Age- and sex-related incidence of surgically treated primary hyperparathyroidism.

Background: Primary hyperparathyroidism (1 degrees HPT) is reported most often in women over the age of 50. Beyond that, little is known about the epidemiology of this condition, and no studies have specifically examined the age and gender distribution of patients with 1 degrees HPT.

Methods: We analyzed patients from the Nationwide Inpatient Sample (NIS), a 20% random sample of all hospital stays from 2000-2004, and also from the University of Michigan endocrine surgery database from 1999-2005.

Hospital volume and inpatient mortality outcomes of total hip arthroplasty in the United States.

The purpose of this study was to examine the effect of hospital volume on outcomes for primary and revision total hip arthroplasty (THA). The Nationwide Inpatient Sample database was used to identify our patient set. These data include a sample of non-Medicare and Medicare patients who are unique to this study, increasing external validity compared with other studies.

Changes in the utilization of spinal fusion in the United States.

Objective: Several reports suggest that spine surgery has experienced rapid growth in the past decade. Limited data exist, however, documenting the increase in spinal fusion. The objective of this work was to quantify and characterize the contemporary practice of spinal fusion in the United States.

The effect of secondary operations on mortality following abdominal aortic aneurysm repair in the United States: 1988-2001.

Certain complications following open repair of abdominal aortic aneurysms (AAAs) require additional operations or invasive procedures. The purpose of this study was to determine the effect of secondary interventions on mortality rate following open repair of intact and ruptured AAAs in the United States. Clinical data on 98,193 patients treated from 1988 to 2001 with an International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) primary procedure code 38.

Hemiarthroplasty for femoral neck fracture in the elderly surgeon and hospital volume-related outcomes.

The elderly patient with a displaced femoral neck fracture is commonly treated via hemiarthroplasty. The objectives of this study were to: 1) determine the rates of in-hospital mortality, complications, and prolonged length of stay (LOS) in such patients; 2) elucidate the patient characteristics that predict these occurrences; and 3) investigate the influence of surgeon and hospital volumes on these outcomes. Using the Nationwide Inpatient Sample (NIS), 173,508 cases of hemiarthroplasty for femoral neck fracture were identified in patients > or =65 years of age.

Severe chronic venous insufficiency: magnitude of the problem and consequences.

The aim of this study was to characterize patients requiring hospitalization for severe chronic venous insufficiency (CVI) at the local and national levels and to analyze factors related to primary amputation. An administrative database (Nationwide Inpatient Sample, 1988-2000) and a single institution (1992-2000) were reviewed using the International Classification of Diseases, 9th ed., Clinical Modification, codes for CVI, excluding phlegmasia and concomitant peripheral vascular occlusive disease codes.

Osteomyelitis of the foot and toe in adults is a surgical disease: conservative management worsens lower extremity salvage.

Objective: To characterize the national epidemiology of adult osteomyelitis (OM) and, using a single institutions' experience, test the hypothesis that early surgical therapy as compared with antibiotics alone results in an improved chance of wound healing and limb salvage.

Background: Foot and digit OM is a very common problem for which management is variable and for which few guidelines exist.

Methods: The Nationwide Inpatient Sample (NIS) and a single institution review from 1993 to 2000 form the basis of this study, using ICD-9CM codes for lower extremity foot and digit OM.

Venous thromboembolism: regional differences in the nationwide inpatient sample, 1993 to 2000.

Venous thromboembolism (VTE) is a costly complication of hospitalization. The sequelae make it a concern for public health planners. The Nationwide Inpatient Sample (NIS) contains data for hospital discharges in the United States.

Variation in outcomes after percutaneous coronary intervention in the United States and predictors of periprocedural mortality.

The objective of this study was to characterize variation in mortality rates across hospitals performing percutaneous coronary intervention (PCI) in the United States. For this purpose, data (n = 735,022) from the Nationwide Inpatient Sample from 1996 to 2001 were analyzed. The primary outcome for the analysis was postprocedural in-hospital mortality.

Epidemiology of surgically treated abdominal aortic aneurysms in the United States, 1988 to 2000.

Abdominal aortic aneurysm (AAA) repair is a complex procedure about which little information exists regarding trends in surgical practice in the United States. This study was undertaken to define benchmark data regarding performance and outcomes of conventional AAA repair that might be used in comparisons with endovascular AAA repair data. Patients undergoing repair of intact (n = 87,728) or ruptured (n = 16,295) AAAs in the Nationwide Inpatient Sample (NIS) for 1988 to 2000 were studied.

National trends in outcomes for esophageal resection.

Background: Case-series reports from tertiary centers report improved outcomes for esophageal resection in recent years. The objective of the current study was to determine trends in short-term outcomes after esophageal resection in a representative sample of United States (US) hospitals.

Methods: Observational study of all adult patients in the Nationwide Inpatient Sample who underwent esophageal resection from 1988 to 2000 (N = 8,657).

Trends in utilization of adrenalectomy in the United States: have indications changed?

Minimally invasive approaches have dramatically reduced morbidity associated with adrenalectomy. There has been concern that an increased frequency of adrenal imaging along with the advantages of less morbidity could influence the indications for adrenalectomy. We tested the hypothesis that adrenalectomy has become more common over time and that benign diseases have been increasingly represented among procedural indications.

Diffusion of new technology in health care: the case of aorto-iliac occlusive disease.

Background: The objective of the current study was to characterize temporal trends in the treatment of aorto-iliac occlusive disease (AIOD) and the impact of the introduction of less invasive therapy on overall intervention rates.

Methods: Patients with diagnostic codes for AIOD, and procedure codes for aortofemoral bypass (AFB) or iliac artery angioplasty and stenting were selected from the Nationwide Inpatient Sample for 1996 to 2000. Utilization rates of both intervention types were determined.

National trends in the use and outcomes of hepatic resection.

Background: Hepatic resection is increasingly performed for primary and metastatic tumors. Reports from tertiary care centers show improved outcomes over time with lower operative mortality rates. The objective of this investigation was to characterize trends in the use and outcomes of hepatic resection in the US during a recent 13-year period.

Should older patients be selectively referred to high-volume centers for abdominal aortic surgery?

The objective of the current study was to determine the effect of hospital volume on outcomes of abdominal aortic surgery for patients older than and younger than 65 years. In order to perform this investigation, information on all adult patients who underwent abdominal aortic surgery in Maryland from 1994 to 1996 (N = 2,987 patients) in 45 acute care hospitals was obtained. Hospitals were designated as low (< 20/year), medium (20 to 36/year), or high (> 36/year) volume according to the annual number of procedures performed.

Effect of increasing patient age on complication rates following intact abdominal aortic aneurysm repair in the United States.

Introduction: Advanced age is generally acknowledged as a risk factor for adverse surgical outcomes, but little information exists to define the magnitude of this association from a population-based perspective. This study was undertaken to determine the relation of patient age to complications following abdominal aortic aneurysm (AAA) repair in a population-based experience.

Methods: This study was based upon data from 6397 patients with a primary diagnosis of intact AAA and a procedure code for repair of AAA from the Nationwide Inpatient Sample (NIS) in 2000.

Outcomes after cerebral aneurysm clip occlusion in the United States: the need for evidence-based hospital referral.

Object: In an age of multimodality and multidisciplinary treatment of cerebral aneurysms, patient outcomes have improved significantly. For a number of complex surgical procedures, hospitals with high case volumes yield superior outcomes. The effect of hospital volume on the mortality rate after emergency and elective cerebral aneurysm clip occlusion in a nationally representative sample of patients is unknown.

Who performs endocrine operations in the United States?

Background: Endocrine surgery is a discipline that is dedicated to high-quality care of patients with endocrine surgical disease. The relationship between its "identity" as a separate field and clinical practice patterns is not known.

Methods: The National Inpatient Sample was searched by the International Classification of Diseases-9th revision-Clinical Modification codes for parathyroidectomy, thyroidectomy, and adrenalectomy for the years 1988 through 2000.

National variation in operative mortality rates for esophageal resection and the need for quality improvement.

Hypothesis: Operative mortality rates for esophageal resection vary across hospital volume groups in a nationally representative sample of hospitals.

Design: Cross-sectional study of all adult patients in the Nationwide Inpatient Sample who underwent esophageal resection from 1995 through 1999 (N = 3023). Operative mortality was determined for hospital volume quartiles (low, <3 per year; medium, 3-5 per year; high, 6-16 per year; very high, >16 per year).

Epidemiology of surgically treated gastric cancer in the United States, 1988-2000.

The incidence of gastric cancer and the need for subsequent surgery has been decreasing in the United States. However, very few population-based studies on the magnitude of these changes are available. The objective of the present study was to characterize temporal trends in the use of gastric resection in the treatment of gastric cancer.

A national and single institutional experience in the contemporary treatment of acute lower extremity ischemia.

Objective: To determine the contemporary clinical relevance of acute lower extremity ischemia and the factors associated with amputation and in-hospital mortality.

Summary Background Data: Acute lower extremity ischemia is considered limb- and life-threatening and usually requires therapy within 24 hours. The equivalency of thrombolytic therapy and surgery for the treatment of subacute limb ischemia up to 14 days duration is accepted fact.

Payer status is related to differences in access and outcomes of abdominal aortic aneurysm repair in the United States.

Background: The hypothesis of this study was that differences exist among patients with private insurance compared with patients with Medicaid or no insurance, regarding access to the timely treatment of abdominal aortic aneurysms (AAAs) and the outcomes of AAA repair.

Methods: The study comprised 5363 patients aged less than 65 years (mean age, 59 years) with a diagnostic code for intact or ruptured AAA and a procedure code for AAA repair in the National Inpatient Sample for 1995 to 2000. Dependent variables included ruptured AAA, intact AAA, and in-hospital postoperative mortality rates.

Ruptured thoracoabdominal aortic aneurysm treatment in the United States: 1988 to 1998.

Objective: Thoracoabdominal aortic aneurysm (TAAA) rupture usually results in death. The outcome remains poor for patients who reach the operating room. The objective of this investigation was to define contemporary surgical experience with ruptured TAAA in the United States.

Hospital volume-related differences in aorto-bifemoral bypass operative mortality in the United States.

Purpose: Aorto-bifemoral bypass (AFB) is commonly performed in US hospitals. Durable long-term outcome is achieved after AFB performed to treat aortoiliac occlusive disease. However, short-term outcome for complex surgical procedures is not uniform across medical centers.