Biomedical subjects

E M Olmstead

Publications and source records attributed to E M Olmstead.

12 recordsLinked to original sources

PubMed1992

Multivariate prediction of in-hospital mortality associated with coronary artery bypass graft surgery. Northern New England Cardiovascular Disease Study Group.

BACKGROUND: A prospective regional study was conducted to identify factors associated with in-hospital mortality among patients undergoing isolated coronary artery bypass graft surgery (CABG). A prediction rule was developed and validated based on the data collected. METHODS AND RESULTS: Data from 3,055 patients were collected from five clinical centers between July 1, 1987, and April 15, 1989. Logistic regression analysis was used to predict the risk of in-hospital mortality. A prediction rule was developed on a training set of data and validated on an independent test set. The metric used to assess the performance of the prediction rule was the area under the relative operating characteristic (ROC) curve. Variables used to construct the regression model of in-hospital mortality included age, sex, body surface area, presence of comorbid disease, history of CABG, left ventricular end-diastolic pressure, ejection fraction score, and priority of surgery. The model significantly predicted the occurrence of in-hospital mortality. The area under the ROC curve obtained from the training set of data was 0.74 (perfect, 1.0). The prediction rule performed well when used on a test set of data (area, 0.76). The correlation between observed and expected numbers of deaths was 0.99. CONCLUSIONS: The prediction rule described in this report was developed using regional data, uses only eight variables, has good performance characteristics, and is easily available to clinicians with access to a microcomputer or programmable calculator. This validated multivariate prediction rule would be useful both to calculate the risk of mortality for an individual patient and to contrast observed and expected mortality rates for an institution or a particular clinician.

Aged↗

PubMed1992

Impact of dyspnea and physiologic function on general health status in patients with chronic obstructive pulmonary disease.

STUDY OBJECTIVE: To examine the relationship among clinical dyspnea ratings, physiologic pulmonary function, and general health status in symptomatic patients with chronic obstructive pulmonary disease (COPD). DESIGN: Observational data collected at a baseline state. SETTING: Outpatient pulmonary disease clinics at a university hospital and two VA medical centers. PATIENTS: One hundred ten male patients with COPD with no significant comorbidity were recruited. MEASUREMENTS AND RESULTS: Clinical ratings of dyspnea were measured by the multidimensional baseline dyspnea index (BDI). Pulmonary function tests included forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), and maximal inspiratory mouth pressure (PImax). General health status was assessed with the Medical Outcomes Study short-form survey, which consists of 20 questions that cover six health components. The mean age of the patients was 67 +/- 8 yr (+/- SD). The mean value for FVC was 2.84 +/- 0.84 L (68 +/- 18 percent of predicted), for FEV1 was 1.28 +/- 0.59 L (44 +/- 17 percent of predicted), and for PImax was 59.0 +/- 25.0 cm H2O. The BDI score and PImax were significantly correlated with five of the six components of general health status. Only three of the six components of general health were significantly correlated with FEV1 as percent predicted (rs value range, 0.30 to 0.44) and with FVC as percent predicted (rs value range, 0.25 to 0.33). Statistical comparisons showed that the BDI score had significantly higher correlations than FVC (percent predicted), FEV1 (percent predicted), and PImax values with physical functioning and role functioning. Multiple linear regression analysis showed that the BDI score was the only statistically significant predictor of role functioning, mental health, and health perceptions for general health status, whereas both the BDI score and FEV1 (percent predicted) were independent predictors of physical functioning and social functioning. CONCLUSION: Dyspnea ratings influence and predict general health status to a greater extent than do physiologic measurements in symptomatic patients with COPD. A shift in focus from the pathophysiology of disease to assessment and relief of symptoms may provide more meaningful benefits for the individual patient in terms of quality of life. This consideration requires that health-care providers use available measuring tools in clinical practice to quantify symptoms, as well as overall health status.

Adult↗

PubMed1992

Concordance between clinician and patient assessment of physical and mental health status.

The degree of concordance between clinicians' and patients' assessment of the patient's physical and mental functioning was examined in 166 consecutive eligible outpatients with rheumatoid arthritis (RA) using 4-category ordinal scales. The weighted kappa statistic was 0.39 for physical functioning and 0.30 for mental functioning, both indicating a fair degree of concordance. This disagreement differed in magnitude and direction depending on the level of disability present. We conclude that clinicians and their patients with RA often disagree in their assessment of the degree of physical and mental impairment that the patient experiences. These disagreements demonstrate the need for formal assessments of outcome and should be recognized and resolved when managing individual patients.

Adolescent↗

PubMed1991

A regional prospective study of in-hospital mortality associated with coronary artery bypass grafting. The Northern New England Cardiovascular Disease Study Group.

OBJECTIVE: A prospective regional study was conducted to determine if the observed differences in in-hospital mortality rates associated with coronary artery bypass grafting (CABG) are solely the result of differences in patient case mix. DESIGN-Regional prospective cohort study. Data including patient demographic and historical data, body surface area, cardiac catheterization results, priority of surgery, comorbidity, and status at hospital discharge were collected. This study presents data for 3055 CABG patients between July 1, 1987, and April 15, 1989. SETTING: This study includes data from all surgeons performing cardiothoracic surgery in Maine, New Hampshire, and Vermont; the data were collected from five regional medical centers. PATIENTS: Data were collected from all consecutive isolated CABG surgery patients during the study period. MAIN OUTCOME MEASURES: Crude and adjusted in-hospital mortality rates associated with CABG. MAIN RESULTS: The overall crude in-hospital mortality rate for isolated CABG was 4.3%. The rate varied among centers (range, 3.1% to 6.3%) and among surgeons (range, 1.9% to 9.2%). Predictors of in-hospital mortality included increased age, female gender, small body surface area, greater comorbidity, reoperation, poorer cardiac function as indicated by a lower ejection fraction, increased left ventricular end diastolic pressure and emergent or urgent surgery. After adjusting for the effects of potentially confounding variables, substantial and statistically significant variability was observed among medical centers (P = .021) and among surgeons (P = .025). CONCLUSION: We conclude that the observed differences in in-hospital mortality rates among institutions and among surgeons in northern New England are not solely the result of differences in case mix as described by these variables and may reflect differences in currently unknown aspects of patient care. Understanding this variation requires a detailed understanding of the processes of care.

Adult↗

PubMed1991

Measurement of breathlessness during exercise in asthmatics. Predictor variables, reliability, and responsiveness.

The purpose of this study was to determine the predictor variables for breathlessness and to investigate the criteria of reliability and responsiveness for measuring breathlessness during progressive, incremental exercise on the cycle ergometer. We studied a heterogeneous group of patients with stable asthma (mean +/- SEM age, 46 +/- 4 yr) for four visits at weekly intervals. Predictor variables were determined at the first visit. Nine independent physiologic variables were obtained at each minute during exercise; the Borg rating of breathlessness (range 0 to 10) was used as the dependent variable. The regression model relating the physiologic parameters to the Borg rating of breathlessness was highly significant (model F = 43.4; p = 0.0001). Backward elimination selected the strongest predictors of the Borg rating: peak inspiratory flow (VI); tidal volume (VT)/FVC; frequency of respiration (f); and peak inspiratory mouth pressures (Pm). These four variables explained 63% of the variance in the rating of dyspnea. Each of the four variables exhibited a linear relationship with the Borg rating. Test-retest reliability was assessed by comparing results at the first and second visits. Individual slopes (except for VT/FVC) and intercepts for the four predictor variables versus Borg ratings were highly reliable. The slope for work intensity (watts) and Borg ratings, but not the intercept, was highly reliable. Responsiveness was evaluated by randomly administering inhaled methacholine or inhaled metaproterenol, alternately, at the third and fourth visits to induce acute changes in lung function before exercise.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1989

Lack of correlation between the Steinbrocker staging of hand radiographs and the functional health status of individuals with rheumatoid arthritis.

We evaluated the correlation between destructive changes seen on hand radiographs and disability in 54 patients with definite or classic rheumatoid arthritis. No statistically significant correlation was found between radiographic findings and patient disability as determined by patient and physician assessment or by the patient's score on the Arthritis Impact Measurement Scales questionnaire. These findings call into question the appropriateness of using hand radiographs as a determinant of disability or as a criterion for disability insurance benefits.

Adolescent↗

PubMed1989

Reverse first night effect in insomnia.

This study evaluates the reverse first night effect (FNE) in insomniacs. All insomniacs evaluated at the Dartmouth Sleep Disorders Center between 1975 and 1980 were studied if they met specific criteria (n = 89). First night effects were assessed using the following four variables: sleep efficiency, sleep latency, percentage of rapid eye movement (REM) sleep, and REM latency. The 20 subjects who showed the strongest normal FNE were compared with the 20 showing the strongest reverse FNE. The two groups were similar in age, sex, and most aspects of reported home sleep. They differed in their sleep on night 1, but on nights 2 and 3 their sleep was quite similar. Both groups overestimated their sleep latencies on night 1 (by subjective reports) but unlike the normal FNE group, the reverse FNE patients very accurately assessed their sleep latency on nights 2 and 3. Reverse FNE patients had significantly higher scores than normal FNE patients on the Minnesota Multiphasic Personality Inventory (MMPI) K (defensiveness, guardedness) and Pa (paranoia) scales, and they were less depressed, marginally less anxious, and somewhat more sensation-seeking and more susceptible to boredom. This study concluded that evaluations using only 1 night in the laboratory may be missing the larger picture of a patient's insomnia. When data from only 1 laboratory night are available for an insomniac, care should be taken with the label of "subjective complaint without objective findings" in patients who are defensive, guarded, and sensation-seeking.

Arousal↗

PubMed1989

An overview of randomized trials of rehabilitation with exercise after myocardial infarction.

Of 22 randomized trials of rehabilitation with exercise after myocardial infarction (MI), one trial had results that achieved conventional statistical significance. To determine whether or not these studies, in the aggregate, show a significant benefit of rehabilitation after myocardial infarction, we performed an overview of all randomized trials, involving 4,554 patients; we evaluated total and cardiovascular mortality, sudden death, and fatal and nonfatal reinfarction. For each endpoint, we calculated an odds ratio (OR) and 95% confidence interval (95% CI) for the trials combined. After an average of 3 years of follow-up, the ORs were significantly lower in the rehabilitation than in the comparison group: specifically, total mortality (OR = 0.80 [0.66, 0.96]), cardiovascular mortality (OR = 0.78 [0.63, 0.96]), and fatal reinfarction (OR = 0.75 [0.59, 0.95]). The OR for sudden death was significantly lower in the rehabilitation than in the comparison group at 1 year (OR = 0.63 [0.41, 0.97]). The data were compatible with a benefit at 2 (OR = 0.76 [0.54, 1.06]) and 3 years (OR = 0.92 [0.69, 1.23]), but these findings were not statistically significant. For nonfatal reinfarction, there were no significant differences between the two groups after 1 (OR = 1.09 [0.76, 1.57]), 2 (OR = 1.10 [0.82, 1.47]), or 3 years (OR = 1.09 [0.88, 1.34]) of follow-up. The observed 20% reduction in overall mortality reflects a decreased risk of cardiovascular mortality and fatal reinfarction throughout at least 3 years and a reduction in sudden death during the 1st year after infarction and possibly for 2-3 years. With respect to the independent effects of the physical exercise component of cardiac rehabilitation, the relatively small number of "exercise only" trials, combined with the possibility that they may have had a formal or informal nonexercise component precludes the possibility of reaching any definitive conclusion. To do so would require a randomized trial of sufficient size to distinguish between no effect and the most plausible effect based on the results of this overview.

Clinical Trials as Topic↗

PubMed1989

Steroid treatment of laryngotracheitis: a meta-analysis of the evidence from randomized trials.

The use of adrenocorticoids to reduce the morbidity associated with laryngotracheitis (croup) remains controversial despite ten published reports of randomized trials involving 1,286 patients. To determine whether, viewed in aggregate, these studies demonstrate a significant benefit of steroid treatment for this disorder, a meta-analysis of the nine methodologically satisfactory trials was performed. Clinical improvement 12 and 24 hours posttreatment and incidence of endotracheal intubation were evaluated. For each end point, an estimate of the overall effect was obtained by calculating a typical odds ratio and 95% confidence interval. This analysis indicates that the use of steroids in children hospitalized with croup is associated with a significantly increased proportion of patients showing clinical improvement 12 hours (odds ratio = 2.25, 95% confidence interval = 1.66, 3.06) and 24 hours (odds ratio = 3.19, 95% confidence interval = 1.70, 5.99) posttreatment and a significantly reduced incidence of endotracheal intubation (odds ratio = 0.21, 95% confidence interval = 0.05, 0.84). Higher initial doses of steroid (greater than or equal to 125 mg of cortisone or greater than or equal to 100 mg of hydrocortisone) were associated with a larger proportion of patients improved 12 hours posttreatment than was seen with lower doses. These results support the use of steroids in the treatment of hospitalized children with croup and, in the absence of a randomized clinical trial of sufficient size, provide the most reliable estimate of the impact of steroid therapy on the morbidity associated with croup. In addition, the results of this meta-analysis may be used to estimate the number of subjects who would be required to conduct a randomized clinical trial of steroids for the treatment of croup.

Child, Preschool↗

PubMed1989

Detection of hepatotoxicity associated with methotrexate therapy for psoriasis.

To determine whether liver function tests and clinical and demographic information would predict methotrexate-associated hepatotoxicity, we identified 78 patients who had undergone 147 liver biopsies associated with methotrexate therapy for psoriasis. The joint sensitivity of aspartate aminotransferase, alkaline phosphatase, and total bilirubin values in detecting abnormal results from a biopsy specimen obtained after treatment was .86; the predictive value of negative test results was .93. A logistic regression model significantly predicted the presence of abnormal (grade III or higher) liver biopsy specimen results. The concordance index was .92 (perfect, 1.0). Regression coefficients may be used along with information from a specific patient to calculate the predicted probability of an abnormal result from a liver biopsy specimen after treatment. We conclude that this multivariate risk estimation model significantly predicts the likelihood of positive findings from liver biopsy specimens in this patient population. The clinical use of this model awaits further validation.

Biopsy↗

PubMedDate not supplied

A physician-completed patient registry system: pilot results for unstable angina in the elderly. The Northern New England Cardiovascular Disease Study Group and the Dartmouth Primary Care COOP.

OBJECTIVE: For many common conditions, such as unstable angina pectoris (UAP) in the elderly, the course of the disease and the influence of treatments on outcome need to be better described. In this report the authors demonstrate how a simple pocket-sized card system can be used by busy clinicians to identify patient cohorts and follow the courses of their illnesses. DESIGN AND SETTING: Twelve university-based and 12 rural clinicians enrolled consecutive patients over the age of 64 with UAP. One week and six weeks after patient enrollment the physicians described treatments, diagnoses, and patient outcomes. RESULTS: The median age of the 76 patients was 73 years. Within one week of enrollment for UAP, ten (13%) suffered myocardial infarctions or died; by six weeks this adverse event rate was 26%. The presence of three or more clinical criteria for UAP (odds ratio 9.9; 95% CI 2.4-41.5) and "ST changes" by electrocardiography (odds ratio 9.5; 95% CI 2.5-35.6) were strongly associated with death or myocardial infarction within a week after enrollment. CONCLUSION: These findings suggest that the use of a clinician-completed patient registry will allow designation of clinically important high- and low-risk UAP. A registry system such as that described here may be useful for the initial evaluation of treatment and outcomes of illness.

Aged↗

PubMedDate not supplied

A meta-analysis of randomized trials of fish oil in prevention of restenosis following coronary angioplasty.

The efficacy of fish oil in decreasing restenosis following percutaneous transluminal coronary angioplasty (PTCA) remains controversial despite seven published reports of randomized trials involving 951 patients. We performed a meta-analysis to determine whether these trials, viewed in aggregate, demonstrate a significant benefit. We evaluated rates of restenosis two to 12 months after PTCA and calculated an estimate of the overall effect and 95% confidence interval (CI). The typical odds ratio (treatment versus control) was 0.71 (95% CI 0.54, 0.94), P = 0.016 (two-tailed). The data show a strong and highly significant (P less than .0001) relationship between daily fish oil dose and gastrointestinal side effects. While compatible with a small to moderate benefit of fish oil on rates of restenosis, these results require confirmation in a randomized clinical trial large enough to distinguish reliably between a clinically meaningful benefit and a null result.

Angioplasty, Balloon, Coronary↗