Using Radiological Data to Estimate Ischemic Stroke Severity.

BACKGROUND: Risk-adjusted poststroke mortality has been proposed for use as a measure of stroke care quality. Although valid measures of stroke severity (e.g., the National Institutes of Health Stroke Scale [NIHSS]) are not typically available in administrative datasets, radiology reports are often available within electronic health records. We sought to examine whether admission head computed tomography data could be used to estimate stroke severity. MATERIALS AND METHODS: Using chart review data from a cohort of acute ischemic stroke patients (1998-2003), we developed a radiographic measure ([BIS]) of stroke severity in a two-third development set and assessed in a one-third validation set. The retrospective NIHSS was dichotomized as mild/moderate (<10) and severe (≥10). We compared the association of this radiographic score with NIHSS and in-hospital mortality at the patient level. RESULTS: Among 1348 stroke patients, 86.5% had abnormal findings on initial head computed tomography. The c-statistic for the BIS for modeling severe stroke (development, .581; validation, .579) and in-hospital mortality (development, .623; validation, .678) were generated. CONCLUSIONS: Although the c-statistics were only moderate, the BIS provided significant risk stratification information with a 2-variable score. Until administrative data routinely includes a valid measure of stroke severity, radiographic data may provide information for use in risk adjustment.

Anemia is associated with poor outcomes in patients with less severe ischemic stroke.

Anemia is a known predictor of in-hospital mortality among patients with such vascular conditions as acute myocardial infarction, congestive heart failure, and chronic kidney disease. The role of anemia in patients with acute ischemic stroke is less well understood. We sought to examine the association between anemia at hospital admission and the combined outcome of in-hospital mortality and discharge to hospice in patients with acute ischemic stroke. We evaluated data from a retrospective cohort of consecutive ischemic stroke patients presenting within 48 hours of symptom onset at 5 hospitals between 1998 and 2003. Anemia was defined as an admission hematocrit value of <30%. Less severe stroke was defined as an admission National Institutes of Health Stroke Scale score of <10. The outcome was the combined endpoint of in-hospital mortality or discharge to hospice. Among 1306 patients with stroke, anemia was present on admission in 6.4%, and the combined outcome of death or discharge to hospice was present in 10.1%. Anemia was not associated with outcome in patients with severe stroke (anemia, 17.2% [5 of 29] vs no anemia, 28,4% [98 of 345]; P = .20), but was associated with outcome in patients with less severe stroke (anemia, 13.0% [7 of 54] vs no anemia, 2.5% [22 of 878]; P < .0001). After adjustment for stroke severity, admission anemia was independently associated with outcome in patients with less severe stroke (adjusted odds ratio, 4.17; 95% confidence interval, 1.47-11.90), but not in patients with more severe strokes (adjusted odds ratio, 0.82; 95% confidence interval, 0.30-2.22). Our data indicate that anemia is associated with in-hospital mortality or discharge to hospice in patients with less severe ischemic stroke.

Thrombocytopenia and in-hospital mortality risk among ischemic stroke patients.

BACKGROUND: Thrombocytopenia has been associated with increased mortality in nonstroke conditions. Because its role in acute ischemic stroke is less well understood, we sought to determine whether thrombocytopenia at admission for acute ischemic stroke was associated with in-hospital mortality. METHODS: We used data from a retrospective cohort of stroke patients (1998-2003) at 5 U.S. hospitals. Risk factors considered included conditions that can lead to thrombocytopenia (e.g., liver disease), increase bleeding risk (e.g., hemophilia), medications with antiplatelet effects (e.g., aspirin), and known predictors of mortality (e.g., National Institutes of Health Stroke Scale and Charlson Comorbidity Index scores). Logistic regression modeling evaluated the adjusted association between thrombocytopenia, defined as platelets <100,000/µL, and in-hospital mortality. RESULTS: Among 1233 acute ischemic stroke patients, thrombocytopenia was present in 2.3% (n = 28). A total of 6.1% (n = 75) of patients died in the hospital. In unadjusted analyses, thrombocytopenia was associated with higher mortality (8/28 [28.6%] v 67/1205 [5.6%]; P < .0001). Thrombocytopenia was also independently associated with in-hospital mortality after adjustment for National Institutes of Health Stroke Scale score and comorbidities, with an odds ratio of 6.6 (95% confidence interval 2.3-18.6). CONCLUSIONS: Admission thrombocytopenia among patients presenting with acute ischemic stroke predicts in-hospital mortality.

Derivation and validation of a clinical system for predicting pneumonia in acute stroke.

AIMS: We derived and validated a clinical prediction rule that can be used to predict post-stroke pneumonia. METHODS: We conducted a retrospective cohort study of patients admitted to hospital with a stroke. The cohort was subdivided into a derivation group and a validation group. Within the derivation group, a point scoring system was developed to predict pneumonia based on a logistic regression model. The point scoring system was then tested within the validation group. RESULTS: Of the 1,363 patients with stroke, 10.5% of patients experienced new pneumonia. The most points were assigned for abnormal swallowing result and history of pneumonia (4 points), followed by greater NIHSS score (3 points), patient being 'found down' at symptom onset (3 points), and age >70 years (2 points). A 3-level classification system was created denoting low, medium and high risks of pneumonia, which accurately predicted pneumonia in the validation group. The discriminatory accuracy of the 3-level clinical prediction rule exceeded the acceptable range in both the derivation group (c statistic: 0.78) and validation group (c statistic: 0.76). CONCLUSION: A simple scoring system was derived and validated. This clinical scoring system may better identify stroke patients who are at high risk of developing new pneumonia.

Molecular markers and death from prostate cancer.

BACKGROUND: Current methods to assess the prognosis of prostate cancer at the time of diagnosis are limited. OBJECTIVE: To determine whether molecular markers of cell cycle regulation (bcl-2 and p53) and angiogenesis (beta-3 integrin, vascular endothelial growth factor, and microvessel density) are associated with increased long-term risk for death among men with prostate cancer. DESIGN: Observational cohort study from 1991 to 2006. SETTING: The Veterans Affairs Healthcare System in New England. PATIENTS: Among 64 545 veterans at least 50 years of age, 1313 patients who had incident prostate cancer from 1991 to 1995 were identified. Clinical data were available for 1270 men and complete for 1172 men. MEASUREMENTS: Data were extracted from medical records, including patient age, race, and comorbid conditions, as well as tumor-related anatomical extent, histologic grade (Gleason score), prostate-specific antigen level, symptoms, and treatment. Immunohistochemical analyses of tissue obtained at diagnosis, which used antibodies against the selected markers, were also conducted. Proportional hazards analysis was used to evaluate the association of these factors with death from prostate cancer through 2006. RESULTS: At diagnosis, the median age was 72 years, the median prostate-specific antigen level was 10.0 microg/L, and most tumors were moderately differentiated. During an 11- to 16-year follow-up, 71.8% (842 of 1172) of men died, with 21.5% (181 of 842) of deaths attributable to prostate cancer. Among 1007 men with results for all pertinent markers and after adjustment for age and clinical characteristics, bcl-2 (adjusted hazard ratio [HR] for positive vs. negative staining, 1.61 [95% CI, 1.01 to 2.57]; P = 0.045), p53 (adjusted HR for positive vs. negative staining, 1.48 [CI, 1.06 to 2.08]; P = 0.022), and microvessel density (adjusted HR for highest vs. lowest quartile, 3.20 [CI, 1.77 to 5.78]; P < 0.001) were associated with death from prostate cancer. LIMITATIONS: Results may be affected by residual confounding. Some patients were not included in complete case analyses because information was not available from clinical care records (7.5%) or tissue staining (12.6%). CONCLUSION: Immunohistochemical evidence of bcl-2, p53, or high microvessel density in prostate cancer biopsy specimens at diagnosis is associated with an increased long-term risk for death from prostate cancer. PRIMARY FUNDING SOURCE: Office of Research and Development, Veterans Health Administration.

Reporting of multivariable methods in the medical literature.

BACKGROUND: Multivariable models are frequently used in the medical literature, but many clinicians have limited training in these analytic methods. Our objective was to assess the prevalence of multivariable methods in medical literature, quantify reporting of methodological criteria applicable to most methods, and determine if assumptions specific to logistic regression or proportional hazards analysis were evaluated. METHODS: We examined all original articles in Annals of Internal Medicine, British Medical Journal, Journal of the American Medical Association, Lancet, and New England Journal of Medicine, from January through June 2006. Articles reporting multivariable methods underwent a comprehensive review; reporting of methodological criteria was based on each article's primary analysis. RESULTS: Among 452 articles, 272 (60%) used multivariable analysis; logistic regression (89 [33%] of 272) and proportional hazards (76 [28%] of 272) were most prominent. Reporting of methodological criteria, when applicable, ranged from 5% (12/265) for assessing influential observations to 84% (222/265) for description of variable coding. Discussion of interpreting odds ratios occurred in 13% (12/89) of articles reporting logistic regression as the primary method and discussion of the proportional hazards assumption occurred in 21% (16/76) of articles using Cox proportional hazards as the primary method. CONCLUSIONS: More complete reporting of multivariable analysis in the medical literature can improve understanding, interpretation, and perhaps application of these methods.

Trajectories of prostate-specific antigen after treatment for prostate cancer.

Prostate-specific antigen (PSA) measurements after primary treatment reflect residual tumor burden among men with prostate cancer. Using a mixture model analysis, we identified distinct trajectories of post-treatment PSA measurements and evaluated their associations with prostate cancer mortality. The study sample included 623 US Veterans treated for prostate cancer with curative intent during 1991-1995; 225 men received surgery and 398 men received radiation therapy. Post-treatment PSA measurements over a 2-year period for each patient were evaluated in latent class mixture models using the SAS TRAJ procedure, and groups of men with distinct trajectories of PSA were identified. These groups were then assessed for associations with 10-year prostate cancer mortality using proportional hazards analysis. Analyses identified three distinct groups-representing patterns of both initial values and changes in PSA over time-after surgery (n=172/31/14) and radiation therapy (n=253/103/22). Men in groups with patterns of higher (compared with the group with lowest) PSA values tended to have worse survival experience: HRs for prostate cancer mortality were 3.45 (P=0.18) and 22.7 (P<0.001) for surgery, and 2.70 (P=0.005) and 18.1 (P<0.001) for radiation therapy. The results indicate that PSA measurements after surgery or radiation therapy with curative intent include groups of men with a diverse spectrum of prognosis for prostate cancer mortality. Although contemporary PSA levels are lower than those observed in the study sample, the corresponding trajectory patterns may become evident shortly after the time of diagnosis and treatment.

Dietary fish or seafood consumption is not related to cerebrovascular disease risk in twin veterans.

BACKGROUND/AIMS: The results of studies about dietary fish consumption and stroke risk have been conflicting. We sought to examine the relationship between dietary fish and seafood consumption and the risk of stroke or transient ischemic attack (TIA). METHODS: We used data from the National Academy of Sciences-National Research Council Twin Registry, a prospective cohort of white male twins born in the US (1917-1927). Participants were asked about fish and seafood consumption in 1972 and 1985. Self-report or death-certificate report of stroke or TIA was obtained in 1996-1998. RESULTS: Among 5,355 participants, 579 (10.8%) had a stroke or TIA. In unmatched analyses, dietary fish and seafood consumption was not associated with stroke or TIA: 10.4% (91/872) of frequent fish or seafood consumers had a stroke or TIA versus 10.9% (488/4,483) of infrequent consumers, p = 0.70. In an analysis of matched twin pairs, frequent fish or seafood consumption was also not associated with stroke or TIA: hazard ratio 0.89, 95% CI 0.59-1.36. CONCLUSIONS: These data, from a prospective cohort of white male twins, do not support an association between dietary fish and seafood consumption and stroke or TIA.

Molecular markers and mortality in prostate cancer.

OBJECTIVE: To evaluate prognosis in prostate cancer by assessing the independent effect of selected molecular factors (e.g. markers of cell-cycle regulation), in addition to the effect of traditional clinical factors (e.g. anatomical stage, histological grade), in predicting long-term mortality among men newly diagnosed with prostate cancer. PATIENTS AND METHODS: In a community-based population of 64 545 USA veterans aged >/= 50 years and receiving ambulatory care during 1989-90 at nine Veterans Affairs (VA) medical centres in New England, 1274 had incident prostate cancer during 1991-95. We obtained the medical records and diagnostic tissue for these men, and then extracted demographic data and clinical information, and conducted immunohistochemical assays of molecular markers in biopsy tissue, as potential prognostic factors. In this interim analysis, data on 250 patients were analysed; the main outcome was overall mortality to 31 December 2003, providing 8-13 years of follow-up. RESULTS: In 228 (91%) patients with available medical record and laboratory data, the median age was 72 years and the median prostate-specific antigen level was 10.4 ng/mL. In adjusted (multivariate) analyses that included traditional prognostic factors, bcl-2 staining (hazard ratio 2.14, 95% confidence interval 1.27-3.58, P = 0.004) and high microvessel density (1.76, 1.19-2.60; P = 0.005) had an independent effect on the outcome. CONCLUSIONS: Bcl-2 and microvessel density are independent predictors of subsequent death among men with prostate cancer and might have a clinical role in assisting in deciding on treatment.

The effectiveness of screening for prostate cancer: a nested case-control study.

BACKGROUND: Screening for prostate cancer is done commonly in clinical practice, using prostate-specific antigen (PSA) tests or digital rectal examination (DRE). Evidence is lacking, however, to confirm a survival benefit among screened patients. We evaluated the effectiveness of PSA, with or without DRE, in reducing mortality. METHODS: We conducted a multicenter nested case-control study at 10 Veterans Affairs medical centers in New England. Among 71 661 patients receiving ambulatory care between 1989 and 1990, 501 case patients were identified as men who were diagnosed as having adenocarcinoma of the prostate from 1991 through 1995 and who died sometime between 1991 and 1999. Control patients were men who were alive at the time the corresponding case patient had died, matched (1:1 ratio) for age and Veterans Affairs facility. The exposure variable (determined blind to case-control status) was whether PSA testing or DRE was performed for screening prior to the diagnosis of prostate cancer among case patients, with the same time interval for control patients. The association of screening and overall or cause-specific (prostate cancer) mortality was adjusted for race and comorbidity. RESULTS: A benefit of screening was not found in our primary analysis assessing PSA screening and all-cause mortality (adjusted odds ratio, 1.08; 95% confidence interval, 0.71-1.64; P=.72), nor in a secondary analysis of PSA and/or DRE screening and cause-specific mortality (adjusted odds ratio, 1.13; 95% confidence interval, 0.63-2.06; P=.68). CONCLUSIONS: These results do not suggest that screening with PSA or DRE is effective in reducing mortality. Recommendations for obtaining "verbal informed consent" from men regarding such screening should continue.

Prostate-specific antigen 'velocity' as a diagnostic test for prostate cancer.

BACKGROUND: Prostate-specific antigen "velocity" (slope) is promoted as a diagnostic test for prostate cancer, but its clinical usefulness is uncertain. Accordingly, we evaluated the sensitivity of prostate-specific antigen (PSA) velocity among men who are diagnosed subsequently with prostate cancer. METHODS: Among 64,545 men receiving primary care at any of nine Veterans Affairs Medical Centers during 1989-1990, 1,313 men at least 50 years old had an incident diagnosis of prostate cancer during 1991-1995. PSA velocity values obtained prior to diagnosis ("test") were compared with results from prostate biopsies ("truth"). RESULTS: Among men (n = 493) with at least two tests before diagnosis, the sensitivity of PSA velocity > or = 0.75 ng/mL/yr was 75.5% (95% confidence interval [CI] 71.7-79.3) overall and 48.1% (95% CI 34.8-61.5) among men with normal values of PSA (< 4.0 ng/mL). Based on published data for specificity and prevalence, the estimated positive predictive value of PSA velocity > or = 0.75 ng/mL/yr is as low as 5%. CONCLUSION: PSA velocity may have limited usefulness as a diagnostic test for prostate cancer.

Prognostic implications of clinical practice guidelines among hemodialysis patients.

Although the National Kidney Foundation (NKF) has published clinical practice guidelines for the management of risk factors for cardiovascular disease, these guidelines have not been tested rigorously for their effectiveness. We conducted an observational study among patients with end-stage kidney disease to examine the prognostic impact of threshold levels recommended by the NKF for blood pressure, hemoglobin, calcium-phosphate product, parathyroid hormone, low-density lipoprotein, and glycosylated hemoglobin. The study population (N = 197) was assembled from a previously completed randomized trial examining arteriovenous graft thrombosis. Cox proportional hazard analysis was used to calculate hazard ratios for the association of levels outside guideline recommended targets and death, adjusting for age, comorbidity, race, and albumin. The proportion of patients outside guideline targets ranged from 33% to 81%, and the impact of levels outside guideline targets on mortality varied substantially. Elevated calcium-phosphate product and glycosylated hemoglobin had harmful effects, with adjusted hazard ratios of 1.58 (95% CI 1.00-2.50; p = 0.050) and 2.21 (95% CI 0.99-4.97; p = 0.054), respectively. Nontarget levels for blood pressure, hemoglobin, and parathyroid hormone had little effect, with adjusted hazard ratios of 1.15 (95% CI 0.74-1.78; p = 0.542), 1.04 (95% CI 0.65-1.68; p = 0.866), and 0.90 (95% CI 0.50-1.61; p = 0.722), respectively. Elevated low-density lipoprotein had a paradoxically beneficial effect, with an adjusted hazard ratio of 0.48 (95% CI 0.23-1.00; p = 0.049). These results suggest that the prognostic impact of current threshold levels recommended by select NKF guidelines on mortality is variable. Accordingly, the development and implementation of clinical practice guidelines should be accompanied by corresponding efforts to confirm their impact on patient outcomes. Such efforts are essential for the improvement of guidelines and to inform health policy optimally.

Velocity and doubling time of prostate-specific antigen: mathematics can matter.

Changes in prostate-specific antigen (PSA) values are often reported as velocity or doubling time. We compared the association of these two calculations-at the time of PSA failure after primary treatment for prostate cancer-with prostate cancer mortality. From a source population of 1313 US Veterans with prostate cancer, including 623 treated with curative intent, the study population included 242 men experiencing biochemical failure, 81 after surgery and 161 after radiation therapy. Clinically relevant calculations of PSA velocity (linear slope) and PSA doubling time (logarithmic slope) were assessed for their association with 11-16 years of mortality from prostate cancer. Death due to prostate cancer occurred in 52/242 (21.5%) men. Among men receiving surgery, PSA velocity ≥1.0 ng/mL/year was associated with increased prostate cancer mortality (HR=4.2, p value=0.037), whereas doubling time ≤12 months did not confer risk (HR=1.0, p value=0.95). Conversely, among patients receiving radiation therapy, doubling time ≤12 months was associated with increased prostate cancer mortality (HR=2.4, p value=0.049), but velocity did not confer a statistically significant risk (HR=3.8, p value=0.19). When assessing risk of prostate cancer mortality, PSA velocity can be more predictive after surgery and PSA doubling time can be more predictive after radiation therapy.

Racial disparities in stroke risk factors: the impact of socioeconomic status.

BACKGROUND AND PURPOSE: In the US, blacks have a higher incidence of stroke and more severe strokes than whites. Our objective was to determine if differences in income, education, and insurance, as well as differences in the prevalence of stroke risk factors, accounted for the association between ethnicity and stroke. METHODS: We used data from the Third National Health and Nutrition Survey (NHANES III), a cross-sectional sample of the noninstitutionalized US population (1988-1994), and included blacks and whites aged 40 years or older with a self-reported stroke history. Income was assessed using a ratio of income to US Census Bureau annual poverty threshold. RESULTS: Among 11 163 participants, 2752 (25%) were black and 619 (6%) had a stroke history (blacks: 160/2752 [6%]; whites: 459/8411 [6%]; P=0.48). Blacks had a higher prevalence of 5 risk factors independently associated with stroke: hypertension, treated diabetes, claudication, higher C-reactive protein, and inactivity; whites had a higher prevalence of 3 risk factors: older age, myocardial infarction, and lower high-density lipoprotein cholesterol. Ethnicity was independently associated with stroke after adjusting for the 8 risk factors (adjusted odds ratio, 1.32; 95% CI, 1.04 to 1.67). Ethnicity was not independently associated with stroke after adjustment for income and income was independently associated with stroke (adjusted odds ratios for: ethnicity, 1.15; 95% CI, 0.88 to 1.49; income, 0.89; 95% CI, 0.82 to 0.95). Adjustment for neither education nor insurance altered the ethnicity-stroke association. CONCLUSIONS: In this study of community-dwelling stroke survivors, ethnic differences exist in the prevalence of stroke risk factors and income may explain the association between ethnicity and stroke.

Altruism as a reason for participation in clinical trials was independently associated with adherence.

BACKGROUND: To determine whether altruism as reason for participation in research is independently associated with adherence to a medical regimen in a clinical trial. METHODS: Participants were 475 participants in the Women's Estrogen for Stroke Trial. Before randomization to estrogen or placebo, all women were questioned about reason for participation and baseline features that may contribute to adherence. Adherence was defined as completion of at least 80% of expected pill intake during the trial. RESULTS: Women who reported at least one altruistic reason for participation were more likely to be college educated, have a higher level of social support, and a better functional status. They were also more likely to be adherent to their study medication {155 of 212 (73%) vs. 158 of 253 (62.5%), P < .01}. On stratified analysis and multivariable regression, the relationship between altruism as reason for participation and adherence was independent of other sociodemographic, psychosocial, and clinical features (relative risk 1.17, Confidence interval 1.03-1.32). CONCLUSION: Altruism may explain a small portion of the variation in adherence among research participants. This relationship may have implications for recruitment of participants in clinical research. The possible contribution of altruism to the relationship between adherence and outcomes in clinical trials is worthy of further investigation.

Two measures of insulin sensitivity provided similar information in a U.S. population.

BACKGROUND AND OBJECTIVE: Two methods for measuring insulin sensitivity, fasting plasma insulin (FPI) and homeostasis model assessment (HOMA) have been proposed for use in large epidemiological research and clinical practice. This project describes the range of observed values of the HOMA and FPI in a large sample of the U.S. population. METHODS: We used fasting plasma glucose and insulin values from the Third National Health and Nutrition Survey (NHANES III) to identify the FPI and HOMA values. For both FPI and HOMA, higher values indicate lower insulin sensitivity. RESULTS: Among 6,511 participants without treated diabetes mellitus, FPI ranged from 1.8 to 175.8 microU/mL, with 25th percentile=6.7, median=9.3, 75th percentile=13.3, and mean+/-1 SD=11.2+/-7.5; HOMA ranged from 0.3 to 52.6 (mmol)(microU)/L(2), with 25th percentile=1.5, median=2.2, 75th percentile=3.3, and mean+/-SD=2.8+/-2.4. CONCLUSION: These findings describe the spectrum of insulin sensitivity and may be useful in helping physicians develop a clinical understanding of the dynamic range of both FPI and HOMA measures.

A comparison of three rating scales for measuring subjective phenomena in clinical research. II. Use of experimentally controlled visual stimuli.

BACKGROUND: In a previous study of three types of global scales we found that verbal rating scales were particularly reliable for rating auditory stimuli. We now wanted to check the performance of the scales for rating experimentally controlled visual stimuli. METHODS: We used a prospective, experimentally controlled, clinimetric study, which was conducted at the Department of Psychiatry of the Autonomous University of Puebla Medical School in the state capital city of Puebla, Mexico. A total of 20 fifth-year medical students participated in the study. Visual stimuli consisted of 15 cards with five different intensities on the gray-to-black scale, administered randomly in three sessions to each subject. With regard to main outcome measurement, validity and consistency indices were determined for visual analog scale (VAS), numerical rating score (NRS), and verbal rating scale (VRS) to rate visual stimuli. RESULTS: For validity, correlation coefficients between scales and reference standard were high, especially in VRS (r=0.902). For consistency, VRS had highest kappa value (k(w)=0.71) for interobserver variability. CONCLUSIONS: Three instruments could be hierarchically ranked for their indices of validity and consistency. Being more consistent than VAS and NRS, VRS merits more frequent usage in clinical research.

Comparison of three rating scales for measuring subjective phenomena in clinical research. I. Use of experimentally controlled auditory stimuli.

BACKGROUND: An interest in measuring subjective phenomena such as pain, nausea, anxiety, etc. has led clinicians to develop three types of ratings: the visual analog scale (VAS); the verbal rating scale (VRS), and the numeric rating score (NRS). These ratings are regarded as global scales because they lack criteria to demarcate diverse dimensions or categories that comprise each scale. The purpose of this study was to evaluate validity and consistency of usage for these scales. Criterion for validity consisted of an experimentally controlled intensity for auditory stimuli. METHODS: We conducted a prospective, experimentally controlled, clinimetric study at the Audiology Department at the Hospital of Puebla Autonomous University (in Puebla State, Mexico). Participants included 25 medical students, two psychology students, and three practicing physicians. Interventions consisted of pure 1,000 Hz tones in five different intensities applied for 3 sec with a 1-min interval between stimuli at three sessions for each observer. Main outcome measure was validity and consistency of usage for VAS, VRS, and NRS scales. RESULTS: Correlation coefficients between scale results and standard stimuli were 0.818 for VAS, 0.735 for NRS, and 0.796 for VRS. Mean weighted kappa indices for intraobserver agreement were 0.70, 0.59, and 0.65, respectively, for scales with five categories each. Mean weighted kappa indices for inter-observer variability were 0.61, 0.48, and 0.54 for VAS, NRS, and VRS again with five categories each. CONCLUSIONS: The three instruments appeared reasonably accurate, with VAS having highest scores. VRS appeared sufficiently consistent to be regarded as providing reliable scientific information.

'Race' and prostate cancer mortality in equal-access healthcare systems.

BACKGROUND: Reports suggest worse health-related outcomes among black (vs white) men diagnosed with prostate cancer, but appropriate cause-effect inferences are complicated by the relationship of race and other prognostic factors. METHODS: We searched the literature to find contemporary articles focusing on mortality among black and white men with prostate cancer in equal-access healthcare systems. We also directly assessed the association of race and prostate cancer mortality by conducting an observational cohort analysis of 1270 veterans diagnosed with prostate cancer and followed for 11 to 16 years at 9 medical centers within the Veterans Health Administration. RESULTS: Among 5 reports providing quantitative results for the association of race and mortality among men with prostate cancer in equal-access systems, outcomes were similar for black and white men. Race also was not a prognostic factor in the observational cohort analysis of US veterans, with an adjusted hazard ratio for black (vs white) men and prostate cancer mortality of 0.90 (95% confidence interval, 0.58-1.40; P = .65). CONCLUSIONS: Mortality among black and white patients with prostate cancer is similar in equal-access healthcare systems. Studies that find racial differences in mortality (including cause-specific mortality) among men with prostate cancer may not account fully for socioeconomic and clinical factors.