POEMs P ATIENT O RIENTED E VIDENCE THAT M ATTERS. Trial of labor after cesarean section is safe. What is a POEM?

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1 POEMs Practice Recommendations from Key Studies Trial of labor after cesarean section is safe Guise JM, McDonagh MS, Osterweil P, Nygren P, Chan BK, Helfand M. Systematic review of the incidence and consequences of uterine rupture in women with previous cesarean section. BMJ 2004; 329: How risky is a trial of labor after cesarean delivery for uterine rupture and other patientoriented outcomes? Based on the best research we have, as compared with trial of labor, approximately 370 welective repeat cesarean sectins would have to be performed to avoid 1 symptomatic uterine rupture. More than 7000 elective repeat cesarean sections would be needed to prevent 1 perinatal death associated with uterine rupture, and almost 3000 to prevent 1 hysterectomy. There were no maternal deaths among women who chose trial of labor or repeat cesarean section in the studies included in this review. Evidence is insufficient to judge whether induction of labor with oxytocin or prostaglandins increases the risk of symptomatic uterine rupture. This information should be included in the consent process for women who must choose between trial of labor and repeat cesarean section. (Level of evidence [LOE]=2a) Meta-analysis (other) Various (meta-analysis) This skillfully performed evidence review, conducted for the Agency for Healthcare Research and Quality, evaluated the risk of uterine rupture, and maternal and perinatal consequences of uterine rupture, for women who choose either trial of labor or cesarean section after a previous cesarean delivery. Included were 21 cohort and casecontrol studies of at least fair quality. No randomized controlled trials were available. Studies based on ICD-9 codes in administrative data sets were specifically excluded because of the poor diagnostic accuracy of such data. The incidence of symptomatic uterine rupture was 3.8 per 1000 in the trial of labor groups and 1.1 per 1000 in the elective repeat cesarean section groups, or an additional 2.7 per 1000 (95% confidence interval [CI], ; number What is a POEM? Each month, the POEMs (Patient-Oriented Evidence that Matters) editorial team reviews 105 research journals in many specialties, and selects and evaluates studies that investigate important primary care problems, measure meaningful outcomes, and have the potential to change the way medicine is practiced. Each POEM offers a Bottom Line observation and summarizes the study's objective, patient population, study design and validity, and results. InfoPOEMs, Info-Retriever and POEMS for Primary Care are registered trademarks of InfoPOEM, Inc. POEMS and Patient-Oriented Evidence that Matters are trademarks of InfoPOEM, Inc. These POEMs are copyrighted by, and published with the express permission of InfoPOEM, Inc. and may not be copied or otherwise reproduced without the prior written consent of InfoPOEM, Inc. 766 OCTOBER 2004 / VOL 53, NO 10 The Journal of Family Practice

2 needed to treat to harm [NNTH]=370). Overall, 6 perinatal deaths were reported for 74 symptomatic ruptures or 1.4 per 10,000 (95% CI, 0 9.8; NNTH=7143). There were 7 hysterectomies among 60 women with symptomatic rupture among women choosing trial of labor, or 3.4 per 10,000 (95% CI, ; NNTH=2941), and no significant difference in hysterectomy rates overall. There were no maternal deaths. No difference was found in the incidence of asymptomatic uterine rupture. Oxytocin was associated with a two- to fourfold increase in risk of uterine rupture in 2 case-control studies, but use of oxytocin or prostaglandin was not associated with increased risk of uterine rupture in prospective cohort studies. Renal colic: NSAIDs more effective, less noxious than opioid analgesics Holdgate A, Pollock T. Systematic review of the relative efficacy of non-steroidal anti-inflammatory drugs and opioids in the treatment of acute renal colic. BMJ 2004; 328: Are intravenous nonsteroidal anti-inflammatory drugs (NSAIDs) more effective than narcotics for the treatment of patients with acute renal colic? NSAIDs produce equivalent or better analgesia than opioid narcotics, reduce the need for additional analgesia, and result in less vomiting among patients with renal colic. Not studied was a potential benefit of NSAIDs on the duration of colic; their ability to cause ureteral dilation may hasten stone passage. (LOE=1a) Meta-analysis (randomized controlled trials) Various (meta-analysis) The authors of this study scoured nephrology textbooks, review articles, study bibliographies, conference proceedings, and 4 databases to find the 20 trials that compared (usually) intravenous NSAIDs with opioids for a total of 1613 patients with acute renal colic. The authors didn t describe how this search was performed or how articles were selected for inclusion. Of the 9 trials that evaluated pain at a fixed time after therapy was given, pain reports were slightly but significantly lower in the NSAID group. Studies with ketorolac (Toradol) produced heterogeneous results, but other NSAIDs produced scores that were lower, on average, by 4.6 mm on a 100-mm visual analog scale (a difference of 13 mm to 15 mm is considered clinically relevant). The number of patients with complete pain relief at 30 or 60 minutes was similar in the 2 groups. However, the risk of patients requiring rescue (ie, additional) analgesia was significantly less in the NSAID group (relative risk=0.75; 95% confidence interval [CI], ). Approximately 16 patients treated with an NSAID instead of a narcotic (9 of 10 trials used meperidine [Demerol]) would need to be treated for 1 additional patient to avoid the need for additional analgesia (number needed to treat=16; 95% CI, 10 57). Vomiting occurred less often with NSAIDs than with narcotic treatment (relative risk = 0.35; 95% CI, ), with 1 fewer patient vomiting for every 8 patients treated with an NSAID instead of an opioid (95% CI, 7 11). Vomiting risk was highest with meperidine. The effect of the type of analgesia on the duration of colic was not evaluated in these studies, although their pharmacology would suggest NSAIDs, by causing relaxation of the greeters, would produce more rapid resolution. 768 OCTOBER 2004 / VOL 53, NO 10 The Journal of Family Practice

3 THE JOURNAL OF FAMILY PRACTICE Evidence-based medicine ratings THE JOURNAL OF FAMILY PRACTICE uses a simplified rating system system called the Strength of Recommendation Taxonomy (SORT). More detailed information can be found in the February 2003 issue, Simplifying the language of patient care, pages Strength of Recommendation (SOR) ratings are given for key recommendations for readers. SORs should be based on the highest-quality evidence available. A B C Recommendation based on consistent and good-quality patient oriented evidence. Recommendation based on inconsistent or limited-quality patient-oriented evidence. Recommendation based on consensus, usual practice, opinion, disease-oriented evidence, or case series for studies of diagnosis, treatment, prevention, or screening Levels of evidence determine whether a study measuring patient-oriented outcomes is of good or limited quality, and whether the results are consistent or inconsistent between studies. STUDY QUALITY 1 Good-quality, patient-oriented evidence (eg, validated clinical decision rules, systematic reviews and meta-analyses of randomized controlled trials [RCTs] with consistent results, high-quality RCTs, or diagnostic cohort studies) 2 Lower-quality patient-oriented evidence (eg, unvalidated clinical decision rules, lower-quality clinical trials, retrospective cohort studies, case control studies, case series) 3 Other evidence (eg, consensus guidelines, usual practice, opinion, case series for studies of diagnosis, treatment, prevention, or screening) Consistency across studies Consistent Most studies found similar or at least coherent conclusions (coherence means that differences are explainable); or If high-quality and up-to-date systematic reviews or meta-analyses exist, they support the recommendation Inconsistent Considerable variation among study findings and lack of coherence; or If high-quality and up-to-date systematic reviews or meta-analyses exist, they do not find consistent evidence in favor of the recommendation P ATIENT O RIENTED E VIDENCE THAT M ATTERS Cough suppressants ineffective for children Paul IM, Yoder KE, Crowell KR, et al. Effect of dextromethorphan, diphenhydramine, and placebo on nocturnal cough and sleep quality for coughing children and their parents. Pediatrics 2004; 114:e85 e90. Do cough suppressants improve the sleep of children with respiratory infections, or the sleep of their parents? In this single-dose study, placebo worked just as well as either dextromethorphan or diphenhydramine to decrease cough frequency or severity for children. Also, the active drugs provided no additional benefit on parents report of their own or their child s sleep. This is both bad news and good news. The bad news is that these drugs don t work any better than placebo (which, actually, was reported to work pretty well). The good news is that when parents feel the need to do something when their child has a cold, all products work equally well. (LOE=1b ) Randomized controlled trial (double-blinded) Outpatient (primary care) When a young child coughs at night, parents don t get much sleep. Although the American Academy of Pediatrics recommends against antitussives because of their lack of demonstrated benefit, these products fly off pharmacy shelves in the winter months. This study identified 100 children experiencing rhinitis and cough symptoms for 1 week or less, who didn t have asthma or allergies; in other words, children with a cold. The average 770 OCTOBER 2004 / VOL 53, NO 10 The Journal of Family Practice

4 age was slightly older than 4 years (range=2 16 years). The children were randomized (allocation concealment uncertain) to receive a single dose of placebo, diphenhydramine (Diphen), or dextromethorphan (Benylin), for the single night of the study. Using a 7-point Likert scale, parents were asked to rate the effect of treatment on the child s cough frequency, as well as the effect on their own sleep and that of the child. As compared with ratings obtained for the night before the study night, parents overall reported a significant decrease in cough frequency and severity (from somewhat to occasional on the descriptive scale). The combined symptom score decreased from 19.8 to 8.9 (of a possible 30) with any treatment (P<.01). Parents also reported a significant improvement in both their sleep and their childrens sleep. However, the results were not different whether the child was treated with either drug or placebo. Adverse effects were reported equally in all 3 study groups. The study had the power to find a 1-point change in scores of the 3 arms, if one truly existed. Folate worsens outcomes after placement of coronary stent Lange H, Suryapranata H, DeLuca G, et al. Folate therapy and in-stent restenosis after coronary stenting. N Engl J Med 2004; 350: Does B-vitamin supplementation reduce the risk of restenosis after coronary stenting? Intensive folate therapy seems to increase the risk of restenosis after coronary stent placement, particularly in men, those without diabetes, and those with normal homocysteine levels. (LOE=1b) Randomized controlled trial (double-blinded) ALLOCATION Uncertain Inpatient (any location) with outpatient follow-up Homocysteine is a risk factor for heart disease, so anything that modifies homocysteine levels among high-risk patients must be helpful, right? Not necessarily. These German and Dutch researchers randomized patients following placement of a coronary stent to receive folate therapy (n=316) or matching placebo (n=320). Folate therapy consisted of intravenous boluses of 1 mg folic acid, 5 mg vitamin B6, and 1 mg vitamin B12, followed daily oral doses of 1.2 mg folic acid, 48 mg vitamin B6, and 60 µg vitamin B12. Patients with recent myocardial infarction, renal dysfunction, left main disease, or in-stent restenosis were excluded, as were those already taking vitamins. Groups were balanced at the start of the study, analysis was by intention to treat, but allocation concealment was not described. At the end of the 8-month study period, major adverse coronary events were more likely in the folate group (16.8% vs 10.9%; P=.03; number needed to treat=17), primarily related to an increase in the need for target vessel revascularization. Subgroup analysis found that the risk of restenosis was especially noteworthy in men, patients without diabetes, and patients with a baseline homocysteine level lower than 15 µmol/l. However, the converse was not true: women, patients with diabetes, and those with elevated homocysteine levels did not see any significant benefit from folate therapy. 772 OCTOBER 2004 / VOL 53, NO 10 The Journal of Family Practice

5 P ATIENT O RIENTED E VIDENCE THAT M ATTERS A single negative ultrasound rules out DVT Stevens SM, Elliott CG, Chan KJ. Withholding anticoagulation after a negative result on duplex ultrasonography for suspected symptomatic deep venous thrombosis. Ann Intern Med 2004; 140: Is a follow-up ultrasound necessary after an initial negative finding for patients with symptoms of deep vein thrombosis (DVT)? For patients with suspected DVT, but a single negative Doppler ultrasound, the recommended follow-up ultrasound 1 week later does not seem to be necessary. Less than 3 in 100, at most, of these patients will be found to have a DVT over the subsequent 3 months. This study specifically excluded patients with calf vein thrombosis, who still may require follow-up ultrasound to check for extension. (LOE=1b) Watch for these Clinical Inquiries coming soon How effective is gastric bypass for weight loss? Does acyclovir help herpes simplex virus cold sores if treatment is delayed? How should thyroid replacement be initiated? Cohort (prospective) Outpatient (specialty) The researchers enrolled 445 consecutive patients referred for Doppler ultrasound to rule out DVT. It was the first suspected episode of DVT for all patients. The ultrasound results were reviewed by 1 of 2 certified vascular surgeons. Only patients deemed to have a noncompressible deep vein received anticoagulation. DVT was indicated for 13.7% of patients, although almost one third of these had a calf DVT. Of the patients with negative results, 0.8% (95% confidence interval, ) had a symptomatic DVT in the following 3 months; none had a pulmonary embolism or other serious events. In a primary care patient with knee pain, how predictive is the physical examination for meniscal injury? Do steroid injections help with osteoarthritis of the knee? OCTOBER 2004 / VOL 53, NO 10 The Journal of Family Practice 773