD.

Laboratory safety monitoring of chronic medications in ambulatory care settings.

OBJECTIVE: To evaluate laboratory safety monitoring in patients taking selected chronic prescription drugs. DESIGN: Retrospective study using 1999-2001 claims data to calculate rates of missed laboratory tests (potential laboratory monitoring errors). Eleven drugs/drug groups and 64 laboratory tests were evaluated. SETTING: Two staff/network model health maintenance organizations. PATIENTS: Continuously enrolled health plan members age> or =19 years taking > or =1 chronic medications. MEASUREMENTS AND MAIN RESULTS: Among patients taking chronic medications (N=29,823 in 1999, N=32,423 in 2000, and N=36,811 in 2001), 47.1% in 1999, 45.0% in 2000, and 44.0% in 2001 did not receive > or =1 test recommended for safety monitoring. Taking into account that patients were sometimes missing more than 1 test for a given drug and that patients were frequently taking multiple drugs, the rate of all potential laboratory monitoring errors was 849/1,000 patients/year in 1999, 810/1,000 patients/year in 2000, and 797/1,000 patients/year in 2001. Rates of potential laboratory monitoring errors varied considerably across individual drugs and laboratory tests. CONCLUSIONS: Lapses in laboratory monitoring of patients taking selected chronic medications were common. Further research is needed to determine whether, and to what extent, this failure to monitor patients is associated with adverse clinical outcomes.

Economic evaluation of treating chronic obstructive pulmonary disease with inhaled corticosteroids and long-acting beta2-agonists in a health maintenance organization.

OBJECTIVES: In light of recent results from observational studies showing prolonged survival in subjects taking long-acting beta2-agonists (LABA) and/or inhaled corticosteroids (ICS) for chronic obstructive pulmonary disease (COPD), we investigated their cost-effectiveness (CE). METHODS: Costs and survival data were collected for a sample of members enrolled in a large Health Maintenance Organization in the United States. An observational study design was used to evaluate cumulative costs and health benefits of LABA, ICS, ICS+LABA, or comparison drugs. Survival was estimated using a parametric regression model. Costs were adjusted for censoring and prognostic factors. CE was evaluated over a time horizon of 36 months and the remaining lifetime of subjects. RESULTS: Over 36 months, life expectancy and costs were: 2.4 years (95% confidence interval (CI): 2.3; 2.5) and $28,030 (CI: $23,400; $33,570) for not receiving ICS or LABA; 2.6 years (CI: 2.6; 2.7) and $35,170 (CI: $29,970; $40,620) for ICS alone; 2.6 years (CI: 2.5; 2.7) and $27,380 (CI: $21,780; $32,510) for LABA alone; and, 2.7 years (CI: 2.6; 2.8) and $33,780 (CI: $28,700; $39,440) for subjects treated with ICS+LABA. The lifetime analysis showed similar trends. CONCLUSIONS: There is an acute need to find effective, life-extending treatments for persons with COPD. ICS, LABA or their combination represent promising treatment options and are currently being tested in randomized trials. If the impact on survival seen in these trials compares to that seen in observational studies, LABA and the combination treatment are likely to be cost-effective in the United States.

Predicting the costs of managing patients with chronic obstructive pulmonary disease.

The economic consequences of chronic obstructive pulmonary disease (COPD) are considerable, although the factors that best predict costs are largely unknown. This study used a population-based cohort to identify the clinical factors during an index year that were most predictive of increased direct medical costs in the subsequent year, and to develop a predictive model that described the cost variations in COPD. The medical records of 2116 patients enrolled in one regional health system who had COPD and health-care resource utilisation data for 1998 and 1999, were abstracted for information about symptoms, smoking history, chronic illnesses, and pulmonary function data. All inpatient, outpatient and pharmacy utilisation data for each subject for 1999 were extracted from the database. Total costs for each individual were transformed to a log scale. Potential causes of cost variability (predictor variables) were defined and classified into sets (or domains). Multiple linear regression models were fitted for each domain. The study demonstrated that severity of airflow obstruction, as assessed by FEV(1)% predicted, is a significant but weak predictor of future health-care resource utilisation-prior hospitalisation and home oxygen use, the presence of comorbid conditions and symptoms of dyspnoea are better predictors of costs. Those interested in the economic benefits of new COPD treatments and disease management programs need to carefully account for these factors.

Analysis of serological responses to Cryptosporidium antigen among NHANES III participants.

PURPOSE: Sera from 1356 National Health and Nutrition Examination Survey (NHANES) III participants from seven primary sampling units were tested for serological responses to two Cryptosporidium antigen groups. Intensity of responses was compared by geographic area, age, sex, race/ethnicity, income, and hepatitis A seropositivity. METHODS: Cryptosporidium seropositivity for the 15/17-kDa and the 27-kDa antigen groups were defined by the intensity of the responses. Conditional and unconditional logistic regression was used to identify significant risk factors. RESULTS: Hispanics, blacks, and females had a higher seropositivity. Younger participants and those with higher income had a lower seropositivity. Being hepatitis A seropositive was strongly related to a weak serological response to the 27-kDa antigen group. Family size was unrelated to Cryptosporidium seropositivity. Significantly higher Cryptosporidium seropositivity was observed for three of the seven primary sampling units. CONCLUSIONS: This study found significant geographical differences in the occurrence and the intensity of serological response. Strong serological responses to the 15/17-kDa antigen occurred more commonly in blacks and Hispanics, individuals not having high incomes, and in older age groups.

Serological evidence of endemic waterborne cryptosporidium infections.

PURPOSE: Cryptosporidium oocysts are commonly detected in surface-derived drinking water, however, the public health significance of these findings is unclear. This study compared the evidence of prior Cryptosporidium infection for people drinking water derived from surface versus ground water sources. METHODS: This study measured serological responses to two Cryptosporidium antigen groups for blood donors from two midwestern United States cities with different drinking water sources: filtered and chlorinated river water receiving agricultural and domestic sewage upstream versus chlorinated water from an underground aquifer. Initial and nine-month paired serological responses to two Cryptosporidium antigen groups were compared. RESULTS: Initially, donors from the surface water city had a higher relative prevalence (RP) of a serological response (54% vs. 38%, RP = 1.39 (1.21,1.60)). Donors with a detectable baseline response who resided in the surface water city had a higher relative risk (RR) of an increased intensity of response on the follow-up blood draw (15/17-kDa, 40/100 vs. 11/100, RR = 3.78 (1.89,7.58)), (27-kDa 38/100 vs. 18/100, RR = 2.07 (1.31,3.25)). Donors with no baseline response to the 15/17-kDa marker who resided in the surface water city also had a higher risk of serconversion (38/100 vs. 14/100, RR = 2.63 (1.78,3.91)). CONCLUSIONS: These rates of both background and drinking water related Cryptosporidium infections are substantially higher than previously estimated, however, the risk of illness from infection may be lower.

Costs and clinical outcomes associated with low-molecular-weight heparin vs unfractionated heparin for perioperative bridging in patients receiving long-term oral anticoagulant therapy.

STUDY OBJECTIVES: There have been no health-care cost evaluations comparing the use of low-molecular-weight heparin (LMWH) to unfractionated heparin (UH) as "bridge therapy" in the perioperative period in patients receiving long-term oral anticoagulant (OAC) therapy who need interruption of therapy to undergo an elective surgical procedure. We performed a retrospective analysis of the medical and administrative records of health plan members in a managed care organization who underwent bridge therapy perioperatively with either i.v. UH, administered in a hospital setting, or LMWH, administered primarily in the outpatient setting using disease management guidelines. DESIGN: A retrospective analysis of medical and administrative records of treated health plan members meeting inclusion/exclusion criteria during the two study periods (ie, from 1994 to 1996 and from 1998 to 2000). SETTING: Staff-model health maintenance organization serving New Mexico. PATIENTS: The UH group included persons receiving long-term warfarin therapy from 1994 to 1996 (26 patients), and the LMWH group included persons receiving long-term warfarin therapy from 1998 to 2000 (40 patients) with perioperative use of heparin (either UH or LMWH) as bridge therapy for an elective surgical procedure. INTERVENTIONS: Costs were calculated for the period from 10 days before the procedure through 30 days after the procedure. The rates of adverse events (ie, valvular or mural thrombus, intracranial event, transient ischemic attack, peripheral arterial event, venous thromboembolic event, major and minor bleeding, thrombocytopenia, and death) occurring 1 to 30 days postprocedure were determined. MEASUREMENTS AND RESULTS: The groups were similar in age, sex, Charlson score, indication for long-term warfarin therapy (ie, arterial/cardiac vs venous), mean international normalized ratio prior to procedure, procedure duration, use of intraprocedural anticoagulant agents or thrombolytic agents, and use of general anesthesia during the procedure (all p > 0.05). A total of 34.6% of UH patients and 40.0% of LMWH patients experienced one or more clinical adverse events within 30 days of the postoperative period, a difference that was not statistically significant (p = 0.67). The mean total health-care costs were 31,625 dollars in the UH group and 18,511 dollars in the LMWH group (p < 0.01). The mean inpatient costs were 28,515 dollars in the UH group and 14,330 dollars in the LMWH group (p < 0.01). Outpatient surgery costs (1,159 dollars vs 53 dollars, respectively; p = 0.01) and pharmacy costs (639 dollars vs 133 dollars, respectively; p < 0.01) were higher in the LMWH group. CONCLUSIONS: The mean total health-care costs in the perioperative period were significantly lower (by 13,114 dollars) in patients receiving long-term OAC therapy using LMWH compared to those receiving it using UH for an elective surgical procedure. The cost savings associated with LMWH use were accomplished through the avoidance or minimization of inpatient stays and no increase in the overall rate of clinical adverse events in the postoperative period.

Measuring patient safety in ambulatory care: potential for identifying medical group drug-drug interaction rates using claims data.

OBJECTIVE: To evaluate the feasibility of using health-plan administrative data to measure potential drug-drug interaction (DDI) rates in the ambulatory setting at the medical-group level and to assess the potential use of DDI rates in performance measurement, quality improvement, and research in patient safety. STUDY DESIGN: We combined administrative and pharmacy claims data from 2 large health plans to calculate the rates at which member users of selected chronic medications were potentially exposed to a second drug known to pose a risk of harmful interactions. METHODS: We divided 44 medication combinations with risk of adverse interactions into those with DDIs of moderate/severe clinical significance and those with DDIs of mild significance. We then calculated yearly rates of potential DDIs in continuously enrolled members aged 19 and older from 1998 through 2001. Rates were calculated for all members, overall base-medication users, and, individual medical groups responsible for their care. RESULTS: The analytic data set included 756 047 patient-years of data and 110 to 123 medical groups per year. During the 4-year interval, one or more unique potential DDIs occurred in 6.2% to 6.7% of base-drug users and 2.0% to 2.3% of all adult health-plan members per year. Medical-group mean user rates were slightly lower (5.33%-5.81%), with wide variance (SD = 2.6%-3.1%) and high stability over time. CONCLUSION: Potential DDI rates calculated from health-plan data have promise for measurement in patient medication safety. This readily available and inexpensive evaluation tool has potential for monitoring, improvement, and research purposes if further studies validate their relationship to actual adverse events.

Identifying US populations for the study of health effects related to drinking water arsenic.

The US Environmental Protection Agency recently set a new maximum contaminant level (MCL) for arsenic in drinking water of 10 micro g/l. In this paper, we review the completeness and accuracy of drinking water arsenic occurrence data in the United States and identify populations exposed to elevated arsenic concentrations that would be suitable for epidemiological studies of arsenic health effects. Using existing data from the Environmental Protection Agency Arsenic Occurrence and Exposure Database and additional data from state health and environment departments and water utilities, we identified 33 counties in 11 states with an estimated mean drinking water arsenic concentration of 10 micro g/l or greater. A total of 11 of these 'confirmed' counties had an estimated mean arsenic concentration of 20 micro g/l or more and two had an estimated mean arsenic concentration 50 micro g/l or more. Based on census data, between 1950 and 1999 there were approximately 51.1 million person-years of exposure to drinking water arsenic at levels of 10 micro g/l or more, 8.2 million at levels of 20 micro g/l or more arsenic and 0.9 million at levels of 50 micro g/l or more. Mortality and incidence of diseases known to be associated with arsenic exposure can and should be examined in these counties as part of a comprehensive assessment of arsenic health effects in US populations.

Mortality among children residing near the American Smelting and Refining Company (ASARCO) copper smelter in Ruston, Washington.

A retrospective cohort study was undertaken to determine whether childhood exposure to ambient arsenic was associated with increased mortality rates. Cohort members comprised children who had lived within 4.0 km (2.5 mi) of the American Smelting and Refining Company (ASARCO) copper smelter and arsenic refinery in Ruston, Washington, for at least 2 yr during the time period from 1907 to 1932. The cohort included 1,827 boys and 1,305 girls identified from school census records. Exposure intensity was computed as the total number of years a child had lived at a residence less than 1.6 km (1.0 mi) from the smelter stack during the study period. In only one exposure intensity group (i.e., residence > or = 10.0 yr less than 1.6 km [1.0 mi] from the smelter) for boys were Cox proportional hazards ratios significantly higher than 1.00: for all causes of death (1.52), ischemic heart disease (1.77), and external causes (1.93). For girls, hazard ratios were not elevated significantly for any cause of death in any exposure intensity group.

Is contaminated groundwater an important cause of viral gastroenteritis in the United States?

The large volume of human sewage discharged into the ground has raised concerns about contamination of underground water supplies and possible human health risks. Few groundwater outbreaks reported in the United States, however, have been linked to enteric viruses. Studies on the occurrence of groundwater enteric viruses have detected viruses in groundwater, but many of these studies selected high-risk wells for testing. The results likely overestimated the occurrence of virus contamination in groundwater as well as the resulting public-health risks. This study found only limited evidence for viral contamination of groundwater in the absence of bacterial indicators of sewage contamination. From current studies of virus contamination in groundwater, the authors could not identify a sufficient population with evidence of exposure convincing enough to make an epidemiological investigation feasible and thus were unable to epidemiologically evaluate health risks that may be associated with viral contamination of groundwater. To better estimate the potential health risks, surveys should look at the occurrence of groundwater virus contamination in water that does not have bacterial indicators of sewage contamination and in water that has not been adequately disinfected. These surveys should include groundwater from a wide range of geological conditions.

Predictors for mortality in hospitalized patients with chronic obstructive pulmonary disease.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) has been the only leading cause of death associated with a continuously increasing trend in the US over the past 30 years. OBJECTIVES: The aim of this research was to identify predictors for all-cause in-hospital mortality for COPD patients. METHODS: We conducted a cross-sectional study of patients with the discharge diagnosis of COPD, utilizing the 2007 Premier Perspective database. Inpatients aged 40 years and above were selected if they had a discharge with a primary diagnosis of COPD between January 1, 2007 and December 31, 2007. All data analyses were based on individual level. If a patient had multiple discharges, only the last discharge was included for mortality analysis. Predictors for mortality were identified by multiple logistic regressions. Bonferroni correction for multiple logistic regression models was adapted to control for family-wise errors. RESULTS: The total of 57,224 patients was selected for data analysis in the study. All-cause in-hospital mortality for patients with COPD was 2.4%. Older age, insurance coverage, elective admission, intensive care unit admission, prolonged length of stay, increased Deyo-adapted Charlson Index (DCI) score and Elixhauser comorbidities of renal failure, metastatic cancer, solid tumor without metastasis, and weight loss were identified as independent predictors for all-cause in-hospital mortality. Antibiotics and ß-blockers were predictors of lower all-cause in-hospital mortality risk after adjusting for other factors. CONCLUSIONS: The nationwide discharge database provides useful information to identify predictors for all-cause in-hospital mortality of patients with COPD.

Can outpatient pharmacy data identify persons with undiagnosed COPD?

OBJECTIVE: To develop and validate a method for identifying persons with undiagnosed chronic obstructive pulmonary disease (COPD) using outpatient pharmacy data. STUDY DESIGN: Case-control analysis of managed care administrative data with clinical validation by spirometry and standardized questionnaires. METHODS: Patients with a new diagnosis of COPD were matched to 3 control subjects by age and sex. Outpatient pharmacy utilization for the 2 years prior to the initial diagnosis was captured. Drugs associated with an eventual diagnosis of COPD were identified using conditional logistic regression, and then entered into a predictive algorithm using discriminant function analysis. The algorithm was tested in a second population from the same health plan and externally validated using 2 large multicenter databases. This system was clinically validated by testing 100 individuals identified by the algorithm with spirometry plus health status and respiratory symptoms questionnaires. RESULTS: COPD patients used significantly more antibiotics, cardiac medications, and respiratory drugs than their matched controls. The final algorithm identified COPD patients with a sensitivity of 60% and specificity of 70%, without the benefit of knowing any patient's smoking history. Of the first 100 persons identified by the algorithm as being at risk and recruited for testing, 25 were proven to have previously undiagnosed COPD. CONCLUSIONS: Pharmacy utilization increases in the years prior to initial COPD diagnosis. Algorithms based on pharmacy utilization can efficiently identify persons at risk for undiagnosed COPD.

Mortality impact of less-than-standard therapy in older breast cancer patients.

BACKGROUND: The purpose of this study was to compare the rates of all-cause and breast cancer-specific mortality after breast-conserving surgery (BCS) only, BCS plus radiation therapy (RT), mastectomy, and the receipt of adjuvant tamoxifen in a large population-based cohort of older women with early-stage disease. STUDY DESIGN: This cohort study was conducted within six US integrated health-care delivery systems. Automated administrative databases, medical records, and tumor registries were used to identify women aged 65 years or older who received BCS or mastectomy to treat stage I or II breast cancer diagnosed from January 1, 1990, through December 31, 1994. We compared cause-specific 10-year mortality rates across treatment categories by fitting Cox proportional hazards models adjusted for demographics and tumor characteristics. RESULTS: We identified 1,837 women having operations for stage I or II breast cancer. Compared with women receiving mastectomy, those receiving BCS without RT were twice as likely to die of breast cancer (adjusted hazards ratio [HR]=2.19, 95% confidence interval [CI], 1.51 to 3.18). Breast cancer mortality rates were similar between women receiving BCS plus RT and women receiving mastectomy (adjusted HR=1.08, 95% CI, 0.79 to 1.48). In the subset of 886 chemotherapy-naive women treated with tamoxifen, those treated with tamoxifen for less than 1 year had a substantially higher breast cancer mortality rate than those exposed 5 years or more (adjusted HR=6.26, 95% CI, 3.10 to 12.64). CONCLUSIONS: Our findings indicate that older women receiving BCS alone have higher rates of breast cancer death than those receiving BCS + RT or mastectomy and that the survival benefit from tamoxifen increases with increasing duration of treatment.