The central role of comorbidity in predicting ambulatory care sensitive hospitalizations.

BACKGROUND: Ambulatory care sensitive hospitalizations (ACSHs) are commonly used as measures of access to and quality of care. They are defined as hospitalizations for certain acute and chronic conditions; yet, they are most commonly used in analyses comparing different groups without adjustment for individual-level comorbidity. We present an exploration of their roles in predicting ACSHs for acute and chronic conditions. METHODS: Using 1998-99 US Medicare claims for 1 06 930 SEER-Medicare control subjects and 1999 Area Resource File data, we modelled occurrence of acute and chronic ACSHs with logistic regression, examining effects of different predictors on model discriminatory power. RESULTS: Flags for the presence of a few comorbid conditions-congestive heart failure, chronic obstructive pulmonary disease, diabetes, hypertension and, for acute ACSHs, dementia-contributed virtually all of the discriminative ability for predicting ACSHs. C-statistics were up to 0.96 for models predicting chronic ACSHs and up to 0.87 for predicting acute ACSHs. C-statistics for models lacking comorbidity flags were lower, at best 0.73, for both acute and chronic ACSHs. CONCLUSION: Comorbidity is far more important in predicting ACSH risk than any other factor, both for acute and chronic ACSHs. Imputations about quality and access should not be made from analyses that do not control for presence of important comorbid conditions. Acute and chronic ACSHs differ enough that they should be modelled separately. Unaggregated models restricted to persons with the relevant diagnoses are most appropriate for chronic ACSHs.

Primary care residency choice and participation in an extracurricular longitudinal medical school program to promote practice with medically underserved populations.

PURPOSE: In 2006, the University of Washington School of Medicine (UWSOM) launched the Underserved Pathway (UP), an extracurricular longitudinal experience supporting student interest in caring for underserved populations. This study examined the association between UP participation and residency choice. METHOD: The study population was 663 UWSOM graduates who matched to a residency from 2008 to 2011; 69 were UP participants. Outcomes included matching to primary care residencies (family medicine, internal medicine, pediatrics, or medicine-pediatrics). The authors calculated graduate rates and odds of UP participants versus nonparticipants matching to primary care residencies overall and to residencies in individual primary care specialties. This analysis included all graduates and 513 graduates who had dual interest in primary care and underserved care at matriculation. Of 336 graduates matching to primary care, the authors calculated rates of entering the individual specialties with respect to UP participation. RESULTS: UP participants matched at significantly higher rates than nonparticipants to primary care (72.5% versus 48.1%, adjusted odds ratio [OR] 2.2) and family medicine residencies (33.3% versus 15.0%, adjusted OR 2.9). Of graduates with dual matriculation interest in primary care and underserved care, 73.4% of participants versus 53.5% of nonparticipants matched to primary care (adjusted OR 1.9), and 31.2% of participants versus 18.0% of nonparticipants matched to family medicine (adjusted OR 2.1). Of primary care matched graduates, 46.0% of participants versus 31.1% of nonparticipants entered family medicine. CONCLUSIONS: Supporting student interest in underserved careers is associated with higher rates of graduates entering primary care residencies, specifically family medicine.

Receipt of general medical care by colorectal cancer patients: a longitudinal study.

BACKGROUND: cancer diagnosis has the potential to overshadow patients' general medical care needs. This study examined changes in general medical care among elderly patients with colorectal cancer (CRC), from before diagnosis through long-term survival. METHODS: this longitudinal cohort study used 1993 to 1999 Surveillance, Epidemiology, and End Results and 1991 to 2001 Medicare claims data for 22,161 patients with stage 0 to 3 CRC and 81,669 controls aged 67 to 89 years. Outcomes were preventive services (influenza vaccination, mammography) and, among diabetics, HgbA1c and lipid testing in the phase before diagnosis, the phase after initial treatment, the surveillance phase, and the survival care phase. Logistic regression provided adjusted relative risks of care receipt for patients with stage 0 to 1 cancer, stage 2 to 3 cancer, and no cancer. RESULTS: in the phase before diagnosis through the surveillance phase, patients with stage 0 to 1 CRC had the highest annual preventive service rates. Patients with stage 2 to 3 CRC made substantial gains in preventive service use, especially mammography, after diagnosis (influenza vaccination, 46.4% before diagnosis to 50.2% after initial treatment; mammography, 31.4% before diagnosis to 40.2% after initial treatment) but not in diabetes care (eg, HgbA1c, 53.4% before diagnosis to 54.9% after initial treatment). CONCLUSIONS: CRC diagnosis seems to facilitate receipt of preventive services but not diabetes care for elderly, later-stage patients. Additional strategies such as strengthening partnerships between cancer patients, primary care physicians, and cancer care physicians are needed to improve care for a chronic disease like diabetes.

No pain, but no gain? The disappearance of angina hospitalizations, 1992-1999.

BACKGROUND: Hospitalization for angina is commonly considered an ambulatory care sensitive hospitalization and used as a measure of access to primary care. OBJECTIVE: To analyze time trends in angina-related hospitalizations and seek possible explanations for an observed, marked decline during 1992 to 1999. RESEARCH DESIGN: We analyzed Medicare claims of SEER-Medicare control subjects for occurrence of angina hospital discharges, using the Agency for Healthcare Research and Quality Prevention Quality Indicator (PQI) definition, along with occurrence of related events including angina admissions with revascularization, angina admissions discharged as coronary artery disease (CAD) or myocardial infarction, and overall ischemic heart disease discharges. SUBJECTS: Approximately 124,000 cancer-free Medicare beneficiary/ies, with subjects contributing data for 1 to 8 years. RESULTS: Angina PQI hospital discharges declined 75% between 1992 and 1999. CAD hospital discharges rose in a reciprocal pattern, while angina discharges with revascularization declined and discharges for myocardial infarction and ischemic heart disease were relatively constant during this time period. CONCLUSIONS: The marked decline in angina PQI hospital discharges during 1992-1999 does not appear to represent improvements in access to care or prevention of heart disease, but rather increased coding of more specific discharge diagnoses for CAD. Our findings suggest that angina hospitalization is not a valid measure for monitoring access to care and, more generally, demonstrate the need for careful, periodic re-evaluation of quality measures.

The contribution of longitudinal comorbidity measurements to survival analysis.

BACKGROUND: Many clinical and health services research studies are longitudinal, raising questions about how best to use an individual's comorbidity measurements over time to predict survival. OBJECTIVES: To evaluate the performance of different approaches to longitudinal comorbidity measurement in predicting survival, and to examine strategies for addressing the inevitable issue of missing data. RESEARCH DESIGN: Retrospective cohort study using Cox regression analysis to examine the association between various Romano-Charlson comorbidity measures and survival. SUBJECTS: Fifty thousand cancer-free individuals aged 66 or older enrolled in Medicare between 1991 and 1999 for at least 1 year. RESULTS: The best fitting model combined both time independent baseline comorbidity and the time dependent prior year comorbidity measure. The worst fitting model included baseline comorbidity only. Overall, the models fit best when using the "rolling" comorbidity measures that assumed chronic conditions persisted rather than measures using only prior year's recorded diagnoses. CONCLUSIONS: Longitudinal comorbidity is an important predictor of survival, and investigators should make use of individuals' longitudinal comorbidity data in their regression modeling.

Access to cancer services for rural colorectal cancer patients.

CONTEXT: Cancer care requires specialty surgical and medical resources that are less likely to be found in rural areas. PURPOSE: To examine the travel patterns and distances of rural and urban colorectal cancer (CRC) patients to 3 types of specialty cancer care services--surgery, medical oncology consultation, and radiation oncology consultation. METHODS: Descriptive cross-sectional study using linked Surveillance, Epidemiology, and End Results (SEER) cancer registry and Medicare claims data for 27,143 individuals ages 66 and older diagnosed with stages I through III CRC between 1992 and 1996. FINDINGS: Over 90% of rural CRC patients lived within 30 miles of a surgical hospital offering CRC surgery, but less than 50% of CRC patients living in small and isolated small rural areas had a medical or radiation oncologist within 30 miles. Rural CRC patients who traveled outside their geographic areas for their cancer care often went great distances. The median distance traveled by rural cancer patients who traveled to urban cancer care providers was 47.8 miles or more. A substantial proportion (between 19.4% and 26.0%) of all rural patients bypassed their closest medical and radiation oncology services by at least 30 miles. CONCLUSIONS: Rural CRC patients often travel long distances for their CRC care, with potential associated burdens of time, cost, and discomfort. Better understanding of whether this travel investment is paid off in improved quality of care would help rural cancer patients, most of whom are elderly, make informed decisions about how to use their resources during their cancer treatment.

Does surgeon case volume influence nonfatal adverse outcomes after rectal cancer resection?

BACKGROUND: The aim of this study was to assess the relationship between surgeon and hospital volume and major postoperative complications after rectal cancer surgery, and to define other surgeon and hospital characteristics that may explain observed volume-complication relationships. STUDY DESIGN: This was a retrospective cohort design using data from the Surveillance, Epidemiology, and End Results (SEER) cancer registry program for individuals with stage I to III rectal cancer diagnosed between 1992 and 1999 and treated with resection. The patients' Surveillance, Epidemiology, and End Results data were linked with Medicare claims data from 1991 to 2000. The primary outcomes were 30-day postoperative procedural interventions (PPI) to treat surgical complications, such as reoperation. The association between surgeon volume and PPI was examined using logistic regression modeling with adjustment for covariates. RESULTS: The odds of a rectal cancer patient requiring a PPI is notably less if the operation is performed by one of a small subset of very high volume surgeons (unadjusted odds ratio 0.53; 95% CI 0.31 to 0.92). Board certification in colorectal surgery did not alter the relationship between surgeon volume and PPI, although surgeon age did, with mid-career surgeons having the lowest rates of PPI, regardless of practice volume. When adjusted for surgeon age, surgeon volume is no longer a marked predictor of complications (adjusted odds ratio 0.57; 95% CI 0.30 to 1.09). CONCLUSIONS: Overall, rectal cancer operations are safe, with a low frequency of severe complications. A subset of very high volume rectal surgeons performs these operations with fewer complications that require procedural intervention or reoperation. Surgeon age, as an indicator of experience, also contributes modestly to outcomes. These data do not justify regionalizing rectal cancer care based on safety concerns.

Survival benefits and trends in use of adjuvant therapy among elderly stage II and III rectal cancer patients in the general population.

BACKGROUND: This study examined elderly stage II and III rectal cancer patients' adjuvant chemoradiation therapy adherence, trends in adherence over time, and the relation of levels of adherence to mortality. METHODS: The authors studied 2886 stage II and III rectal cancer patients who had surgical resection and who appeared in 1992-1999 linked SEER-Medicare claims data. The authors compared measures of adjuvant radiation and chemotherapy receipt and completion between stage II and III patients. Adjusted risk of cancer-related 5-year mortality was calculated by multivariate logistic regression for different levels of chemoradiation adherence among stage II and III patients. RESULTS: Of the 2886 patients, 45.4% received both adjuvant radiation and chemotherapy. Stage III patients were more likely to receive chemoradiation than stage II patients. The receipt of chemoradiation by stage II patients increased significantly from 1992 to 1999. Stage III patients were more likely to complete radiation therapy (96.6%), chemotherapy (68.2%), and both modalities (67.5%) than stage II patients (91.5%, 49.8%, 47.6%, respectively). Only a complete course of both radiation and chemotherapy for both stage II (relative risk [RR] 0.74; 95% CI, 0.54, 0.97) and III (RR 0.80; 95% CI, 0.65, 0.96) decreased the adjusted 5-year cancer mortality risk compared with counterparts with no adjuvant therapy. CONCLUSIONS: Even though stage II rectal cancer patients were less likely than stage III patients to receive and complete adjuvant chemoradiation, both patient groups in the general population had lower cancer-related mortality if they completed chemoradiation. These patients deserve support and encouragement to complete treatment.

Reoperation as a quality indicator in colorectal surgery: a population-based analysis.

OBJECTIVE: To describe unplanned procedures following colorectal cancer surgery that might be used as intermediate outcome measures, and to determine their association with mortality and length of stay. SUMMARY BACKGROUND: Variation in the quality of surgical care, especially for common illnesses like colorectal cancer, has received increasing attention. Nonfatal complications resulting in procedural interventions are likely to play a role in poor outcomes but have not been well explored. METHODS: Cohort analysis of 26,638 stage I to III colorectal cancer patients in the 1992 to 1996 SEER-Medicare database. INDEPENDENT VARIABLES: sociodemographics, tumor characteristics, comorbidity, and acuity. PRIMARY OUTCOME: postoperative procedural intervention. ANALYSIS: Logistic regression identified patient characteristics predicting postoperative procedures and the adjusted risk of 30-day mortality and prolonged hospitalization among patients with postoperative procedures. RESULTS: A total of 5.8% of patients required postoperative intervention. Patient characteristics had little impact on the frequency of postoperative procedures, except for acute medical conditions, including bowel perforation (relative risk [RR] = 3.0, 95% confidence interval [CI] = 2.5-3.6), obstruction (RR = 1.6; 95% CI = 1.4-1.8), and emergent admission (RR = 1.3; 95% CI = 1.1-1.4). After a postoperative procedure, patients were more likely to experience early mortality (RR = 2.4; 95% CI = 2.1-2.9) and prolonged hospitalization (RR = 2.2; 95% CI = 2.1-2.4). The most common interventions were performed for abdominal infection (31.7%; RR mortality = 2.9; 95% CI = 2.3-3.7), wound complications (21.1%; RR mortality = 0.7; 95% CI = 0.4-1.3), and organ injury (18.7%; RR mortality = 1.6; 95% CI = 1.1-2.3). CONCLUSIONS: Postoperative complications requiring additional procedures among colorectal cancer patients correlate with established measures of surgical quality. Prospective tracking of postoperative procedures as complication markers may facilitate outcome studies and quality improvement programs.

Completion of therapy by Medicare patients with stage III colon cancer.

BACKGROUND: Certain factors, such as race or age, are known to be associated with variation in initiation of adjuvant chemotherapy for stage III colon cancer, but little is known about what factors are associated with completion of adjuvant therapy. To determine whether predictors of initiation also predict completion, we analyzed Surveillance, Epidemiology, and End Results (SEER) program data linked to Medicare claims. We investigated mortality as a means to testing the validity of the completion measure that we created. METHODS: We studied 3193 stage III colon cancer patients whose diagnosis was recorded in 1992-1996 SEER program data linked to 1991-1998 Medicare claims and who initiated adjuvant chemotherapy after colon cancer resection. We defined a measure of adjuvant chemotherapy completion as one chemotherapy administration claim in a month. We tested the validity of the created measure and its relation to 3-year cancer mortality adjusted for demographic, clinical, and environmental variables. We explored the association of patient characteristics and treating physician characteristics with chemotherapy completion by use of multivariable logistic regression modeling. RESULTS: Of the 3193 patients, 2497 (78.2%) completed the course. Risk of cancer-related mortality was statistically significantly lower among those completing chemotherapy (relative risk = 0.79, 95% confidence interval = 0.69 to 0.89) than those with no adjuvant therapy. Patients who were female, widowed, increasingly elderly, rehospitalized, and living in certain regions were less likely to complete adjuvant chemotherapy than other patients. Race and other clinical, environmental, and physician characteristics were not associated with completion of therapy. CONCLUSIONS: Factors associated with incomplete adjuvant chemotherapy may represent physical frailty, treatment complications, and lack of social and psychological support. Interventions to mitigate these influences are a logical next step toward increasing chemotherapy completion rates.

Wyoming physicians are significant providers of safety net care.

BACKGROUND: This study describes the contributions of family and general practice physicians from Wyoming to the health care safety net. METHODS: We surveyed family and general practice physicians in Wyoming about provider demographics, practice composition, and policies for treating the underinsured or uninsured. Two-tailed chi(2) tests and limited logistic regressions were used to test for differences among characteristics of safety net providers. RESULTS: From a 50% response rate, 61% made less than the national mean family physician income (USD$130,000), and women are less likely than men to make this mean income, even when controlling for hours worked (OR, 0.09; CI, 0.009, 0.862). Close to two thirds claimed bad debt of over USD $10,000, and 29.3% noted forgiven debt of over USD $10,000. Physicians with less income than the prior year were more likely to decrease their charity care. CONCLUSIONS: Wyoming family and general practice physicians provide significant amounts of informal safety net care, which is threatened by income loss. Thoughtful public policy is needed to ensure that vulnerable rural Americans have access to care that is not tied to the financial well being of their health care providers.

Explaining black-white differences in receipt of recommended colon cancer treatment.

BACKGROUND: Black-white disparities exist in receipt of recommended medical care, including colorectal cancer treatment. This retrospective cohort study examines the degree to which health systems (e.g., physician, hospital) factors explain black-white disparities in colon cancer care. METHODS: Data from the Surveillance, Epidemiology, and End Results program; Medicare claims; the American Medical Association Masterfile; and hospital surveys were linked to examine chemotherapy receipt after stage III colon cancer resection among 5294 elderly (> or = 66 years of age) black and white Medicare-insured patients. Logistic regression analysis was used to identify factors associated with black-white differences in chemotherapy use. All statistical tests were two-sided. RESULTS: Black and white patients were equally likely to consult with a medical oncologist, but among patients who had such a consultation, black patients were less likely than white patients (59.3% versus 70.4%, difference = 10.9%, 95% confidence interval [CI] = 5.1% to 16.4%, P < .001) to receive chemotherapy. This black-white disparity was highest among patients aged 66-70 years (black patients 65.7%, white patients 86.3%, difference = 20.6%, 95% CI = 10.7% to 30.4%, P < .001) and decreased with age. The disparity among patients aged 66-70 years also remained statistically significant in the regression analysis. Overall, patient, physician, hospital, and environmental factors accounted for approximately 50% of the disparity in chemotherapy receipt among patients aged 66-70 years; surgical length of stay and neighborhood socioeconomic status accounted for approximately 27% of the disparity in this age group, and health systems factors accounted for 12%. CONCLUSIONS: Black and white Medicare-insured colon cancer patients have an equal opportunity to learn about adjuvant chemotherapy from a medical oncologist but do not receive chemotherapy equally. Little disparity was explained by health systems; more was explained by illness severity, social support, and environment. Further qualitative research is needed to understand the factors that influence the lower receipt of chemotherapy by black patients.