Minimizing variability of cascade impaction measurements in inhalers and nebulizers.

The purpose of this article is to catalogue in a systematic way the available information about factors that may influence the outcome and variability of cascade impactor (CI) measurements of pharmaceutical aerosols for inhalation, such as those obtained from metered dose inhalers (MDIs), dry powder inhalers (DPIs) or products for nebulization; and to suggest ways to minimize the influence of such factors. To accomplish this task, the authors constructed a cause-and-effect Ishikawa diagram for a CI measurement and considered the influence of each root cause based on industry experience and thorough literature review. The results illustrate the intricate network of underlying causes of CI variability, with the potential for several multi-way statistical interactions.

Racial and ethnic differences in breast cancer survival: how much is explained by screening, tumor severity, biology, treatment, comorbidities, and demographics?

Background: The reasons for race/ethnicity (R/E) differences in breast cancer survival have been difficult to disentangle.

Methods: Surveillance, Epidemiology, and End Results (SEER)-Medicare data were used to identify 41,020 women aged > or =68 years with incident breast cancer between 1994-1999 including African American (2479), Hispanic (1172), Asian/Pacific Island (1086), and white women (35,878). A Cox proportional hazards model assessed overall and stage-specific (0/I, II/III, and IV) R/E differences in breast cancer survival after adjusting for mammography screening, tumor characteristics at diagnosis, biologic markers, treatment, comorbidity, and demographics.

Can Medicare billing claims data be used to assess mammography utilization among women ages 65 and older?

Background: Medicare data may be a useful source for determining the utilization of mammography among elderly women, but the accuracy of these data has not been established.

Objective: We determined whether Medicare physician billing claims are an accurate reflection of mammography utilization among women ages 65 and older and whether they can be used to assess the use of screening as compared with diagnostic mammography.

Data Sources: Mammography use was assessed using Medicare billing claims and radiology reports from 2 mammography registries; the San Francisco Mammography Registry and the New Mexico Mammography Registry.

Differences in the quality of breast cancer care among vulnerable populations.

Background: It is unknown whether differences in the quality of breast cancer care among women from racial and ethnic minority groups, the elderly, and rural areas have changed over time across the continuum of care.

Methods: The linked Surveillance, Epidemiology, and End Results-Medicare database identified 22,701 women ages 66-79 years diagnosed with early stage breast cancer from 1992-1999. Multiple breast cancer processes of care were measured, including breast-conserving surgery, radiation therapy, documentation of estrogen receptor status, surveillance mammography, and a combined measure of "adequate care".

Physician predictors of mammographic accuracy.

Background: The association between physician experience and the accuracy of screening mammography in community practice is not well studied. We identified characteristics of U.S.