J Lau

Pontifical Xavierian University (Bogota), Bogotá, Bogota D.C., Colombia

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Publications (101)860.8 Total impact

  • Article: Short-term treatment with proton pump inhibitors, H2-receptor antagonists and prokinetics for gastro-oesophageal reflux disease-like symptoms and endoscopy negative reflux disease.
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    ABSTRACT: Approximately 25% of adults experience heartburn, the cardinal feature of gastro-oesophageal reflux disease (GORD), at least monthly. The evaluation and treatment of patients with suspected GORD is associated with a substantial economic burden. Most patients are treated empirically (without specific diagnostic evaluation). They include a wide range of underlying oesophageal injury. The severity of oesophageal injury can only be established in those who have undergone upper endoscopy. Patients without visible damage to the oesophagus have been referred to as having endoscopy negative reflux disease (ENRD). The pathogenesis of ENRD as well as its response to treatment may differ from GORD with oesophagitis. Summarise, quantify and compare the efficacy of the short-term use of proton pump inhibitors (PPI), H2-receptor antagonists (H2RA) and prokinetics in adults with GORD, treated empirically and in those with endoscopy negative reflux disease (ENRD). We searched the Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 4, 2005), MEDLINE (January 1966 to December 2005), EMBASE (January 1988 to December 2005). Randomised controlled trials focussing on symptomatic outcome after short-term treatment for GORD using proton pump inhibitors, H2-receptor antagonists or prokinetic agents. Studies were included provided that participants could be classified in the empirical treatment group (no endoscopy used in treatment allocation) or in the endoscopy negative reflux disease group (no endoscopic signs of erosive oesophagitis). Two reviewers independently assessed trial quality and extracted data. Thirty-one trials (9457 participants) were included: fifteen in the empirical treatment group, twelve in the ENRD group and four in both. In empirical treatment of GORD the relative risk (RR) for heartburn remission (the primary efficacy variable) in placebo-controlled trials for PPI was 0.37 (two trials, 95% confidence interval (CI) 0.32 to 0.44), for H2RAs 0.77 (two trials, 95% CI 0.60 to 0.99) and for prokinetics 0.86 (one trial, 95% CI 0.73 to 1.01). In a direct comparison PPIs were more effective than H2RAs (seven trials, RR 0.66, 95% CI 0.60 to 0.73) and prokinetics (two trials, RR 0.53, 95% CI 0.32 to 0.87). In treatment of ENRD, the RR for heartburn remission for PPI versus placebo was 0.69 (seven trials, 95% CI 0.62 to 0.78) and for H2RA versus placebo was 0.84 (two trials, 95% CI 0.74 to 0.95). The RR for PPI versus H2RA was 0.78 (three trials, 95% CI 0.62 to 0.97) and for PPI versus prokinetic 0.72 (one trial, 95% CI 0.56 to 0.92). PPIs are more effective than H2RAs in relieving heartburn in patients with GORD who are treated empirically and in those with ENRD, although the magnitude of benefit is greater for those treated empirically.
    Cochrane database of systematic reviews (Online) 02/2006; · 5.72 Impact Factor
  • Article: Patient controlled opioid analgesia versus conventional opioid analgesia for postoperative pain.
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    ABSTRACT: Patients may control postoperative pain by self-administration of intravenous opioids using devices designed for this purpose (patient controlled analgesia or PCA). A 1992 meta-analysis by Ballantyne found a strong patient preference for PCA over conventional analgesia but disclosed no differences in analgesic consumption or length of postoperative hospital stay. Although Ballantyne's meta-analysis found that PCA did have a small but statistically significant benefit upon pain intensity, Walder's review in 2001 did not find a significant differences in pain intensity and pain relief between PCA and conventionally treated groups. To evaluate the efficacy of PCA versus conventional analgesia (such as a nurse administering an analgesic upon a patient's request) for postoperative pain control. Randomized controlled trials (RCTs) were identified from the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2004, Issue 3), MEDLINE (1966 to 2004), and EMBASE (1994 to 2004). Additional reports were identified from the reference lists of retrieved papers. RCTs of PCA versus conventional analgesia that employed pain intensity as a primary or secondary outcome were selected. These trials included RCTs that compared PCA without a continuous background infusion versus conventional parenteral analgesic regimens. Studies that explicitly stated they involved patients with chronic pain were excluded. Trials were scored using the Oxford Quality Scale. Meta-analyses were performed of outcomes that included analgesic efficacy assessed by a Visual Analog Scale (VAS), analgesic consumption, patient satisfaction, length of stay and adverse effects. A sufficient number of the retrieved trials reported these parameters to permit meta-analyses. Fifty-five studies with 2023 patients receiving PCA and 1838 patients assigned to a control group met inclusion criteria. PCA provided better pain control and greater patient satisfaction than conventional parenteral 'as-needed' analgesia. Patients using PCA consumed higher amounts of opioids than the controls and had a higher incidence of pruritus (itching) but had a similar incidence of other adverse effects. There was no difference in the length of hospital stay. This review provides evidence that PCA is an efficacious alternative to conventional systemic analgesia for postoperative pain control.
    Cochrane database of systematic reviews (Online) 02/2006; · 5.72 Impact Factor
  • Article: Music for pain relief.
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    ABSTRACT: The efficacy of music for the treatment of pain has not been established. To evaluate the effect of music on acute, chronic or cancer pain intensity, pain relief, and analgesic requirements. We searched The Cochrane Library, MEDLINE, EMBASE, PsycINFO, LILACS and the references in retrieved manuscripts. There was no language restriction. We included randomized controlled trials that evaluated the effect of music on any type of pain in children or adults. We excluded trials that reported results of concurrent non-pharmacological therapies. Data was extracted by two independent review authors. We calculated the mean difference in pain intensity levels, percentage of patients with at least 50% pain relief, and opioid requirements. We converted opioid consumption to morphine equivalents. To explore heterogeneity, studies that evaluated adults, children, acute, chronic, malignant, labor, procedural, or experimental pain were evaluated separately, as well as those studies in which patients chose the type of music. Fifty-one studies involving 1867 subjects exposed to music and 1796 controls met inclusion criteria. In the 31 studies evaluating mean pain intensity there was a considerable variation in the effect of music, indicating statistical heterogeneity ( I(2) = 85.3%). After grouping the studies according to the pain model, this heterogeneity remained, with the exception of the studies that evaluated acute postoperative pain. In this last group, patients exposed to music had pain intensity that was 0.5 units lower on a zero to ten scale than unexposed subjects (95% CI: -0.9 to -0.2). Studies that permitted patients to select the music did not reveal a benefit from music; the decline in pain intensity was 0.2 units, 95% CI (-0.7 to 0.2). Four studies reported the proportion of subjects with at least 50% pain relief; subjects exposed to music had a 70% higher likelihood of having pain relief than unexposed subjects (95% CI: 1.21 to 2.37). NNT = 5 (95% CI: 4 to 13). Three studies evaluated opioid requirements two hours after surgery: subjects exposed to music required 1.0 mg (18.4%) less morphine (95% CI: -2.0 to -0.2) than unexposed subjects. Five studies assessed requirements 24 hours after surgery: the music group required 5.7 mg (15.4%) less morphine than the unexposed group (95% CI: -8.8 to -2.6). Five studies evaluated requirements during painful procedures: the difference in requirements showed a trend towards favoring the music group (-0.7 mg, 95% CI: -1.8 to 0.4). Listening to music reduces pain intensity levels and opioid requirements, but the magnitude of these benefits is small and, therefore, its clinical importance unclear.
    Cochrane database of systematic reviews (Online) 02/2006; · 5.72 Impact Factor
  • Article: Effects of soy on health outcomes.
    Evidence report/technology assessment (Summary) 09/2005;
  • Source
    Article: Update on acute bacterial rhinosinusitis.
    Evidence report/technology assessment (Summary) 07/2005;
  • Article: Effects of omega-3 fatty acids on organ transplantation.
    Evidence report/technology assessment (Summary) 03/2005;
  • Article: NSAIDS or paracetamol, alone or combined with opioids, for cancer pain.
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    ABSTRACT: NSAIDs are widely applied to treat cancer pain and are frequently combined with opioids in combination preparations for this purpose. However, it is unclear which agent is most clinically efficacious for relieving cancer-related pain, or even what may be the additional benefit of combining an NSAID with an opioid in this setting. To assess the effects of NSAIDs, alone or combined with opioids, for the treatment of cancer pain. We searched the Cochrane Central Register of Controlled Trials (Issue 2, 2002), MEDLINE (January 1966 to March 2003), EMBASE (January 1980 to December 2001), LILACS (January 1984 to December 2001) and reference list of articles. Randomized controlled trials and controlled clinical trials that compared NSAID versus placebo; NSAID versus NSAID; NSAID versus NSAID plus opioid; opioid versus opioid plus NSAID; or NSAID versus opioid. Two reviewers independently assessed trial quality and extracted data. Study authors were contacted for additional information. Adverse event information was collected from trials. Where there was disagreement between reviewers, the opinion of an additional reviewer was sought to resolve the issue. Forty-two trials involving 3084 patients were included. Clinical heterogeneity of study methods and outcomes precluded meta-analyses and only supported a qualitative systematic review. Seven of eight papers that compared NSAID with placebo demonstrated superior efficacy of NSAID with no difference in side effects. Thirteen papers compared one NSAID with another; four reported increased efficacy of one NSAID over another. Four different studies found that one NSAID had fewer side effects than one or more others. Twenty-three studies compared NSAIDs and opioids in combination or alone with NSAID/opioid combinations. Thirteen out of 14 studies found no difference, or low clinical difference, when combining an NSAID plus an opioid versus either drug alone. Comparisons between various NSAID/opioid combinations were inconclusive. Nine studies assessed the association between dose and efficacy and safety. Four papers demonstrated increased efficacy with increased dose, but no dose-dependent increase in side effects within the dose ranges studied. Study duration ranged from single dose studies performed over six hours to crossover studies lasting six weeks; however the majority of studies were of less than seven days duration. Based upon limited data, NSAIDs appear to be more effective than placebo for cancer pain; clear evidence to support superior safety or efficacy of one NSAID over another is lacking; and trials of combinations of an NSAID with an opioid have disclosed either no difference (4 out of 14 papers), a statistically insignificant trend towards superiority (1 out of 14 papers), or at most a slight but statistically significant advantage (9 out of 14 papers), compared with either single entity. The short duration of studies undermines generalization of their findings on efficacy and safety of NSAIDs for cancer pain.
    Cochrane database of systematic reviews (Online) 02/2005; · 5.72 Impact Factor
  • Article: Local anesthetic sympathetic blockade for complex regional pain syndrome.
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    ABSTRACT: Local anesthetic blockade of the sympathetic chain is widely used to treat reflex sympathetic dystrophy (RSD) and causalgia. These two pain syndromes are now conceptualized as variants of a single entity: complex regional pain syndrome (CRPS). A recent meta-analysis of the topic has been published. However, this study only evaluated studies in English language and therefore it could have overlooked some randomized controlled trials. This systematic review had three objectives: to determine the likelihood of pain alleviation after sympathetic blockade with local anesthetics in the patient with CRPS; to assess how long any benefit persists; and to evaluate the incidence of adverse effects of the procedure. We searched the Cochrane Pain, Palliative and Supportive Care Register, the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, LILACS, and conference abstracts of the World Congresses of the International Association for the Study of Pain. Bibliographies from retrieved articles were also searched for additional studies. We considered for inclusion randomized controlled trials that evaluated the effect of sympathetic blockade with local anesthetics in children or in adult patients to treat RSD, causalgia, or CRPS. The outcomes of interest were the number of patients who obtained at least 50% of pain relief shortly after sympathetic blockade (30 minutes to 2 hours) and 48 hours or later. We also assessed the presence of adverse effects in each treatment arm. A random effects model was used to combine the studies. Two small randomized double blind cross over studies that evaluated 23 subjects were found. The combined effect of the two trials produced a relative risk (RR) to achieve at least 50% of pain relief 30 minutes to 2 hours after the sympathetic blockade of 1.17 (95% CI 0.80-1.72). It was not possible to determine the effect of sympathetic blockade on long-term pain relief because the authors of the two studies evaluated different outcomes. This systematic review revealed the scarcity of published evidence to support the use of local anesthetic sympathetic blockade as the 'gold standard' treatment for CRPS. The two randomized studies that met inclusion criteria had very small sample sizes, therefore, no conclusion concerning the effectiveness of this procedure could be drawn. There is a need to conduct randomized controlled trials to address the value of sympathetic blockade with local anesthetic for the treatment of CRPS.
    Cochrane database of systematic reviews (Online) 02/2005; · 5.72 Impact Factor
  • Article: [Trial therapy with proton pump inhibitors is not a suitable test for gastroesophageal reflux disease; a meta-analysis of the diagnostic test characteristics].
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    ABSTRACT: To determine the value of successful trial therapy with proton-pump inhibitors (PPIs) as a diagnostic test for gastro-oesophageal reflux disease (GERD). Systematic review and meta-analysis. Studies were included in which the clinical response to a short course (1-4 weeks) of PPI therapy could be related to abnormal results of 24-hr pH monitoring, gastroscopy, and/or diagnostic questionnaires. The sensitivity and specificity of the trial therapy were calculated. The ROC method was used to summarize the test characteristics across studies. With 24-hr pH monitoring as the reference standard, the positive likelihood ratio of the diagnosis 'reflux disease' ranged from 1.63 to 1.87 and the combined estimates of sensitivity and specificity in the various studies were 0.78 (95% CI: 0.66-0.86) and 0.54 (0.44-0.65), respectively. These values were lower with the other reference standards. Although there were insufficient data to determine the effect of varying dosages of PPIs and duration of therapy on the test characteristics, successful short-term treatment with PPIs in patients suspected of having GERD provides insufficient certainty as to the diagnosis.
    Nederlands tijdschrift voor geneeskunde 10/2004; 148(39):1924-8.
  • Article: Effects of omega-3 fatty acids on cardiovascular disease.
    Evidence report/technology assessment (Summary) 04/2004;
  • Article: Effects of omega-3 fatty acids on cardiovascular risk factors and intermediate markers of cardiovascular disease.
    Evidence report/technology assessment (Summary) 04/2004;
  • Article: Effects of omega-3 fatty acids on arrhythmogenic mechanisms in animal and isolated organ/cell culture studies.
    Evidence report/technology assessment (Summary) 04/2004;
  • Article: Criteria for determining disability in infants and children: short stature.
    Evidence report/technology assessment (Summary) 04/2003;
  • Article: Criteria for determining disability in infants and children: failure to thrive.
    Evidence report/technology assessment (Summary) 04/2003;
  • Source
    Article: Management of cancer symptoms: pain, depression, and fatigue.
    Evidence report/technology assessment (Summary) 08/2002;
  • Article: Management of allergic and nonallergic rhinitis.
    Evidence report/technology assessment (Summary) 06/2002;
  • Article: Effect of biocompatibility of hemodialysis membranes on mortality in acute renal failure: a meta-analysis.
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    ABSTRACT: The effect of biocompatibility of hemodialysis membranes on mortality in acute renal failure (ARF) has been a subject of intense debate, with some, but not all studies reporting a lower risk of death among patients with ARF dialyzed with biocompatible membranes (BCM) compared to bioincompatible membranes (BICM). We performed a meta-analysis of group data extracted from previously published studies of controlled clinical trials to assess the impact of BCM on the mortality among patients with ARF who required intermittent hemodialysis (IHD). BCM and BICM were defined as synthetic and cellulose-derived membranes (cuprophan and cellulose acetate), respectively. All controlled clinical trials comparing the effect of BCM to BICM on clinical outcomes in the setting of ARF were included. Original articles as well as abstracts were included. Data in Tables, Figures, and text were independently extracted by 2 of the authors. Risk ratios (RR) for mortality were combined using the random-effects model. Seven studies with a total of 722 patients met the inclusion criteria. One hundred seventy-two (45%) of 384 patients died in the BCM group, compared with 156 (46%) of 338 patients in the BICM group. The RRs for mortality ranged from 0.56-1.28. Overall, the pooled RR for mortality was 0.92 (95% CI = 0.76-1.13) in favor of the BCM group. However, the test for heterogeneity in RR among studies was significant (chi2 = 8.6, p < 0.05). One study accounted for this significance, and once removed from the model, the RR for mortality was 0.94 (95% CI = 0.79-1.12), and the test for heterogeneity among studies lost its significance. Subgroup analyses comparing BCM to cuprophan membranes revealed that the RR for mortality was 0.82 (95% CI = 0.62 - 1.08) in favor of the BCM group, whereas in the subgroup of studies comparing BCM to cellulose acetate, the RR for mortality was 1.11 (95% CI = 0.87-1.44) in favor of the BCM group. This metaanalysis demonstrates that the use of BCM does not significantly affect mortality among patients with ARF who require IHD. However, subgroup analyses suggest that cellulose acetate membranes may offer a survival advantage when compared with synthetic membranes, which, in turn, may be more beneficial than cuprophan membranes. Available evidence does not permit a recommendation for or against the use of BCM in ARF. Large trials and pooled analyses of individual patient-level data will be required to assess sources of variability among studies and non-fatal outcomes of ARF.
    Clinical nephrology 04/2002; 57(4):274-82. · 1.17 Impact Factor
  • Article: Management of clinically inapparent adrenal mass.
    Evidence report/technology assessment (Summary) 03/2002;
  • Article: Meta-analysis of randomized controlled trials on the comparative efficacy and safety of azithromycin against other antibiotics for upper respiratory tract infections.
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    ABSTRACT: We carried out a meta-analysis of randomized controlled trials comparing 3-5 days of azithromycin with other antibiotics that are typically given in longer courses for the treatment of upper respiratory tract infections. For acute otitis media (19 comparisons including 3421 patients), acute sinusitis (11 comparisons including 1742 patients) and acute pharyngitis (16 comparisons including 2447 patients), azithromycin had similar clinical failure rates to the other antibiotics [random effects odds ratios 1.12, 95% confidence interval (CI) 0.81-1.54; 0.91, 95% CI 0.60-1.39; and 1.07, 95% CI 0.59-1.94, respectively]. The difference in clinical failures was <0.5%, and no 95% CIs exceeded 2.0%. There was no heterogeneity between studies. Subtle differences between comparators could have been due to chance. There were no significant differences in bacteriological outcomes. Azithromycin was discontinued because of adverse events in only 37 of 4870 (0.8%) patients. Short courses of azithromycin are as effective as longer courses of other antibiotics for upper respiratory tract infections. Convenience of dosing should be balanced against the increased cost of this regimen for the treatment of these common infections, where often no antibiotic may be indicated at all.
    Journal of Antimicrobial Chemotherapy 12/2001; 48(5):677-89. · 5.07 Impact Factor
  • Article: Meta-analysis of randomized controlled trials on the comparative efficacy and safety of azithromycin against other antibiotics for lower respiratory tract infections.
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    ABSTRACT: We carried out a meta-analysis of randomized controlled trials of azithromycin compared with other antibiotics in the treatment of lower respiratory tract infections, including acute bronchitis (five comparisons including 1372 patients), acute exacerbations of chronic bronchitis (13 comparisons including 1342 patients) and community-acquired pneumonia (18 comparisons with 1664 patients). For the first two indications, azithromycin did not offer any statistically significant reduction in clinical failures [random effects odds ratios 0.84, 95% confidence interval (CI) 0.54-1.31 and 0.64, 95% CI 0.31-1.32, respectively] and absolute risk differences were small. For community-acquired pneumonia, azithromycin significantly reduced clinical failures by about one-third (random effects odds ratio 0.63, 95% CI 0.41-0.95). The absolute incremental benefit was approximately one clinical failure prevented per 50 treated patients with community-acquired pneumonia. There was no significant heterogeneity for different comparators and for bacterial versus atypical pneumonias. Azithromycin was discontinued because of adverse events in only 23 of 3487 patients (0.7%). Although results should be interpreted cautiously as most trials were open-label and susceptible to bias, the meta-analysis indicates that, compared with antibiotics with traditional pharmacokinetics that require more prolonged courses, azithromycin offers no significant advantage for bronchitis, but may be more effective in community-acquired pneumonia.
    Journal of Antimicrobial Chemotherapy 12/2001; 48(5):691-703. · 5.07 Impact Factor

Institutions

  • 2005
    • Pontifical Xavierian University (Bogota)
      Bogotá, Bogota D.C., Colombia
  • 2004
    • Universitair Medisch Centrum Utrecht
      Utrecht, Provincie Utrecht, Netherlands
  • 1999–2001
    • University Hospital of Ioannina
      Ioánnina, Ipeiros, Greece
  • 1995–2001
    • Tufts University
      • • Clinical Research Division
      • • Department of Medicine
      Boston, GA, USA
    • New England Baptist Hospital
      Boston, MA, USA
  • 2000
    • National Cancer Institute (USA)
      Bethesda, MD, USA
  • 1998–1999
    • National Institute of Allergy and Infectious Diseases
      Bethesda, MD, USA
    • National Institutes of Health
      Bethesda, MD, USA
    • Massachusetts General Hospital
      Boston, MA, USA
  • 1994
    • Mount Sinai School of Medicine
      Manhattan, NY, USA
    • University of Sydney
      Sydney, New South Wales, Australia
  • 1993–1994
    • Boston Children's Hospital
      Boston, MA, USA
  • 1992
    • U.S. Department of Veterans Affairs
      Washington, D. C., DC, USA
    • Harvard University
      • Department of Health Policy and Management
      Boston, MA, USA
    • Brigham and Women's Hospital
      • Department of Medicine
      Boston, MA, USA