A population-based study of tumor gene expression and risk of breast cancer death among lymph node-negative patients.

Introduction: The Oncotype DX assay was recently reported to predict risk for distant recurrence among a clinical trial population of tamoxifen-treated patients with lymph node-negative, estrogen receptor (ER)-positive breast cancer. To confirm and extend these findings, we evaluated the performance of this 21-gene assay among node-negative patients from a community hospital setting.

Methods: A case-control study was conducted among 4,964 Kaiser Permanente patients diagnosed with node-negative invasive breast cancer from 1985 to 1994 and not treated with adjuvant chemotherapy.

Medication error in the care of HIV/AIDS patients: electronic surveillance, confirmation, and adverse events.

Background: Medication error occurring during the care of HIV-infected patients may lead to treatment failure, drug toxicity, or even death.

Objective: The objective of this study was to ascertain and confirm 5 categories of medication error in the care of HIV-infected patients.

Research Design: This study was a retrospective study to describe the occurrence of preventable medication error and to determine if adverse events were associated with confirmed errors.