An official ATS statement: grading the quality of evidence and strength of recommendations in ATS guidelines and recommendations.
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Publications and source records attributed to Deborah J Cook.
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STUDY OBJECTIVE: The use of vasopressin in patients with cardiac arrest presenting with specific rhythms is controversial. We performed an evidence-based emergency medicine review of evidence comparing vasopressin to epinephrine in structured cardiac arrest protocols. METHODS: We searched MEDLINE, EMBASE, the Cochrane Library, and other databases for randomized trials or systematic reviews comparing vasopressin to epinephrine for adults with cardiac arrest and measuring survival to hospital discharge and neurologic function in survivors. We used standard criteria to appraise the quality of published trials and systematic reviews. We used the random effects model in supplementary analyses to summarize results and to test for significant differences across subgroups of patients presenting with different arrest rhythms. RESULTS: We found 3 high-quality well-reported randomized trials and 1 rigorous meta-analysis. The evidence does not confirm a consistent benefit of vasopressin over epinephrine in increasing survival or improving neurologic outcome in survivors. Subgroup analysis reveals a large difference in effect of vasopressin over epinephrine in cardiac arrest patients with asystole, compared to other arrest rhythms, coming from within-trial comparisons. The difference is not consistent across otherwise similar trials, is not statistically significant, may reflect the application of multiple unplanned subgroup analyses, and is not supported by a plausible biological hypothesis. CONCLUSION: Evidence from randomized trials does not establish a benefit of vasopressin over epinephrine in increasing survival to discharge or improving neurologic outcomes in adult patients with nontraumatic cardiac arrest.
PURPOSE: To review end of life care issues in the intensive care unit (ICU) and how practice variation might affect the ultimate outcome of acute brain injury. SOURCES: Bibliographic literature search and personal files. FINDINGS: In Canada, 10-20% of critically ill adults die in the ICU. Many of these deaths follow acute brain injury in the setting of clinical deterioration, life support limitation and brain death. This brief review addresses some key elements of end of life care for critically ill brain injured patients, including family interactions, making survival predictions, and factors influencing decision-making about cardiopulmonary resuscitation and withdrawal of mechanical ventilation. CONCLUSIONS: Provision of compassionate high quality end of life care should be standard of practice for brain injured and all other critically ill patients who cannot survive. Inconsistencies in end of life care may affect where, when and how patients die, the quality of their death and whether or not they are considered for organ and tissue donation.
OBJECTIVE: Quality improvement is an important activity for all members of the interdisciplinary critical care team. Although an increasing number of resources are available to guide clinicians, quality improvement activities can be overwhelming. Therefore, the Society of Critical Care Medicine charged this Outcomes Task Force with creating a "how-to" guide that focuses on critical care, summarizes key concepts, and outlines a practical approach to the development, implementation, evaluation, and maintenance of an interdisciplinary quality improvement program in the intensive care unit. DATA SOURCES AND METHODS: The task force met in person twice and by conference call twice to write this document. We also conducted a literature search on "quality improvement" and "critical care or intensive care" and searched online for additional resources. DATA SYNTHESIS AND OVERVIEW: We present an overview of quality improvement in the intensive care unit setting and then describe the following steps for initiating or improving an interdisciplinary critical care quality improvement program: a) identify local motivation, support teamwork, and develop strong leadership; b) prioritize potential projects and choose the first target; c) operationalize the measures, build support for the project, and develop a business plan; d) perform an environmental scan to better understand the problem, potential barriers, opportunities, and resources for the project; e) create a data collection system that accurately measures baseline performance and future improvements; f) create a data reporting system that allows clinicians and others to understand the problem; g) introduce effective strategies to change clinician behavior. In addition, we identify four steps for evaluating and maintaining this program: a) determine whether the target is changing with periodic data collection; b) modify behavior change strategies to improve or sustain improvements; c) focus on interdisciplinary collaboration; and d) develop and sustain support from the hospital leadership. We also identify a number of online resources to complement this overview. CONCLUSIONS: This Society of Critical Care Medicine Task Force report provides an overview for clinicians interested in developing or improving a quality improvement program using a step-wise approach. Success depends not only on committed interdisciplinary work that is incremental and continuous but also on strong leadership. Further research is needed to refine the methods and identify the most cost-effective means of improving the quality of health care received by critically ill patients and their families.
OBJECTIVES: To characterize the perceived utilization of sedative, analgesic, and neuromuscular blocking agents, the use of sedation scales, algorithms, and daily sedative interruption in mechanically ventilated adults, and to define clinical factors that influence these practices. DESIGN: Cross-sectional mail survey. PARTICIPANTS: Canadian critical care practitioners. MEASUREMENTS AND MAIN RESULTS: A total of 273 of 448 eligible physicians (60%) responded. Respondents were well distributed with regard to age, years of practice, specialist certification, size of intensive care unit and hospital, and location of practice. Twenty-nine percent responded that a protocol/care pathway/guideline for the use of sedatives or analgesics is currently in use in their intensive care unit. Daily interruption of continuous infusions of sedatives or analgesics is practiced by 40% of intensivists. A sedation scoring system is used by 49% of respondents. Of these, 67% use the Ramsay scale, 10% use the Sedation-Agitation Scale, 9% use the Glasgow Coma Scale, and 8% use the Motor Activity Assessment Scale. Only 3.7% of intensivists use a delirium scoring system in their intensive care units. Only 22% of respondents currently have a protocol for the use of neuromuscular blocking agents in their intensive care unit, and 84% of respondents use peripheral nerve stimulation for monitoring. In patients receiving neuromuscular blocking agents for >24 hrs, 63.7% of respondents discontinue the neuromuscular blocking agent daily. Intensivists working in university-affiliated hospitals are more likely to employ a sedation protocol and scale (p < .0001), as are intensivists working in larger intensive care units (>or=15 beds, p < .01). Intensivists with anesthesiology training (and no formal critical care training) are more likely to use a protocol and sedation scale, and critical care-trained intensivists are more likely to use daily interruption. Younger physicians (<40 yrs) are more likely to practice daily interruption (p = .0092). CONCLUSIONS: There is significant variation in critical care sedation, analgesia, and neuromuscular blockade practice. Given the potential effect of practices regarding these medications on patient outcome, future research and educational efforts related to evidence-based protocols for the use of these agents in mechanically ventilated patients might be worthwhile.
OBJECTIVE: Risk-prediction models offer potential advantages over physician predictions of outcomes in the intensive care unit (ICU). Our systematic review compared the accuracy of ICU physicians' and scoring system predictions of ICU or hospital mortality of critically ill adults. DATA SOURCE: MEDLINE (1966-2005), CINAHL (1982-2005), Ovid Healthstar (1975-2004), EMBASE (1980-2005), SciSearch (1980-2005), PsychLit (1985-2004), the Cochrane Library (Issue 1, 2005), PubMed "related articles," personal files, abstract proceedings, and reference lists. STUDY SELECTION: We considered all studies that compared physician predictions of ICU or hospital survival of critically ill adults to an objective scoring system, computer model, or prediction rule. We excluded studies if they focused exclusively on the development or economic evaluation of a scoring system, computer model, or prediction rule. DATA EXTRACTION AND ANALYSIS: We independently abstracted data and assessed study quality in duplicate. We determined summary receiver operating characteristic curves and areas under the summary receiver operating characteristic curves+/-se and summary diagnostic odds ratios. DATA SYNTHESIS: We included 12 observational studies of moderate methodological quality. The area under the summary receiver operating characteristic curves for seven studies was 0.85+/-0.03 for physician predictions compared with 0.63+/-0.06 for scoring system predictions (p=.002). Physicians' summary diagnostic odds ratios derived from the area under the summary receiver operating characteristic curves were significantly higher (12.43; 95% confidence interval 5.47, 27.11) than scoring systems' summary diagnostic odds ratios (2.25; 95% confidence interval 0.78, 6.52, p=.001). Combined results of all 12 studies indicated that physicians predict mortality more accurately than do scoring systems: ratio of diagnostic odds ratios (95% confidence interval) 1.92 (1.19, 3.08) (p=.007). CONCLUSIONS: Observational studies suggest that ICU physicians discriminate between survivors and nonsurvivors more accurately than do scoring systems in the first 24 hrs of ICU admission. The overall accuracy of both predictions of patient mortality was moderate, implying limited usefulness of outcome prediction in the first 24 hrs for clinical decision making.
BACKGROUND: Critical care services represent a large and growing proportion of health care expenditures. Limiting the magnitude of these costs while maintaining a just allocation of these services will require rationing. We define rationing as "the allocation of healthcare resources in the face of limited availability, which necessarily means that beneficial interventions are withheld from some individuals." Although some have maintained that rationing of health care is unethical, we argue that rationing is not only unavoidable but essential to ensuring the ethical distribution of medical goods and services. PRINCIPAL FINDINGS: Intensivists have little to guide them in the rationing of critical care services. We have developed a taxonomy of the rationing choices faced by intensivists as a framework for ethical analysis. This taxonomy divides rationing decisions into three categories. First are those rationing decisions that may be justified by external constraints (such as not prescribing a potentially beneficial medication because it is not available on the hospital formulary). Second are those that may be justified by reference to clinical guidelines (as, for example, not prescribing a potentially beneficial medication because a valid guideline recommends treatment with a less expensive alternative). Third are those that are justified by individual clinical judgment (such as choosing which of two patients should be admitted into the last ICU bed, in the absence of any evidence-based guidance). Judgments made on the basis of clinical judgment deserve particular scrutiny, since they may mask unethical prejudices or bias. CONCLUSIONS: Although this taxonomy does not by itself determine which decisions are ethical, it does clarify the type of evidence that is appropriate to supporting the decision that is made. Additional work is needed to elucidate how both empirical evidence and ethical analysis can further inform the rationing decisions that arise in the taxonomy described here.
OBJECTIVE: To assess the intrarater and interrater reliability of electrocardiogram (ECG) interpretation in critically ill patients and to assess the effect of knowledge of cardiac troponin values on these reliability estimates. DESIGN: Prospective cohort study. SETTING: Fifteen-bed medical-surgical intensive care unit. PATIENTS: Consecutive adults admitted over a 2-month period. MEASUREMENTS AND RESULTS: All consecutive 12-lead ECGs were interpreted independently by two raters for the presence of myocardial ischemia or infarction and secondarily for specific ischemic ECG abnormalities. The ECGs were first interpreted blinded to the patient's troponin levels and reinterpreted on two separate occasions, blinded and unblinded to the troponin values. Results are reported using chance-independent agreement (phi) with associated 95% confidence intervals. For the presence of ischemia or infarction, the intrarater reliability ranged from fair to moderate (phi = 0.35 [95% confidence interval = 0.16, 0.52] and 0.59 [0.33, 0.77] for the two raters, respectively); interrater reliability was slight when blinded to troponin levels (phi = 0.18 [0.03, 0.32]) and increased to moderate when the raters were unblinded to troponin values (phi = 0.52 [0.33, 0.66], p value for the difference = .004). For specific ECG changes, the intrarater and interrater reliability were low for T-wave flattening, whereas detection of a left bundle branch block showed high reliability. CONCLUSIONS: ECG interpretation in critically ill patients for the presence of myocardial ischemia or infarction showed moderate reliability at best; however, there was high reliability for specific ECG changes. Knowledge of the patient's troponin values increased the reliability for all studied ECG changes and resulted in a statistically significant increase in the interrater reliability for diagnosing myocardial ischemia or infarction. Additional studies assessing the appropriate methods of diagnosing myocardial ischemia and infarction and assessing the reliability of these diagnostic tests in critically ill patients are required.
OBJECTIVE: One in five Americans dies following treatment in an intensive care unit (ICU), and evidence indicates the need to improve end-of-life care for ICU patients. We conducted this study to elicit the views and experiences of ICU directors regarding barriers to optimal end-of-life care and to identify the type, availability, and perceived benefit of specific strategies that may improve this care. DESIGN: Self-administered mail survey. SETTING: Six hundred intensive care units. PARTICIPANTS: A random, nationally representative sample of nursing and physician directors of 600 adult ICUs in the United States. INTERVENTIONS: Mail survey. MEASUREMENTS AND MAIN RESULTS: We asked participants about barriers to end-of-life care (1 = huge to 5 = not at all a barrier), perceived benefit of strategies to improve end-of-life care, and availability of these strategies. From 468 ICUs (78.0% of sample), 590 ICU directors participated (406 nurses [65.1% response] and 184 physicians [31.7% response]). Respondents had a mean of 16.6 yrs (sd 7.6 yrs) of ICU experience. Important barriers to better end-of-life care included patient/family factors, including unrealistic patient/family expectations 2.5 (1.0), inability of patients to participate in discussions 2.7 (0.9), and lack of advance directives 2.9 (1.0); clinician factors, which included insufficient physician training in communication 2.9 (1.1) and competing demands on physicians' time 3.0 (1.1); and institution/ICU factors, such as suboptimal space for family meetings 3.5 (1.2) and lack of a palliative care service 3.4 (1.2). More than 80% of respondents rated 14 of 14 strategies as likely to improve end-of-life care, including trainee role modeling by experienced clinicians, clinician training in communication and symptom management, regular meetings of senior clinicians with families, bereavement programs, and end-of-life care quality monitoring. However, few of these strategies were widely available. CONCLUSIONS: Intensive care unit directors perceive important barriers to optimal end-of-life care but also universally endorse many practical strategies for quality improvement.
BACKGROUND: A description of current platelet (PLT) transfusion practice in the intensive care unit (ICU) is needed. STUDY DESIGN AND METHODS: All thrombocytopenic patients (PLT count, <150 x 10(9)/L) who received PLT transfusions were identified from a previous prospective study of consecutive medical-surgical ICU patients; trauma, orthopedic, and cardiac surgery were exclusions. Risk factors for ineffective transfusions were examined. RESULTS: Of 261 ICU patients, 118 (45.2%) had thrombocytopenia and a PLT count nadir of less than 50 x 10(9) per L (n = 22), 50 to 99 x 10(9) per L (n = 37), and 100 to 149 x 10(9) per L (n = 59). Twenty-seven (22.9%) patients received PLT transfusions (n = 76 transfusions) and 37 (31.4%) had major bleeding. PLT dose was approximately 3 to 4 x 10(11) per L transfusion. Therapeutic (n = 24) and prophylactic (n = 52) PLT transfusion triggers were 51 x 10(9) per L (interquartile range [IQR], 26 to 68) and 41 x 10(9) per L (IQR, 20 to 57), respectively, as measured at a median of 4.5 hours (IQR, <1.6 to 6.9) before transfusion. A single PLT transfusion resulted in a median PLT increase of 14 x 10(9) per L (IQR, -2 to 30) measured at 5.2 hours (IQR, 1.8 to 8.8) after the transfusion; however, no PLT count increase was observed after 17 transfusions given to 13 (48.1%) patients. No risk factors for ineffective transfusions were identified. CONCLUSIONS: Among critically ill patients, most PLT transfusions were administered to prevent, rather than to treat, bleeding, with a transfusion trigger of 40 to 50 x 10(9) per L. Nearly half of ICU patients who received transfusions failed to mount a PLT count increase after a single transfusion. Prospective studies are needed to determine the effects of PLT transfusions on bleeding and predictors of ineffective transfusions in the ICU.
Aprotinin, a potent antifibrinolytic drug, reduces the proportion of adults who receive blood transfusions during cardiac surgery, although the effect in children remains unclear. We performed a systematic review of the literature to identify all English language, randomized controlled trials of aprotinin involving children undergoing corrective or palliative cardiac surgery with cardiopulmonary bypass. All studies were assessed for methodological quality, and sources of heterogeneity were examined. We measured the effect of aprotinin on the proportion of children transfused, the volume of blood transfused, and the volume of chest tube drainage. Twelve trials enrolling 626 eligible children met the inclusion criteria. Aprotinin reduced the proportion of children who received red blood cell or whole blood transfusions during cardiac surgery by 33% (relative risk = 0.67; 95% confidence interval, 0.51 to 0.89). Aprotinin did not have a significant effect on the volume of blood transfused or on the amount of postoperative chest tube drainage. Most of the studies were of poor methodological quality and predefined transfusion triggers were infrequently used. Overall, aprotinin reduced the proportion of children who received blood transfusion during cardiac surgery with cardiopulmonary bypass. Further high-quality trials with clinically important outcomes may be warranted before aprotinin can be routinely recommended in this population.
BACKGROUND: Levels of cardiac troponin, a sensitive and specific marker of myocardial injury, are often elevated in critically ill patients. OBJECTIVES: To document elevated levels of cardiac troponin I in patients in a medical-surgical intensive care unit and the relationship between elevated levels and electrocardiographic findings and mortality. METHODS: A total of 198 patients expected to remain in the intensive care unit for at least 72 hours were classified as having myocardial infarction (cardiac troponin I level >or=1.2 microg/L and ischemic electrocardiographic changes), elevated troponin level only (>or=1.2 microg/L and no ischemic electrocardiographic changes), or normal troponin levels. Events were classified as prevalent if they occurred within 48 hours after admission and as incident if they occurred 48 hours or later after admission. Factors associated with mortality were examined by using regression analysis. RESULTS: A total of 171 patients had at least one troponin level measured in the first 48 hours. The prevalence of elevated troponin level was 42.1% (72 patients); 38 patients (22.2%) had myocardial infarction, and 34 (19.9%) had elevated troponin level only. After the first 48 hours, 136 patients had at least 1 troponin measurement. The incidence of elevated troponin level was 11.8% (16 patients); 7 patients (5.1%) met criteria for myocardial infarction, and 2 (1.5%) had elevated troponin level only. Elevated levels of troponin I at any time during admission were associated with mortality in the univariate but not the multivariate analysis. CONCLUSIONS: Elevated levels of cardiac troponin I in critically ill patients do not always indicate myocardial infarction or an adverse prognosis.
CONTEXT: Randomized clinical trials (RCTs) that stop earlier than planned because of apparent benefit often receive great attention and affect clinical practice. Their prevalence, the magnitude and plausibility of their treatment effects, and the extent to which they report information about how investigators decided to stop early are, however, unknown. OBJECTIVE: To evaluate the epidemiology and reporting quality of RCTs involving interventions stopped early for benefit. DATA SOURCES: Systematic review up to November 2004 of MEDLINE, EMBASE, Current Contents, and full-text journal content databases to identify RCTs stopped early for benefit. STUDY SELECTION: Randomized clinical trials of any intervention reported as having stopped early because of results favoring the intervention. There were no exclusion criteria. DATA EXTRACTION: Twelve reviewers working independently and in duplicate abstracted data on content area and type of intervention tested, reporting of funding, type of end point driving study termination, treatment effect, length of follow-up, estimated sample size and total sample studied, role of a data and safety monitoring board in stopping the study, number of interim analyses planned and conducted, and existence and type of monitoring methods, statistical boundaries, and adjustment procedures for interim analyses and early stopping. DATA SYNTHESIS: Of 143 RCTs stopped early for benefit, the majority (92) were published in 5 high-impact medical journals. Typically, these were industry-funded drug trials in cardiology, cancer, and human immunodeficiency virus/AIDS. The proportion of all RCTs published in high-impact journals that were stopped early for benefit increased from 0.5% in 1990-1994 to 1.2% in 2000-2004 (P<.001 for trend). On average, RCTs recruited 63% (SD, 25%) of the planned sample and stopped after a median of 13 (interquartile range [IQR], 3-25) months of follow-up, 1 interim analysis, and when a median of 66 (IQR, 23-195) patients had experienced the end point driving study termination (event). The median risk ratio among truncated RCTs was 0.53 (IQR, 0.28-0.66). One hundred thirty-five (94%) of the 143 RCTs did not report at least 1 of the following: the planned sample size (n = 28), the interim analysis after which the trial was stopped (n = 45), whether a stopping rule informed the decision (n = 48), or an adjusted analysis accounting for interim monitoring and truncation (n = 129). Trials with fewer events yielded greater treatment effects (odds ratio, 28; 95% confidence interval, 11-73). CONCLUSIONS: RCTs stopped early for benefit are becoming more common, often fail to adequately report relevant information about the decision to stop early, and show implausibly large treatment effects, particularly when the number of events is small. These findings suggest clinicians should view the results of such trials with skepticism.
INTRODUCTION: Elevated troponin levels indicate myocardial injury but may occur in critically ill patients without evidence of myocardial ischemia. An elevated troponin alone cannot establish a diagnosis of myocardial infarction (MI), yet the optimal methods for diagnosing MI in the intensive care unit (ICU) are not established. The study objective was to estimate the frequency of MI using troponin T measurements, 12-lead electrocardiograms (ECGs) and echocardiography, and to examine the association of elevated troponin and MI with ICU and hospital mortality and length of stay. METHOD: In this 2-month single centre prospective cohort study, all consecutive patients admitted to our medical-surgical ICU were classified in duplicate by two investigators as having MI or no MI based on troponin, ECGs and echocardiograms obtained during the ICU stay. The diagnosis of MI was based on an adaptation of the joint European Society of Cardiology/American College of Cardiology definition: a typical rise or fall of an elevated troponin measurement, in addition to ischemic symptoms, ischemic ECG changes, a coronary artery intervention, or a new cardiac wall motion abnormality. RESULTS: We screened 117 ICU admissions and enrolled 115 predominantly medical patients. Of these, 93 (80.9%) had at least one ECG and one troponin; 44 of these 93 (47.3%) had at least one elevated troponin and 24 (25.8%) had an MI. Patients with MI had significantly higher mortality in the ICU (37.5% versus 17.6%; P = 0.050) and hospital (50.0% versus 22.0%; P = 0.010) than those without MI. After adjusting for Acute Physiology and Chronic Health Evaluation II score and need for inotropes or vasopressors, MI was an independent predictor of hospital mortality (odds ratio 3.22, 95% confidence interval 1.04-9.96). The presence of an elevated troponin (among those patients in whom troponin was measured) was not independently predictive of ICU or hospital mortality. CONCLUSION: In this study, 47% of critically ill patients had an elevated troponin but only 26% of these met criteria for MI. An elevated troponin without ischemic ECG changes was not associated with adverse outcomes; however, MI in the ICU setting was an independent predictor of hospital mortality.
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This is the first of 2 articles evaluating cardiac events in patients undergoing noncardiac surgery. In this article, we review the magnitude of the problem, the pathophysiology of these events, approaches to risk assessment and communication of risk. The number of patients undergoing noncardiac surgery worldwide is growing, and annually 500,000 to 900,000 of these patients experience perioperative cardiac death, nonfatal myocardial infarction (MI) or nonfatal cardiac arrest. Although the evidence is limited, a substantial proportion of fatal perioperative MIs may not share the same pathophysiology as nonoperative MIs. A clearer understanding of the pathophysiology is needed to direct future research evaluating prophylactic, acute and long-term interventions. Researchers have developed tools to facilitate the estimation of perioperative cardiac risk. Studies suggest that the Lee index is the most accurate generic perioperative cardiac risk index. The limitations of the studies evaluating the ability of noninvasive cardiac tests to predict perioperative cardiac risk reveals considerable uncertainty as to the role of these popular tests. Similarly, there is uncertainty as to the predictive accuracy of the American College of Cardiology/American Heart Association algorithm for cardiac risk assessment. Patients are likely to benefit from improved estimation and communication of cardiac risk because the majority of noncardiac surgeries are elective and accurate risk estimation is important to allow informed patient and physician decision-making.
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BACKGROUND: Diclectin(R) (DCL) is an effective antiemetic used for relief of nausea and vomiting in pregnancy. It is unknown whether DCL is effective in the prevention of postoperative nausea and vomiting (PONV). METHODS: We conducted a randomized, stratified, double-blind placebo-controlled trial to examine the incidence of PONV in women undergoing elective laparoscopic tubal ligation in the day surgery setting. DCL (doxylamine succinate 10 mg and pyridoxine hydrochloride 10 mg) was administered orally the night before surgery, the morning of surgery, and upon hospital discharge. RESULTS: We enrolled 146 women in the trial, 127 of whom were included in the effectiveness analysis and 102 of whom were included in the efficacy analysis. We did not detect a difference in the incidence of nausea and vomiting in the first six hours postoperatively after adjusting for additional antiemetics administered. Patients receiving DCL as compared with placebo were significantly less likely to experience vomiting six to 24 hr postoperatively [5/59 (8.5%) vs 14/55 (25.4%), P < 0.017]. Treated patients tended to return to work earlier than those who received placebo (1.74 vs 3.7 days P = NS). CONCLUSION: Perioperative oral DCL reduces the incidence of postoperative vomiting in women undergoing elective laparoscopic tubal ligation, and may accelerate return to work.