A recent study calls into question use of VTE prophylaxis rates as a measure of quality of care because of likely surveillance bias. Bilimoria and colleagues () looked at almost a million surgical patients in almost 3000 hospitals and looked at VTE prophylaxis rates, VTE event rates, and use of imaging in VTE screening. They found that greater hospital VTE prophylaxis adherence rates were weakly associated with worse risk-adjusted VTE event rates. When they looked at hospitals with higher “structural” quality scores (based on 8 factors commonly thought to be associated with higher commitment to quality) they found higher VTE prophylaxis adherence rates but worse risk-adjusted VTE rates. Risk-adjusted VTE rates increased significantly with VTE imaging use rates in a stepwise fashion, leading to their conclusion that surveillance bias limits the usefulness of the VTE quality measure for hospitals. They also note that their study is not the first to note that higher VTE prophylaxis rates do not necessarily result in lower VTE rates. They note that these findings and the likely effect of surveillance bias call into question the use of a VTE prophylaxis metric as a quality measure in public reporting or pay-for-perfomance programs.
The accompanying editorial (Livingston 2013) agrees that public reporting of VTE rates should be reconsidered or curtailed. It also raises the question that the high compliance rates with VTE prophylaxis may mean that many patients are receiving treatments they are unlikely to benefit from.
In our February 15, 2011 Patient Safety Tip of the Week “Controversies in VTE Prophylaxis” we highlighted a study by some very respected investigators in the surgical quality improvement field (Qadan 2011) that questioned the current recommendations on venous thrombembolism (VTE) prophylaxis in elective major surgery. The authors collected data on DVT and PE in patients electively undergoing 4 major surgical procedures (colorectal resection, total knee replacement, total hip replacement, and hysterectomy) from a large database from a consortium of academic medical centers for two periods of time (2003-2004 vs. 2007-2008). The study demonstrated a substantial increase in the use of pharmacologic DVT prophylaxis between the two time periods. Yet the rates of DVT and PE were not significantly impacted by this increased use of such prophylaxis. Moreover, the overall rates of DVT and PE were actually quite low and the rates in patients who did not receive pharmacoprophylaxis actually decreased between the two time periods. The authors concluded that this may show that clinical judgment of physicians in choosing which patients need pharmacoprophylaxis is remarkable.
Unfortunately, the study did not have available data on complications of pharmacoprophylaxis (such as hemorrhage, heparin-induced thrombocytopenia, etc.) which might show that the net benefit of prophylaxis may be even lower.
One of the most striking revelations of this paper is that the overall rate of VTE in this elective surgery population is quite low (0.6% to 3.2%). One of the biggest areas of controversy in all prior investigations on VTE has been the means by which DVT is diagnosed. Most randomized controlled trials have used ultrasound techniques to look for evidence of DVT. Many have argued that such techniques artificially increase the incidence and prevalence of DVT by including many cases that will never be clinically relevant. The authors point out industry funding of studies that may overestimate the true VTE rate. They point out that the number needed to treat (NNT) to prevent a single PE in the elective surgical population is about 125 and an even higher NNT would apply to fatal PE. (We, of course, would argue that even one fatal PE is one too many.)
Pertinent to the comments by Qadan et al. about the influence of “industry” in driving the many clinical studies that have led to larger use of pharmacological VTE prophylaxis, a study just published provided interesting insights into potential conflicts of interest amongst panelists involved in development of the widely used ACCP guidelines (Neumann 2013). Those authors estimated the compliance with a conflict of interest policy by attendees voting on controversies for which they were conflicted. Sixty-three panelists voted in at least one controversy at the final conference; the percentage of conflicted panelists varied from 6% to 39% for eight controversies. The compliance with the COI policy varied from 5% to 33% in seven of the controversies voted on. In two of the controversies (“Compression device plus aspirin vs low-molecular-weight heparin in thromboprophylaxis in orthopedic surgery” and “Low-molecular-weight heparin vs vitamin K antagonists for treatment”), the low compliance may have affected the final recommendations.
The new study by Bilimoria et al, combined with the study by Qada et al. and a study that challenged the use of VTE as a marker of quality of care in trauma patients (Huseynova 2009) all raise the question about whether the VTE metrics included in current quality and pay-for-performance programs should be revisited.
Bilimoria KY, Chung J, Ju MH, et al. Evaluation of Surveillance Bias and the Validity of the Venous Thromboembolism Quality Measure. JAMA 2013; 310(14): 1482-1489
Livingston EH. Postoperative Venous Thromboembolic Disease: Prevention, Public Reporting, and Patient Protection. JAMA. 2013; 310(14): 1453-145
Qadan M, Polk HC, Hohmann SF, Fry DE. A reassessment of needs and practice patterns in pharmacologic prophylaxis of venous thromboembolism following elective major surgery. Ann Surg 2011; 253(2): 215-220
Neumann I, Akl EA, Valdes M, et al. Low Anonymous Voting Compliance With the Novel Policy for Managing Conflicts of Interest Implemented in the 9th Version of the American College of Chest Physicians Antithrombotic Guidelines. Chest. 2013; 144(4): 1111-1116
Huseynova K, Xiong W, Ray JG et al. Venous Thromboembolism as a Marker of Quality of Care in Trauma. J Am Coll Surg 2009; 208: 547-552
Our September 3, 2013 Patient Safety Tip of the Week “Predicting Perioperative Complications: Slow and Simple” showed a simple way of predicting postoperative complications. Now we’ll show you an even simpler way!
Our regular readers know we’ve long advocated major change in the way we prepare patients, particularly the elderly, for surgery (see our August 17, 2010 Patient Safety Tip of the Week “” and the multiple columns listed at the end of this column). Historically the pre-op workup has included multiple testing that has little impact on patient outcomes and we continue to see lots of unnecessary testing and lack of focus on potentially more meaningful evaluations. For example, identification of patients at risk for delirium, those who are frail, and those who have diagnosed or undiagnosed sleep apnea is much more likely to identify patients at risk for complications than doing extensive cardiac studies in patients lacking a history of heart disease.
Assessments of frailty are particularly strong predictors of postoperative complications. We’ve done multiple columns on the ability of measures of frailty to predict postoperative complications, morbidity and mortality, and discharge to institutional settings. We have previously highlighted the contributions by Makary and colleagues (Makary et al 2010) and Robinson and colleagues (Robinson 2009, Robinson 2011, Robinson 2013a, Robinson 2013b) in predicting postoperative complications based on frailty measures. And a new study using the Hopkins Frailty Score found that scoring in the “frail” or “intermediately frail” ranges predicted postoperative complications (Revenig 2013).
Many of those studies looking at frailty have emphasized gait speed or the ability of the Timed Up and Go test (see our November 2011 What’s New in the Patient Safety World column “Timed Up-and-Go Test and Surgical Outcomes”) to predict postoperative morbidity and complications. Our September 3, 2013 Patient Safety Tip of the Week “Predicting Perioperative Complications: Slow and Simple” highlighted a study by Robinson’s group (Robinson 2013b) that found a slower Timed Up and Go predicted increased postoperative complications and 1-year mortality across surgical specialties and that, regardless of operation performed, the Timed Up and Go compared favorably to more complex risk calculators at forecasting postoperative complications.
Now a new study from Robinson’s group (Jones 2013) demonstrates an even simpler yet very powerful way to predict postoperative complications: just take a fall history! The researchers looked at 235 patients aged 65 and older who were going to have colorectal or cardiac surgery and compared those who had fallen at least once in the previous 6 months (about a third of the group) with those lacking a history of falls. Independent of advancing age, those who had a history of a fall were more than twice as likely to have a postoperative complication after either type of surgery. Moreover, those with a history of falls had a higher likelihood of discharge to institutional care and higher likelihood of 30-day readmission. There was also a correlation between the number of falls and the number of postoperative complications.
Just taking that history of falls was comparable to using the Charlson (comorbidity index) score and was favorable to using the ASA score or chronological age for predicting postoperative complications.
The authors note that a history of falls potentially can be taken from several areas of the medical record and might easily be incorporated into data sets like the NSQIP database, from which pre-op risk calculations are made (see our September 3, 2013 “Predicting Perioperative Complications: Slow and Simple” regarding the ACS NSQIP Surgical Risk Calculator).
Simple! But elegant! Robinson’s group continues to add practical contributions to the management of geriatric patients.
Some of our prior columns on preoperative assessment and frailty:
· March 31, 2009 “Screening Patients for Risk of Delirium”
· January 26, 2010 “Preventing Postoperative Delirium”
· June 2010 “The Frailty Index and Surgical Outcomes”
· August 17, 2010 “”
· August 31, 2010 “”
· August 9, 2011 “Frailty and the Surgical Patient”
· September 2011 “Modified HELP Helps Outcomes in Elderly Undergoing Abdominal Surgery”)
· October 18, 2011 “High Risk Surgical Patients”
· November 2011 “Timed Up-and-Go Test and Surgical Outcomes”
· April 3, 2012 “New Risk for Postoperative Delirium: Obstructive Sleep Apnea”
· August 7, 2012 “Cognition, Post-Op Delirium, and Post-Op Outcomes”
· August 14, 2012 “Gait Speed: A New Vital Sign?”
· September 25, 2012 “Preoperative Assessment for Geriatric Patients”
· September 3, 2013 “Predicting Perioperative Complications: Slow and Simple”
Makary MA, Segeve DL, Pronovost PJ, et al. Frailty as a Predictor of Surgical Outcomes in Older Patients. Journal of the American College of Surgeons 2010; 210(6): 901-908, June 2010
Robinson TN, Eiseman B, Wallace JI, et al. Redefining Geriatric Preoperative Assessment Using Frailty, Disability and Co-Morbidity. Annals of Surgery 2009; 250(3): 449-455, September 2009
Robinson TN, Wallace JI, Wu DS, et al. Accumulated Frailty Characteristics Predict Postoperative Discharge Institutionalization in the Geriatric Patient. J Am Coll Surg 2011; 213(1): 37-42, July 2011
Robinson TN, Wu DS, Pointer L, et al. Simple frailty score predicts postoperative complications across surgical specialties. Am J Surg 2013; published online 22 July 2013
Robinson TN, Wu DS, Sauaia A, et al. Slower Walking Speed Forecasts Increased Postoperative Morbidity and 1-Year Mortality Across Surgical Specialties. Annals of Surgery 2013; Published ahead of print 23 August 2013
Revenig LM, Canter DJ, Taylor MD, et al. Too Frail for Surgery? Initial Results of a Large Multidisciplinary Prospective Study Examining Preoperative Variables Predictive of Poor Surgical Outcomes. Journal of the American College of Surgeons 2013; 217(4): 665-670.e1, October 2013
Jones TS, Dunn CL, Wu DS, et al. Relationship Between Asking an Older Adult About Falls and Surgical Outcomes. JAMA Surg 2013; (). doi: 10.1001/jamasurg.2013.2741
Pubslished online first October 09, 2013
ACS NSQIP Surgical Risk Calculator
From a strictly numerical perspective we’ve probably done more columns on CAUTI’s and catheter complications than any other topic (see the links at the end of today’s column).
Much of the literature base on these topics comes from clinical researchers at the University of Michigan. Recently they’ve again done a series of very useful articles on urinary catheters. One is a meta-analysis of strategies and interventions to reduce unnecessary use of urinary catheters and other strategies to prevent CAUTI’s (Meddings 2013a). It highlights multiple interventions to both avoid initial placement of urinary catheters and strategies to promote prompt removal of catheters that are no longer necessary. These include making available guidelines for appropriate use of catheters and examples of inappropriate use, alternatives to indwelling catheters, use of paper or computerized reminder tools, automatic stop orders, nurse-empowered removal protocols, etc. and the article discusses potential pitfalls with the strategies. It has good discussions on implementation strategies and monitoring and feedback. It is a comprehensive review of the field with good statistics on success rates and a great bibliography.
Lead author of that first paper, Jennifer Meddings, also did an editorial with many of the same recommendations (Meddings 2013b) in commenting on a study reported by a group from The Netherlands (Janzen 2013). The latter study was a simple study that showed increasing physician awareness through educational sessions plus daily review of catheter necessity successfully reduced catheter duration, CAUTI’s and LOS. But Meddings’ editorial comments are even more helpful since they discuss the barriers and impediments one may encounter in various settings. She notes how pre-existing behavior (physician and nurse), communication patterns, and workflow issues are all important in choosing a strategy that will work best in your setting.
The last article, again from the University of Michigan group, is a systematic review and meta-analysis of the noninfectious complications of indwelling urinary catheters (Hollingsworth 2013). Our May 2012 What’s New in the Patient Safety World column “Foley Catheter Hazards” touched upon a few noninfectious complications of urinary catheters. This new meta-analysis, however, is more comprehensive than any previous individual studies on the topic. The authors find that noninfectious complications occur at least as frequently as CAUTI in patients with short-term catheterization and the rates are 4 times higher in those with long-term catheterization.
Some complications may be minor, like leakage of urine around the catheter. But others are more serious, including gross hematuria, urethral strictures and erosions, false passage, accidental removal, and catheter blockage. Long-term catheterizations and indwelling catheters in spinal cord-injured patients may also be associated with bladder calculi and bladder cancer. The meta-analysis provides lots of statistics on the reported frequencies of these complications, noting that considerable variation exists related to quality of the studies and sex differences in the reported populations.
The authors stress that the best way to avoid such complications is to avoid catheterization in the first place. However, recognizing that indwelling urinary catheters may be necessary in some cases, they also emphasize education and skill training for those inserting catheters.
They also point out that data on the costs of noninfectious complications is very scant at this time and should be a focus of future research.
Overall, these are a series of easy-to-read, practical recommendations on dealing with very common problems. Very informative work coming from the group at the forefront of improving patient safety related to urinary catheters.
Our other columns on urinary catheter-associated UTI’s:
Meddings J, Rogers MAM, Krein SL, et al. Reducing unnecessary urinary catheter use and other strategies to prevent catheter-associated urinary tract infection: an integrative review. BMJ Qual Saf 2013; Published Online First: 27 September 2013
Meddings J. Interventions to reduce urinary catheter use: it worked for them, but will it work for us? BMJ Qual Saf 2013; Published Online First: 19 September 2013
Janzen J, Buurman BM, Spanjaard L, et al. Reduction of unnecessary use of indwelling urinary catheters. BMJ Qual Saf bmjqs-2013-001908Published Online First: 6 June 2013
Hollingsworth JM, Rogers MAM, Krein SL, et al. Determining the Noninfectious Complications of Indwelling Urethral Catheters: A Systematic Review and Meta-analysis. Ann Intern Med 2013; 159(6): 401-410
The “weekend effect” is a term used to refer to an increase in untoward events or suboptimal outcomes occurring in patients admitted to hospitals over the weekend. In some cases we use the term “after hours effect” since some of the same issues occur in patients admitted at night. We’ve discussed the numerous factors that may contribute to the “weekend effect” in our previous columns listed at the end of today’s column.
Though few doubt the phenomenon exists, debate remains whether it reflects suboptimal medical care or simply that patients admitted on weekends tend to be sicker. Various studies have demonstrated higher mortality rates for patients admitted on weekends with strokes, atrial fibrillation, diverticulosis surgery, a variety of other surgical procedures, head trauma, COPD, CHF, perinatal events, ICU admissions, ESRD, and other conditions. In fact, in our June 2011 What’s New in the Patient Safety World “Another Study on Dangers of Weekend Admissions” we noted a study (Ricciardi 2011) that found that mortality rates were higher for 15 of 26 major diagnostic categories when patients were admitted on weekends. Even after adjustment for comorbidities and a variety of other clinical and demographic characteristics there remained a significant increase in mortality, on the order of 10% higher for those admitted on weekends.
Now a new study from Austrailia (Concha 2013) has used large linked databases to delve further into the issue. They analyzed over 3 million emergency department admissions over a 7-year period. 27% of all admissions came on weekends and such admissions accounted for 28% of all deaths at one week after admission. Sixteen of 430 diagnosis groups had a significantly raised mortality risk after weekend admission (and no DRG’s were associated with lower mortality for weekend admissions). But the timing of deaths was not uniform and several patterns were seen. One pattern was death within the first 24 hours, seen only in patients with the DRG for major arrhythmia and cardiac arrest. A second pattern of steady risk by day was seen primarily in patients with cancer. The most common pattern, however, was a “mixed” effect in which there was a spike in mortality over the weekend that reduced on exposure to weekday care but remained elevated thereafter. Their overall conclusion is that for most of the DRG’s showing excess mortality with weekend admission there are both patient-related factors and care-related factors in play.
Our healthcare systems clearly do not deliver uniform care 24x7. The differences between the hospital during weekday daytime hours and the hospital at night and on weekends is striking. Staffing patterns (both in terms of volume and experience) are the most obvious difference but there are many others as well. Many diagnostic tests are not as readily available during these times. Physician and consultant availability may be different and cross-coverage by physicians who lack detailed knowledge about individual patients is common. You also see more verbal orders, which of course are error-prone, at night and on weekends.
But often it is the difference in non-clinical staffing that is a root cause. Our December 15, 2009 Patient Safety Tip of the Week “The Weekend Effect” discussed how adding non-clinical administrative tasks to already overburdened nursing staff on weekends may be detrimental to patient care. Just do rounds on one of your med/surg floors or ICU’s on a weekend. You’ll see nurses answering phones all day long, causing interruptions in some attention-critical nursing activities. Calls from radiology and the lab that might go directly to physicians now go first to the nurse on the floor, who then has to try to track down the physician. They end up filing lab and radiology reports or faxing medication orders down to pharmacy, activities often done by clerical staff during daytime hours. Even in those facilities that have CPOE, nurses off-hours often end up entering those orders into the computer because the physicians are off-site and are phoning in verbal orders. You’ll also see nurses giving directions to the increased numbers of visitors typically seen on weekends. They even end up doing some housekeeping chores. All of these interruptions and distractions obviously interfere with nurses’ ability to attend to their clinically important tasks (see our Patient Safety Tips of the Week for August 25, 2009 “ ” and May 4, 2010 “More on the Impact of Interruptions”).
Maybe if hospitals were able to quantify the weekend effect in financial terms they might pay more attention to the root causes of the phenomenon. The weekend effect includes not just excess mortality but also morbidities and complications and also impaired throughput that leads to longer lengths of stay. These can all lead to excess costs. One recent study (Gilmore 2013) showed that colectomies performed on Mondays were associated with significantly shorter lengths of stay than those performed any other day of the week. The authors attribute that to patients taking full advantage of hospital resources and ancillary support. Another recent review of obstetrical complications (Snowden 2013) showed that on weekends, relatively high-volume days were significantly associated with an elevated risk of infant asphyxia, whereas no association was present on weekdays. Cost of care of such infants is very expensive. Both are examples where providing adequate resources up front can save money on the back end.
The weekend effect is complex and involves both patient-related factors and quality of care factors. And it affects primarily a subset of the total hospital patient population. While there may be little we can do about the patient-related factors, certainly we can do a better job on the quality-related factors. Greater attention to providing adequate resources for patients with those conditions and DRG’s known to be impacted by the weekend effect should be a focus for all.
Some of our previous columns on the “weekend effect”:
Ricciardi R, Roberts PL, Read TE, et al. Mortality Rate After Nonelective Hospital Admission. Arch Surg. 2011; 146(5): 545-551
Concha OP, Gallego B, Hillman K, et al. Do variations in hospital mortality patterns after weekend admission reflect reduced quality of care or different patient cohorts? A population-based study. BMJ Qual Saf 2013; published online 25 October 2013 doi:10.1136/bmjqs-2013-002218
Gilmore DM, Curran T, Gautam S, Nagle D, et al. Timing is everything—colectomy performed on Monday decreases length of stay. Am J Surg 2013; 206(3): 340-345, September 2013
Snowden JM, Darney BG, Cheng YW, et al. Systems Factors in Obstetric Care: The Role of Daily Obstetric Volume. Obstetrics & Gynecology2013; 122(4): 851-857
It seems like we are doing a column on perioperative beta blockers almost every month! Well, not quite but see the list below of all our prior columns on the topic.
Yet another study is questioning the use of beta blockers perioperatively. Dalal and colleagues (Dalal 2013) did a retrospective review of over 750 randomly chosen patients who underwent non-cardiac surgery. Beta-blocker use was found to increase the odds of having an acute coronary event by a factor of 21.76. Beta blocker use was also associated with decompensated heart failure (odds ratio 4.50). Unexpectedly, the risk of arrhythmias was also increased in patients on beta blockers (odds ration 2.28).
But there have been enough retrospective reviews, some concluding that perioperative beta blockers are good and others that they are bad. The controversy is not going to go away until a large randomized controlled trial is undertaken using a beta-blockade regimen that everyone can agree upon.
Our prior columns on perioperative use of beta blockers:
November 20, 2007 “New Evidence Questions Perioperative Beta Blocker Use”
November 4, 2008 “Beta Blockers Take More Hits”
December 2009 “Updated Perioperative Beta Blocker Guidelines”
November 2010 “More Perioperative Beta Blocker Controversy”
November 2012 “Beta Blockers Losing Their Luster?”
May 2013 “Beta Blocker Debate Just Won’t Go Away”
September 2013 “More Perioperative Beta-Blocker Controversy”
Dalal P, Varma D, Hegazy H. Do Beta-Blockers Increase Perioperative Cardiac Morbidity? Chest 2013; 144(4_MeetingAbstracts):166A. doi:10.1378/chest.1704913