Correlation between Patient Outcomes, Care by New Interns and Residents

Newswise — Concern for patient safety, among other reasons, recently prompted sweeping changes in resident work policies in the United States. Recent studies have shown trends toward centralization of complex neurosurgical care at high-volume centers, which are often academic centers, and an increasing proportion of pediatric brain tumor surgeries being performed at teaching hospitals. Some have speculated that the annual arrival of new interns and residents at teaching hospitals in July might cause a transient increase of poor patient outcomes and inefficient care.

Several studies of care at academic hospitals have sought to demonstrate the so-called "July phenomenon," usually concluding that available quality of care standards remain uniform throughout the academic year. No such studies have specifically addressed neurosurgical care. In the study "Is there a 'July effect' in Pediatric Neurosurgery at Teaching Hospitals?", a population-based national administrative database was utilized to study measures of quality and efficiency of pediatric neurosurgical care at academic hospitals throughout the year. The results of this study will be presented by Edward R. Smith, MD from 4:00 to 4:15 p.m. on Monday, April 18, 2005, during the 73rd Annual Meeting of the American Association of Neurological Surgeons in New Orleans. Co-authors of the study are Frederick G. Barker II, MD and William E. Butler, MD.

In this study, neurosurgeons examined craniotomy for tumor and cerebrospinal shunt operations performed in United States teaching hospitals between 1988 and 2000, assessing mortality rate, discharge disposition, neurological complications, transfusion rate, and length of stay and hospital charges.

The data source for this study were the Nationwide Inpatient Sample (NIS) hospital discharge database for the years 1988 to 2000, which was obtained from the Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality (AHRQ), Rockville, Md. The NIS is a hospital discharge database that represents approximately 20 percent of all inpatient admissions to nonfederal hospitals in the United States. For these years, the NIS contains discharge data on 100 percent of discharges from a stratified random sample of nonfederal hospitals in eight to 28 states, which produces a representative 20 percent subsample of all United States nonfederal hospital discharges.

Pediatric craniotomy for tumor and cerebrospinal shunting operations were used with the same patient cohorts from previous studies employing the NIS database. An admission for craniotomy for resection of pediatric brain tumor was defined as hospital admission of a patient age 18 or younger with primary diagnosis of a malignant brain neoplasm, benign brain neoplasm, brain neoplasm of uncertain behavior, or brain neoplasm, not otherwise specified; and primary procedure of lobectomy or excision/destruction of brain tissue or lesion.

For shunt surgeries, neonates were excluded because poor outcomes in such patients might reflect complex comorbidities rather than fairly representing the results of neurosurgical care. Thus, hospital admissions were identified for which patients age 90 days to 18 years underwent a principal procedure of ventricular shunt to abdominal cavity and organs, replacement of ventricular shunt excluding distal revision, or incision of peritoneum. Only patients with a primary or secondary diagnosis indicating either hydrocephalus or mechanical malfunction or infection of a nervous system device or implant were included.

In-hospital mortality was coded directly in the NIS database and analyzed using logistic regression. Discharge disposition was coded on a 4-level scale (death, discharge to a long-term facility, discharge to other facilities, or discharge directly home) and was analyzed using ordinal logistic regression. Postoperative neurological complications were identified by ICD-9-CM codes and included infarction or hemorrhage and transfusion of packed red blood cells.

Efficiency of care endpoints of length of stay (LOS) and total hospital charges were coded in NIS data and were analyzed only for patients discharged from the hospital alive. LOS and hospital charge data were highly positively skewed and were analyzed as logarithmic transforms. To correct for possible clustering of similar outcomes within hospitals, which could falsely inflate estimates of the statistical significance of regression coefficients, standard errors were calculated using a Huber-White sandwich variance-covariance matrix that was estimated from the data, with adjustment for clustering by hospital.

The results of this study examined a patient pool of 3,272 craniotomies for tumor surgery performed from 1988 to 2000, and 5,500 shunt placements or revisions performed from 1998 to 2000. "We found that there were no significant increases, or decreases, in any adverse endpoint for either tumor or shunt operations performed during July or August," said Dr. Smith.

"Although moderate increases in some adverse endpoints could not be excluded, there was no evidence for more frequent adverse patient outcome or inefficient care in July and August for pediatric brain tumor or shunt surgery at teaching hospitals in the United States," concluded Dr. Smith.

Founded in 1931 as the Harvey Cushing Society, the American Association of Neurological Surgeons (AANS) is a scientific and educational association with more than 6,800 members worldwide. The AANS is dedicated to advancing the specialty of neurological surgery in order to provide the highest quality of neurosurgical care to the public. All active members of the AANS are certified by the American Board of Neurological Surgery, the Royal College of Physicians and Surgeons (Neurosurgery) of Canada or the Mexican Council of Neurological Surgery, AC. Neurological surgery is the medical specialty concerned with the prevention, diagnosis, treatment and rehabilitation of disorders that affect the entire nervous system, including the spinal column, spinal cord, brain and peripheral nerves.