Yoshinori Noguchi

The effects of cessation from cigarette smoking on the lipid and lipoprotein profiles: a meta-analysis

BACKGROUND Cross-sectional studies revealed that cigarette smokers have lower high-density lipoprotein cholesterol (HDL-C) levels and higher levels of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and triglycerides (TG) than nonsmokers. But prospective studies on the effects of cigarette smoking cessation on lipid profile have yielded inconclusive results. METHODS Relevant English articles were retrieved by keyword searches of MEDLINE (1966-October 2000), Cochrane Library (2000, Issue 2), and cited references. Twenty-seven studies met the following inclusion criteria: (1) prospective cohort study including clinical trials, (2) measuring smoking status and lipid profile of HDL-C, TC, LDL-C, and TG, (3) reporting the changes of lipid concentrations in abstinent smokers, and (4) not using adjuvant antihyperlipidemic drugs. RESULTS Overall Q statistics for net change of HDL-C, TC, LDL-C, and TG showed heterogeneity. Using a random-effects model, HDL-C level increased significantly [0.100 (CI 0.074 to 0.127) mmol/L] after smoking cessation. However, levels of TC [+0.003 (CI -0.042 to 0.048)], LDL-C [-0.064 (CI -0.149 to 0.021)], and TG [+0.028 (CI -0.014 to 0.071)] did not change significantly after smoking cessation. CONCLUSIONS Cigarette smoking cessation increases serum levels of HDL-C but not of TC, LDL-C, and TG.

Early Versus Delayed Cholecystectomy for Acute Cholecystitis: A Meta-analysis of Randomized Controlled Trials

PurposeWe performed a meta-analysis of randomized controlled trials to determine the optimal timing of laparoscopic cholecystectomy and open cholecystectomy for acute cholecystitis.MethodsWe retrieved randomized controlled trials (RCTs) that compared early with delayed cholecystectomy for acute cholecystitis by systematically searching Medline and the Cochrane Library for studies published between 1966 and 2003. The outcomes of primary interest were mortality and morbidity.ResultsThe ten trials we analyzed comprised 1 014 subjects; 534 were assigned to the early group and 480 assigned to the delayed group. The combined risk difference of mortality appeared to favor open cholecystectomy in the early period (risk difference, −0.02; 95% confidence interval, −0.44 to −0.00), but no differences were found among laparoscopic procedures or among all procedures. The combined risk difference of morbidity showed no differences between the open and laparoscopic procedures. The combined risk difference of the rate of conversion to open surgery showed no differences in the included laparoscopic studies; however, the combined total hospital stay was significantly shorter in the early group than in the delayed group.ConclusionsThere is no advantage to delaying cholecystectomy for acute cholecystitis on the basis of outcomes in mortality, morbidity, rate of conversion to open surgery, and mean hospital stay. Thus, early cholecystectomy should be performed for patients with acute cholecystitis.

Diagnostic value of adenosine deaminase in tuberculous pleural effusion: a meta-analysis

Background: Many studies have investigated the usefulness of adenosine deaminase activity (ADA) in pleural fluid for the early diagnosis of tuberculous pleurisy. To summarize the diagnostic characteristics of ADA we undertook a meta-analysis using a summary receiver operating characteristic (SROC) curve method. Methods: Data sources were MEDLINE (1966-1999), the Cochrane Library and bibliographies of review and original articles. Studies were included if the absolute numbers of true positive, false negative, true negative and false positive observations were available or could be derived from the data presented; gold standards were described explicitly; and the criteria for a positive ADA result were reported. We constructed an SROC curve based on these extracted data to estimate the test characteristics. Results: Forty articles were available for analysis. The gold standards used were pleural biopsy histology, microbiological examination of pleural fluid, pleural biopsy and sputum and the patients clinical course or combinations of these. The sensitivity of ADA reported in the articles ranged from 47·1% to 100% and the specificity from 50·0% to 100%. The summary measure of test characteristics derived from the SROC curve was 92·2% for both sensitivity and specificity. Conclusions: The test performance of ADA in tuberculous pleural effusion is reasonably good. Measurement of pleural ADA is thus likely to be a useful diagnostic tool for tuberculous pleurisy.

Treatment of acute pancreatitis with protease inhibitors: a meta-analysis

Objectives Protease inhibitors are used to treat acute pancreatitis, but their effectiveness remains unclear. We performed a meta-analysis to determine whether treatment with protease inhibitors reduces overall mortality or morbidity from acute pancreatitis. Methods Articles of randomized controlled trials evaluating effects of protease inhibitors for acute pancreatitis were retrieved by systematically searching Medline, the Cochrane Library and Journal@ovid databases published from January 1966 through December 2003. References of review articles were also searched manually. The main outcome in interest was the overall mortality rate from acute pancreatitis. Results Ten studies met the inclusion criteria. Treatment with protease inhibitors did not significantly reduce the mortality rate from acute pancreatitis (pooled risk difference, −0.03; 95% confidence interval, −0.07 to 0.01). Subgroup analyses showed that treatment with protease inhibitors significantly reduced the mortality rate in patients with moderate to severe pancreatitis (pooled risk difference, −0.07; 95% confidence interval, −0.13 to −0.01) as defined by mortality rate in the control group (control mortality rate > 0.10). The decrease in mortality rate was not significant in mild pancreatitis (pooled risk difference, 0.00; 95% confidence interval, −0.04 to 0.05). Conclusions Treatment with protease inhibitors does not significantly reduce the mortality in patients with acute or mild pancreatitis, but may reduce the mortality in patients with moderate to severe pancreatitis.

Comparison of effects in randomized controlled trials with observational studies in digestive surgery.

Objectives:To compare the results of randomized controlled trials versus observational studies in meta-analyses of digestive surgical topics. Summary Background Data:While randomized controlled trials have been recognized as providing the highest standard of evidence, claims have been made that observational studies may overestimate treatment benefits. This debate has recently been renewed, particularly with regard to pharmacotherapies. Methods:The PubMed (1966 to April 2004), EMBASE (1986 to April 2004) and Cochrane databases (Issue 2, 2004) were searched to identify meta-analyses of randomized controlled trials in digestive surgery. Fifty-two outcomes of 18 topics were identified from 276 original articles (96 randomized trials, 180 observational studies) and included in meta-analyses. All available binary data and study characteristics were extracted and combined separately for randomized and observational studies. In each selected digestive surgical topic, summary odds ratios or relative risks from randomized controlled trials were compared with observational studies using an equivalent calculation method. Results:Significant between-study heterogeneity was seen more often among observational studies (5 of 12 topics) than among randomized trials (1 of 9 topics). In 4 of the 16 primary outcomes compared (10 of 52 total outcomes), summary estimates of treatment effects showed significant discrepancies between the two designs. Conclusions:One fourth of observational studies gave different results than randomized trials, and between-study heterogeneity was more common in observational studies in the field of digestive surgery.

Quantitative Evaluation of the Diagnostic Thinking Process in Medical Students

OBJECTIVE: To explore the diagnostic thinking process of medical students.SUBJECTS AND METHODS: Two hundred twenty-four medical students were presented with 3 clinical scenarios corresponding to high, low, and intermediate pre-test probability of coronary artery disease. Estimates of test characteristics of the exercise stress test, and pre-test and post-test probability for each scenario were elicited from the students (intuitive estimates) and from the literature (reference estimates). Post-test probabilities were calculated using Bayes’ theorem based upon the intuitive estimates (Bayesian estimates of post-test probability) and upon the reference estimates (reference estimates of post-test probability). The differences between the reference estimates and the intuitive estimates, and between Bayesian estimates and the intuitive estimates were used for assessing knowledge of test characteristics, and ability of estimating pre-test and post-test probability of disease.RESULTS: Medical students could not rule out disease in low or intermediate pre-test probability settings, mainly because of poor pre-test estimates of disease probability. They were also easily confused by test results that differed from their anticipated results, probably because of their inaptitude in applying Bayes’ theorem to real clinical situations. These diagnostic thinking patterns account for medical students or novice physicians repeating unnecessary examinations.CONCLUSIONS: Medical students’ diagnostic ability may be enhanced by the following educational strategies: 1) emphasizing the importance of ruling out disease in clinical practice, 2) training in the estimation of pre-test disease probability based upon history and physical examination, and 3) incorporation of the Bayesian probabilistic thinking and its application to real clinical situations.

Optimal Strategy for the First Episode of Primary Spontaneous Pneumothorax in Young Men: A Decision Analysis

OBJECTIVE: Primary spontaneous pneumothorax (PSP) is not uncommon in young men and is associated with frequent recurrence. The frequent recurrence after conservative treatment and resultant anxiety for recurrence are sources of disability. We explored which procedure is more appropriate as the initial therapy in terms of quality-adjusted life expectancy (QALE).DESIGN: Decision analysis using a Markov model.DATA SOURCES: Structured literature review for clinical probability. Utility derived from patients and medical staff using time trade-off method.SETTING: Hypothetical cohort.PATIENTS: Twenty-year-old men with a first episode of PSP for which simple aspiration was ineffective.INTERVENTIONS: One of the following treatment options: 1) thoracoscopic surgery, 2) pleural drainage followed by thoracoscopic surgery for recurrence, 3) pleural drainage followed by thoracoscopic surgery for the second recurrence, 4) pleurodesis followed by thoracoscopic surgery for recurrence, 5) pleurodesis followed by thoracoscopic surgery for the second recurrence, 6) pleural drainage followed by pleurodesis for the first recurrence and thoracoscopic surgery for the second recurrence.MEASUREMENTS AND MAIN RESULTS: During the 1-year period after one of the initial treatments, the QALE was 9.49 months for thoracoscopic surgery, 9.47 for pleurodesis, and 7.80–7.99 for pleural drainage. The QALE for thoracoscopic surgery was the longest among the 6 strategies during the period from 5 to 24 months. None of the variables in sensitivity analyses altered the main results except for thoracoscopic surgical death rate. When it exceeds 0.3%, pleurodesis becomes the preferred strategy.CONCLUSION: On the basis of the current best available data and patients’ preference, thoracoscopic surgery can be considered the treatment of choice for the first episode of PSP.

Single- versus two- layer intestinal anastomosis: a meta-analysis of randomized controlled trials

BackgroundTo compare single- with two- layer intestinal anastomosis after intestinal resection: a meta-analysis of randomized controlled trials.MethodsRandomized controlled trials comparing single- with two-layer intestinal anastomosis were identified using a systematic search of Medline, Embase and the Cochrane Library Databases covering articles published from 1966 to 2004. Outcome of primary interest was postoperative leak. A risk ratio for trial outcomes and weighted pooled estimates for data were calculated. A fixed-effect model weighted using Mantel-Haenszel methods and a random-effect model using DerSimonian-Laird methods were employed.ResultsSix trials were analyzed, comprising 670 participants (single-layer group, n = 299; two-layer group, n = 371). Data on leaks were available from all included studies. Combined risk ratio using DerSimonian-Laird methods was 0.91 (95% CI = 0.49 to 1.69), and indicated no significant difference. Inter-study heterogeneity was significant (χ2 = 10.5, d.f. = 5, p = 0.06).ConclusionNo evidence was found that two-layer intestinal anastomosis leads to fewer post-operative leaks than single layer. Considering duration of the anastomosis procedure and medical expenses, single-layer intestinal anastomosis appears to represent the optimal choice for most surgical situations.

Protease inhibitors for preventing complications associated with ERCP: an updated meta-analysis

BACKGROUND AND OBJECTIVES The prophylactic use of protease inhibitors in patients undergoing ERCP is still controversial. Our purpose was to evaluate the efficacy of protease inhibitors in preventing ERCP-associated complications. DESIGN AND SETTING Meta-analysis; randomized trials that evaluated the efficacy of protease inhibitors were identified. PATIENTS A total of 4966 patients were evaluated. MAIN OUTCOME MEASUREMENTS ERCP-associated pancreatitis, hyperamylasemia, abdominal pain, and death. RESULTS Eighteen studies (19 cohorts) met the inclusion criteria. Overall results for protease inhibitors showed a significant but small risk reduction in ERCP-associated pancreatitis (pooled risk difference [RD]: -0.029; 95% CI, -0.051 to -0.008 and the number needed to treat, 34.5; 95% CI, 19.6-125). Subgroup analysis in 8 high-quality studies showed a borderline significant efficacy (pooled RD, -0.027; 95% CI, -0.051 to -0.004). Subgroup analysis in 8 gabexate studies did not show significant efficacy (pooled RD, -0.030; 95% CI, -0.062 to 0.003). Subgroup analysis in 5 ulinastatin studies was significant (pooled RD, -0.035; 95% CI, -0.063 to -0.006). Two high-quality studies on ulinastatin yielded nonsignificant results. Analyses for the other outcomes were all nonsignificant. Sensitivity analysis showed that the effect size and level of statistical significance were decreased with increasing study quality. CONCLUSIONS At present, there is no solid evidence to support the use of protease inhibitors to prevent ERCP-associated complications. Although overall and ulinastatin subgroup analyses showed a small risk reduction for pancreatitis, it seems very possible that low-quality primary studies produced a veneer of efficacy.

Estimating the effect of bystander-initiated cardiopulmonary resuscitation in Japan

Low incidence of bystander-initiated cardiopulmonary resuscitation (CPR) is allegedly responsible for poor survival from out-of-hospital cardiac arrest (OHCA) in Japan. This study was conducted to determine significant predictors for survival after collapse-witnessed OHCA of presumed cardiac etiology to investigate the impact of bystander-initiated CPR. Logistic regression analysis of OHCA of presumed cardiac etiology was performed on retrospective data sets from three Japanese suburban communities. All arrest incidents were witnessed and occurred prior to the arrival of EMS personnel. Outcome measure was survival to discharge. Initial electrocardiogram (ECG) rhythm (ventricular fibrillation (VF) or not), interval from collapse to CPR (within 5 min or not), and initial ECG rhythm/collapse-to-CPR interval interaction were significantly associated with survival. Patient age (70 years or less/over 70 years), interval from collapse to EMS response, and bystander-initiated CPR were significantly associated with VF in an initial ECG. The effectiveness of bystander-initiated CPR for OHCA can be successfully predicted based on the interval from collapse to CPR and initial ECG rhythm. The increase in the proportion of bystander-initiated CPR from the present level of 20-50% would be expected to rescue another 1800 victims of OHCA per year in Japan.