Nonclinical factors associated with the treatment of older women with newly diagnosed low-grade ductal carcinoma in situ

BACKGROUND

Ductal carcinoma in situ (DCIS) is the most common form of noninvasive breast cancer and is associated with an excellent prognosis. As a result, there is concern about overdiagnosis and overtreatment of DCIS because most patients with DCIS are treated as though they have invasive breast cancer and undergo either breast-conserving surgery (BCS)-most commonly followed by radiation therapy (RT)-or mastectomy. Little research to date has focused on nonclinical factors influencing treatments for DCIS.

METHODS

Population-based data were analyzed from five state cancer registries (California, Florida, New Jersey, New York, and Texas) on women aged 65 years and older newly diagnosed with DCIS during the years 2003 to 2014 using a retrospective cohort design and multinominal logistic modeling. The registry records with Medicare enrollment data and fee-for-service claims to obtain treatments (BCS alone, BCS with RT, or mastectomy) were merged. Surgeon practice structure was identified through physician surveys and internet searches.

RESULTS

Patients of surgeons employed by cancer centers or health systems were less likely to receive BCS with RT or mastectomy than patients of surgeons in single specialty or multispecialty practices. There also was substantial geographic variation in treatments, with patients in New York, New Jersey, and California being less likely to receive BCS with RT or mastectomy than patients in Texas or Florida.

CONCLUSIONS

These findings suggest nonclinical factors including the culture of the practice and/or financial incentives are significantly associated with the types of treatment received for DCIS. Increasing awareness and targeted efforts to educate physicians about DCIS management among older women with low-grade DCIS could reduce patient harm and yield substantial cost savings.

Adherence to hormonal therapy after surgery among older women with ductal carcinoma in situ: Implications for breast cancer-related adverse health events

BACKGROUND

Evidence from randomized clinical trials (RCTs) shows that receipt of hormonal therapy after surgery for estrogen receptor-positive ductal carcinoma in situ (DCIS) reduces the risk of DCIS and contralateral invasive breast cancer (IBC) but not death from breast cancer. RCTs examined homogeneous samples, and therefore whether this evidence can be generalized to diverse populations is unclear.

METHODS

Population-based data from four state cancer registries (California, New Jersey, New York, and Texas) were analyzed on women aged 65 years and older newly diagnosed with DCIS who underwent surgery with or without radiation during the years 2006-2013. Registry records were merged with Medicare enrollment in Parts A and/or B and D (prescription drugs) and associated claims. Whether adherence to hormonal therapy was associated with adverse breast cancer-related health events was analyzed.

RESULTS

Achieving excellent adherence did not affect death from breast cancer. In contrast, the risk of developing a subsequent breast tumor was 6.24 percentage points (breast-conserving surgery [BCS] with radiation therapy [RT]) and 10.54 percentage points (BCS alone) lower for women with excellent versus low adherence (p < .00001). For excellent versus good adherence, the reduced risk among women who had BCS with and without RT was approximately 3 and 5 percentage points, respectively. A similar pattern emerged for the risk of IBC among women who achieved excellent versus good or low adherence, whereas good versus low adherence comparisons were not significant.

CONCLUSIONS

This analysis of a diverse population-based cohort of women with DCIS demonstrates that achieving excellent adherence to hormonal therapy is critical to minimizing the occurrence of developing subsequent breast tumors.

PLAIN LANGUAGE SUMMARY

Our analysis of a diverse population-based cohort of women with ductal carcinoma in situ demonstrates that achieving excellent adherence to hormonal therapy is critical to minimizing the occurrence of developing subsequent breast tumors.

Barriers and Strategies Used to Continue School-Based Health Services During the COVID-19 Pandemic

OBJECTIVE

To examine perceived barriers and strategies adopted to continue the delivery of school-based health services when schools reopened in Fall of 2021 during the COVID-19 pandemic and to assess whether these barriers and strategies varied by locality.

METHODS

We developed and subsequently conducted an online survey of school nurses who worked at the 1178 public elementary schools in Virginia in May 2021 to describe the impact of the COVID-19 pandemic on the delivery of school-based health services. We compared perceived barriers, strategies adopted and the effectiveness of strategies to continue the delivery of school-based health services by geographic locality (city vs. rural; suburban vs. rural and city vs. suburban).

RESULTS

More than half of schools located in cities expected nine of ten potential barriers to affect the delivery of school-based health services during Fall 2021. More than 50% of responding schools located in urban, suburban and rural area indicated that external barriers outside of their control, including insufficient funding and families not able to bring students to school, were likely to be barriers to delivering care. Strategies identified as "very effective" did not vary by locality. Across all localities, more schools reported virtual strategies were less effective than in-person strategies.

CONCLUSIONS FOR PRACTICE

Lessons from the early stages of the COVID-19 pandemic provide critical information for natural disaster and public health emergency preparedness. School locality should be considered in the development of plans to continue the delivery of school-based health services after natural disasters or during public health emergencies.

Is perinatal substance abuse falling through the cracks?

OBJECTIVES

Perinatal substance abuse (PSA) is associated with increased risk of prematurity, low birth weight, neonatal abstinence syndrome, behavioral issues and learning difficulties. It is imperative that robust care pathways are in place for these high-risk pregnancies and that staff and patient education are optimized. The present study explores the knowledge and attitudes of healthcare professionals toward PSA to identify knowledge gaps to enhance care and reduce stigma.

METHODS

This is a cross-sectional study using questionnaires to survey healthcare professionals (HCPs) working in a tertiary maternity unit (n = 172).

RESULTS

The majority of HCPs were not confident in the antenatal management (75.6%, n = 130) or postnatal management (67.5%, n = 116) of PSA. More than half of HCPs surveyed (53.5%, n = 92) did not know the referral pathway and 32% (n = 55) did not know when to make a TUSLA referral. The vast majority (96.5%, n = 166) felt that they would benefit from further training, and 94.8% (n = 163) agreed or strongly agreed that the unit would benefit from a drug liaison midwife. Among study participants, 54.1% (n = 93) agreed or strongly agreed that PSA should be considered a form of child abuse and 58.7% (n = 101) believe that the mother is responsible for damage done to her child.

CONCLUSIONS

Our study highlights the urgent need for increased training on PSA to enhance care and reduce stigma. It is imperative that staff training, drug liaison midwives and dedicated clinics are introduced to hospitals as a matter of high priority.

Can Anti-Müllerian Hormone levels predict future pregnancy outcomes in recurrent pregnancy loss?

OBJECTIVE

Serum Anti-Müllerian Hormone (AMH) levels have been shown to be lower among women who have experienced recurrent pregnancy loss (RPL) compared with the general population. However, it is unclear whether it can predict livebirth. This study aims to determine whether AMH can predict the likelihood of a livebirth in women with RPL.

STUDY DESIGN

Prospective analysis of a consecutive cohort of women undergoing investigation for RPL in a tertiary referral centre over a seven year period (August 2014 -December 2021). Analysis was performed using descriptive statistics, chi-square models and logistic regression models adjusting for maternal age and previous livebirth. Exclusion criteria for the regression analysis included abnormal parental karyotype and abnormal pelvic ultrasound scan. Pregnancy outcome was defined as livebirth or further pregnancy loss.

RESULTS

There were 488 women who underwent investigation of RPL during the study period. Of these, 65.2% (n = 318) conceived following attendance at the clinic. The majority of these women (69.4%, n = 221) proceeded to have a livebirth. There were no differences in median AMH levels between the livebirth group and the further pregnancy loss group (11 pmol/L vs 9 pmol/L respectively (p = 0.083). AMH did not affect clinical pregnancy rates (p = 0.77, 95% CI = 0.99 [0.98, 1.01]) or pregnancy outcome (p = 0.30, 95% CI = 1.01 [0.99, 1.04]). Abnormal pelvic ultrasonography (p = 0.04) and an abnormal parental karyotype (p = 0.04) were associated with an increased likelihood of a subsequent pregnancy loss.

CONCLUSION

Although AMH levels may have some utility in counselling of some couples with RPL, these contemporaneous data indicate that low AMH does not negatively influence subsequent pregnancy outcome in women with recurrent pregnancy loss.

The Influence of Practice Structure on Urologists' Treatment of Men With Low-Risk Prostate Cancer

BACKGROUND

Vertical and horizontal integration among health care providers has transformed the practice arrangements under which many physicians work.

OBJECTIVE

To examine the influence of type of practice structure, and by implication the financial incentives associated with each structure, on treatment received among men newly diagnosed with low-risk prostate cancer.

RESEARCH DESIGN

We compiled a unique database from cancer registry records from 4 large states, Medicare enrollment and claims for the years 2005-2014 and SK & A physician surveys corroborated by extensive internet searches. We estimated a multinomial logit model to examine the influence of urologist practice structure on type of initial treatment received.

RESULTS

The probability of being monitored with active surveillance was 7.4% and 4.2% points higher for men treated by health system and nonhealth system employed urologists ( P <0.01), respectively, in comparison to men treated by single specialty urology practices. Among multispecialty practices, the rate of active surveillance use was 3% points higher compared with single specialty urology practices( P <0.01). Use of intensity modulated radiation therapy among urologists with ownership in intensity modulated radiation therapy was 17.4% points higher compared with urologists working in small single specialty practices.

CONCLUSIONS

Physician practice structure attributes are significantly associated with type of treatment received but few studies control for such factors. Our findings-coupled with the observation that urologist practice structure shifted substantially over this time period due to mergers of small urology groups-provide one explanation for the limited uptake of active surveillance among men with low-risk disease in the US.

Association Between Receipt of Definitive Treatment for Localized Prostate Cancer and Adverse Health Outcomes: A Claims-Based Approach

OBJECTIVES

This study aimed to examine adverse health outcomes associated with receipt of definitive treatments (prostatectomy, intensity-modulated radiation therapy [IMRT] and brachytherapy).

METHODS

We identified men aged 65 years and older who received a new diagnosis of localized prostate cancer from 4 state cancer registries (CA, FL, NJ, and TX) during the years 2006 to 2013. We merged the registry records for this cohort with Medicare enrollment and claims. We constructed indicators of treatment-related adverse outcomes using diagnosis codes reported on the claims. Stage 1 models the choice of definitive treatment versus active surveillance. Stage 2 examines the probability of experiencing a treatment-related adverse health outcome among men who chose definitive treatment.

RESULTS

Notably, 81.4% of our cohort of 61 187 men received definitive treatment whereas 18.6% were monitored with active surveillance. The 5-year prostate cancer death rate was 0.28% to 1.75% irrespective of treatment received. Men monitored with active surveillance experienced minimal adverse health outcomes (0.16%-0.75%). The risks of urinary incontinence associated with prostatectomy were 31 and 39.5 percentage points higher than brachytherapy and IMRT, respectively. For erectile dysfunction, the risks were nearly 23 and 27.5 percentage points higher, respectively, than brachytherapy and IMRT. Prostatectomy was associated with lower risk of urinary dysfunction and bowel dysfunction than either brachytherapy or IMRT. Compared with brachytherapy, IMRT was associated with a lower risk of erectile dysfunction (32%), urinary incontinence (84%), and urinary dysfunction (30%).

CONCLUSIONS

This evidence should be of value to patient-physician decision making regarding the choice of definitive treatments versus active surveillance for men with localized disease.

School-Based Health Services in Virginia and the COVID-19 Pandemic

BACKGROUND

Schools have a long history of delivering health services, but it is unclear how the COVID-19 pandemic may have disrupted this. This study examined changes in school-based health services and student needs before and during the pandemic and the factors important for delivering school-based health services.

METHODS

A web-based survey regarding the impact of the pandemic on school-based health services was distributed via email to all 1178 Virginia public elementary schools during May 2021.

RESULTS

Responding schools (N = 767, response rate = 65%) reported providing fewer school-based health services during the 2020-2021 school year than before the pandemic, with the largest declines reported for dental screenings (51% vs 15%) and dental services (40% vs 12%). Reports show that mental health was a top concern for students increased from 15% before the pandemic to 27% (P < .001). Support from families and school staff were identified by most respondents (86% and 83%, respectively) as very important for the delivery of school-based health services.

CONCLUSIONS

Schools reported delivering fewer health services to students during the 2020-2021 school year and heightened concern about students' mental health. Understanding what schools need to deliver health services can assist state and local education and health officials and promote child health.

Vertical Integration Versus Physician Owners: Trends in Practice Structure Among Breast Cancer Surgeons

OBJECTIVE

The objective of this study was to document changes in physician practice structure among surgeons who treat women with breast cancer.

DESIGN

We merged cancer registry records from 5 large states with Medicare Part B claims to identify each surgeon who treated women with breast cancer. We added information from SK&A surveys and extensive internet searches. We analyzed changes in breast surgeons' practice structure over time.

MEASURES

We assigned each surgeon-year a practice structure type: (1) small single-specialty practice; (2) single-specialty surgery or multispecialty practice with ownership in an ambulatory surgery center (ASC); (3) physician-owned hospital; (4) multispecialty; (5) employed.

RESULTS

In 2003, nearly 74% of breast cancer surgeons belonged to small single-specialty practices. By 2014, this percentage fell to 51%. A shift to being employed (vertical integration) accounted for only a portion of this decline; between 2003 and 2014, the percentage of surgeons who were employed increased from 10% to 20%. The remainder of this decline is due to surgeons opting to acquire ownership in an ASC or a specialty hospital. Between 2003 and 2014, the percentage of surgeons with ownership in an ASC or specialty hospital increased from 4% to 17%.

CONCLUSIONS

Dramatic changes in surgeon practice structure occurred between 2003 and 2014 across the 5 states we examined. The most notable was the sharp decline in the prevalence of the small single-specialty practice and large increases in the proportion of surgeons either employed or with ownership in ACSs or hospitals.

Documenting Horizontal Integration Among Urologists Who Treat Prostate Cancer

Relatively little is known about the extent and effects of horizontal mergers among physician specialists. We developed and implemented a methodology to document changes in physician practice structure resulting from horizontal integration among urology groups. We merged cancer registry records from four large states with Medicare Part B claims to identify all urologists who treated men with prostate cancer. We added information from SK & A surveys and extensive internet searches to assign a practice structure to each urologist-year (2005-2014). Horizontal integration among small urology groups led to a sharp increase in the proportion of urologists who belong to large urology practices with ownership in intensity modulated radiation therapy and/or anatomical pathology services. By 2014, more than half of New Jersey urologists and about 43% of urologists in Florida and Texas were members of such large practices, whereas small percentages (7%-16%) were employed by a health system. In contrast, more than 27% of California urologists were employed but only 17.5% had ownership in intensity modulated radiation therapy and/or pathology services. Importantly, we found our indicators of market share of urologists associated with each practice structure type were highly concordant with indicators of market share based on number of prostate cancer episodes treated by each practice structure type.

Effect of early-stage Alzheimer's disease on household financial outcomes

Significant limitations and rapid declines in financial capacity are a hallmark of patients with early-stage Alzheimer's disease (AD). We use linked Health and Retirement Study and Medicare claims data spanning 1992-2014 to examine the effect of early-stage AD, from the start of first symptoms to diagnosis, on household financial outcomes. We estimate household fixed-effects models and examine continuous measures of liquid assets and net wealth, as well as dichotomous indicators for a large change in either outcome. We find robust evidence that early-stage AD places households at significant risk for large adverse changes in liquid assets. Further, we find some, but more limited, evidence that early-stage AD reduces net wealth. Our findings are consequential because financial vulnerability during the disease's early-stage impacts the ability of afflicted individuals and their families to pay for care in the disease's later stage. Additionally, the findings speak to the value that earlier diagnosis may provide by helping avert adverse financial outcomes that occur before the disease is currently diagnosable with available tools. These results also point to a potentially important role for financial institutions in helping reduce exposure of vulnerable elderly to poor outcomes.

First live birth after uterus transplantation in the United States

Uterus transplantation has proven to be a successful treatment for women with absolute uterine infertility, caused either by the absence of a uterus or the presence of a nonfunctioning uterus. We report the first birth of a healthy child following uterus transplantation in the United States, from a recipient of a uterus allograft procured from an altruistic living donor. Two major modifications from the previously reported live births characterized this uterus transplant. First, the transplanted uterus relied upon and sustained the pregnancy while having only the utero-ovarian vein as venous outflow. The implication is a significantly simplified living donor surgery that paves the way for minimally invasive laparoscopic or robot-assisted techniques for the donor hysterectomy. Second, the time from transplantation to embryo transfer was significantly shortened from prior protocols, allowing for an overall shorter exposure to immunosuppression by the recipient and lowering the risk for potential adverse effects from these medications.

Specialization and production cost efficiency: evidence from ambulatory surgery centers

In the U.S. health care sector, the economic logic of specialization as an organizing principle has come under active debate in recent years. An understudied case is that of ambulatory surgery centers (ASCs), which recently have become the dominant provider of specific surgical procedures. While the majority of ASCs focus on a single specialty, a growing number are diversifying to offer a wide range of surgical services. We take a multiple output cost function approach to an empirical investigation that compares production economies in single specialty ASCs with those in multispecialty ASCs. We applied generalized estimating equation techniques to a sample of Pennsylvania ASCs for the period 2004-2014, including 73 ASCs that specialized in gastrointestinal procedures and 60 ASCs that performed gastrointestinal as well as other specialty procedures. Results indicated that both types of ASC had small room for expansion. In simulation analysis, production of GI services in specialized ASCs had a cost advantage over joint production of GI with other specialty procedures. Our results provide support for the focused factory model of production in the ASC sector.

Treatments and Health Outcomes of Medicare Patients With Back Pain

Back pain treatments are costly and frequently involve use of procedures that may have minimal benefit on improving patients' functional status. Two recent studies evaluated adverse outcomes (mortality and major medical complications) following receipt of spinal surgery but neither examined whether such treatments affected functional ability. Using a sample composed of Medicare patients with persistent back pain, we examined whether functional ability improved after treatment, comparing patients treated with back surgery or spinal injections to nonrecipients. We analyzed four binary variables that measure whether the ability to perform routine tasks improved. We used instrumental variables analysis to address the nonrandom selection of treatment received due to unobservable confounding. Contrary to the observational results, the instrumental variable estimates suggest that receipt of either back surgery or spinal injections does not improve back patients' functional ability. Failure to account for selection into treatment can lead to overestimating the benefits of specific treatments.

Specialization as an Organizing Principle: The Case of Ambulatory Surgery Centers

Ambulatory surgery centers (ASCs) recently have grown to become the dominant provider of specific surgical procedures in the United States. While the majority of ASCs focus primarily on a single specialty, many have diversified to offer a wide range of surgical specialties. We exploited a unique data set from Pennsylvania for the years 2004 to 2014 to conduct an empirical investigation of the relative cost of production in ASCs over varying degrees of specialization. We found that for the majority of ASCs, focus on a specialty was associated with lower facility costs. In addition, ASCs appeared to be capturing economies of scale over a broad range of service volume. In contrast to studies of cost efficiency in specialty hospitals, our results provide evidence that supports the focused factory model of production in the ASC sector.

Living Donor Uterus Transplantation: A Single Center's Observations and Lessons Learned From Early Setbacks to Technical Success

Uterus transplantation is a vascularized composite allograft transplantation. It allows women who do not have a uterus to become pregnant and deliver a baby. In this paper, we analyze the first five cases of living donor uterus transplantation performed in the United States. The first three recipients lost their uterus grafts at days 14, 12, and 6, respectively, after transplant. Vascular complications, related to both inflow and outflow problems, were identified as the primary reason for the graft losses. Two recipients, at 6 and 3 mo, respectively, after transplant, have functioning grafts with regular menstrual cycles. Ultimate success will be claimed only after a live birth. This paper is an in-depth analysis of evaluation, surgical technique, and follow-up of these five living donor uterus transplants. The lessons learned were instrumental in allowing us to evolve from failure to technical and functional success. We aim to share our conclusions and build on knowledge in the evolving field of uterus transplantation.

Physician Self-Referral of Physical Therapy Services for Patients with Low Back Pain: Implications for Use, Types of Treatments Received and Expenditures

Prior research on treatment of low back pain has documented large increases in use of spinal surgery, MRIs and lumbosacral injections linked to physician self-referral arrangements. No recent research has examined whether physician ownership of physical therapy services results in greater use of physical therapy to treat low back pain. The objective of this study is to investigate whether physician ownership of physical therapy services affects frequency of use, visits and types of physical therapy services received by patients with low back pain. Using claims records from insured patients covered by Blue Cross Blue Shield of Texas (2008-2011) we compared several metrics of use of physical therapy services for low back pain episodes controlling for self-referral status. We identified 158,151 low back pain episodes, 27% met the criteria to be classified as "self-referral." Only 10% of "non-self-referral" episodes received physical therapy compared to 26% of self-referral episodes (p<0.001). The unadjusted and regression adjusted self-referral effect was identical - about 16 percentage point difference (p<0.001). Among patients who received some physical therapy, self-referral episodes were comprised of 2.26 fewer visits and 11 fewer physical therapy service units (p<0.001). Non-self-referring episodes included a significantly higher proportion of "active" (hands on or patient engaged) as opposed to "passive" treatments (p<0.001). The regression-adjusted difference was 30 percentage points when measured as actual counts and 29 percentage points when measured in RVUs (p<0.001). Total spending on back-related care was 35% higher for self-referred episodes compared to their non-self-referred counterparts (p<0.001). Ownership of physical therapy services influence physicians' referral to initiate a course of physical therapy to treat low back pain, but also affect the types of physical therapy services a patient receives.

Use of Physical Therapy Following Total Knee Replacement Surgery: Implications of Orthopedic Surgeons' Ownership of Physical Therapy Services

OBJECTIVE

To examine whether the course of physical therapy treatments received by patients who undergo total knee replacement (TKR) surgery differs depending on whether the orthopedic surgeon has a financial stake in physical therapy services.

DATA

Sample of Medicare beneficiaries who underwent TKR surgery during the years 2007-2009.

STUDY DESIGN

We used regression analysis to evaluate the effect of physician self-referral on the following outcomes: (1) time from discharge to first physical therapy visit; (2) episode length; (3) number of physical therapy visits per episode; (4) number of physical therapy service units per episode; and (5) number of physical therapy services per episode expressed in relative value units.

PRINCIPAL FINDINGS

TKR patients who underwent physical therapy treatment at a physician-owned clinic received on average twice as many physical therapy visits (8.3 more) than patients whose TKR surgery was performed by a orthopedic surgeon who did not self-refer physical therapy services (p < .001). Regression-adjusted results show that TKR patients treated at physician-owned clinics received almost nine fewer physical therapy service units during an episode compared with patients treated by nonself-referring providers (p < .001). In relative value units, this difference was 4 (p < .001). In contrast, episodes where the orthopedic surgeon owner does not profit from physical therapy services rendered to the patient look virtually identical to episodes where the TKR surgery was performed by a surgeon nonowner.

CONCLUSIONS

Physical therapists not involved with physician-owned clinics saw patients for fewer visits, but the composition of physical therapy services rendered during each visit included more individualized therapeutic exercises.

Factors affecting receipt of expensive cancer treatments and mortality: evidence from stem cell transplantation for leukemia and lymphoma

OBJECTIVE

To identify factors that affect whether patients diagnosed with either leukemia or lymphoma receive a stem cell transplant and secondly if receipt of stem cell transplantation is linked to improved survival.

DATA

California inpatient discharge records (2002-2003) for patients with either leukemia or lymphoma linked with vital statistics death records (2002-2005).

STUDY DESIGN

Bivariate Probit treatment effects model that accounts for both the type of treatment received and survival while controlling for nonrandom selection due to unobservable factors.

PRINCIPAL FINDINGS

Having private insurance coverage and residence in a well-educated county increased the chances a patient with either disease received HSCT. Increasing age and travel distance to the nearest transplant hospital had the opposite effect. Receipt of HSCT had a significant impact on mortality. We found the probability of death was 4.3 percentage points higher for leukemia patients who did NOT have HSCT. Receipt of HSCT reduced the chances of dying by almost 50 percent. The likelihood of death among lymphoma patients who underwent HSCT was almost 5 percentage points lower, a 70 percent reduction in the probability of death.

CONCLUSIONS

The findings raise concern about access to expensive, but highly effective cancer treatments for patients with certain hematologic malignancies.

Urologists' use of intensity-modulated radiation therapy for prostate cancer

BACKGROUND

Some urology groups have integrated intensity-modulated radiation therapy (IMRT), a radiation treatment with a high reimbursement rate, into their practice. This is permitted by the exception for in-office ancillary services in the federal prohibition against self-referral. I examined the association between ownership of IMRT services and use of IMRT to treat prostate cancer.

METHODS

Using Medicare claims from 2005 through 2010, I constructed two samples: one comprising 35 self-referring urology groups in private practice and a matched control group comprising 35 non-self-referring urology groups in private practice, and the other comprising non-self-referring urologists employed at 11 National Comprehensive Cancer Network centers matched with 11 self-referring urology groups in private practice. I compared the use of IMRT in the periods before and during ownership and used a difference-in-differences analysis to evaluate changes in IMRT use according to self-referral status.

RESULTS

The rate of IMRT use by self-referring urologists in private practice increased from 13.1 to 32.3%, an increase of 19.2 percentage points (P<0.001). Among non-self-referring urologists, the rate of IMRT use increased from 14.3 to 15.6%, an increase of 1.3 percentage points (P=0.05). The unadjusted difference-in-differences effect was 17.9 percentage points (P<0.001). The regression-adjusted increase in IMRT use associated with self-referral was 16.4 percentage points (P<0.001). The rate of IMRT use by urologists working at National Comprehensive Cancer Network centers remained stable at 8.0% but increased by 33.0 percentage points among the 11 matched self-referring urology groups. The regression-adjusted difference-in-differences effect was 29.3 percentage points (P<0.001).

CONCLUSIONS

Urologists who acquired ownership of IMRT services increased their use of IMRT substantially more than urologists who did not own such services. Allowing urologists to self-refer for IMRT may contribute to increased use of this expensive therapy. (Funded by the American Society for Radiation Oncology.).

Linkages between utilization of prostate surgical pathology services and physician self-referral

OBJECTIVE

Federal law prohibits a physician from referring Medicare patients for procedures or services to health care entities in which the physician has a financial relationship. This law has exceptions which enable physicians to self-refer under certain conditions. This study evaluates the effects of self-referral on use rates of surgical pathology services performed in conjunction with prostate biopsies and whether such changes are linked to urologist self-referral arrangements.

DATA AND SAMPLE

A targeted market area case study design was employed to identify the sample from Medicare claims data. The sample included male beneficiaries who resided in geographically dispersed counties; were continuously enrolled in Medicare fee-for-service (FFS) during 2005-2007; and who met the criteria to be a potential candidate to undergo a prostate biopsy.

OUTCOMES

Prostate biopsy procedures per 1000 male Medicare beneficiaries in each county; counts of surgical pathology specimens (jars) associated with prostate biopsy procedures per 1000 male Medicare beneficiaries in each county.

FINDINGS

Regression analysis shows the self-referral share (percentage) of total utilization was associated with significant increases in the use rate of prostate surgical pathology specimens (p<.01). The use rate of prostate surgical pathology specimens (jars) would be 41.5 units higher in a county where the self-referral share of total utilization was 50% compared to a county with no self-referral (share equals 0%).

CONCLUSIONS

The findings show that urologist self-referral of prostate surgical pathology services results in increased utilization and higher Medicare spending. The results suggest that exceptions in federal and state self-referral prohibitions need to be reevaluated.

Effect of physician ownership of specialty hospitals and ambulatory surgery centers on frequency of use of outpatient orthopedic surgery

BACKGROUND

Physician-owned specialty hospitals and ambulatory surgery centers have become commonplace in many markets throughout the United States. Little is known about whether the financial incentives linked to ownership affect frequency of outpatient surgery.

OBJECTIVE

To evaluate if financial incentives linked to physician ownership influence frequency of outpatient orthopedic surgical procedures.

DESIGN AND SETTING

We analyzed 5 years of claims data from a large private insurer in Idaho to compare frequency by orthopedic surgeon owners and nonowners of surgical procedures that could be performed in either ambulatory surgery centers or hospital outpatient surgery departments.

MAIN OUTCOME MEASURE

Frequency of use, calculated as number of patients treated with the specific diagnoses who received the surgical procedure of interest divided by the number of patients with such diagnoses treated by each physician.

RESULTS

Age- and sex-adjusted odds ratios indicate that the likelihood of having carpal tunnel repair was 54% to 129% higher for patients of surgeon owners compared with surgeon nonowners. For rotator cuff repair, the adjusted odds ratios of having surgery were 33% to 100% higher for patients treated by physician owners. The age- and sex-adjusted probability of arthroscopic surgery was 27% to 78% higher for patients of surgeon owners compared with surgeon nonowners.

CONCLUSION

The consistent finding of higher use rates by physician owners across time clearly suggests that financial incentives linked to ownership of either specialty hospitals or ambulatory surgery centers influence physicians' practice patterns.

Controlling the Escalating Use of Advanced Imaging

Since the late 1990s, the use of advanced diagnostic imaging modalities has increased by double-digit rates, outpacing the rate of increase of medical spending overall. In an attempt to assure the appropriate use of advanced imaging procedures, private insurers are increasingly contracting with radiology benefit management programs (RBMs) to reduce overall use and expenditures for radiology services. This article describes the services offered by RBMs and then presents trends in utilization of advanced imaging procedures from three health plans that adopted RBM prior authorization protocols. The implementation of prior authorization protocols by each plan was associated with declines in use of advanced imaging procedures, especially during the first year of the program. Although more rigorous empirical analysis is required in order to draw definitive conclusions, these trends suggest that RBM prior authorization initiatives may be a viable approach for addressing concerns about appropriate use of advanced imaging.

Health supervision visits among SSI-eligible children in the D.C. Medicaid program: a comparison of enrollees in fee-for-service and partially capitated managed care

Managed care plans that involve some form of capitation may have adverse effects on children with special health care needs because the financial incentives to control costs may result in under-treatment and restrict access to expensive services and specialty providers. Proponents highlight the advantages of a managed care model, including case management and coordination of services. In light of this debate, only a few state Medicaid programs have implemented a managed care option for children with special health care needs. This study evaluates the effects of plan choice (partially capitated managed care versus fee-for-service) on whether children with disabilities eligible for Supplemental Security Income (SSI) and enrolled in the District of Columbia's Medicaid program are in compliance with the guidelines for health supervision visits established by the American Academy of Pediatrics (AAP). Our findings, based on five years of claims data, show that SSI-eligible children with disabilities enrolled in a partially capitated managed care plan are significantly more likely to be in compliance with the AAP guidelines for health supervision visits compared to their fee-for-service counterparts. Moreover, we find that selection due to unobservable characteristics does not significantly bias the estimated program effects.

Receipt of preventive dental care among special-needs children enrolled in Medicaid: a crisis in need of attention

Although not widely recognized, tooth decay is the most common childhood chronic disease among children ages five to seventeen. Despite higher rates of dental caries and greater needs, low-income minority children enrolled in Medicaid are more likely to go untreated relative to their higher income counterparts. No research has examined this issue for children with special needs. We analyzed Medicaid enrollment and claims data for special-needs children enrolled in the District of Columbia Medicaid program to evaluate receipt of recommended preventive dental care. Use of preventive dental care is abysmally low and has declined over time. Enrollment in managed care rather than fee for service improves the likelihood that special-needs children receive recommended preventive dental services, whereas residing farther from the Metro is an impediment to receipt of dental care.

Utilization changes following market entry by physician-owned specialty hospitals

Physician ownership of specialty hospitals has become commonplace in recent years in several states where certificate-of-need laws do not exist. The study examines trends in utilization rates for complex and simple spinal fusion procedures performed on injured workers with back/spine disorders in two markets in Oklahoma. During the time period we examine, physician-owned spine or orthopedic specialty hospitals entered both market areas in Oklahoma. Because there were no market areas in Oklahoma without physician-owned spine or orthopedic hospitals to use as a comparison group, we also analyzed trends in utilization for these surgical procedures performed on Medicare beneficiaries. We compared utilization for these procedures in Oklahoma and three other states with a high concentration of physician-owned specialty hospitals (Kansas, South Dakota, and Arizona) to utilization rates for back surgery performed on Medicare patients who reside in the Northeast region. States in the Northeast constitute an appropriate control group because there are no physician-owned specialty hospitals in this region. Both analyses indicate that the entry of the physician-owned specialty hospitals was followed by substantial increases in the market area utilization rates for complex spinal fusion surgery. Conversely, such dramatic changes did not occur in the Northeast where physician-owned specialty hospitals do not exist. After considering but ruling out alternative explanations, the findings imply that the financial incentives linked to ownership coincided with significant changes in physicians' practice patterns.

The prevalence of physician self-referral arrangements after Stark II: evidence from advanced diagnostic imaging

Using data from a large insurer in California, we identified the self-referral status of providers who billed for advanced imaging in 2004. Nearly 33 percent of providers who submitted bills for magnetic resonance imaging (MRI) scans, 22 percent of those who submitted bills for computed tomography (CT) scans, and 17 percent of those who submitted bills for positron-emission tomography (PET) scans were classified as "self-referral." Among them, 61 percent of those who billed for MRI and 64 percent of those who billed for CT did not own the imaging equipment. Rather, they were involved in lease or payment-per-scan referral arrangements that might violate federal and state laws.

Caregivers' ratings of access: do children with special health care needs fare better under fee-for-service or partially capitated managed care?

OBJECTIVE

The objective of this study was to evaluate how enrollment in a partially capitated managed care (MC) option versus the fee-for-service (FFS) system affects caregivers' ratings of dimensions of access to services among children with special health care needs (SHCN).

SUBJECTS

The data were collected from telephone interviews during the summer and fall of 2002 with a random sample of 1088 caregivers of children with SHCN who qualified for Supplemental Security Income and therefore were enrolled the Medicaid program for children with SHCN in the District of Columbia.

RESEARCH DESIGN

We used a 2-step procedure in which we first estimated plan choice and then constructed a selectivity correction to control for the potential selection bias linked to plan choice. We estimated the second stage equations predicting caregiver's ratings of dimensions of access as a function of the selectivity correction, the plan choice dummy variable and other exogenous variables.

RESULTS

After controlling for the potential selection bias linked to plan choice and other confounding factors, we find that caregivers of children in FFS are significantly more likely than caregivers of children enrolled in the partially capitated MC plan to rate the following dimensions of access as either fair or poor: "access to specialists' care" (P < 0.01), "access to emergency room care" (P < 0.01), "convenience of the doctor's office" (P < 0.01), and "waiting time between making the appointment actual visit" (P < 0.05).

CONCLUSIONS

We attribute these differences in caregivers' ratings of dimensions of access that exist between partially capitated MC and FFS enrollees to case management and care coordination services along with higher fees paid for pediatrician's and specialists' services available under MC option.

Effects of physician-owned limited-service hospitals: evidence from Arizona

In recent years physician ownership of so-called limited-service hospitals has become commonplace in many states lacking certificate-of-need regulations. Empirical evidence documenting the effects of these facilities is sparse. This study compares practice patterns of physician-owners of limited-service cardiac hospitals and physician-nonowners who treat cardiac patients at competing full-service community hospitals. Analyses of six years of Arizona inpatient discharge data show that physician-owners treat higher volumes of profitable cardiac surgical diagnosis-related groups (DRGs), higher percentages of low-severity cases, and higher percentages of cases with generous insurance compared with physician-nonowners who treat cardiac patients in community hospitals.

Partially capitated managed care versus FFS for special needs children

Little research has examined whether Medicaid managed care plans (MCPs) that incorporate case management are effective in coordinating services for children with special health care needs (CSHCN). This study evaluates the effects of enrollment of special needs children into a partially capitated MCP (with ongoing case management) versus the fee-for-service (FFS) option on use of therapeutic services, specifically speech, occupational, and physical therapy by site of service (school versus health care sector). Results show that special needs children enrolled in the partially capitated MCP are significantly more likely to obtain occupational and physical therapy at school relative to their FFS counterparts. Moreover, children enrolled in FFS are significantly less likely to be either regular or frequent users of each type of therapy relative to children enrolled in managed care. We attribute much of these disparities in use of therapeutic services at school to the availability of case management and coordination that is an integral component of the partially capitated MCP.

Plan choice and changes in access to care over time for SSI-eligible children with disabilities

This paper analyzes how voluntary enrollment in the fee-for-service (FFS) system versus a partially capitated managed care plan affects changes in access to care over time for special needs children who receive Supplemental Security Income (SSI) due to a disability. Four indicators of access are evaluated, including specialty care, hospital care, emergency care, and access to a regular doctor. We employ the Heckman two-step estimation procedure to correct for the potential nonrandom selection bias linked to plan choice. The findings show that relative to their counterparts in the partially capitated managed care plan, SSI children enrolled in the FFS plan are significantly more likely to encounter an access problem during either of the time periods studied. Similarly, FFS enrollees are significantly more likely than partially capitated managed care participants to experience persistent access problems across three of the four dimensions of care. Possible explanations for the deterioration in access associated with FFS include the lack of case management services, lower reimbursement relative to the partially capitated managed care plan, and provider availability.

An oral carcinogenicity and toxicity study of senna (Tinnevelly senna fruits) in the rat

Senna (Tinnevelly senna fruits), a known laxative derived from plants, was administered by gavage to Sprague-Dawley (Crl:CD (SD) BR) rats once daily at dose levels of 0, 25, 100 and 300 mg/kg/day for up to 104 consecutive weeks. Based upon clinical signs related to the laxation effect of senna, the highest dose (300 mg/kg/day) was considered to be a maximum tolerated dose. Sixty animals per sex were assigned to the control and dose groups. Assessments included clinical chemistry, hematology, full histology (control and high-dose groups; in addition, low and mid dose: intestinal tract, adrenals, liver, kidneys, brain and gross lesions) and toxicokinetics. The primary treatment-related clinical observation was mucoid feces seen at 300 mg/kg/day. When compared to controls, animals administered 300 mg/kg/day had slightly reduced body weights, increased water consumption and notable changes in electrolytes in serum (increases in potassium and chloride) and urine (decreases in sodium, potassium and chloride). The changes in electrolytes are most likely physiologic adaptations to the laxative effect of senna. At necropsy, dark discoloration of the kidneys was observed in animals in all treated groups. Histological changes were seen in the kidneys of animals from all treated groups and included slight to moderate tubular basophilia and tubular pigment deposits. In addition, for all treated groups, minimal to slight hyperplasia was evident in the colon and cecum. These histological changes, together with the changes seen in the evaluation of clinical chemistry and urine parameters, have been shown to be reversible in a previous 13-week rat study of senna. No treatment-related neoplastic changes were observed in any of the examined organs. Based upon these data, it is concluded that senna is not carcinogenic even after daily administration for 2 years at dosages of up to 300 mg/kg/day in Sprague-Dawley rats.

Factors affecting plan choice and unmet need among supplemental security income eligible children with disabilities

OBJECTIVE

To evaluate factors affecting plan choice (partially capitated managed care [MC] option versus the fee-for-service [FFS] system) and unmet needs for health care services among children who qualified for supplemental security income (SSI) because of a disability.

DATA SOURCES

We conducted telephone interviews during the summer and fall of 2002 with a random sample of close to 1,088 caregivers of SSI eligible children who resided in the District of Columbia.

RESEARCH DESIGN

We employed a two-step procedure where we first estimated plan choice and then constructed a selectivity correction to control for the potential selection bias associated with plan choice. We included the selectivity correction, the dummy variable indicating plan choice and other exogenous regressors in the second stage equations predicting unmet need. The dependent variables in the second stage equations include: (1) having an unmet need for any service or equipment; (2) having an unmet need for physician or hospital services; (3) having an unmet need for medical equipment; (4) having an unmet need for prescription drugs; (5) having an unmet need for dental care.

PRINCIPAL FINDINGS

More disabled children (those with birth defects, chronic conditions, and/or more limitations in activities of daily living) were more likely to enroll in FFS. Children of caregivers with some college education were more likely to opt for FFS, whereas children from higher income households were more prone to enroll in the partially capitated MC plan. Children in FFS were 9.9 percentage points more likely than children enrolled in partially capitated MC to experience an unmet need for any type of health care services (p<.01), while FFS children were 4.5 percentage points more likely than partially capitated MC enrollees to incur a medical equipment unmet need (p<.05). FFS children were also more likely than partially capitated MC enrollees to experience unmet needs for prescription drugs and dental care, however these differences were only marginally significant.

CONCLUSIONS

We speculate that the case management services available under the MC option, low Medicaid FFS reimbursements and provider availability account for some of the differences in unmet need that exist between partially capitated MC and FFS enrollees.

Health status and access to care for children with special health care needs

BACKGROUND

About 11-14% of children with special health care needs (CSHCN) have unmet needs during a given year. Little is known about the determinants of unmet health care needs for CSHCN.

AIMS OF THE STUDY

The objective of this study was to explore the association between access to care (unmet needs) among CSHCN and their caregivers' mental health status as well as children's mental health status.

METHODS

We surveyed a random sample of 1,088 caregivers of CSHCN who resided in the District of Columbia during the summer and fall of 2002. In the survey, we collected information on children's unmet needs mental health status (PARS) and their caregivers' mental health status (CES-D). We estimated the association between mental health status determinants of unmet needs adjusting for selection bias associated with plan choice (partially capitated managed care versus FFS) with an instrumental variables probit estimation technique. We used caregivers' preferences about physicians and hospitals networks, and whether the caregiver and child had the same last name to identify the plan choice equation.

RESULTS

We found that caregivers with symptoms of depression were 26.3% more likely to report any unmet need, 67.6% more likely to report unmet hospital and physician need, 66.1% more likely to report unmet mental health care need and 38.8% more likely to report unmet need for other health care services. Caregivers of children with poor psychological adjustment were 26.3% more likely to report their child had an unmet need and 92.3% more likely to report an unmet mental health care need.

DISCUSSION

Our analyses show that children whose caregivers experience symptoms of depression are significantly more likely to encounter difficulties obtaining needed medical and mental health care services. Furthermore, the findings reported here indicate that children with poor psychological adjustment are significantly more likely to experience unmet needs for medical and mental health care services. Our study has some limitations. First, most of the children in our sample are African-American, so these findings may differ for children of other races. Second, these findings may not be applicable to CSHCN who reside in rural areas. Third, we recognize the possibility that child and caregiver mental health is potentially endogenous.

IMPLICATIONS FOR HEALTH CARE PROVISION AND USE

The mental health status of CSHCN and their caregivers are barriers to care.

IMPLICATIONS FOR HEALTH POLICIES

Policymakers should be concerned about the mental health status of children with special health care needs and their caregivers as such problems appear to be barriers to obtaining care. Therefore, to adequately address the access problems of children with special health care needs, policy must address the mental health problems of children and their caregivers. Providing mental health care for caregivers and children has the potential for improving overall access for CSHCN.

IMPLICATION FOR FURTHER RESEARCH

Future research should determine the causal relationship between mental health problems of CSHCN and their caregivers and the level unmet health care needs.

Do children receiving Supplemental Security Income who are enrolled in Medicaid fare better under a fee-for-service or comprehensive capitation model?

CONTEXT

States have been reluctant to enroll children with special health care needs (SHCN) into capitated managed care, because the financial incentives inherent in such plans may elicit undertreatment, restrict access to specific services and providers, and have adverse effects on quality. Little research has examined how children with SHCN who qualify for Supplemental Security Income (SSI) fare under managed care versus the fee-for-service (FFS) system.

OBJECTIVE

To examine how enrollment of children with SHCN with SSI into a Medicaid capitated managed care plan differs from regular FFS with respect to unmet needs and access to care in the District of Columbia.

DESIGN, SETTING, AND PARTICIPANTS

We conducted telephone interviews with a random sample of 1088 caregivers of children with SHCN who resided in the District of Columbia during the summer and fall of 2002.

MAIN OUTCOME MEASURES

1) Usual source of care; 2) unmet need for the following services during the 6-month period prior to the interview: physician/hospital, mental health, therapy services, dental care, durable medical equipment and supplies, prescription drugs, and home health services; and 3) caregivers' ratings of dimensions of access to services.

RESULTS

The percentage of FFS children who did not receive needed dental care, durable medical equipment/supplies, or prescription drugs was significantly larger than the percentage of children enrolled in the capitated managed care plan. We found no significant differences by plan type in unmet need for physician/hospital care, mental health services, home health service, or therapy services. The most problematic areas of access seem to be "wait time between making an appointment and the actual visit," "waiting time in the doctor's office," "office hours for appointments," "getting medical advice by phone," and "getting specialist's care if needed." For each of these dimensions of access, children in the FFS system experienced significantly more of such access problems, compared with children in Health Services for Children With Special Needs (HSCSN). These 4 dimensions of access cause problems for 18% to 29% of FFS parents but only 13.6% to 22.3% of caregivers with a child in HSCSN. Three other dimensions of access, "convenience of doctor's office," "getting emergency care if needed," and "getting hospital care if needed," also seemed to pose significantly more problems for caregivers with children in FFS plans, compared with those in HSCSN. These dimensions of access were only problematic for 9% to 14% of FFS caregivers and 5.9% to 7.7% of caregivers with children enrolled in HSCSN.

CONCLUSIONS

Children in the managed care option have lower levels of unmet need than children in FFS plans. Caregivers of children in FFS plans encountered more difficulties in navigating the health care system, compared with those with children in managed care. We conclude that a combination of factors that characterize the capitated managed care plan are responsible for improving access to care and mitigating the level of unmet need among children with SHCN. These include the comprehensive care plan assessment, ongoing case management, primary care providers' gatekeeping role, and higher physician reimbursement.

Spillover effects of Medicare fee reductions: evidence from ophthalmology

Relatively little research has examined physicians' supply responses to Medicare fee cuts especially whether fee reductions for specific procedures have "spillover" effects that cause physicians to increase the supply of other services they provide. In this study we investigate whether ophthalmologist changed their provision of non-cataract services to Medicare patients over the time period 1992-1994, when the Medicare Fee Schedule (MFS) resulted in a 17.4% reduction in the average fee paid for a cataract extraction. Following the McGuire-Pauly model of physician behavior (McGuire and Pauly, 1991), we estimated a supply function for non-cataract procedures that included three price variables (own-price, a Medicare cross-price and a private cross-price) and an income effect. The Medicare cross-price and income variables capture spillover effects. Consistent with the model's predictions, we found that the Medicare cross-price is significant and negative, implying that a 10% reduction in the fee for a cataract extraction will cause ophthalmologists to supply about 5% more non-cataract services. Second, the income variable is highly significant, but its impact on the supply of non-cataract services is trivial. The suggests that physicians behave more like profit maximizing firms than target income seekers. We also found that the own-price and the private cross-price variables are highly significant and have the expected positive and negative effects on the volume of non-cataract services respectively. Our results demonstrate the importance of evaluating volume responses to fee changes for the array of services the physician performs, not just the procedure whose fee has been reduced. Focusing only on the procedure whose fee has been cut will yield an incomplete picture of how fee reductions for specific procedures affect physician supply decisions.

The growth of managed care and changes in physicians' incomes, autonomy, and satisfaction, 1991-1997

Using survey data collected in 1991 and 1997 from a panel of almost 1,500 physicians, we analyzed the relationship between changes in physicians' incomes, practice autonomy, and satisfaction, and the growth of HMOs and physicians' perceived financial incentives. Both the growth of HMOs and financial incentives to reduce services were significantly related to lower income growth, reductions in practice autonomy, and decreases in satisfaction. Changes in income and autonomy were both positively and significantly related to changes in satisfaction. Controlling for changes in income and autonomy, HMO growth was no longer significantly related to changes in satisfaction. Having a perceived financial incentive to reduce services remained a negative and significant determinant of the change in career satisfaction.

Medicare breast surgery fees and treatment received by older women with localized breast cancer

OBJECTIVE

To determine whether area-level Medicare physician fees for mastectomy and breast conserving surgery were associated with treatment received by Medicare beneficiaries with localized breast cancer and to compare these results with an earlier analysis conducted using small areas (three-digit zip codes) as the unit of observation.

DATA SOURCE

Medicare claims and physician survey data for a national sample of elderly (aged 67 or older) Medicare beneficiaries with localized breast cancer treated in 1994 (unweighted n = 1,787).

STUDY DESIGN

Multinomial logistic regression analysis was used to estimate a model of treatment received as a function of Medicare fees, controlling for other area economic factors, patient demographic and clinical characteristics, physician experience, and region.

PRINCIPAL FINDINGS

In 1994, average Medicare fees (adjusted for the effects of modifiers and procedure mix) for mastectomy (MST) and breast conserving surgery (BCS) were 904 dollars and 305 dollars, respectively. Holding other fees and factors fixed, a 10 percent increase in the BCS fee increased the odds of breast conserving surgery with radiation therapy relative to mastectomy to 1.34 (p = 0.02), while a 10 percent decrease in the MST fee increased the odds of breast conserving surgery with radiation therapy to 1.86 (p < 0.01).

CONCLUSIONS

Among older women with localized breast cancer, financial incentives appear to influence the use of mastectomy and breast conserving surgery with radiation therapy. This finding is consistent with the hypothesis that physicians are responsive to financial incentives when the alternative procedures have clinically equivalent outcomes and the patient's clinical condition does not dominate the treatment choice. We also find that the fee effects derived from this analysis of individual data with more precise measurement of both diagnosis and treatment are qualitatively similar to the results of the small-area analysis. This suggests that the earlier study was not severely affected by ecological bias or other data limitations inherent in Medicare claims data.

An exploratory instrumental variable analysis of the outcomes of localized breast cancer treatments in a medicare population

This study is motivated by the potential problem of using observational data to draw inferences about treatment outcomes when experimental data are not available. We compare two statistical approaches, ordinary least-squares (OLS) and instrumental variables (IV) regression analysis, to estimate the outcomes (three-year post-treatment survival) of three treatments for early stage breast cancer in elderly women: mastectomy (MST), breast conserving surgery with radiation therapy (BCSRT), and breast conserving surgery only (BCSO). The primary data source was Medicare claims for a national random sample of 2907 women (age 67 or older) with localized breast cancer who were treated between 1992 and 1994. Contrary to randomized clinical trial (RCT) results, analysis with the observational data found highly significant differences in survival among the three treatment alternatives: 79.2% survival for BCSO, 85.3% for MST, and 93.0% for BCSRT. Using OLS to control for the effects of observable characteristics narrowed the estimated survival rate differences, which remained statistically significant. In contrast, the IV analysis estimated survival rate differences that were not significantly different from 0. However, the IV-point estimates of the treatment effects were quantitatively larger than the OLS estimates, unstable, and not significantly different from the OLS results. In addition, both sets of estimates were in the same quantitative range as the RCT results.We conclude that unadjusted observational data on health outcomes of alternative treatments for localized breast cancer should not be used for cost-effectiveness studies. Our comparisons suggest that whether one places greater confidence in the OLS or the IV results depends on at least three factors: (1) the extent of observable health information that can be used as controls in OLS estimation, (2) the outcomes of statistical tests of the validity of the instrumental variable method, and (3) the similarity of the OLS and IV estimates. In this particular analysis, the OLS estimates appear to be preferable because of the instability of the IV estimates.

Determinants of differences among radiologists in starting salaries

OBJECTIVE

We sought to ascertain the actual effect of each of a broad range of factors that plausibly might affect starting salary.

MATERIALS AND METHODS

We surveyed radiologists who completed training in 1997 and obtained 487 relevant responses. Multiple regression analysis was used to identify the independent effects of characteristics of the physician, his or her job and employment search, and market area characteristics of his or her practice locality.

RESULTS

Academic starting salaries were, other things equal, 6% below private practice. Residency-only graduates had incomes 7% below a typical fellowship income. Only a few fellowship fields garnered incomes that were significantly different from the typical income. More managed care in a locality was associated with lower income, and a higher percentage of elderly in the locality was associated with a higher income. We found no statistically significant (p < 0.05) effects of sex, job location constraints, local per capita income, local cost of living, or (generally) graduate quality as measured by the ranking of a graduate's residency program.

CONCLUSION

The determinants of income are multiple and varied, including physician characteristics, such as field of subspecialty training; job characteristics, such as academic versus private practice employment; and market area characteristics. However, the study yielded as many puzzling, negative findings, such as the lack of effect of physician quality or of even severe locational constraints, as positive, expected findings.

Lambda spectra in 11.6A GeV/c Au-Au collisions

E896 has measured Lambda production in 11.6A GeV/c Au-Au collisions over virtually the whole rapidity phase space. The midrapidity p(t) distributions have been measured for the first time at this energy and appear to indicate that the Lambda hyperons have different freeze-out conditions than protons. A comparison with the relativistic quantum molecular dynamics model shows that while there is good shape agreement at high rapidity the model predicts significantly different slopes of the m(t) spectra at midrapidity. The data, where overlap occurs, are consistent with previously reported measurements.

Medicare fees and small area variations in breast-conserving surgery among elderly women

This study used data from Medicare files, the American Hospital Association's Annual Survey of Hospitals, and the 1990 census to investigate whether Medicare fees for breast-conserving surgery (BCS) and mastectomy (MST) affected the rate of BCS across 799 3-digit ZIP code areas in 1994. The full model, which was based on the conceptual framework of the supply of and demand for different treatments, explained 51 percent of the variation in BCS rates. Medicare fees were statistically significant and had the hypothesized effects: a 10 percent higher BCS fee was associated with a 7 to 10 percent higher BCS rate, while a 10 percent higher MST fee was associated with a 2 to 3 percent lower proportion receiving BCS. Other significant economic variables were proximity to a radiation therapy hospital, a teaching hospital or a cancer center, and the percentage of elderly women with incomes below the poverty rate, which were negatively related to the BCS rate. Variations in age, race, and metropolitan populations had small or insignificant effects. The single most important was the percentage of cases with one or more comorbidities.

Ultrasonographic surveillance in red blood cell alloimmunization

OBJECTIVE

This study was undertaken to audit ultrasonographic measurements of fetal liver length and middle cerebral artery peak velocity in cases of red blood cell alloimmunization between 1986 and 1999.

STUDY DESIGN

A total of 200 fetuses at risk for anemia because of red blood cell alloimmunization underwent ultrasonographic measurement of the length of the right lobe of the liver, 45 underwent Doppler recording of middle cerebral artery peak velocity, and 119 underwent fetal blood sampling.

RESULTS

The overall survival was 188 of 200 (94%). Among 69 fetuses found to have anemia, liver length values in 64 (93%) were at the 95th percentile or greater, and the other 5 were in the upper part of the normal range. The middle cerebral artery peak velocity was > or =95th percentile in 15 of the 19 cases of anemia in which this value was measured (79%). Among those measured within 1 week of birth, all liver lengths were at least in the upper part of the normal range, with most >95th percentile, including 1 case with a cord blood hemoglobin concentration <90 g/L.

CONCLUSIONS

All fetuses with anemia identified at fetal blood sampling had enlarged livers with 93% at > or =95th percentile. The peak velocity in the middle cerebral artery was abnormal in most fetuses with anemia.

New molybdenum catalysts for alkyl olefin epoxidation. Their implications for the mechanism of oxygen atom transfer

We report here the design, synthesis, and characterization of new (dioxo)Mo(VI) epoxidation catalysts based on monoanionic tridentate ligands. Two important features distinguish these catalysts from those previously reported. First, their coordination environment remains well-defined during the epoxidation reaction. Second, the ligand design does not permit simultaneous coordination of olefin and alkyl hydroperoxide. Based on the study of these new catalysts, we conclude that direct oxygen atom transfer from coordinated alkyl peroxide to olefin remains the simplest mechanism consistent with the available data. We discuss literature discrepancies in this regard.

Differential access in the receipt of antiretroviral drugs for the treatment of AIDS and its implications for survival

BACKGROUND

Recently published research based on selected samples of patients treated at human immunodeficiency virus clinics documents that use of more intensive antiretroviral drug therapies is responsible for significant declines in morbidity and mortality in persons living with human immunodeficiency virus or acquired immunodeficiency syndrome (PLWHAs). In this study, we evaluate whether receipt of more recently developed antiretroviral therapies varies by sex and race/ethnicity in a large population-based sample of PLWHAs and whether receipt of such drugs has any impact on survival.

METHODS

Analysis of Florida Medicaid eligibility, enrollment, and claims data for PLWHAs for 1993 through 1997. Receipt of 2 nucleoside analogs (TWONUKES) and receipt of 1 protease inhibitor and a nucleoside combination (PI+NUKES) was constructed from claims data. The probability of dying was constructed from eligibility and enrollment data.

RESULTS

The probabilities of receiving TWONUKES and PI+NUKES are 0.16 and 0.09, respectively, lower for women relative to men (P<.01 for both). Blacks are more likely to receive TWONUKES than whites, whereas the reverse is true for Hispanics; this probability is almost 0.04 higher for blacks and 0.03 lower for Hispanics relative to whites (P<.01). In contrast, blacks are significantly less likely to receive PI+NUKES (P<.01). Both drug variables have large statistically significant negative effects on the probability of death. The PLWHAs who received PI+NUKES are 60% as likely to die each month (P<.01). Receipt of TWONUKES lowers the relative hazard of death by close to 66% each month (P<.01). Survival varies significantly by sex and race/ethnicity. Controlling for receipt of drug therapy and diagnosed health throughout the period, women are 56% as likely to die as men (P<.01). Hispanics are almost 14% less likely to die each month relative to whites (relative hazard, 0.87), and blacks are 20% more likely to die than whites (relative hazard, 1.21).

CONCLUSIONS

States need to investigate why women are less likely to receive antiretroviral drug therapies than men and to consider policies that might foster better access to antiretroviral therapies for women with acquired immunodeficiency syndrome because these efforts might yield even further reductions in mortality in women. Given the large reductions in mortality that accompany receipt of antiretroviral therapies, states need to foster policies that promote widespread use of new drug treatment protocols.

Physicians' responses to Medicare fee schedule reductions

BACKGROUND

Relatively little empirical research has addressed physicians' responses to fee changes under the Medicare Fee Schedule.

OBJECTIVES

We analyzed Medicare claims data for ophthalmologists and orthopedic surgeons for the years 1991 through 1994 to evaluate the relative importance of profit-maximizing and target-income theories in determining physicians' supply responses to specific Medicare fee reductions.

RESEARCH DESIGN

This study was designed to estimate the impact of fee reductions for cataract extractions and major joint repair/replacement procedures through pooled cross-section time series data.

RESULTS

The supply function for cataract extractions has both strong own-price and cross-price effects, as well as a highly significant negative income effect. Yet, the magnitude of the income effect is small; thus, the substitution effect dominates the income effect. Similarly, in the supply functions for joint procedures, the own price has the expected positive sign, implying that as the fee declines, orthopedic surgeons will perform fewer joint surgeries. However, the cross-price variable has the correct sign only if treated as exogenous, and the variables measuring the income effect have the wrong sign, although their magnitude is small.

CONCLUSIONS

These results suggest that the Medicare Fee Schedule does have the potential to influence physicians' supply decisions, but these effects may vary by specialty and service.

Measuring the effects of managed care on physicians' perceptions of their personal financial incentives

Using data from the 1997 Resurvey of Young Physicians (N = 1,549), this study examines whether several measures of physicians' contractual arrangements with health plans are associated with their perceptions of overall financial incentives to either decrease or increase the volume of services to patients. Results indicate the following factors were significantly associated with an increased likelihood of reporting an incentive to decrease services: a gatekeeper arrangement with a compensation incentive; the perception of a high risk of plan deselection for physicians with high costs; the perception that referrals received depended on the costs of care provided; communication prohibiting or discouraging the disclosure to patients of the physician's financial relationship with the health plan; receiving capitation payments from at least one plan; and employment in a health maintenance organization. Being compensated on a fee-for-service basis or receiving a salary with incentive or bonus provisions (compared to straight salary) were associated with an increased likelihood of reporting an incentive to increase services to patients. Physicians' overall methods of compensation had a relatively small impact on their perceived financial incentives compared to other statistically significant factors. Our findings suggest that physicians' self-reported, overall personal financial incentives within their practices are a valid summary measure of the heterogeneous mix of specific financial arrangements faced by most physicians.