Publications

2008
Paula A Rochon, Sharon-Lise Normand, Tara Gomes, Sudeep S Gill, Geoffrey M Anderson, Magda Melo, Kathy Sykora, Lorraine Lipscombe, Chaim M Bell, and Jerry H Gurwitz. 2008. “Antipsychotic therapy and short-term serious events in older adults with dementia.” Arch Intern Med, 168, 10, Pp. 1090-6.Abstract
BACKGROUND: Antipsychotic therapy is widely used to treat behavioral problems in older adults with dementia. Cohort studies evaluating the safety of antipsychotic therapy generally focus on a single adverse event. We compared the rate of developing any serious event, a composite outcome defined as an event serious enough to lead to an acute care hospital admission or death within 30 days of initiating antipsychotic therapy, to better estimate the overall burden of short-term harm associated with these agents. METHODS: In this population-based, retrospective cohort study, we identified 20 682 matched older adults with dementia living in the community and 20 559 matched individuals living in a nursing home between April 1, 1997, and March 31, 2004. Propensity-based matching was used to balance differences between the drug exposure groups in each setting. To examine the effects of antipsychotic drug use on the composite outcome of any serious event we used a conditional logistic regression model. We also estimated adjusted odds ratios using models that included all covariates with a standard difference greater than 0.10. RESULTS: Relative to those who received no antipsychotic therapy, community-dwelling older adults newly dispensed an atypical antipsychotic therapy were 3.2 times more likely (95% confidence interval, 2.77-3.68) and those who received conventional antipsychotic therapy were 3.8 times more likely (95% confidence interval, 3.31-4.39) to develop any serious event during the 30 days of follow-up. The pattern of serious events was similar but less pronounced among older adults living in a nursing home. CONCLUSIONS: Serious events, as indicated by a hospital admission or death, are frequent following the short-term use of antipsychotic drugs in older adults with dementia. Antipsychotic drugs should be used with caution even when short-term therapy is being prescribed.
Sue M Marcus, Juned Siddique, Thomas Ten R Have, Robert D Gibbons, Elizabeth Stuart, and Sharon-Lise T Normand. 2008. “Balancing Treatment Comparisons in Longitudinal Studies.” Psychiatr Ann, 38, 12, Pp. 805-811.
Maria A Johnson, Sharon-Lise T Normand, and Harlan M Krumholz. 2008. “Cardiology patient pages. How are our hospitals measuring up?: "hospital compare": a resource for hospital quality of care.” Circulation, 118, 13, Pp. e498-500.
Justin W Timbie and Sharon-Lise T Normand. 2008. “A comparison of methods for combining quality and efficiency performance measures: profiling the value of hospital care following acute myocardial infarction.” Stat Med, 27, 9, Pp. 1351-70.Abstract
Health plans have begun to combine data on the quality and cost of medical providers in an attempt to identify and reward those that offer the greatest 'value.' The analytical methods used to combine these measures in the context of provider profiling have not been rigorously studied. We propose three methods to measure and compare the value of hospital care following acute myocardial infarction by combining a single measure of quality, in-hospital survival, and the cost of an episode of acute care. To illustrate these methods, we use administrative data for heart attack patients treated at 69 acute care hospitals in Massachusetts in fiscal year 2003. In the first method we reproduce a common approach to value profiling by modeling the two case mix-standardized outcomes independently. In the second approach, survival is regressed on patient risk factors and the average cost of care at each hospital. The third method models survival and cost for each hospital jointly and combines the outcomes on a common scale using a cost-effectiveness framework. For each method we use the resulting parameter estimates or functions of the estimates to compute posterior tail probabilities, representing the probability of being classified in the upper or lower quartile of the statewide distribution. Hospitals estimated to have the highest and lowest value according to each method are compared for consistency, and the advantages and disadvantages of each approach are discussed.
David M Shahian and Sharon-Lise T Normand. 2008. “Comparison of "risk-adjusted" hospital outcomes.” Circulation, 117, 15, Pp. 1955-63.Abstract
BACKGROUND: A frequent challenge in outcomes research is the comparison of rates from different populations. One common example with substantial health policy implications involves the determination and comparison of hospital outcomes. The concept of "risk-adjusted" outcomes is frequently misunderstood, particularly when it is used to justify the direct comparison of performance at 2 specific institutions. METHODS AND RESULTS: Data from 14 Massachusetts hospitals were analyzed for 4393 adults undergoing isolated coronary artery bypass graft surgery in 2003. Mortality estimates were adjusted using clinical data prospectively collected by hospital personnel and submitted to a data coordinating center designated by the state. The primary outcome was hospital-specific, risk-standardized, 30-day all-cause mortality after surgery. Propensity scores were used to assess the comparability of case mix (covariate balance) for each Massachusetts hospital relative to the pool of patients undergoing coronary artery bypass grafting surgery at the remaining hospitals and for selected pairwise comparisons. Using hierarchical logistic regression, we indirectly standardized the mortality rate of each hospital using its expected rate. Predictive cross-validation was used to avoid underidentification of true outlying hospitals. Overall, there was sufficient overlap between the case mix of each hospital and that of all other Massachusetts hospitals to justify comparison of individual hospital performance with that of the remaining hospitals. As expected, some pairwise hospital comparisons indicated lack of comparability. This finding illustrates the fallacy of assuming that risk adjustment per se is sufficient to permit direct side-by-side comparison of healthcare providers. In some instances, such analyses may be facilitated by the use of propensity scores to improve covariate balance between institutions and to justify such comparisons. CONCLUSIONS: Risk-adjusted outcomes, commonly the focus of public report cards, have a specific interpretation. Using indirect standardization, these outcomes reflect a provider's performance for its specific case mix relative to the expected performance of an average provider for that same case mix. Unless study design or post hoc adjustments have resulted in reasonable overlap of case-mix distributions, such risk-adjusted outcomes should not be used to directly compare one institution with another.
Justin W Timbie, Joseph P Newhouse, Meredith B Rosenthal, and Sharon-Lise T Normand. 2008. “A cost-effectiveness framework for profiling the value of hospital care.” Med Decis Making, 28, 3, Pp. 419-34.Abstract
Provider profiling and performance-based incentive programs have expanded in recent years but need a theoretical framework for measuring and comparing the "value'' of clinical care across medical providers. Cost-effectiveness analysis provides such a framework but has rarely been used outside of the treatment choice context. The authors present a profiling framework based on cost-effectiveness methods and illustrate their approach using data on in-hospital survival and the cost of care for a heart attack from a sample of Massachusetts hospitals during fiscal year 2003. They model each outcome using hierarchical models that allow performance to vary across hospitals as a function of a latent quality effect and an effect of case mix. They also estimate incremental outcomes by conditioning on each hospital's pair of random effects, using indirect standardization to estimate "expected'' outcomes, and then taking their difference. Incremental cost and effectiveness outcomes are combined using incremental net monetary benefits. Using cost-effectiveness methods to profile hospital "value'' permits the comparison of the benefit of a service relative to the cost using existing societal weights.
Joshua Breslau, Kristin N Javaras, Deborah Blacker, Jane M Murphy, and Sharon-Lise T Normand. 2008. “Differential item functioning between ethnic groups in the epidemiological assessment of depression.” J Nerv Ment Dis, 196, 4, Pp. 297-306.Abstract
A potential explanation for the finding that disadvantaged minority status is associated with a lower lifetime risk for depression is that individuals from minority ethnic groups may be less likely to endorse survey questions about depression even when they have the same level of depression. We examine this possibility using a nonparametric item response theory approach to assess differential item functioning (DIF) in a national survey of psychiatric disorders, the National Comorbidity Survey. Of 20 questions used to assess depression symptoms, we found evidence of DIF in 3 questions when comparing non-Hispanic blacks with non-Hispanic whites and in 3 questions when comparing Hispanics with non-Hispanic whites. However, removal of the questions with DIF did not alter the relative prevalence of depression between ethnic groups. Ethnic differences do exist in response to questions concerning depression, but these differences do not account for the finding of relatively low prevalence of depression among minority groups.
Sharon-Lise T Normand, Robert E Wolf, and Barbara J McNeil. 2008. “Discriminating quality of hospital care in the United States.” Med Decis Making, 28, 3, Pp. 308-22.Abstract
BACKGROUND AND OBJECTIVE: The Centers for Medicare and Medicaid Services (CMS) report quality of care for patients hospitalized with acute myocardial infarction (AMI), congestive heart failure (CHF), and community-acquired pneumonia (CAP) with the intention of rewarding superior performing hospitals. The aim of the study was to compare identification of superior hospitals for providing financial rewards using 2 different scoring systems: a latent score that weights individual clinical performance measures according to how well each discriminated hospital quality and a raw sum score (the system adopted by CMS). METHODS: This observational cohort study used 2761 acute care hospitals in the United States reporting AMI clinical performance measures, 3271 reporting CHF measures, and 3714 hospitals reporting CAP measures. For each clinical condition, the main outcome measures included the average raw sum score, the latent score estimated from an item response theory (IRT) model, and the percentage of false negative superior designations made on the basis of raw sum scores relative to latent scores. RESULTS: The average raw sum score was highest for AMI (88.8%) and lower for CHF (73.1%) and CAP (76.3%). AMI measures were equally nondiscriminating of hospital quality; hospital discharge instruction was most discriminating of CHF quality; pneumococcal vaccination was most discriminating of CAP quality. False negative rates varied 2-fold: AMI (10%), CHF (16%), and CAP (24%). CONCLUSIONS: Neither the AMI raw sum score nor latent score discriminates hospital quality due to ceiling effects. Current methods for aggregating measures result in different hospital superior designations than those based on the latent score. Organizations that financially reward hospitals on the basis of such scores need to assess predictive validity of scores and determine a minimum level of classification accuracy.
Pallav Garg, Sharon-Lise T Normand, Treacy S Silbaugh, Robert E Wolf, Katya Zelevinsky, Ann Lovett, Manu R Varma, Zheng Zhou, and Laura Mauri. 2008. “Drug-eluting or bare-metal stenting in patients with diabetes mellitus: results from the Massachusetts Data Analysis Center Registry.” Circulation, 118, 22, Pp. 2277-85, 7p following 2285.Abstract
BACKGROUND: Patients with diabetes mellitus (DM) are at high risk for restenosis, myocardial infarction, and cardiac mortality after coronary stenting, and the long-term safety of drug-eluting stents (DES) relative to bare-metal stents (BMS) in DM is uncertain. We report on a large consecutive series of patients with DM followed up for 3 years after DES and BMS from a regional contemporary US practice with mandatory reporting. METHODS AND RESULTS: All adults with DM undergoing percutaneous coronary intervention with stenting between April 1, 2003, and September 30, 2004, at all acute care nonfederal hospitals in Massachusetts were identified from a mandatory state database. According to index admission stent type, patients were classified as DES treated if all stents were drug eluting and as BMS treated if all stents were bare metal; patients treated with both types of stents were excluded from the primary analysis. Mortality rates were obtained from vital statistics records, and myocardial infarction and revascularization rates were obtained from the state database with complete 3 years of follow-up on the entire cohort. Risk-adjusted mortality, myocardial infarction, and revascularization differences (DES-BMS) were estimated with propensity-score matching based on clinical, procedural, hospital, and insurance information collected at the index admission. DM was present in 5051 patients (29% of the population) treated with DES or BMS during the study. Patients with DM were more likely to receive DES than BMS (66.1% versus 33.9%; P<0.001). The unadjusted cumulative incidence of mortality at 3 years was 14.4% in DES versus 22.2% in BMS (P<0.001). Based on propensity-score analysis of 1:1 matched DES versus BMS patients (1476 DES:1476 BMS), the risk-adjusted mortality, MI, and target vessel revascularization rates at 3 years were 17.5% versus 20.7% (risk difference, -3.2%; 95% confidence interval, -6.0 to -0.4; P=0.02), 13.8% versus 16.9% (-3.0%; 95% confidence interval, -5.6 to 0.5; P=0.02), and 18.4% versus 23.7% (-5.4%; confidence interval, -8.3 to -2.4; P<0.001), respectively. CONCLUSIONS: In a real-world diabetic patient population with mandatory reporting and follow-up, DES were associated with reduced mortality, myocardial infarction, and revascularization rates at long-term follow-up compared with BMS.
Laura Mauri, Treacy S Silbaugh, Pallav Garg, Robert E Wolf, Katya Zelevinsky, Ann Lovett, Manu R Varma, Zheng Zhou, and Sharon-Lise T Normand. 2008. “Drug-eluting or bare-metal stents for acute myocardial infarction.” N Engl J Med, 359, 13, Pp. 1330-42.Abstract
BACKGROUND: Studies comparing percutaneous coronary intervention (PCI) with drug-eluting and bare-metal coronary stents in acute myocardial infarction have been limited in size and duration. METHODS: We identified all adults undergoing PCI with stenting for acute myocardial infarction between April 1, 2003, and September 30, 2004, at any acute care, nonfederal hospital in Massachusetts with the use of a state-mandated database of PCI procedures. We performed propensity-score matching on three groups of patients: all patients with acute myocardial infarction, all those with acute myocardial infarction with ST-segment elevation, and all those with acute myocardial infarction without ST-segment elevation. Propensity-score analyses were based on clinical, procedural, hospital, and insurance information collected at the time of the index procedure. Differences in the risk of death between patients receiving drug-eluting stents and those receiving bare-metal stents were determined from vital-statistics records. RESULTS: A total of 7217 patients were treated for acute myocardial infarction (4016 with drug-eluting stents and 3201 with bare-metal stents). According to analysis of matched pairs, the 2-year, risk-adjusted mortality rates were lower for drug-eluting stents than for bare-metal stents among all patients with myocardial infarction (10.7% vs. 12.8%, P=0.02), among patients with myocardial infarction with ST-segment elevation (8.5% vs. 11.6%, P=0.008), and among patients with myocardial infarction without ST-segment elevation (12.8% vs. 15.6%, P=0.04). The 2-year, risk-adjusted rates of recurrent myocardial infarction were reduced in patients with myocardial infarction without ST-segment elevation who were treated with drug-eluting stents, and repeat revascularization rates were significantly reduced with the use of drug-eluting stents as compared with bare-metal stents in all groups. CONCLUSIONS: In patients presenting with acute myocardial infarction, treatment with drug-eluting stents is associated with decreased 2-year mortality rates and a reduction in the need for repeat revascularization procedures as compared with treatment with bare-metal stents.
Margarita Alegría, Antonio Polo, Shan Gao, Luz Santana, Dan Rothstein, Aida Jimenez, Mary Lyons Hunter, Frances Mendieta, Vanessa Oddo, and Sharon-Lise Normand. 2008. “Evaluation of a patient activation and empowerment intervention in mental health care.” Med Care, 46, 3, Pp. 247-56.Abstract
BACKGROUND: Evidence suggests that minority populations have lower levels of attendance and retention in mental health care than non-Latino whites. Patient activation and empowerment interventions may be effective in increasing minority patients' attendance and retention. OBJECTIVES: This study developed and evaluated a patient self-reported activation and empowerment strategy in mental health care. RESEARCH DESIGN: The Right Question Project-Mental Health (RQP-MH) trainings consisted of 3 individual sessions using a pre/post test comparison group design with patients from 2 community mental health clinics. The RQP-MH intervention taught participants to identify questions that would help them consider their role, process and reasons behind a decision; and empowerment strategies to better manage their care. SUBJECTS: A total of 231 participated, completing at least the pretest interview (n = 141 intervention site, 90 comparison site). MEASURES: Four main outcomes were linked to the intervention: changes in self-reported patient activation; changes in self-reported patient empowerment; treatment attendance; and retention in treatment. RESULTS: Findings show that intervention participants were over twice as likely to be retained in treatment and over 3 times more likely than comparison participants to have scheduled at least 1 visit during the 6-month follow-up period. Similarly, intervention participants demonstrated 29% more attendance to scheduled visits than comparison patients. There was no evidence of an effect on self-reported patient empowerment, only on self-reported patient activation. CONCLUSIONS: Results demonstrate the intervention's potential to increase self-reported patient activation, retention, and attendance in mental health care for minority populations. By facilitating patient-provider communication, the RQP-MH intervention may help minorities effectively participate in mental health care.
Thomas W Concannon, David M Kent, Sharon-Lise Normand, Joseph P Newhouse, John L Griffith, Robin Ruthazer, Joni R Beshansky, John B Wong, Thomas Aversano, and Harry P Selker. 2008. “A geospatial analysis of emergency transport and inter-hospital transfer in ST-segment elevation myocardial infarction.” Am J Cardiol, 101, 1, Pp. 69-74.Abstract
Primary percutaneous coronary intervention (PCI) yields better outcomes than thrombolytic therapy in the treatment of patients with ST-segment elevation myocardial infarctions (STEMIs). Emergency medical service systems are potentially important partners in efforts to expand the use of PCI. This study was conducted to explore the probable impact on patient mortality and hospital volumes of competing strategies for the emergency transport of patients with STEMIs. Emergency transport was simulated for 2,000 patients with STEMIs from the Atlantic Cardiovascular Patient Outcomes Research Team (C-PORT) trial in a geospatial model of Dallas County, Texas. Patient mortality estimates were obtained from a recently developed predictive model comparing PCI and thrombolytic therapy. A strategy of transporting patients to the closest hospital and treating with PCI if available and thrombolytic therapy if not yielded a 5.2% 30-day mortality rate (95% confidence interval [CI] 4.2% to 6.3%). A strategy of universal PCI, in which patients were transported only to PCI-capable hospitals, yielded 4.4% (95% CI 3.6% to 5.4%) mortality and an increase in patient volume at 2 full-time PCI hospitals of >1,000%. A strategy of targeted PCI, in which high-benefit patients were transported or transferred to PCI-capable hospitals, yielded 4.5% (95% CI 3.8% to 5.5%) mortality if transfers were decided in the emergency department and 4.2% (95% CI 3.4% to 5.1%) if transport was decided in the emergency vehicle. Targeted PCI strategies increased patient volumes at full-time PCI hospitals by about 700%. In conclusion, the selection of high-benefit patients for transport or transfer to PCI-capable hospitals can reduce mortality while minimizing major shifts in hospital patient volumes.
Joseph S Ross, Sharon-Lise T Normand, Yun Wang, Brahmajee K Nallamothu, Judith H Lichtman, and Harlan M Krumholz. 2008. “Hospital remoteness and thirty-day mortality from three serious conditions.” Health Aff (Millwood), 27, 6, Pp. 1707-17.Abstract
Rural U.S. communities face major challenges in ensuring the availability of high-quality health care. We examined whether hospital-specific, all-cause, thirty-day risk-standardized mortality rates (RSMRs) following acute myocardial infarction, heart failure, and pneumonia varied by hospitals' geographic remoteness. We analyzed 2001-2003 Medicare administrative data, comparing RSMRs among hospitals located in urban, large rural, small rural, or remote small rural regions. We found only small mortality differences across remoteness regions for hospitalizations for the three conditions. We examine the implications of these findings for the millions of Americans who rely upon rural hospitals for their care.
Margarita Alegría, Ora Nakash, Sheri Lapatin, Vanessa Oddo, Shan Gao, Julia Lin, and Sharon-Lise Normand. 2008. “How missing information in diagnosis can lead to disparities in the clinical encounter.” J Public Health Manag Pract, 14 Suppl, Pp. S26-35.Abstract
Previous studies have documented diagnostic bias and noted that its reduction could eliminate misdiagnosis and improve mental health service delivery. Few studies have investigated clinicians' methods of obtaining and using information during the initial clinical encounter. We describe a study examining contributions to clinician bias during diagnostic assessment of ethnic/racial minority patients. A total of 129 mental health intakes were videotaped, involving 47 mental health clinicians from 8 primarily safety-net clinics. Videos were coded by another clinician using an information checklist, blind to the diagnoses provided by the original clinician. We found high levels of concordance between clinicians for substance-related disorders, low levels for depressive disorders, and anxiety disorders except panic. Most clinicians rely on patients' mention of depression, anxiety, or substance use to identify disorders, without assessing specific criteria. With limited diagnostic information, clinicians can optimize the clinical intake time to establish rapport with patients. We found Latino ethnicity to be a modifying factor of the association between symptom reports and likelihood of a depression diagnosis. Differential discussion of symptom areas, depending on patient ethnicity, may lead to differential diagnosis and increased likelihood of diagnostic bias.
Thomas R Ten Have, Sharon-Lise T Normand, Sue M Marcus, Hendricks C Brown, Philip Lavori, and Naihua Duan. 2008. “Intent-to-Treat vs. Non-Intent-to-Treat Analyses under Treatment Non-Adherence in Mental Health Randomized Trials.” Psychiatr Ann, 38, 12, Pp. 772-783.
Laura Mauri, Treacy S Silbaugh, Robert E Wolf, Katya Zelevinsky, Ann Lovett, Zheng Zhou, Frederic S Resnic, and Sharon-Lise T Normand. 2008. “Long-term clinical outcomes after drug-eluting and bare-metal stenting in Massachusetts.” Circulation, 118, 18, Pp. 1817-27.Abstract
BACKGROUND: Drug-eluting stents (DES) reduce the need for repeat revascularization, but their long-term safety relative to that of bare-metal stents (BMS) in general use remains uncertain. We sought to compare the clinical outcome of patients treated with DES with that of BMS. METHODS AND RESULTS: All adults undergoing percutaneous coronary intervention with stenting between April 1, 2003, and September 30, 2004, at non-US government hospitals in Massachusetts were identified from a mandatory state database. Patients were classified from the index admission according to stent types used. Clinical and procedural risk factors were collected prospectively. Risk-adjusted mortality, myocardial infarction, and revascularization rate differences (DES-BMS) were estimated through propensity score matching without replacement. A total of 11 556 patients were treated with DES, and 6237 were treated with BMS, with unadjusted 2-year mortality rates of 7.0% and 12.6%, respectively (P<0.0001). In 5549 DES patients matched to 5549 BMS patients, 2-year risk-adjusted mortality rates were 9.8% and 12.0%, respectively (P=0.0002), whereas the respective rates for myocardial infarction and target-vessel revascularization were 8.3% versus 10.3% (P=0.0005) and 11.0% versus 16.8% (P<0.0001). CONCLUSIONS: DES treatment was associated with lower rates of mortality, myocardial infarction, and target-vessel revascularization than BMS treatment in similar patients in a matched population-based study. Comprehensive follow-up in this inclusive population is warranted to identify whether similar safety and efficacy remain beyond 2 years.
David M Shahian and Sharon-Lise T Normand. 2008. “Low-volume coronary artery bypass surgery: measuring and optimizing performance.” J Thorac Cardiovasc Surg, 135, 6, Pp. 1202-9.
Jacob Glazer, Thomas McGuire, and Sharon-Lise T Normand. 2008. “Mitigating the Problem of Unmeasured Outcomes in Quality Reports.” B E J Econom Anal Policy, 8, 2, Pp. 7.Abstract
Quality reports or profiles of health care providers are inevitably based on only a measurable subset of the "outputs" of the organization. Hospitals, for example, are being profiled on their mortality in the cardiac area but not in some other areas where mortality does not seem to be the appropriate measure of quality. If inputs used for outputs included in the profile also affect outputs outside the scope of the profile, it can be taken into account in constructing a profile of the measured outputs. This paper presents a theory for how such a commonality in production should be taken into account in designing a profile for a hospital or other health care provider. We distinguish between "conventional" weights in a quality profile, and "optimal" weights that take into account a commonality in the production process. The basic idea is to increase the weights on discharges for which output is measured that use inputs that are important to other discharges whose outputs are not included in the profile.
Jersey Chen and Sharon-Lise T Normand. 2008. “Myocardial infarction and quality of care.” CMAJ, 179, 9, Pp. 875-6.
Bruce E Landon and Sharon-Lise T Normand. 2008. “Performance measurement in the small office practice: challenges and potential solutions.” Ann Intern Med, 148, 5, Pp. 353-7.Abstract
Great strides have been made in the creation of programs aimed at improving the safety and quality of health care in the United States, including measurement systems and corresponding standards in the ambulatory setting that are used for public reporting or pay-for-performance. The diversity of physician practices in the United States makes measurement challenging. In many parts of the country, substantial proportions of both primary care and specialist physicians continue to practice in solo or small group practices. This article reviews the practice landscape in the United States; describes performance measurement challenges in small practice settings, including financial and staffing implications; discusses statistical issues that affect assessment of practice quality; and describes potential solutions to the issues raised. Challenges of performance measurement in small practice settings include lack of infrastructure and health information technology, lack of support staff, and increased burden. These issues are compounded by the difficulty of assessing a smaller number of patients spread over multiple payers. To overcome some of these challenges, design and measure selection recommendations for the performance assessment system are presented and practice-level and health plan-level interventions are suggested that might facilitate the inclusion of small practice settings in performance assessment programs. Because a high proportion of U.S. physicians practice in small settings, programs and policies based on physician performance measurement should incorporate features that facilitate the inclusion of these physicians.

Pages