Randomized controlled trials in industrial low back pain. Part 3. Subacute/chronic pain interventions.

The most significant costs attributed to settlement of workplace back injury claims are related to chronic low back pain (LBP). Unfortunately, our knowledge of this fact has not led to a reduction of the considerable costs paid out annually by employers and insurers to deal with the chronic pain syndrome. This article is the third in a series of reviews on randomized controlled trials found in the English language medical literature between 1975 and 1993. Of more than 4,000 LBP citations, 35 studies met-the selection criteria of randomization, reasonable concurrent controls and work return comparisons. This review focuses on the 12 studies utilizing nonsurgical interventions for subacute and chronic LBP, including multidisciplinary pain clinics, exercise, cognitive-behavioral strategies, and others. A 26-point quality system was again used to compare the methodologic rigor of each study. The majority of prospective studies investigating return to work after chronic LBP have methodological limitations; additional research is clearly needed to more confidently answer the question of what interventions improve work capacity in patients with chronic LBP.

Randomized controlled trials in industrial low back pain relating to return to work. Part 2. Discogenic low back pain.

The purpose of this review was to determine the efficacy of treatments for discogenic low back pain (LBP) by examining all randomized controlled trials (RCTs) of discogenic LBP published in the English language literature between 1975 and 1993 with "return to work" (RTW) as the end point. From more than 4,000 LBP citations, nearly 600 articles were initially reviewed; 35 studies met our selection criteria. Twenty-two studies were discussed in Part 1 (Acute Interventions) or will be discussed in Part 3 (Chronic Interventions). In this review, of 13 RCTs assessing interventions for LBP with sciatica, 9 were appropriate for their focus on, and radiologic confirmation of, discogenic LBP. The treatments assessed included chemonucleolysis, surgical discectomy, and epidural steroid injection. A 26-point system to assess the quality of methodologic rigor was used for each article. Our literature survey found a need for additional studies comparing surgery, conservative care, epidural steroids, traction, and other approaches to determine their individual effects for RTW after discogenic disease.

Randomized controlled trials in industrial low back pain relating to return to work. Part 1. Acute interventions.

Employers and insurers are interested in being able to use cost-effective interventions for returning injured workers to the workplace. Unfortunately, truly objective information is lacking. The purpose of this and two subsequent review articles was to perform thorough scrutiny and methodologic comparison among all obtainable, published randomized and controlled studies on low back pain (LBP) interventions leading to return to work. The study was confined to English language articles published from 1975 through 1993. Of more than 4,000 LBP citations, more than 500 were chosen for review. Of that number, 35 articles met the selection criteria of randomization, reasonable controls, and work return comparisons. This paper focuses on the 10 articles relating to interventions for acute (less than 4 weeks) LBP, and considers bed rest, exercise, spinal manipulation, back school, and case management. A 26-point quality system was used to compare the methodologic rigor of each article. This literature survey demonstrated the meager scientific foundations on which our industrial rehabilitation programs are based.

Sources of variability in the human lymphocyte micronucleus assay: a population-based study.

The cytokinesis block method was used to examine the intraclass correlation coefficient of the human lymphocyte micronucleus assay, sources of variability, and practical issues regarding the number of samples per subject. Twenty samples of 100 binucleate cells from a single phlebotomy per subject were analyzed (n = 112), using methods to evaluate variance components. The results showed marked intraindividual (sampling error) variation greater than interindividual variation, and no between-group contribution to the total variance. The intraclass correlation was 41.6%, indicating that slightly greater than half of the total variation in micronucleus outcomes was due to error variance (i.e., 58.4%). After adjusting for age, the intraclass correlation coefficient decreased trivially from 41.6% to 39.8%. There was a strong differential gender effect, favoring a greater micronuclei frequency in women. In conclusion, the data suggest that most of the variability in our data set for the micronucleus assay was due to sampling error; a strong differential gender effect favoring females was also verified. Equally important, in terms of practical applications, our analysis of the appropriate number of samples per subject revealed that scoring greater than 1,000 cells (10 determinations per subject) yielded no substantial improvement in statistical sensitivity, compared to the traditional 20 determinations. We suggest that more attention should be directed toward improving the assay's utility, while reducing sampling error.

n-3 fatty acid effects on lipids, lipoproteins, and apolipoproteins at very low doses: results of a randomized controlled trial in hypertriglyceridemic subjects.

Although the hypotriglyceridemic effect of large doses of n-3 fatty acids (n-3 FAs) is well established, the effects of prolonged use of very low doses on lipids, lipoproteins, and apolipoproteins have not been clearly defined. This investigation compares the relative effects of very low, clinically practical doses of n-3 FAs on lipids, lipoproteins, and apolipoproteins in hypertriglyceridemic subjects. Ten subjects received 2.2 g n-3 FAs/d (group 1), seven received 1.1 g n-3 FAs/d (group 2), and eight received olive oil (group 3, placebo control) for 20-wk treatment period. In group 1, both low-density-lipoprotein cholesterol (LDL-C) and LDL-apolipoprotein B concentrations increased significantly from baseline values (28% and 23%, respectively; p less than 0.05) after treatment. Compared with the placebo group, the increase in LDL apolipoprotein B in both fish oil groups was statistically and clinically significant (p less than 0.05). Only minor changes in plasma triglyceride concentrations occurred. The data suggest that very low doses of n-3 FAs may cause potentially adverse increases in LDL-C and LDL-apolipoprotein B concentrations.

Decision rules and clinical prediction of pneumonia: evaluation of low-yield criteria.

Prediction rules have been recommended for guiding the ordering of diagnostic tests. Such rules can be used to define low-yield criteria (LYC) for the purpose of identifying patients with an extremely low probability of disease and hence discouraging test ordering by the physician on patients meeting LYC. In this study, community hospital emergency department populations of adults (n = 255) and children (n = 78) were evaluated prospectively for the presence of predictive clinical parameters and the physician's estimate of pneumonia prior to obtaining a chest film. We developed LYC and analyzed published LYC for obtaining chest films on patients considered at risk for pneumonia by means of logistic regression, receiver operating characteristics curve, and negative predictive value analyses. We were unable to derive or validate clinically useful LYC to improve on the seasoned clinician's probability estimate of pneumonia. We discuss the inherent limitations in the development and application of LYC that must be understood by those who seek to limit the ordering of chest films by the application of guidelines developed from decision rules.

Ibuprofen interferes with the efficacy of antihypertensive drugs. A randomized, double-blind, placebo-controlled trial of ibuprofen compared with acetaminophen.

STUDY OBJECTIVE: To assess the effects of ibuprofen on blood pressure control in patients being treated with antihypertensive drugs. DESIGN: Randomized, blinded, placebo-controlled, parallel trial of ibuprofen compared with acetaminophen and with placebo in 3-week treatment periods. SETTING: A general internal medicine clinic at a university hospital. PATIENTS: Forty-five patients with essential hypertension controlled by treatment with at least two antihypertensive drugs were enrolled. Of these, 41 completed the study; treatment was discontinued in 3 of the 15 patients in the ibuprofen group due to breakage of the drug capsules, and after randomization in 1 of the 14 patients in the placebo group due to unstable angina. All 15 patients in the acetaminophen group completed the study. INTERVENTIONS: All previous antihypertensive regimens were continued. During the 3-week treatment, ibuprofen, 400 mg, was administered orally every 8 hours; acetaminophen, 1 g, orally every 8 hours; or placebo, 2 capsules, orally every 8 hours. MEASUREMENTS AND MAIN RESULTS: In the ibuprofen group, the mean increase from baseline after 3 weeks of treatment was significant in the average supine diastolic blood pressure (6.4 mm Hg; 95% confidence interval [CI], 1.05 to 11.75; p = 0.0239); supine mean arterial pressure (6.6 mm Hg; 95% CI, 1.25 to 11.95; p = 0.0205); and sitting mean arterial pressure (5.8 mm Hg; 95% CI, 1.57 to 10.04; p = 0.0123). The mean increase in blood pressure variables in the ibuprofen group was significantly different compared with the mean increase in the variables in the placebo group after 3 weeks of treatment: supine systolic blood pressure (7.1 mm Hg compared with -4.5 mm Hg; 95% CI for the difference in means, 2.5 to 20.6; p = 0.0133); supine diastolic pressure (6.4 mm Hg compared with 0.0; 95% CI for difference in means, 0.87 to 12.4; p = 0.0250); supine mean arterial pressure (6.6 mm Hg compared with -1.5; 95% CI for difference in means, 2.0 to 14.2; p = 0.0110); sitting systolic pressure (6.8 mm Hg compared with -3.7; 95% CI for difference in means, 2.0 to 19.0; p = 0.0169); sitting diastolic pressure (5.3 mm Hg compared with -1.1; 95% CI for difference in means, 0.76 to 12.1; p = 0.0273); and sitting mean arterial pressure (5.8 mm Hg compared with -2.0; 95% CI for difference in means, 1.5 to 14.1; p = 0.0169).(ABSTRACT TRUNCATED AT 400 WORDS)

An ambulatory medical education program for internal medicine residents.

Teaching the fundamentals of ambulatory medicine has many well known difficulties. An education program with specific topics covered and modeled after continuing medical education programs for practicing physicians was instituted for residents in a university hospital clinic and was evaluated. The program was effective in improving the residents' knowledge, in enhancing their attitudes toward the clinic, and in improving their performance of influenza vaccinations. No adverse effects of the program were found. This approach, in which a curriculum is carefully defined and participation of the house staff is required, makes the ambulatory medical education process more accountable for what is taught.

The likelihood ratio. An improved measure for reporting and evaluating diagnostic test results.

The principles and use of likelihood ratios are presented as an aid to the reporting and interpretation of diagnostic data. Likelihood ratios can be determined for multiple levels of test results and provide a readily comprehensible and convenient measure for computing the posttest probability of disease. Unlike sensitivity and specificity, they convey an immediate and direct description of a test's ability to revise the initial probability of disease upward or downward. By incorporating all the raw data, the use of likelihood ratios can improve the assessment of the clinical utility of test results. Their application to the diagnostic performance of serum creatine kinase concentrations in predicting patients with suspected myocardial infarction is discussed.

Syncope. Cost-effective patient workup.

Syncope is a common problem in primary care practice that presents a diagnostic challenge. Fortunately, the initial evaluation not only identifies the cause in most patients with an identifiable cause, it also defines the prognosis for these patients. A systematic history, physical examination, and 12-lead ECG are the foundation of this evaluation and provide the most cost-effective diagnostic strategy. When signs and symptoms indicate a neurologic, cardiac, or carotid sinus problem, diagnostic procedures such as angiography, electroencephalography, cardiac catheterization, echocardiography, or carotid sinus massage should be added, but only as necessary to confirm the diagnosis. At the University of Cincinnati, we monitor patients with syncope of unknown origin with 24-hour ambulatory ECG recording and interpret the results as outlined in table 2. If not referred for cardiac or neurologic consultation, these patients are evaluated every three months for a year. This approach can minimize unnecessary testing and improve patient care.