Melony E. S. Sorbero

Why Do Physicians Vary So Widely in Their Referral Rates

AbstractOBJECTIVE: To determine which physician practice and psychological factors contribute to observed variation in primary care physicians’ referral rates.n DESIGN: Cross-sectional questionnaire-based survey and analysis of claims database.n SETTING: A large managed care organization in the Rochester, NY, metropolitan area.n PARTICIPANTS: Internists and family physicians.n MEASUREMENTS AND MAIN RESULTS: Patient referral status (referred or not) was derived from the 1995 claims database of the managed care organization. The claims data were also used to generate a predicted risk of referral based on patient age, gender, and case mix. A physician survey completed by a sample of 182 of the physicians (66% of those eligible) included items on their practice and validated psychological scales on anxiety from uncertainty, risk aversiveness, fear of malpractice, satisfaction with practice, autonomous and controlled motivation for referrals and test ordering, and psychosocial beliefs. The relation between the risk of referral and the physician practice and psychological factors was examined using logistic regression. After adjustment for predicted risk of referral (case mix), patients were more likely to be referred if their physician was female, had more years in practice, was an internist, and used a narrower range of diagnoses (a higher Herfindahl index, also derived from the claims data). Of the psychological factors, only greater psychosocial orientation and malpractice fear was associated with greater likelihood of referral. When the physician practice factors were excluded from the analysis, risk aversion was positively associated with referral likelihood.n CONCLUSIONS: Most of the explainable variation in referral likelihood was accounted for by patient and physician practice factors like case mix, physician gender, years in practice, speciality, and the Herfindahl index. Relatively little variation was explained by any of the examined physician psychological factors.

Effect of Patient Socioeconomic Status and Body Mass Index on the Quality of Breast Cancer Adjuvant Chemotherapy

PURPOSEnThe purpose of this study was to investigate the relationship between socioeconomic status (SES) and the use of intentionally reduced doses of chemotherapy in the adjuvant treatment of breast cancer.nnnPATIENTS AND METHODSnPatients with breast cancer treated with a standard chemotherapy regimen (n = 764) were enrolled in a prospective registry after signing informed consent. Detailed information was collected on patient, disease, and treatment, including chemotherapy doses. Zip code level data on median household income, proportion of people living below the poverty level, and educational attainment were obtained from the US Census. Doses for the first cycle of chemotherapy lower than 85% of standard were considered to be reduced. Univariate analyses and multivariate logistic regression were performed to identify factors associated with the use of reduced first cycle doses.nnnRESULTSnIn univariate analysis, individual education attainment, zip code SES measures, body mass index, and geographic region were all significantly associated with receipt of intentionally reduced doses of chemotherapy. In multivariate analysis, controlling for geography, factors independently associated with reduced doses were obesity (odds ratio [OR], 2.47; 95% CI, 1.36 to 4.51), severe obesity (OR, 4.04; 95% CI, 1.46 to 11.19), and education less than high school (OR, 3.07; 95% CI, 1.57 to 5.99).nnnCONCLUSIONnSocial disparities in breast cancer outcomes may be in part the result of lower quality chemotherapy doses in the adjuvant treatment of breast cancer. Efforts to address such prescribing patterns may help reduce SES disparities in breast cancer survival.

Social and Racial Differences in Selection of Breast Cancer Adjuvant Chemotherapy Regimens

PURPOSEnBreast cancer outcomes are worse among black women and women of lower socioeconomic status. The purpose of this study was to investigate racial and social differences in selection of breast cancer adjuvant chemotherapy regimens.nnnMETHODSnDetailed information on patient, disease, and treatment factors was collected prospectively on 957 patients who were receiving breast cancer adjuvant chemotherapy in 101 oncology practices throughout the United States. Adjuvant chemotherapy regimens included in any of several published guidelines were considered standard. Receipt of nonstandard regimens was examined according to clinical and nonclinical factors. Differences between groups were assessed using chi2 tests. Multivariate logistic regression was used to identify factors associated with use of nonstandard regimens.nnnRESULTSnBlack race (P = .008), lower educational attainment (P = .003), age 70 years (P = .001), higher stage (P < .0001), insurance type (P = .048), employment status (P = .045), employment type (P = .025), and geographic location (P = .021) were associated with the use of nonstandard regimens in univariate analyses. In multivariate analysis, black race (P = .020), lower educational attainment (P = .024), age > or = 70 years (P = .032), and higher stage (P < .0001) were associated with receipt of nonstandard regimens.nnnCONCLUSIONnThe more frequent use of non-guideline-concordant adjuvant chemotherapy regimens in black women and women with lower educational attainment may contribute to less favorable outcomes in these populations. Addressing such differences in care may improve cancer outcomes in vulnerable populations.

Race and Sex Differences in the Receipt of Timely and Appropriate Lung Cancer Treatment

Background:Previous research suggests that disparities in non–small-cell lung cancer (NSCLC) survival can be explained in part by disparities in the receipt of cancer treatment. Few studies, however, have considered race and sex disparities in the timing and appropriateness of treatment across stages of diagnosis. Objective:To evaluate the relationship of sex and race with the receipt of timely and clinically appropriate NSCLC treatment for each stage of diagnosis. Method:Surveillance Epidemiology and End Result data linked to Medicare claims for beneficiaries diagnosed with NSCLC between 1995 and 1999 were used to evaluate the relationship between race and sex with timely and appropriate NSCLC treatment while controlling for other demographic characteristics, comorbidities, socioeconomic status, and provider supply (N = 22,145). Results:Overall adjusted rates of timely and appropriate treatment are 37.2%, 58.1%, and 29.2% for Medicare beneficiaries diagnosed with stage I or II, III, and IV NSCLC, respectively. Among stage I or II patients, women were 25% less likely to receive timely surgical resection relative to men, and blacks were 66% less likely to receive timely and appropriate treatment than whites. Black men were least likely to receive resection (22.2% compared with 43.7% for white men). Blacks were 34% less likely to receive timely surgery, chemotherapy, or radiation for stage III disease and were 51% less likely to receive chemotherapy in a timely fashion for stage IV disease relative to whites. Conclusion:Significant variations in appropriate timely treatment were found within and across stages of diagnosis, confirming that sex and race differences in NSCLC treatment exist.

An exploration of urban and rural differences in lung cancer survival among medicare beneficiaries.

OBJECTIVESnWe tested the relationship between urban or rural residence as defined by rural-urban commuting area codes and risk of mortality in a sample of Medicare beneficiaries with lung cancer.nnnMETHODSnWe used Surveillance, Epidemiology, and End Results data linked with Medicare claims to build proportional hazards models. The models tested hypothesized relationships between individual and community characteristics and overall survival for a cohort of Medicare beneficiaries 65 years and older who were diagnosed with lung cancer between 1995 and 1999 (N=26073).nnnRESULTSnWe found no evidence that lung cancer patients in rural areas have poorer survival than those in urban areas. Rather, individual (Medicaid coverage) and regional (lower census tract-level median income) socioeconomic factors and a smaller supply of subspecialists per 10000 individuals 65 years and older were positively associated with a higher risk of mortality.nnnCONCLUSIONSnAlthough urban versus rural residence did not directly influence survival, rural residents were more likely to live in poorer areas with a smaller supply of health care providers. Therefore, we still need to be aware of rural beneficiaries potential disadvantage when it comes to receiving needed care in a timely fashion.

Comparative Effectiveness of Ductal Carcinoma In Situ Management and the Roles of Margins and Surgeons

BACKGROUNDnThe high incidence of ductal carcinoma in situ (DCIS) and variations in its treatment motivate inquiry into the comparative effectiveness of treatment options. Few such comparative effectiveness studies of DCIS, however, have been performed with detailed information on clinical and treatment attributes.nnnMETHODSnWe collected detailed clinical, nonclinical, pathological, treatment, and long-term outcomes data from multiple medical records of 994 women who were diagnosed with DCIS from 1985 through 2000 in Monroe County (New York) and the Henry Ford Health System (Detroit, MI). We used ipsilateral disease-free survival models to characterize the role of treatments (surgery and radiation therapy) and margin status (positive, close [<2 mm], or negative [≥2 mm]) and logistic regression models to characterize the determinants of treatments and margin status, including the role of surgeons. All statistical tests were two-sided.nnnRESULTSnTreatments and margin status were statistically significant and strong predictors of long-term disease-free survival, but results varied substantially by surgeon. This variation by surgeon accounted for 15%-35% of subsequent ipsilateral 5-year recurrence rates and for 13%-30% of 10-year recurrence rates. The overall differences in predicted 5-year disease-free survival rates for mastectomy (0.993), breast-conserving surgery with radiation therapy (0.945), and breast-conserving surgery without radiation therapy (0.824) were statistically significant (P(diff) < .001 for each of the differences). Similarly, each of the differences at 10 years was statistically significant (P < .001).nnnCONCLUSIONSnOur work demonstrates the contributions of treatments and margin status to long-term ipsilateral disease-free survival and the link between surgeons and these key measures of care. Although variation by surgeon could be generated by patients preferences, the extent of variation and its contribution to long-term health outcomes are troubling. Further work is required to determine why women with positive margins receive no additional treatment and why margin status and receipt of radiation therapy vary by surgeon.

The Effect of Capitation on Switching Primary Care Physicians

OBJECTIVEnTo examine the relationship between patient case-mix, utilization, primary care physician (PCP) payment method, and the probability that patients switch their PCPs.nnnDATA SOURCES/STUDY SETTINGnAdministrative enrollment and claims/encounter data for 1994-1995 from four physician organizations.nnnSTUDY DESIGNnWe developed a conceptual model of patient switching behavior, which we used to guide the specification of multivariate logistic analyses focusing on interactions between patient case-mix, utilization, and PCP reimbursement methods.nnnDATA COLLECTION/EXTRACTION METHODSnClaims data were aggregated to the encounter level; a switch was defined as a change in PCP since the previous encounter. The PCPs were reimbursed on either a capitated or fee-for-service (FFS) basis.nnnPRINCIPAL FINDINGSnPatients with stable chronic conditions (Ambulatory Diagnostic Groups [ADG] 10) and capitated PCPs were 36 percent more likely to switch PCPs than similar patients with FFS PCPs, controlling for patient age and sex and physician fixed effects. When the number of previous encounters was included in the model this relationship was no longer significant. Instead high utilizers with capitated PCPs were significantly more likely to switch PCPs than were similar patients with FFS PCPs.nnnCONCLUSIONSnA patients demographics and utilization are associated with the probability that the patient will switch PCPs. Capitated PCP payment was associated with higher rates of switching among high utilizers of health care resources. These findings raise concerns about the continuity and quality of care experienced by vulnerable patients in an era of changing financial incentives.

Physician referral rates: style without much substance?

BACKGROUNDnPrimary care physicians (PCPs) exhibit widely varying referral rates, resulting in dramatic differences in the exposure of their patients to specialists. The relationships between this physician behavior and costs and patient outcomes are unknown.nnnOBJECTIVESnTo examine the relationships between PCP referral rates and costs, risk of avoidable hospitalization, health status, and satisfaction.nnnDESIGNnCross-sectional analyses of claims and patient survey data.nnnSETTING AND SUBJECTSnIndependent practice association (IPA)-style managed care organization in the Rochester, NY, metropolitan area. The 1995 claims data included 457 PCPs in the IPA and 217,606 adult patients assigned to their panels. Approximately 50 consecutive patients of each of a random sample of 100 PCPs completed a patient survey in 1997-1998.nnnMEASURESnFrom the claims data, total expenditures per panel member, the risk of avoidable hospitalization, and physician referral rate were measured. Measures derived from the survey included SF-12 scores, satisfaction, and physician referral rate.nnnRESULTSnThe relationship between physician referral rate and per-panel-member costs was not statistically significant after case-mix adjustment of the referral rate. There was no relationship between the case-mix-adjusted referral rate and risk of avoidable hospitalization. In the survey data, there was no adjusted relationship between the physicians referral rate and their patients self-rated physical or mental health. There was a modest direct relationship between patient satisfaction and survey-derived referral rate.nnnCONCLUSIONSnDespite stable, wide variations in PCP referral rates, there are few discemible relationships between this physician behavior and costs and patient outcomes. Efforts to constrain PCP referrals to specialists may be misguided.

The pen and the scalpel: effect of diffusion of information on nonclinical variations in surgical treatment.

Background:As information is disseminated about best practices, variations in patterns of care should diminish over time. Objective:To test the hypotheses that differences in rates of a surgical procedure are associated with type of insurance in an era of evolving practice guidelines and that insurance and site differences diminish with time as consensus guidelines disseminate among the medical community. Methods:We use lymph node dissection among women with ductal carcinoma in situ (DCIS) as an example of a procedure with uncertain benefit. Using a sample of 1051 women diagnosed from 1985 through 2000 at 2 geographic sites, we collected detailed demographic, clinical, pathologic, and treatment information through abstraction of multiple medical records. We specified multivariate logistic models with flexible functions of time and time interactions with insurance and treatment site to test hypotheses. Results:Lymph node dissection rates varied significantly according to site of treatment and insurance status after controlling for clinical, pathologic, treatment, and demographic characteristics. Rates of lymph node dissection decreased over time, and differences in lymph node dissection rates according to site and generosity of insurance were no longer significant by the end of the study period. Conclusions:We have demonstrated that rates of a discretionary surgical procedure differ according to nonclinical factors, such as treatment site and type of insurance, and that such unwarranted variation decreases over time with diminishing uncertainty and in an era of diffusion of clinical guidelines.

Structural Estimates of Treatment Effects on Outcomes Using Retrospective Data: An Application to Ductal Carcinoma In Situ

Analysis of observational cohort data is subject to bias from unobservable risk selection. The authors compared econometric models and treatment effectiveness estimates using the linked Surveillance, Epidemiology, and End Results (SEER)–Medicare claims data for women diagnosed with ductal carcinoma in situ. Treatment effectiveness estimates for mastectomy and breast-conserving surgery (BCS) with or without radiotherapy were compared using three different models: simultaneous-equations model, discrete-time survival model with unobserved heterogeneity (frailty), and proportional hazards model. Overall trends in disease-free survival (DFS), or time to first subsequent breast event, by treatment are similar regardless of the model, with mastectomy yielding the highest DFS over 8 years of follow-up, followed by BCS with radiotherapy, and then BCS alone. Absolute rates and direction of bias varied substantially by treatment strategy. DFS was underestimated by single-equation and frailty models compared with the simultaneous-equations model and randomized controlled trial results for BCS with radiotherapy and overestimated for BCS alone.