Biomedical subjects
Cynthia D Brown
Publications and source records attributed to Cynthia D Brown.
Host to an intruder.
Explore the source record for details and available documents.
Lung volume reduction surgery.
Lung volume reduction surgery (LVRS) has been widely studied and has been available for the treatment of advanced emphysema for 10 years. This paper reviews some of the historical attempts at surgical treatment of emphysema, the physiology of LVRS, and the modern data on patient selection, risks, and benefits. Data from the National Emphysema Treatment Trial are presented in the context of the large body of case series and smaller randomized trials that have preceded that study. Future technologies of bronchoscopic lung volume reduction are also discussed.
Minimal clinically important differences in the six-minute walk test and the incremental shuttle walking test.
Simple walking tests are widely used for the assessment of functional status in patients with cardiorespiratory disorders. These tests require far less instrumentation than formal cardiopulmonary exercise tests, but they do require standardization of procedures to achieve reproducible results. The most widely used tests for patients with COPD are the 6-minute walking test (6MWT) and the incremental shuttle walking test (SWT). The 6MWT has been characterized in COPD patients with respect to reproducibility and responsivity to change in health status. The 6MWT results are correlated with pulmonary function, health-related quality of life, maximum exercise capacity, and mortality. The minimal clinically important difference (MCID) for the 6MWT is conservatively estimated to be 54-80 meters using both distributional and discriminative methods. For an individual patient, the 6MWT would need to change by about 86 meters to be statistically confident that there has been a change. The SWT has been less extensively validated than the 6MWT, but has similar reproducibility in COPD (CV = approximately 20%). The SWT results improve with pulmonary rehabilitation and bronchodilation, and are highly correlated with maximum oxygen consumption. There are no studies that address the issue of MCID for the SWT. In addition to the MCID, the design and interpretation of COPD clinical trials should take into account the severity of initial impairment, the asymmetry between positive and negative changes, the proportion of patients who show substantial improvement, and the costs and risks of the treatment.
Health-related quality of life of persons with sarcoidosis.
STUDY OBJECTIVES: To describe the health-related quality of life (HRQL) and mental health of persons with sarcoidosis, as well as to assess physician-patient agreement about the presence of sarcoidosis symptoms. DESIGN AND SETTING: Cross-sectional study at three university medical center outpatient pulmonary clinics. PATIENTS: One hundred eleven outpatients with sarcoidosis seen between March and July 2002. MEASUREMENTS: The HRQL of sarcoidosis patients was measured using generic and respiratory disease-specific forms (ie, Medical Outcomes Study 36-item short form survey [SF-36] and the St. George respiratory questionnaire [SGRQ], respectively). Depression was assessed using the Center for Epidemiologic Studies depression scale, and stress was assessed with the perceived stress scale four-item questionnaire. The kappa-statistic was calculated to compare physician-patient agreement in assessing sarcoidosis-related symptoms. RESULTS: Patients had moderate-to-severe reductions across all measured domains in perceived HRQL. Those patients who were prescribed oral corticosteroids had lower scores on both the SF-36 and the SGRQ than did those patients who were not. These differences were statistically significant and clinically important. The prevalence of depression was 66%, and that of significant stress was 55%. Spirometry values (FEV(1), 82% predicted; FVC, 86% predicted) were associated neither with HRQL nor with patients' perceived sarcoidosis symptoms, although they were correlated (r = 0.43; p < 0.0001) with physicians' perceptions that patients were symptomatic. Physicians and patients had only fair agreement (kappa-statistic range, 0.24 to 0.36 [by center]) in assessing perceived sarcoidosis symptoms. CONCLUSIONS: Outpatients with sarcoidosis had global reductions in measured HRQL and mental health indexes, although patients receiving therapy with oral corticosteroids had significantly worse HRQL. Experienced physicians based their assessments of patients' sarcoidosis symptoms on measures that were not related to issues of importance to patients. HRQL measurement may provide a unique insight into the impact that sarcoidosis may have on a patient's life that is not captured in traditional physiologic measures.
The Sarcoidosis Health Questionnaire: a new measure of health-related quality of life.
The Sarcoidosis Health Questionnaire (SHQ) is a health-related quality-of-life (HRQL) instrument we designed in a two-part study to allow patients to describe their satisfaction with life as it is affected by sarcoidosis. In the Development Study, we created the SHQ from a 151-item pool generated from interviews with 107 patients, a search of the relevant literature, and discussion with sarcoidosis experts. Using clinical impact methodology and the questionnaire responses of a separate group of 149 patients, we reduced the total number of items to 29. The final SHQ has three domains: Daily Functioning, Physical Functioning, and Emotional Functioning. In the Validation Study, performed with a different group of 111 patients, we found that the SHQ had good internal consistency reliability, as well as evidence of content, criterion, and construct validity based on its comparison with other measures of HRQL (Medical Outcomes Study 36-Item short form and the St. George's Respiratory Questionnaire) and of mental health (the Center for Epidemiologic Study-Depression Scale), as well as with clinical variables including spirometry. The SHQ alone was sensitive to differences in HRQL based on the number of involved organ systems. In conclusion, we have developed a self-completed HRQL questionnaire for U.S. patients with sarcoidosis.