OBJECTIVE To examine the relationship of physician versus hospital ownership of small- and medium-sized practices with spending and utilization of care. DATA SOURCE/STUDY SETTING/DATA COLLECTION Survey data for 1,045 primary care-based practices of 1-19 physicians linked to Medicare claims data for 2008 for 282,372 beneficiaries attributed to the 3,010 physicians in these practices. STUDY DESIGN We used generalized linear models to estimate the associations between practice characteristics and outcomes (emergency department visits, index admissions, readmissions, and spending). PRINCIPAL FINDINGS Beneficiaries linked to hospital-owned practices had 7.3 percent more emergency department visits and 6.4 percent higher total spending compared to beneficiaries linked to physician-owned practices. CONCLUSIONS Physician practices are increasingly being purchased by hospitals. This may result in higher total spending on care.

Background: Research on the quality and cost of care traditionally focuses on individual physicians or medical groups. Social network theory suggests that the care a patient receives also depends on the network of physicians with whom a patient's physician is connected.Objectives: The objectives of the study are: (1) identify physician networks; (2) determine whether the rate of ambulatory care-sensitive hospital admissions (ACSAs) varies across networks-even different networks at the same hospital; and (3) determine the relationship between ACSA rates and network characteristics.Research Design: We identified networks by applying network detection algorithms to Medicare 2008 claims for 987,000 beneficiaries in 5 states. We estimated a fixed-effects model to determine the relationship between networks and ACSAs and a multivariable model to determine the relationship between network characteristics and ACSAs.Results: We identified 417 networks. Mean size: 129 physicians; range, 26-963. In the fixed-effects model, ACSA rates varied significantly across networks: there was a 46% difference in rates between networks at the 25th and 75th performance percentiles. At 95% of hospitals with admissions from 2 networks, the networks had significantly different ACSA rates; the mean difference was 36% of the mean ACSA rate. Networks with a higher percentage of primary-care physicians and networks in which patients received care from a larger number of physicians had higher ACSA rates.Conclusions: Physician networks have a relationship with ACSAs that is independent of the physicians in the network. Physician networks could be an important focus for understanding variations in medical care and for intervening to improve care.

1573 Background: To determine if Obstetricians and Gynecologists in New York state would offer risk-reducing salpingectomy (RRS) at the time of benign hysterectomy with ovarian preservation or permanent sterilization. Methods: An anonymous survey was administered to Ob/Gyn physicians at the 2013 Annual American College of Obstetricians and Gynecologists district II meeting. Physicians-in-training were excluded. The survey instrument assessed provider practice to offer RRS before and after reading a brief summary of the clinical position by the Society of Gynecologic Oncology of Canada, entitled “Salpingectomy and Ovarian Cancer Prevention.” Results: Ninety physicians completed the survey. Median age was 52 years (range 30-87), and 91% practiced general Ob/Gyn. Median annual surgical volume was 10 hysterectomies (range 0-150) and 11 surgical sterilizations (range 0-100). More physicians were willing to offer RRS at the time of hysterectomy than at the time of permanent sterilization (54% vs. 14%, p < 0.05). After reading the position statement, there was a 27% increase in the number of physicians who would offer RRS at the time of benign hysterectomy (p<0.01) and 42% at the time of surgical sterilization (p=NS). On univariate analysis, physician practice to offer RRS at the time of hysterectomy was associated with previous knowledge of evidence for RRS (96% of physicians aware vs. 82% not aware, p = 0.04), surgeon age (p<0.05), and practice setting (academic > community, p<0.5). Willingness to perform RRS at time of permanent sterilization was associated with the method of sterilization (laparoscopic, 82%, hysteroscopic, 18%, postpartum tubal, 0% p < 0.07) and volume of sterilization cases per year (p<0.05). On multivariate analysis, the only factor associated with offering RRS was the number of years in practice, 1.6 (95% CI 1.01-1.53, p<0.05). Conclusions: Our data suggest that obstetricians and gynecologists would offer RRS at the time of benign hysterectomy in those women who elect ovarian conservation. The link between fallopian tube as the origin of ovarian serous cancer needs to be elaborated to potentially offer high-risk patients a method of prevention with few long-term consequences.

Nearly two-thirds of US office-based physicians work in practices of fewer than seven physicians. It is often assumed that larger practices provide better care, although there is little evidence for or against this assumption. What is the relationship between practice size--and other practice characteristics, such as ownership or use of medical home processes--and the quality of care? We conducted a national survey of 1,045 primary care-based practices with nineteen or fewer physicians to determine practice characteristics. We used Medicare data to calculate practices' rate of potentially preventable hospital admissions (ambulatory care-sensitive admissions). Compared to practices with 10-19 physicians, practices with 1-2 physicians had 33 percent fewer preventable admissions, and practices with 3-9 physicians had 27 percent fewer. Physician-owned practices had fewer preventable admissions than hospital-owned practices. In an era when health care reform appears to be driving physicians into larger organizations, it is important to measure the comparative performance of practices of all sizes, to learn more about how small practices provide patient care, and to learn more about the types of organizational structures--such as independent practice associations--that may make it possible for small practices to share resources that are useful for improving the quality of care.