Abstract A076: Adherence to adjuvant endocrine therapy: Do racial disparities persist among the insured?

Purpose: Adjuvant endocrine therapy (AET) improves survival in women with hormone receptor-positive (HR+) breast cancer (BC). Yet medication adherence is suboptimal. The aim of this study was to assess adherence to AET among insured women using innovative statistical approaches.

Methods: Black and White women diagnosed with HR+ BC were identified from two health maintenance organizations. Automated pharmacy records captured oral AET prescriptions and refill dates. Logistic regression identified predictors of adherence defined in terms of proportion of days covered (PDC) (>=80%) and medication gap of ≤10 days. A zero-inflated negative binominal (ZINB) regression model identified variables associated with the total number of days of medication gaps.

Results: A total of 1,925 women met inclusion criteria. Eighty percent of women were adherent per the PDC measure; 44% had a medication gap of ≤10 days; and 24% of women had zero days without any medication gaps. Race and age were significant predictors of adherence in all multivariable models. Black women were less likely to have PDC >=80% than Whites (OR=0.72; 95%CI: 0.57-0.90; p<0.01), and they were less likely to have a medication gap of ≤10 days (OR=0.65; 95%CI: 0.54-0.79; p<0.001). Women 25-49 years old were less likely to have PDC >=80% than women 65-93 years old (OR=0.65; 95%CI: 0.48-0.87; p<0.001), and they also were less likely to have a medication gap of ≤10 days (OR=0.73; 95%CI: 0.57-0.93; p<0.01). In the zero-inflated negative binominal model, Black women were less likely to having no medication gaps compared to Whites (OR=0.46; 95%CI: 0.54-0.79; p<0.001), and women 25-49 years old were less likely to have no medication gaps compared to women 65-93 years old (OR=0.61; 95%CI: 0.42-0.88; p<0.01).

Conclusions: Disparities in adherence to AET persist among insured women, particularly in Black and young women, highlighting a need for interventions among this population. Novel statistical approaches to study adherence, such as the ZINB approach, appear to constitute a useful alternative to the dichotomous PDC variable to tailor analysis to adherence patterns.

Citation Format: Dennis Tolsma, Mahlet G. Tadesse, Arnethea Sutton, Lee Cromwell, Georges Adunlin, Teresa M. Salgado, Jun He, Martha Trout, Brandi E. Robinson, Megan C. Edmonds, Hayden B. Bosworth, Vanessa B. Sheppard. Adherence to adjuvant endocrine therapy: Do racial disparities persist among the insured? [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr A076.

Adherence to Adjuvant Endocrine Therapy in Insured Black and White Breast Cancer Survivors: Exploring Adherence Measures in Patient Data

BACKGROUND

Adjuvant endocrine therapy (AET) is a critical therapy in that it improves survival in women with hormone receptor-positive (HR+) breast cancer (BC), but adherence to AET is suboptimal. The purpose of this study was to fill scientific gaps about predictors of adherence to AET among black and white women diagnosed with BC.

OBJECTIVE

To assess AET adherence in black and white insured women using multiple measures, including one that uses an innovative statistical approach.

METHODS

Black and white women newly diagnosed with HR+ BC were identified from 2 health maintenance organizations. Pharmacy records captured the type of oral AET prescriptions and all fill dates. Multivariable logistic regression was used to identify predictors of adherence defined in terms of proportion of days covered (PDC; ≥ 80%) and medication gap of ≤ 10 days. A zero-inflated negative binomial (ZINB) regression model was used to identify variables associated with the total number of days of medication gaps.

RESULTS

1,925 women met inclusion criteria. 80% were PDC adherent (> 80%); 44% had a medication gap of ≤ 10 days; and 24% had no medication gap days. Race and age were significant in all multivariable models. Black women were less likely to be adherent based on PDC than white women (OR = 0.72, 95% CI = 0.57-0.90, P < 0.01), and they were less likely to have a medication gap of ≤ 10 days (OR = 0.65, 95% CI = 0.54-0.79, P < 0.001). Women aged 25-49 years were less likely to be PDC adherent than women aged 65-93 years (OR = 0.65, 95% CI = 0.48-0.87, P < 0.001). In the ZINB model, women were without their medication for an average of 37 days (SD = 50.5).

CONCLUSIONS

Racial disparities in adherence to AET in the study highlight a need for interventions among insured women. Using various measures of adherence may help better understand this multidimensional concept. There might be benefits from using both more common dichotomous measures (e.g., PDC) and integrating novel statistical approaches to allow tailoring adherence to patterns within a specific sample.

DISCLOSURES

This research was funded by the National Institutes of Health (R01CA154848). It was also supported in part by the NIH-NCI Cancer Center Support Grant P30 CA016059, the Laboratory of Telomere Health P30 CA51008, and the TSA Award No. UL1TR002649 from the National Center for Advancing Translational Sciences. The contents of this study are solely the responsibility of the authors and do not necessarily represent official views of the National Center for Advancing Translational Sciences or the National Institutes of Health. Bosworth reports grants from Sanofi, Otsuka, Johnson & Johnson, and Blue Cross/Blue Shield of NC and consulting fees from Sanofi and Otsuka. The other authors have nothing to disclose. The datasets generated during and/or analyzed during the current study are not publicly available due to privacy reasons but are available from the corresponding author on reasonable request. The author does not own these data. Data use was granted to the author as part of a data use agreement between specific agencies and organizations.

Human Papillomavirus Vaccine Effectiveness Against Incident Genital Warts Among Female Health-Plan Enrollees, United States

We examined the effectiveness of human papillomavirus vaccination by dose number and spacing against incident genital warts in a cohort of 64,517 female health-plan enrollees in the United States during 2006-2012. Eligible recipients were classified into groups by regimen: 0, 1, 2 (<6 months apart), 2 (≥6 months apart), or 3 doses. They were followed until a genital wart diagnosis, loss to follow-up, or the end of study. Propensity score weights were used to balance baseline differences across groups. To account for latent genital warts before vaccination, we applied 6- and 12-month buffer periods from last and first vaccine dose, respectively. Incidence rates and hazard ratios were calculated using Poisson regression and Cox models. The propensity score-weighted incidence rate per 100,000 person-years was 762 among unvaccinated participants. Using 6- and 12-month buffer periods, respectively, incidence rates were 641 and 257 for 1 dose, 760 and 577 for the 2-dose (<6-month interval) regimen, 313 and 194 for the 2-dose (≥6-month interval) regimen, and 199 and 162 among 3-dose vaccinees; vaccine effectiveness was 68% and 76% for the 2-dose (≥6-month interval) regimen and 77% and 80% in 3-dose vaccinees compared with unvaccinated participants. Vaccine effectiveness was not significant among vaccinees receiving 1-dose and 2-dose (<6-month interval) regimens compared with unvaccinated participants. Our findings contribute to a better understanding of the real-world effectiveness of HPV vaccination.

Cohort profile: Study of Transition, Outcomes and Gender (STRONG) to assess health status of transgender people

PURPOSE

The Study of Transition, Outcomes and Gender (STRONG) was initiated to assess the health status of transgender people in general and following gender-affirming treatments at Kaiser Permanente health plans in Georgia, Northern California and Southern California. The objectives of this communication are to describe methods of cohort ascertainment and data collection and to characterise the study population.

PARTICIPANTS

A stepwise methodology involving computerised searches of electronic medical records and free-text validation of eligibility and gender identity was used to identify a cohort of 6456 members with first evidence of transgender status (index date) between 2006 and 2014. The cohort included 3475 (54%) transfeminine (TF), 2892 (45%) transmasculine (TM) and 89 (1%) members whose natal sex and gender identity remained undetermined from the records. The cohort was matched to 127 608 enrollees with no transgender evidence (63 825 women and 63 783 men) on year of birth, race/ethnicity, study site and membership year of the index date. Cohort follow-up extends through the end of 2016.

FINDINGS TO DATE

About 58% of TF and 52% of TM cohort members received hormonal therapy at Kaiser Permanente. Chest surgery was more common among TM participants (12% vs 0.3%). The proportions of transgender participants who underwent genital reconstruction surgeries were similar (4%-5%) in the two transgender groups. Results indicate that there are sufficient numbers of events in the TF and TM cohorts to further examine mental health status, cardiovascular events, diabetes, HIV and most common cancers.

FUTURE PLANS

STRONG is well positioned to fill existing knowledge gaps through comparisons of transgender and reference populations and through analyses of health status before and after gender affirmation treatment. Analyses will include incidence of cardiovascular disease, mental health, HIV and diabetes, as well as changes in laboratory-based endpoints (eg, polycythemia and bone density), overall and in relation to gender affirmation therapy.

Biospecimen donation among black and white breast cancer survivors: opportunities to promote precision medicine

PURPOSE

Advances in precision medicine (PM) have potential to reduce and/or eliminate breast cancer disparities in both treatment and survivorship. However, compared to white Americans, black Americans are often underrepresented in genetic research. This report assessed factors that influence receipt of buccal cells via saliva kits.

METHODS

This prospective study recruited women with confirmed hormonal-positive (HR+) breast cancer (BC). A standardized telephone survey collected sociodemographic, socio-cultural (e.g., religiosity), and healthcare process factors. Clinical information was abstracted from medical records. After the baseline survey, return postage-paid envelopes and mouthwash collection kits were mailed. Univariate and adjusted logistic regression models estimated the probability of biospecimen donation.

RESULTS

Seventy percent of the sample provided buccal cells which were of good quality. No differences were noted by race or other demographic factors. In the multivariable logistic model, time spent with providers (OR 1.61 per 1-point increase; 95% CI 1.242, 2.088) and religiosity (OR 0.957 per 1-point increase; 95% CI 0.931, 0.984) remained associated with biospecimen provision. Women with lower-stage cancer (vs. higher stage III+) were more likely to donate biospecimens (p < 0.05).

CONCLUSIONS

Cancer care experiences predicted specimen donation. Understanding the contextual reasons for lower receipt among women with higher religiosity scores and higher stage warrants further examination.

IMPLICATIONS FOR CANCER SURVIVORS

PM is relevant to cancer survivors because of its potential to inform targeted therapies, understand disease resistance, and aide in prediction of toxicity and/or recurrence. Future efforts to launch precision medicine trials with BC survivors may benefit from engaging medical oncologists and/or leveraging patient-provider encounters for trial participation.

Major Physical Health Conditions and Risk of Suicide

INTRODUCTION

Most individuals make healthcare visits before suicide, but many do not have a diagnosed mental health condition. This study seeks to investigate suicide risk among patients with a range of physical health conditions in a U.S. general population sample and whether risk persists after adjustment for mental health and substance use diagnoses.

METHODS

This study included 2,674 individuals who died by suicide between 2000 and 2013 along with 267,400 controls matched on year and location in a case-control study conducted in 2016 across eight Mental Health Research Network healthcare systems. A total of 19 physical health conditions were identified using diagnostic codes within the healthcare systems' Virtual Data Warehouse, including electronic health record and insurance claims data, during the year before index date.

RESULTS

Seventeen physical health conditions were associated with increased suicide risk after adjustment for age and sex (p<0.001); nine associations persisted after additional adjustment for mental health and substance use diagnoses. Three conditions had a more than twofold increased suicide risk: traumatic brain injury (AOR=8.80, p<0.001); sleep disorders; and HIV/AIDS. Multimorbidity was present in 38% of cases versus 15.5% of controls, and represented nearly a twofold increased risk for suicide.

CONCLUSIONS

Although several individual conditions, for example, traumatic brain injury, were associated with high risk of suicide, nearly all physical health conditions increased suicide risk, even after adjustment for potential confounders. In addition, having multiple physical health conditions increased suicide risk substantially. These data support suicide prevention based on the overall burden of physical health.

A novel method for estimating transgender status using electronic medical records

PURPOSE

We describe a novel algorithm for identifying transgender people and determining their male-to-female (MTF) or female-to-male (FTM) identity in electronic medical records of an integrated health system.

METHODS

A computer program scanned Kaiser Permanente Georgia electronic medical records from January 2006 through December 2014 for relevant diagnostic codes, and presence of specific keywords (e.g., "transgender" or "transsexual") in clinical notes. Eligibility was verified by review of de-identified text strings containing targeted keywords, and if needed, by an additional in-depth review of records. Once transgender status was confirmed, FTM or MTF identity was assessed using a second program and another round of text string reviews.

RESULTS

Of 813,737 members, 271 were identified as possibly transgender: 137 through keywords only, 25 through diagnostic codes only, and 109 through both codes and keywords. Of these individuals, 185 (68%, 95% confidence interval [CI]: 62%-74%) were confirmed as definitely transgender. The proportions (95% CIs) of definite transgender status among persons identified via keywords, diagnostic codes, and both were 45% (37%-54%), 56% (35%-75%), and 100% (96%-100%). Of the 185 definitely transgender people, 99 (54%, 95% CI: 46%-61%) were MTF, 84 (45%, 95% CI: 38%-53%) were FTM. For two persons, gender identity remained unknown. Prevalence of transgender people (per 100,000 members) was 4.4 (95% CI: 2.6-7.4) in 2006 and 38.7 (95% CI: 32.4-46.2) in 2014.

CONCLUSIONS

The proposed method of identifying candidates for transgender health studies is low cost and relatively efficient. It can be applied in other similar health care systems.

A novel method for estimating transgender status using electronic medical records

PURPOSE

We describe a novel algorithm for identifying transgender people and determining their male-to-female (MTF) or female-to-male (FTM) identity in electronic medical records of an integrated health system.

METHODS

A computer program scanned Kaiser Permanente Georgia electronic medical records from January 2006 through December 2014 for relevant diagnostic codes, and presence of specific keywords (e.g., "transgender" or "transsexual") in clinical notes. Eligibility was verified by review of de-identified text strings containing targeted keywords, and if needed, by an additional in-depth review of records. Once transgender status was confirmed, FTM or MTF identity was assessed using a second program and another round of text string reviews.

RESULTS

Of 813,737 members, 271 were identified as possibly transgender: 137 through keywords only, 25 through diagnostic codes only, and 109 through both codes and keywords. Of these individuals, 185 (68%, 95% confidence interval [CI]: 62%-74%) were confirmed as definitely transgender. The proportions (95% CIs) of definite transgender status among persons identified via keywords, diagnostic codes, and both were 45% (37%-54%), 56% (35%-75%), and 100% (96%-100%). Of the 185 definitely transgender people, 99 (54%, 95% CI: 46%-61%) were MTF, 84 (45%, 95% CI: 38%-53%) were FTM. For two persons, gender identity remained unknown. Prevalence of transgender people (per 100,000 members) was 4.4 (95% CI: 2.6-7.4) in 2006 and 38.7 (95% CI: 32.4-46.2) in 2014.

CONCLUSIONS

The proposed method of identifying candidates for transgender health studies is low cost and relatively efficient. It can be applied in other similar health care systems.

Childhood asthma acute primary care visits, traffic, and traffic-related pollutants

Previous studies have found associations between traffic-related air pollution and asthma exacerbation in children, where exacerbations were measured according to emergency department visits and hospital admissions. Fewer studies have been undertaken that look at asthma exacerbations in a less severe primary care setting. Therefore, the authors sought to examine the associations between childhood asthma exacerbations, measured as acute visits to a primary care setting, and vehicular-traffic measures in a population of children aged 18 and under in the metropolitan Atlanta area. Statistical tests for differences of mean monthly visits for members with traffic measures above the median compared with below the median and for the upper quartile compared with the lower quartile were conducted. We also compared the odds of having one or more visits in a month for those who lived closer to a major roadway were compared with those who lived farther (greater than 300 m) from a major roadway. Poisson general linear modeling was used to determine associations between daily levels of acute visits for childhood asthma and traffic-related pollutants (zinc, EC [elemental carbon], and PM10 and PM2.5 [particulate matter with an aerodynamic diameter of < or = 10 and < or = 2.5 microm, respectively]) for different levels of traffic and distance measures. This analysis found that both larger traffic volumes and smaller distances to the nearest major roadway were positively and significantly associated with larger numbers of childhood asthma visits, when compared with less traffic and larger distances. Our findings point to motor vehicle traffic as an important contributor to childhood asthma exacerbations.

IMPLICATIONS

Previous studies have found associations between traffic-related air pollution and asthma exacerbation in children. However, these studies were mainly conducted in emergency department or hospital admission settings; little is known regarding less acute health effects. This analysis of the association between vehicular traffic measures and childhood asthma in a primary care setting suggests that motor vehicle traffic is a contributor to less acute asthma episodes in children. The present analysis of traffic-related air pollutants and childhood asthma were less conclusive, likely due to methods limitations outlined in the paper. The implication is that further evidence of adverse respiratory health effects in children due to motor vehicle traffic can be found in a primary care setting and similar studies should be considered.

Ethnic Identity predicts loss-to-follow-up in a health promotion trial

BACKGROUND

Higher rates of attrition in health research have been reported for African Americans (AAs). However, little is known about which AAs are more prone to drop out and why. One potential predictor that has not been explored is Ethnic Identity (EI). This study examined the association between EI and loss-to-follow-up among AAs enrolled in a health promotion intervention to increase fruit and vegetable intake.

METHODS

Five hundred and sixty AA adults from two integrated health care delivery systems in Atlanta and Detroit were enrolled into a randomized intervention trial. At baseline, all participants were classified into six EI core groups: Afrocentric, Black American, Bicultural, Multicultural, Assimilated, and High Cultural Mistrust. We examined loss-to-follow-up rates by these EI type.

RESULTS

Overall, 92 participants (16%) were lost to follow up. Loss-to-follow-up rates were higher among those classified as Afrocentric (24%) than those without an Afrocentric identity (13%). After adjustment for covariates, Afrocentric participants were 1.9 times (CI: 1.1-3.6) more likely to be lost to follow up than participants without this identity type.

CONCLUSIONS

Assessing EI of AAs in research studies may help identify groups at risk for dropout and/or non-response.

A two-time-period comparison of the effects of ambient air pollution on outpatient visits for acute respiratory illnesses

Concentrations of numerous ambient air pollutants have declined in recent years across the United States. Although it can be expected that reductions in air pollutants are associated with reductions in health effects, it is unclear whether this is actually the case. The purpose of this analysis was to compare the levels of and relationships between air pollutants and acute respiratory outpatient visits for two consecutive time periods totaling 53 mo. Air pollution data were collected at a centrally located monitor in Atlanta, GA, and include 24-hr averages of particulate matter (PM) less than 2.5 microm in aerodynamic diameter (PM2.5) and its components; coarse PM (PM10-2.5); PM less than 10 microm in aerodynamic diameter (PM10); oxygenated volatile organic compounds (OVOCs); 8-hr maximum ozone (O3); and 1-hr maximum nitrogen dioxide (NO2), carbon monoxide (CO), and sulfur dioxide (SO2). In addition, several metals and fractions of elemental carbon (EC) and organic carbon (OC) were investigated. Daily outpatient visit data were obtained from the electronic data warehouse of the Atlanta-based region of a nonprofit managed care organization. Poisson general linear modeling determined associations between daily levels of acute visits for four diagnosis groups (adult and child asthma, upper and lower respiratory infection) and air pollution measurements. Overall declining trends were observed in air pollutants and acute visits over the study period. Childhood asthma had the greatest number of significant associations with air pollutants, namely zinc and EC. The significant lag time between pollutant measurement and visit occurrence changed from 3-5 days in the first time period to 6-8 days in the later time period, but there was general consistency in several childhood asthma and pollutant associations over both time periods. The greatest evidence for a reduction in pollution being associated with an improvement in health response was for lower respiratory disease visits, but even in this case changes in other factors that influence health responses make it difficult to demonstrate that changes in pollutant levels influence health outcomes.

Challenges in researching racially sensitive topics in HMOs

When research designed to close the disparities gap is conducted in real-world health care settings, unique sensitivities may arise, particularly when race is the focus of interventions. Researchers encountered this issue in the course of a randomized trial investigating the influence of ethnic identity (EI) among African American (AA) study participants. The study was conducted by the research programs at three health maintenance organizations (HMOs) and the University of Michigan Center for Health Communications Research, as described in this issue of the journal (Resnicow et al., 2009). This commentary describes the research partnership's concerns for the racially sensitive nature of the study and the precautions undertaken to mitigate them. The research study's experiences may be informative and insightful for health plans and research centers invested in health disparities research.

Tailoring a fruit and vegetable intervention on ethnic identity: results of a randomized study

OBJECTIVE

Many targeted interventions have been developed and tested with African Americans (AA); however, AAs are a highly heterogeneous group. One characteristic that varies across AAs is Ethnic Identity (EI). Little research has been conducted on how to incorporate EI into the design of health messages and programs.

DESIGN

We tested whether tailoring a print-based fruit and vegetable (F & V) intervention on EI would enhance program impact. AA adults were recruited from two integrated healthcare delivery systems and then randomized to receive three newsletters focused on F & V behavior change over three months. One set of newsletters was tailored only on demographic and social cognitive variables (control condition), whereas the other (experimental condition) was additionally tailored on EI.

MAIN OUTCOME MEASURES

The primary outcome for the study was F & V intake, assessed at baseline and three months later using the composite of two brief self-report frequency measures.

RESULTS

A total of 560 eligible participants were enrolled, of which 468 provided complete 3-month follow-up data. The experimental group increased their daily mean F & V intake by 1.1 servings compared to .8 servings in the control group (p = .13). Afrocentric experimental group participants showed a 1.4 increase in F & V servings per day compared to a .43 servings per day increase among Afrocentric controls (p < .05).

CONCLUSIONS

Although the overall between-group effects were not significant, tailoring dietary messages on ethnic identity may improve intervention impact for some AA subgroups.

A comparison of smokers' and nonsmokers' fruit and vegetable intake and relevant psychosocial factors

The authors examined the relation between smoking status and fruit and vegetable (FV) consumption among a population-based sample and examined differences in psychosocial factors that may influence diet and inform intervention efforts. The authors recruited adults (N = 2,540) from 5 US health plans to participate in a Web-based dietary intervention trial. At baseline, smokers ate fewer FV servings per day (p < .001) and were less likely to meet the 5 A Day goal (p < .001). Smokers reported lower self-efficacy, overall motivation, and intrinsic motivation for meeting daily FV recommendations. Fewer smokers expected that eating 5 FV servings a day would reduce their risk for diabetes (p = .02) or obesity (p = .008). Smokers are an important target group for dietary intervention. Intervention efforts should attempt to increase smokers' motivation and confidence in their abilities to change their eating patterns and educate them about the health benefits of eating FV.

Cardiology clinical trial participation in community-based healthcare systems: obstacles and opportunities

BACKGROUND

The objective of our study was to examine cardiologists' and organizational leaders' interest in clinical trial participation and perceived barriers and facilitators to participation within ten diverse non-profit healthcare delivery systems. Trials play a pivotal role in advancing knowledge about the safety and efficacy of cardiovascular interventions and tests. Although cardiovascular trials successfully enroll patients, recruitment challenges persist. Community-based health systems could be an important source of participants and investigators, but little is known about community cardiologists' experiences with trials.

METHODS

We interviewed 25 cardiology and administrative leaders and mailed questionnaires to all 280 cardiologists at 10 U.S. healthcare organizations.

RESULTS

The survey received a 73% response rate. While 60% of respondents had not participated in any trials in the past year, nearly 75% wanted greater participation. Cardiologists reported positive attitudes toward trial participation; more than half agreed that trials were their first choice of therapy for patients, if available. Almost all leaders described their organizations as valuing research but not necessarily trials. Major barriers to participation were lack of physician time and insufficient skilled research nurses.

CONCLUSIONS

Cardiologists have considerable interest in trial participation. Major obstacles to increased participation are lack of time and effective infrastructure to support trials. These results suggest that community-based health systems are a rich source for cardiovascular research but additional funding and infrastructure are needed to leverage this resource.

Liver and thyroid monitoring in ambulatory patients prescribed amiodarone in 10 HMOs

BACKGROUND

Amiodarone can cause liver and thyroid toxicity, but little is known about compliance with laboratory tests to evaluate liver and thyroid function among ambulatory patients who are dispensed amiodarone.

OBJECTIVES

The primary objective of this study was to identify the proportion of ambulatory patients who had liver aminotransferase and thyroid function tests during amiodarone therapy. Secondary objectives were to (1) describe factors associated with receipt of laboratory tests and (2) determine the accuracy of administrative data for assessing aminotransferase and thyroid function monitoring.

METHODS

This retrospective cohort study was conducted at 10 health maintenance organizations (HMOs) for the dates of service from January 1, 1999, through June 30, 2001. Participants included 1,055 patients dispensed amiodarone for at least 180 days within this date range; these patients were not necessarily new starts on amiodarone. Administrative claims data were analyzed to assess the percentage of patients with completed alanine/aspartate aminotransferase and thyroid function tests. Depending on the HMO site, electronic or paper medical records were reviewed to evaluate the validity of administrative claims data. Logistic regression models were used to explore factors associated with receipt of laboratory tests.

RESULTS

Both aminotransferase and thyroid function tests were completed in 53.3% of patients within a 210-day follow-up period that included the 180-day period of amiodarone dispensings plus 30 days. Thyroid function, with or without liver function (aminotransferase tests), was assessed in 61.9% of patients, and aminotransferase tests, with or without thyroid function, were assessed in 68.2% of patients. After adjusting for patient characteristics and site, the factor most strongly associated with having both types of laboratory tests evaluated was concomitant therapy with a statin (adjusted odds ratio (OR) 1.55; 95% confidence interval (CI), 1.05-2.29). Other factors associated with having both types of laboratory tests evaluated included the number of outpatient visits in the 6 months before the period of amiodarone dispensings (adjusted OR 1.06; 95% CI, 1.00- 1.13 for each additional 5 visits) and living in a neighborhood where a higher median percentage of people had a high school or higher education (adjusted OR 1.09; 95% CI, 1.00-1.18 for every 10% increase in educational level at the block level). There was no association between monitoring and patient illness severity as measured by the number of comorbid conditions. On the basis of an evaluation of a randomly selected subset of 104 patient records, the sensitivity and specificity of automated data were 94.2% and 85.7% for aminotransferase tests and 83.3% and 81.1% for thyroid function tests, respectively.

CONCLUSIONS

Approximately half of ambulatory patients dispensed amiodarone received both recommended laboratory tests for liver and thyroid function. Improved rates of testing for liver aminotransferase and thyroid function are needed for patients who receive amiodarone.

Building a research consortium of large health systems: the Cancer Research Network

Critical questions about cancer prevention, care, and outcomes increasingly require research involving large patient populations and their care delivery organizations. The Cancer Research Network (CRN) includes 11 integrated health systems funded by the National Cancer Institute (NCI) to conduct collaborative cancer research. This article describes the challenges of constructing a productive consortium of large health systems, and explores the CRN's responses. The CRN was initially funded through an NCI cooperative agreement in 1999 and has since received a second 4-year grant. Leadership and policy development are provided through a steering committee, subcommittees, and an external advisory committee. The CRN includes integral and affiliated research projects supported by a Scientific and Data Resources Core. Three characteristics of the CRN intensified the general challenges of consortium research: 1) its members are large health systems with legitimate concerns about confidentiality of data about enrollees, providers, and the organization; 2) CRN research projects often generate highly sensitive data about quality of care; and therefore 3) each participating organization wants a strong voice in CRN direction. CRN experience to date confirms that a consortium of health systems with internal research capacity can address a range of important cancer research questions that would be difficult to study in other venues. The advantages and challenges of consortium research are explored, with suggestions for the development, execution, and management of multisystem population laboratories.

The role of research in integrated healthcare systems: the HMO Research Network

Science is the basis of medicine. Good science leads to better decisions and more effective systems to support those decisions. Most individuals associate science primarily with academic institutions. However, top-quality research relevant to managing the health of populations and the care of specific clinical conditions is increasingly being carried out by investigators working in integrated healthcare systems. This introduction outlines the activities of the HMO Research Network, whose researchers have made and continue to make important contributions to the field of health research. Its objective is to inform readers of the activities and value of systems-based health research. We describe the importance and extent of the research conducted by HMO Research Network members, as well as the advantages of conducting research in such settings.

Associations and lags between air pollution and acute respiratory visits in an ambulatory care setting: 25-month results from the aerosol research and inhalation epidemiological study

Particulate matter (PM) has been associated with adverse respiratory outcomes in numerous studies that utilized data from emergency room visits, hospital admissions, and mortality records. This study is unique in its investigation of associations of air pollution measures, including components of PM, with health outcomes in an ambulatory-care setting. Visit data were collected from Kaiser Permanente, a not-for-profit health maintenance organization in the metropolitan Atlanta, GA, area. Kaiser Permanente collaborated on the Aerosol Research Inhalation Epidemiological Study (ARIES), which provided detailed information on the characteristics of air pollutants. The Kaiser Permanente study was a time-series investigation of the possible associations between daily levels of suspended PM, inorganic gases, and polar volatile organic compounds and ambulatory care acute visit rates during the 25-month period from August 1, 1998, to August 31, 2000. For this interim analysis, the a priori 0-2 days lagged moving average, as well as the 3-5 days and 6-8 days lagged moving averages, of air quality measures were investigated. Single-pollutant Poisson general linear modeling was used to model daily visit counts for asthma and upper and lower respiratory infections (URI and LRI) by selected air quality metrics, controlling for temporal trends and meteorological variables. Most of the statistically significant positive associations were for the 3-5 days lagged air quality metrics with child asthma and LRI.

Administrative data as a tool for arthritis surveillance: estimating prevalence and utilization of services

The public health burden of arthritis and related conditions is incompletely described by commonly used public health surveillance systems. We examined the potential of administrative data as a supplement. The administrative data sources we used underestimated the prevalence of arthritis and overestimated service utilization for persons with arthritis when data from only one year were used. The use of five year's data doubled the prevalence estimate and reduced the service utilization estimate by half. The demographics of the population covered by administrative data also influence the prevalence estimate. Administrative data may usefully supplement routine public health surveillance systems but must be used with caution.