Spencer S Liu

Summary

Affiliation: Virginia Mason Medical Center
Country: USA

Publications

  1. ncbi Patient-controlled epidural analgesia with bupivacaine and fentanyl on hospital wards: prospective experience with 1,030 surgical patients
    S S Liu
    Department of Anesthesiology, Virginia Mason Medical Center, and the University of Washington, Seattle 98111, USA
    Anesthesiology 88:688-95. 1998
  2. ncbi Hemodynamic responses to intravascular injection of epinephrine-containing epidural test doses in adults during general anesthesia
    S S Liu
    Department of Anesthesiology, Virginia Mason Medical Center, Seattle, Washington 98111, USA
    Anesthesiology 84:81-7. 1996
  3. ncbi Continuous plexus and peripheral nerve blocks for postoperative analgesia
    Spencer S Liu
    Department of Anesthesiology, Virginia Mason Medical Center, Seattle, Washington 98111, USA
    Anesth Analg 96:263-72. 2003
  4. ncbi Effects of perioperative central neuraxial analgesia on outcome after coronary artery bypass surgery: a meta-analysis
    Spencer S Liu
    Department of Anesthesiology, Virginia Mason Medical Center and the University of Washington, Seattle, Washington 98111, USA
    Anesthesiology 101:153-61. 2004
  5. ncbi Effects of Bispectral Index monitoring on ambulatory anesthesia: a meta-analysis of randomized controlled trials and a cost analysis
    Spencer S Liu
    Departments of Anesthesiology, Virginia Mason Medical Center, University of Washington, Seattle, Washington, USA
    Anesthesiology 101:311-5. 2004
  6. ncbi A comparison of regional versus general anesthesia for ambulatory anesthesia: a meta-analysis of randomized controlled trials
    Spencer S Liu
    Department of Anesthesiology, Virginia Mason Medical Center, Seattle, WA 98111, USA
    Anesth Analg 101:1634-42. 2005
  7. ncbi Prospective experience with a 20-gauge Tuohy needle for lumbar epidural steroid injections: Is confirmation with fluoroscopy necessary?
    S S Liu
    Department of Anesthesiology, Virginia Mason Medical Center, Seattle, Washington, USA
    Reg Anesth Pain Med 26:143-6. 2001
  8. ncbi Comparison of three solutions of ropivacaine/fentanyl for postoperative patient-controlled epidural analgesia
    S S Liu
    Department of Anesthesiology, Virginia Mason Medical Center, and the University of Washington, Seattle 98111, USA
    Anesthesiology 90:727-33. 1999
  9. ncbi Dose-response effects of spinal neostigmine added to bupivacaine spinal anesthesia in volunteers
    S S Liu
    Department of Anesthesiology, Virginia Mason Medical Center and the University of Washington, Seattle 98111, USA
    Anesthesiology 90:710-7. 1999
  10. doi Nerve stimulator versus ultrasound guidance for placement of popliteal catheters for foot and ankle surgery
    Daniel Maalouf
    Department of Anesthesiology, Hospital for Special Surgery, New York, NY 10021, USA
    J Clin Anesth 24:44-50. 2012

Detail Information

Publications53

  1. ncbi Patient-controlled epidural analgesia with bupivacaine and fentanyl on hospital wards: prospective experience with 1,030 surgical patients
    S S Liu
    Department of Anesthesiology, Virginia Mason Medical Center, and the University of Washington, Seattle 98111, USA
    Anesthesiology 88:688-95. 1998
    ..The efficacy and safety of patient-controlled epidural analgesia (PCEA) for postoperative analgesia on hospital wards was studied...
  2. ncbi Hemodynamic responses to intravascular injection of epinephrine-containing epidural test doses in adults during general anesthesia
    S S Liu
    Department of Anesthesiology, Virginia Mason Medical Center, Seattle, Washington 98111, USA
    Anesthesiology 84:81-7. 1996
    ..Epidural anesthesia is sometimes initiated during general anesthesia, yet few data exist concerning efficacy of epinephrine-containing test doses...
  3. ncbi Continuous plexus and peripheral nerve blocks for postoperative analgesia
    Spencer S Liu
    Department of Anesthesiology, Virginia Mason Medical Center, Seattle, Washington 98111, USA
    Anesth Analg 96:263-72. 2003
  4. ncbi Effects of perioperative central neuraxial analgesia on outcome after coronary artery bypass surgery: a meta-analysis
    Spencer S Liu
    Department of Anesthesiology, Virginia Mason Medical Center and the University of Washington, Seattle, Washington 98111, USA
    Anesthesiology 101:153-61. 2004
    ..Perioperative central neuraxial analgesia may improve outcome after coronary artery bypass surgery due to attenuation of stress response and superior analgesia...
  5. ncbi Effects of Bispectral Index monitoring on ambulatory anesthesia: a meta-analysis of randomized controlled trials and a cost analysis
    Spencer S Liu
    Departments of Anesthesiology, Virginia Mason Medical Center, University of Washington, Seattle, Washington, USA
    Anesthesiology 101:311-5. 2004
    ..Use of Bispectral Index (BIS) monitoring for titration of general anesthesia may allow use of less anesthetics, reduction in side effects, and faster patient recovery...
  6. ncbi A comparison of regional versus general anesthesia for ambulatory anesthesia: a meta-analysis of randomized controlled trials
    Spencer S Liu
    Department of Anesthesiology, Virginia Mason Medical Center, Seattle, WA 98111, USA
    Anesth Analg 101:1634-42. 2005
    ..Other factors, such as unsuitable discharge criteria and limitations of meta-analysis, may explain this discrepancy...
  7. ncbi Prospective experience with a 20-gauge Tuohy needle for lumbar epidural steroid injections: Is confirmation with fluoroscopy necessary?
    S S Liu
    Department of Anesthesiology, Virginia Mason Medical Center, Seattle, Washington, USA
    Reg Anesth Pain Med 26:143-6. 2001
    ..We prospectively examined the success rate of lumbar epidural steroid placement with loss-of-resistance (LOR) technique compared with fluoroscopy confirmation...
  8. ncbi Comparison of three solutions of ropivacaine/fentanyl for postoperative patient-controlled epidural analgesia
    S S Liu
    Department of Anesthesiology, Virginia Mason Medical Center, and the University of Washington, Seattle 98111, USA
    Anesthesiology 90:727-33. 1999
    ..The addition of 4 microg/ml fentanyl improves analgesia from epidural ropivacaine. Use of a lower concentration of ropivacaine-fentanyl may further improve analgesia or decrease side effects...
  9. ncbi Dose-response effects of spinal neostigmine added to bupivacaine spinal anesthesia in volunteers
    S S Liu
    Department of Anesthesiology, Virginia Mason Medical Center and the University of Washington, Seattle 98111, USA
    Anesthesiology 90:710-7. 1999
    ..Neostigmine is a novel spinal analgesic that could be a useful adjunct, but no data exist to assess the effects of neostigmine on small-dose bupivacaine spinal anesthesia...
  10. doi Nerve stimulator versus ultrasound guidance for placement of popliteal catheters for foot and ankle surgery
    Daniel Maalouf
    Department of Anesthesiology, Hospital for Special Surgery, New York, NY 10021, USA
    J Clin Anesth 24:44-50. 2012
    ..To determine whether ultrasound guidance improves the quality of continuous popliteal block when compared with a nerve stimulator after major foot and ankle surgery...
  11. ncbi The effect of analgesic technique on postoperative patient-reported outcomes including analgesia: a systematic review
    Spencer S Liu
    Department of Anesthesiology, The Hospital of Special Surgery, and the Cornell Weill Medical Center, New York, New York, USA
    Anesth Analg 105:789-808. 2007
    ..We performed a systematic review to examine the effect of postoperative analgesia on patient-reported outcomes...
  12. pmc Predictors for moderate to severe acute postoperative pain after total hip and knee replacement
    Spencer S Liu
    Department of Anesthesiology, Hospital for Special Surgery and Weill Cornell Medical College, 535 East 70th St, New York, NY 10021, USA
    Int Orthop 36:2261-7. 2012
    ..We undertook this multi-centre cross-sectional study to identify preoperative risk factors for moderate to severe pain after total hip (THR) and knee (TKR) replacement...
  13. pmc Association of obesity with inflammation and pain after total hip arthroplasty
    Roja Motaghedi
    Division of Endocrinology and Metabolism at Seattle Children s Hospital University of Washington, Seattle, WA, USA
    Clin Orthop Relat Res 472:1442-8. 2014
    ..As such, it may augment the postoperative inflammatory response, which has been associated with postoperative pain and complications...
  14. pmc Perioperative comparative effectiveness of anesthetic technique in orthopedic patients
    Stavros G Memtsoudis
    Department of Anesthesiology, Hospital for Special Surgery, Weill Medical College of Cornell University, New York, NY, USA
    Anesthesiology 118:1046-58. 2013
    ..We studied a large national sample of primary joint arthroplasty recipients and hypothesized that neuraxial anesthesia favorably influences perioperative outcomes...
  15. ncbi Prospective survey of patient-controlled epidural analgesia with bupivacaine and hydromorphone in 3736 postoperative orthopedic patients
    Spencer S Liu
    Department of Anesthesiology, Hospital for Special Surgery, 535 E 70th St, New York, NY 10021, USA
    Reg Anesth Pain Med 35:351-4. 2010
    ..Hydromorphone has potential advantages, yet there are no data to establish its efficacy and safety. Thus, we prospectively monitored our patients receiving PCEA with bupivacaine combined with hydromorphone after orthopedic surgery...
  16. doi A prospective clinical registry of ultrasound-guided regional anesthesia for ambulatory shoulder surgery
    Spencer S Liu
    Department of Anesthesiology, Hospital for Special Surgery, 535 East 70th St, New York, NY 10021, USA
    Anesth Analg 111:617-23. 2010
    ..Furthermore, ultrasound-guided supraclavicular block is a novel approach for shoulder anesthesia that may have less risk for neurological symptoms than interscalene block...
  17. doi Addition of pregabalin to multimodal analgesic therapy following ankle surgery: a randomized double-blind, placebo-controlled trial
    Jacques T YaDeau
    Department of Anesthesiology, Hospital for Special Surgery, Weill Cornell Medical College, NewYork, NY 10021, USA
    Reg Anesth Pain Med 37:302-7. 2012
    ..Secondary outcomes included measures of opioid and pregabalin adverse effects...
  18. doi The ASRA evidence-based medicine assessment of ultrasound-guided regional anesthesia and pain medicine: Executive summary
    Joseph M Neal
    Virginia Mason Medical Center, Seattle, WA, USA
    Reg Anesth Pain Med 35:S1-9. 2010
    ....
  19. ncbi Comparison of ropivacaine-fentanyl patient-controlled epidural analgesia with morphine intravenous patient-controlled analgesia for perioperative analgesia and recovery after open colon surgery
    Robert B Steinberg
    Department of Anesthesiology, Baystate Medical Center, Tufts University School of Medicine, Springfield, MA 01199, USA
    J Clin Anesth 14:571-7. 2002
    ..To compare the effects of ropivacaine-fentanyl patient-controlled epidural analgesia (PCEA) with morphine intravenous (IV) patient-controlled analgesia (PCA)...
  20. doi Association of perioperative use of nonsteroidal anti-inflammatory drugs with postoperative myocardial infarction after total joint replacement
    Spencer S Liu
    Department of Anesthesiology, Hospital for Special Surgery, and Weill College of Medicine of Cornell University, New York, NY 10021, USA
    Reg Anesth Pain Med 37:45-50. 2012
    ..Thus, we performed this single-center observational cohort study to determine any association between NSAID use and postoperative myocardial infarction (POMI)...
  21. ncbi Demographics, outcomes, and risk factors for adverse events associated with primary and revision total hip arthroplasties in the United States
    Stavros G Memtsoudis
    Department of Anesthesiology, Hospital for Special Surgery Weill Medical College of Cornell University, New York, NY, USA
    Am J Orthop (Belle Mead NJ) 39:E72-7. 2010
    ..Additional studies are warranted to determine causal relationships...
  22. doi A prospective survey of patient-controlled epidural analgesia with bupivacaine and clonidine after total hip replacement: a pre- and postchange comparison with bupivacaine and hydromorphone in 1,000 patients
    Spencer S Liu
    Department of Anesthesiology, Hospital for Special Surgery and Weill Cornell Medical College of Cornell University, 535 East 70th Street, New York, NY 10021, USA
    Anesth Analg 113:1213-7. 2011
    ..We performed this prospective survey to evaluate analgesia and the side effect profile in total hip replacement patients before and after a systematic change from PCEA with bupivacaine/hydromorphone to bupivacaine/clonidine...
  23. ncbi Anesthesia and analgesia for colon surgery
    Spencer S Liu
    Department of Anesthesiology, Virginia Mason Medical Center, Seattle, WA, USA
    Reg Anesth Pain Med 29:52-7. 2004
  24. ncbi Spinal anaesthesia: local anaesthetics and adjuncts in the ambulatory setting
    Francis V Salinas
    Department of Anaesthesiology, Virginia Mason Medical Center, 1100 Ninth Avenue B2 AN, Seattle, WA 98111, USA
    Best Pract Res Clin Anaesthesiol 16:195-210. 2002
    ..Controversies regarding the possible lower risk of TNS with newer spinal anaesthetic techniques and new discharge criteria are reviewed. The final section provides technical pearls to optimize ambulatory spinal anaesthetic outcomes...
  25. doi Cerebral oximetry desaturation during shoulder surgery performed in a sitting position under regional anesthesia
    Jacques T YaDeau
    Department of Anesthesiology, Hospital for Special Surgery, Weill Cornell Medical College, New York, NY 10021, USA
    Can J Anaesth 58:986-92. 2011
    ..Hypotension in the sitting position may reduce cerebral perfusion and oxygenation. We prospectively determined the incidence of cerebral oximetry (rSO2) desaturation in seated patients undergoing ambulatory shoulder arthroscopy...
  26. ncbi The effect of single-injection femoral nerve block versus continuous femoral nerve block after total knee arthroplasty on hospital length of stay and long-term functional recovery within an established clinical pathway
    Francis V Salinas
    Department of Anesthesiology, Virginia Mason Medical Center, Seattle, Washington 9810, USA
    Anesth Analg 102:1234-9. 2006
    ..The lack of effect provided by increased duration of analgesia (from CFNB) after TKA may now have minimal impact on hospital LOS and long-term functional recovery in the contemporary healthcare environment within the United States...
  27. ncbi Modeling cost of ultrasound versus nerve stimulator guidance for nerve blocks with sensitivity analysis
    Spencer S Liu
    Department of Anesthesiology, Hospital for Special Surgery, 535 E 70th St, New York, NY 10021, USA
    Reg Anesth Pain Med 35:57-63. 2010
    ..Sensitivity analysis allows modeling of different scenarios and determination of the relative importance of each cost input for a given scenario...
  28. ncbi Ultrasound-guided regional anesthesia and analgesia: a qualitative systematic review
    Spencer S Liu
    Department of Anesthesiology, Hospital for Special Surgery and Weill Medical College of Cornell University, New York, NY 10021, USA
    Reg Anesth Pain Med 34:47-59. 2009
    ..However, ultrasound was not inferior for efficacy, did not increase risk, and offers other potential patient-oriented benefits. All RCTs are rather small, thus completion of large RCTs and case series are encouraged to confirm findings...
  29. doi Performance characteristics and validation of the Opioid-Related Symptom Distress Scale for evaluation of analgesic side effects after orthopedic surgery
    Jacques T YaDeau
    Department of Anesthesiology, Hospital for Special Surgery, Weill Cornell Medical College, 535 East 70th St, New York, NY 10021, USA
    Anesth Analg 113:369-77. 2011
    ..Additional validation studies were suggested. We investigated performance characteristics and validity of the ORSDS for postoperative analgesia after 4 types of anesthetic and analgesic regimens...
  30. ncbi Effect of postoperative analgesia on major postoperative complications: a systematic update of the evidence
    Spencer S Liu
    Department of Anesthesiology, Hospital for Special Surgery and the Weill College of Medicine of Cornell University, New York, New York 10021, USA
    Anesth Analg 104:689-702. 2007
    ..Few individual clinical trials have had sufficient subject numbers to definitively determine the effects of postoperative analgesia on major outcomes...
  31. ncbi Concurrent expansion of plasma volume and left ventricular end-diastolic volume in patients after rapid infusion of 5% albumin and lactated Ringer's solution
    Francis V Salinas
    Department of Anesthesiology, Virginia Mason Medical Center, Seattle, WA, USA
    J Clin Anesth 18:510-4. 2006
    ....
  32. doi A cross-sectional survey on prevalence and risk factors for persistent postsurgical pain 1 year after total hip and knee replacement
    Spencer S Liu
    Department of Anesthesiology, Hospital for Special Surgery and Weill Cornell Medical College, New York, NY 10021, USA
    Reg Anesth Pain Med 37:415-22. 2012
    ..We surveyed a variety of practices and patients and also correlated persistent pain with health-related quality-of-life outcomes...
  33. doi Stroke, regional anesthesia in the sitting position, and hypotension: a review of 4169 ambulatory surgery patients
    Jacques T YaDeau
    Department of Anesthesiology, Weill Cornell Medical Center, New York, NY, USA
    Reg Anesth Pain Med 36:430-5. 2011
    ....
  34. doi Uncomplicated removal of epidural catheters in 4365 patients with international normalized ratio greater than 1.4 during initiation of warfarin therapy
    Spencer S Liu
    Department of Anesthesiology, Cornell University, New York, NY, USA
    Reg Anesth Pain Med 36:231-5. 2011
    ..However, these guidelines are based primarily on expert consensus, and there is controversy regarding this recommendation as being "too conservative."..
  35. ncbi Prospective comparison of continuous femoral nerve block with nonstimulating catheter placement versus stimulating catheter-guided perineural placement in volunteers
    Francis V Salinas
    Department of Anesthesiology, Virginia Mason Medical Center, 1100 9th Avenue, B2 AN, Seattle, WA 98101, USA
    Reg Anesth Pain Med 29:212-20. 2004
    ..Stimulating catheter-guided perineural placement may potentially increase the success rate and quality of continuous femoral nerve block as compared with a nonstimulating catheter technique. These hypotheses have not been rigorously tested...
  36. pmc Risk of postoperative hypoxemia in ambulatory orthopedic surgery patients with diagnosis of obstructive sleep apnea: a retrospective observational study
    Spencer S Liu
    Department of Anesthesiology, Hospital for Special Surgery, Weill College of Medicine of Cornell University, 535 East 70th Street, New York, NY 10021, USA
    Patient Saf Surg 4:9. 2010
    ..Our OSA patients undergoing ambulatory-type orthopedic procedures are monitored overnight in the PACU, thus we reviewed patient records to determine incidence of complications...
  37. doi Evidence basis for ultrasound-guided block characteristics: onset, quality, and duration
    Spencer S Liu
    Departments of Anesthesiology, Hospital for Special Surgery, Weill College of Medicine of Cornell University, New York, NY 10021, USA
    Reg Anesth Pain Med 35:S26-35. 2010
    ..This systematic review summarizes existing evidence for superior onset, quality, and duration of block for ultrasound (US) guidance versus other techniques for nerve localization...
  38. ncbi Efficacy of continuous wound catheters delivering local anesthetic for postoperative analgesia: a quantitative and qualitative systematic review of randomized controlled trials
    Spencer S Liu
    Department of Anesthesiology, Hospital for Special Surgery and the Weill College of Medicine of Cornell University, New York, NY 10021, USA
    J Am Coll Surg 203:914-32. 2006
  39. ncbi Where in the world is ASRA AcutePOP?
    Spencer S Liu
    Department of Anesthesiology, Hospital for Special Surgery, Weill Cornell Medical College, New York, NY, USA
    Reg Anesth Pain Med 34:269-74. 2009
    ..Development of a Web site and applications continues, and a demonstration is planned for the ASRA 2009 meeting...
  40. doi A prospective, randomized, controlled trial comparing ultrasound versus nerve stimulator guidance for interscalene block for ambulatory shoulder surgery for postoperative neurological symptoms
    Spencer S Liu
    Department of Anesthesiology, Hospital for Special Surgery, Weill College of Medicine of Cornell University, 535 East 70th St, New York City, NY 10021, USA
    Anesth Analg 109:265-71. 2009
    ....
  41. ncbi Hyperbaric spinal levobupivacaine: a comparison to racemic bupivacaine in volunteers
    Elizabeth A Alley
    Department of Anesthesiology, Virginia Mason Medical Center, Seattle, Washington 98111, USA
    Anesth Analg 94:188-93, table of contents. 2002
    ..Hyperbaric spinal levobupivacaine has equivalent clinical efficacy to racemic bupivacaine for spinal anesthesia in doses from 4 to 12 mg...
  42. doi Methodological quality of randomized controlled trials of postoperative epidural analgesia: validation of the Epidural Analgesia Trial Checklist as a specific instrument to evaluate methodology
    Spencer S Liu
    Department of Anesthesiology, Hospital of Special Surgery, Cornell Weill Medical Center, New York, NY, USA
    Reg Anesth Pain Med 35:549-55. 2010
    ..Current instruments for evaluating the quality of methodology are generic; thus, we also developed a specific assessment tool named Epidural Analgesia Trial Checklist (EATC)...
  43. pmc Trends in mortality, complications, and demographics for primary hip arthroplasty in the United States
    Spencer S Liu
    Department of Anesthesiology, Hospital for Special Surgery, Weill Medical College of Cornell University, New York, NY, USA
    Int Orthop 33:643-51. 2009
    ..Multiple temporal changes in outcomes and demographics for THA were found. These changes have implications for clinical care and allocation of health resources...
  44. ncbi Physiology of spinal anaesthesia and practical suggestions for successful spinal anaesthesia
    Francis V Salinas
    Department of Anaesthesiology, Virginia Mason Medical Center, 1100 Ninth Avenue B2 AN, Seattle, WA 98111, USA
    Best Pract Res Clin Anaesthesiol 17:289-303. 2003
    ..Lastly, the sedative and minimum-alveolar-concentration-sparing effects of spinal anaesthesia are discussed to reinforce the need for the judicious use of sedation in the perioperative setting...
  45. doi Perioperative pulmonary outcomes in patients with sleep apnea after noncardiac surgery
    Stavros Memtsoudis
    Department of Anesthesiology, Hospital for Special Surgery, Weill Medical College of Cornell University, 535 East 70th St, New York, NY 10021, USA
    Anesth Analg 112:113-21. 2011
    ....
  46. ncbi Does continuous peripheral nerve block provide superior pain control to opioids? A meta-analysis
    Jeffrey M Richman
    Department of Anesthesiology and Critical Care Medicine, The Johns Hopkins University, Baltimore, Maryland, USA
    Anesth Analg 102:248-57. 2006
    ..001). CPNB analgesia, regardless of catheter location, provided superior postoperative analgesia and fewer opioid-related side effects when compared with opioid analgesia...
  47. ncbi Efficacy of postoperative epidural analgesia: a meta-analysis
    Brian M Block
    Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, Baltimore, MD 21287, USA
    JAMA 290:2455-63. 2003
    ..Whether epidural analgesia is a better method than parenteral opioids for postoperative pain control remains controversial...
  48. ncbi Efficacy of postoperative patient-controlled and continuous infusion epidural analgesia versus intravenous patient-controlled analgesia with opioids: a meta-analysis
    Christopher L Wu
    Department of Anesthesiology and Critical Care Medicine, The Johns Hopkins University, Baltimore, Maryland 21287, USA
    Anesthesiology 103:1079-88; quiz 1109-10. 2005
    ....
  49. ncbi An intensive, structured clinical trial can markedly reduce length of stay after abdominal aortic surgery
    Spencer S Liu
    Anesthesiology 97:1025; author reply 1029-31. 2002
  50. ncbi A lovely idea: forming an ASRA Acute Postoperative Pain (AcutePOP) database
    Spencer S Liu
    Reg Anesth Pain Med 31:291-3. 2006
  51. ncbi Acute post-surgical pain management: a critical appraisal of current practice, December 2-4, 2005
    James P Rathmell
    University of Vermont College of Medicine, Burlington, VT 05403, USA
    Reg Anesth Pain Med 31:1-42. 2006
    ..This manuscript details those opinions and presents a critical analysis of the existing evidence supporting new and emerging techniques used to control postsurgical pain...
  52. ncbi Continuous local anesthetic wound infusion to improve postoperative outcome: back to the periphery?
    Henrik Kehlet
    Anesthesiology 107:369-71. 2007
  53. ncbi Gender and post-dural puncture headache
    Christopher L Wu
    Department of Anesthesiology and Critical Care Medicine, The Johns Hopkins University, MD 21287, USA
    Anesthesiology 105:613-8. 2006
    ..44-0.67). Although the authors found that nonpregnant female subjects seem to have a higher incidence of post-dural puncture headache than males, the etiology behind these findings is not clear from the current meta-analysis...