William M. Briggs

Randomized, controlled clinical trial of point-of-care limited ultrasonography assistance of central venous cannulation: the Third Sonography Outcomes Assessment Program (SOAP-3) Trial.

Context:A 2001 Agency for Healthcare Research and Quality Evidence Report on patient safety addressed point-of-care limited ultrasonography guidance for central venous cannulation and strongly recommended real-time, dynamic guidance for all central cannulas. However, on the basis of one limited study, the report dismissed static assistance, a “quick look” with ultrasound to confirm vein location before preparing the sterile field, as unhelpful. Objective:The objective of this trial was to compare the overall success rate of central cannula placement with use of dynamic ultrasound (D), static ultrasound (S), and anatomical landmarks (LM). Design and Setting:A concealed, randomized, controlled, clinical trial conducted from September 2003 to February 2004 in a U.S. urban teaching hospital. Patients:Two-hundred one patients undergoing internal jugular vein central venous cannulation. Interventions:Patients were randomly assigned to three groups: 60 to D, 72 to S, and 69 to LM. An iLook25 SonoSite was used for all imaging. Measurements and Main Results:Cannulation success, first-attempt success, and number of attempts were noted. Other measures were vein size and clarity of LM. Results, controlled for pretest difficulty assessment, are stated as odds improvement (95% confidence interval) over LM for D and S. D had an odds 53.5 (6.6–440) times higher for success than LM. S had an odds 3 (1.3–7) times higher for success than LM. The unadjusted success rates were 98%, 82%, and 64% for D, S, and LM. For first-attempt success, D had an odds 5.8 (2.7–13) times higher for first success than LM, and S had an odds 3.4 (1.6–7.2) times higher for first success than LM. The unadjusted first-attempt success rates were 62%, 50%, and 23% for D, S, and LM. Conclusions:Ultrasound assistance was superior to LM techniques. D outperformed S but may require more training and personnel. All central cannula placement should be conducted with ultrasound assistance. The 2001 Agency for Healthcare Research and Quality Evidence Report dismissing static assistance was incorrect.

Wavelets and Field Forecast Verification

Current field forecast verification measures are inadequate, primarily because they compress the comparison between two complex spatial field processes into one number. Discrete wavelet transforms (DWTs) applied to analysis and contemporaneous forecast fields prove to be an insightful approach to verification problems. DWTs allow both filtering and compact physically interpretable partitioning of fields. These techniques are used to reduce or eliminate noise in the verification process and develop multivariate measures of field forecasting performance that are shown to improve upon existing verification procedures.

Cardiac Surgery in Select Nonagenarians: Should We or Shouldn’t We?

BACKGROUND Patients aged 90 years and older represent a rapidly growing subset of the population, many of whom are functionally limited by cardiovascular disease. Clinical decision making about cardiac surgical intervention in nonagenarians is hindered by a paucity of data examining survival outcomes in this population. METHODS A consecutive series of nonagenarians who underwent cardiac operations between 1995 and 2004 were retrospectively reviewed. Data collection included baseline preoperative clinical status, intraoperative characteristics, and perioperative course. Area under the Kaplan-Meier survival estimate method was used to calculate mean survival. RESULTS Cardiac surgical procedures were done in 49 patients (51% male); their mean age was 91.9 years (range, 90 to 97 years). Operative mortality was 8% (n = 4). Multivariate Cox proportional hazards models found preoperative chronic renal insufficiency (hazard ratio [HR], 4.88; 95% confidence interval [CI], 1.53 to 15.55; p = 0.007) and ejection fraction (HR, 0.96; 95% CI, 0.93 to 1.00; p = 0.033) were independently associated with death. Overall mean survival was 5.1 +/- 0.5 years (median, 5.2 years). Quality of life outcomes were similar to that of two related norm-based populations based on age and disease process. CONCLUSIONS Cardiac surgical procedures can be performed safely and with therapeutic benefit in carefully selected nonagenarians. We consider physiologic indicators, social factors, and patient preferences to be the main determinants in the patient selection process. Our results support the need for more proactive intervention in symptomatic nonagenarian patients as it relates to earlier consideration of elective, rather than emergency cardiac operations.

Patient-Reported and Physician-Reported Depressive Conditions in Relation to Asthma Severity and Control

BACKGROUND Depressive conditions in asthma patients have been described mostly from patient reports and less often from physician reports. While patient reports can encompass multiple symptoms, physician assessments can attribute symptoms to a mental health etiology. Our objectives were to identify associations between patient- and physician-reported depressive conditions and asthma severity and control. METHODS Patient-reported depressive symptoms were obtained using the Geriatric Depression Scale (GDS) [possible score 0 to 30; higher score indicates more depressive symptoms]. Patients were categorized as having a physician-reported depressive disorder if they had the following: a diagnosis of depression, depressive symptoms described in medical charts, or were prescribed antidepressants at doses used to treat depression. Patients also completed the Severity of Asthma Scale (SOA) [possible score 0 to 28; higher score indicates more severe] and the Asthma Control Questionnaire (ACQ) [possible score 0 to 6; higher score indicates worse control]. RESULTS Two hundred fifty-seven patients were included in this analysis (mean age, 42 years; 75% women). Mean SOA and ACQ (+/- SD) scores were 5.9 +/- 4.2 and 1.4 +/- 1.2, respectively; and mean GDS score was 6.3 +/- 6.4. After adjusting for age, sex, race, Latino ethnicity, education, medication adherence, body mass index, and smoking status, patient-reported depressive symptoms were associated with asthma severity (p = 0.007) and with asthma control (p = 0.0007). In contrast, physician-reported depressive disorders were associated with asthma severity (p = 0.04) but not with asthma control (p = 0.22) after adjusting for covariates. CONCLUSIONS Physician- and patient-reported depressive conditions were associated with asthma severity. In contrast, patient-reported depressive symptoms were more closely associated with asthma control than were physician-reported depressive disorders. Identifying associations between depressive conditions and asthma severity and control is necessary to concurrently treat these conditions in this population. TRIAL REGISTRATION Clinicaltrials.gov Identifier: NCT00195117.

Obesity and exercise habits of asthmatic patients

BACKGROUND National guidelines recommend 20 to 30 minutes of exercise 3 to 5 days a week. However, achieving these goals may be challenging for asthmatic patients whose symptoms are exacerbated by exercise. OBJECTIVE To describe relationships among exercise habits, weight, and asthma severity and control in adults with asthma. METHODS Self-reported exercise habits were obtained from 258 stable patients by using the Paffenbarger Physical Activity and Exercise Index. Disease status was measured by using the Asthma Control Questionnaire and the Severity of Asthma Scale. Exercise habits were evaluated in multivariate analyses with age, sex, education, body mass index, and asthma control and severity as independent variables. RESULTS The mean patient age was 42 years; 75% were women, 62% were college graduates, and 40% were obese. Only 44% of patients did any exercise. In bivariate analysis, patients with well-controlled asthma were more likely to exercise; however, in multivariate analysis, asthma control and severity were not associated, but male sex (P = .01), having more education (P = .04), and not being obese (P < .001) were associated. Asthma control and severity also were not associated with type, duration, or frequency of exercise, but not being obese was associated in multivariate analyses. Only 22% of all patients (49% of those who exercised) met national guidelines for weekly exercise. Not being obese was the only variable associated with meeting guidelines in multivariate analysis (P = .02). CONCLUSIONS Compared with the general population, a lower proportion of asthmatic patients did any routine exercise and met national exercise guidelines. Physicians need to manage asthma and obesity to help asthmatic patients meet exercise goals.

Measuring Physical Activity in Asthma Patients: Two-Minute Walk Test, Repeated Chair Rise Test, and Self-Reported Energy Expenditure

Although prudent exercise is recommended for most patients with well-controlled asthma, many patients avoid exercise and physical activity because they are concerned about triggering asthma. In a sample of 258 asthma patients (mean age 42 years, 75% women), the objectives of this study were to assess the two-minute walk test and the repeated chair rise test and to compare results to self-reported physical activity recorded with the Paffenbarger Physical Activity and Exercise Index (PAEI). Patients walked a mean of 510 feet, required a mean of 14 seconds for the chair rise test, and reported a mean of 1,810 kilocalories per week from activities, mostly walking. In multivariable analysis, male sex, younger age, more education, lower body mass index, and better short-term asthma control, but not long-term asthma severity, were associated with better performance-based test results and more self-reported physical activity. Better short-term control also was associated with less breathing and leg exertion during both tests. Correlations between the PAEI and performance-based tests were approximately 0.38. Performance-based and self-reported measures provide information about various aspects of exercise capacity and can be used during routine clinical practice to assess physical activity in asthma patients.

Incorporating Misclassification Error in Skill Assessment

Abstract It is desirable to account for misclassification error of meteorological observations so that the true skill of the forecast can be assessed. Errors in observations can occur, among other places, in pilot reports of icing and in tornado spotting. Not accounting for misclassification error gives a misleading picture of the forecast’s true performance. An extension to the climate skill score test developed in Briggs and Ruppert is presented to account for possible misclassification error of the meteorological observation. This extension supposes a statistical misclassification-error model where “gold standard” data, or expert opinion, is available to characterize the misclassification-error characteristics of the observation. These model parameters are then inserted into the Briggs and Ruppert skill score for which a statistical test of significance can be performed.

Do pulmonary function tests improve risk stratification before cardiothoracic surgery

OBJECTIVE To assess the added value of pulmonary function tests (PFTs) and different classifications of chronic obstructive pulmonary disease (COPD) to the Society of Thoracic Surgeons (STS) risk model using a clinical definition of lung disease for predicting outcomes after cardiothoracic (CT) surgery. METHODS We evaluated consecutive patients who underwent nonemergency cardiac surgery and underwent PFTs before CT surgery. We used the STS risk model 2.73 to estimate the postoperative risk for respiratory failure (RF; defined as the need for mechanical ventilation for ≥72 hours, or reintubation), prolonged postoperative stay (PPLS; defined as >14 days), and 30-day all-cause mortality. We plotted the receiver operating characteristics curve for STS score for each adverse event, and compared the resulting area under the curve (AUC) with the AUC after adding PFT parameters and COPD classifications. RESULTS Of the 1412 patients with a calculated STS score, 751 underwent PFTs. The AUC of the STS score was 0.65 (95% confidence interval [CI], 0.55-0.74) for RF, 0.67 (95% CI, 0.6-0.74) for prolonged postoperative length of stay (PPLS), and 0.74 (95% CI, 0.6-0.87) for death. None of the PFT parameters or COPD classifications added to the predictive ability of STS for RF, PPLS, or 30-day mortality. CONCLUSIONS Adding individual PFT parameters or different COPD classifications to STS score calculated using clinically based classification of lung disease did not improve model discrimination. Thus, routine preoperative PFTS may have limited clinical utility in patients undergoing CT surgery when the STS score is readily available.

Assessing the Skill of Yes/No Forecasts for Markov Observations

Abstract Briggs and Ruppert recently introduced a new, easy-to-calculate economic skill/value score for use in yes/no forecast decisions, of which precipitation forecast decisions are an example. The advantage of this new skill/value score is that the sampling distribution is known, which allows one to perform hypothesis tests on collections of forecasts and to say whether a given skill/value score is significant or not. Here, the climate skill/value score is taken and extended to the case where the predicted series is first-order Markov in nature, of which, again, precipitation occurrence series can be an example. It is shown that, in general, Markov skill/value is different and more demanding than is persistence skill. Persistence skill is defined as improvement over forecasts that state that the next value in a series will equal the present value. It is also shown that any naive forecasts based solely on the Markov parameters is always at least as skillful/valuable as are persistence forecasts; in gene...

Prevalence and Prognostic Significance of Left Ventricular Noncompaction in Patients Referred for Cardiac Magnetic Resonance ImagingCLINICAL PERSPECTIVE

Background— Presence of prominent left ventricular trabeculation satisfying criteria for left ventricular noncompaction (LVNC) on routine cardiac magnetic resonance examination is frequently encountered; however, the clinical and prognostic significance of these findings remain elusive. This registry aimed to assess LVNC prevalence by 4 current criteria and to prospectively evaluate an association between diagnosis of LVNC by these criteria and adverse events. Methods and Results— There were 700 patients referred for cardiac magnetic resonance: 42% were women, median age was 70 years (range, 45–71 years), mean left ventricular ejection fraction was 51% (±17%), and 32% had late gadolinium enhancement on cardiac magnetic resonance. The cohort underwent diagnostic assessment for LVNC by 4 separate imaging criteria—referenced by their authors as Petersen, Stacey, Jacquier, and Captur, with LVNC prevalence of 39%, 23%, 25% and 3%, respectively. Primary clinical outcome was combined end point of time to death, ischemic stroke, ventricular tachycardia/ventricular fibrillation, and heart failure hospitalization. Secondary clinical outcomes were (1) all-cause mortality and (2) time to the first occurrence of any of the following events: cardiac death, ischemic stroke, ventricular tachycardia/ventricular fibrillation, or heart failure hospitalization. During a median follow-up of 7 years, there were no statistically significant differences in assessed outcomes noted between patients with and without LVNC irrespective of the applied criteria. Conclusions— Current criteria for the diagnosis of LVNC leads to highly variable disease prevalence in patients referred for cardiac magnetic resonance. The diagnosis of LVNC, by any current criteria, was not associated with adverse clinical events on nearly 7 years of follow-up. Limited conclusions can be made for Captur criteria due to low observed prevalence.