2 Minute Medicine Rewind December 23-30, 2013

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In this section, we will highlight the key high-impact studies, updates, and analyses published in medicine during the past week.

Arthroscopic Partial Meniscectomy versus Sham Surgery for a Degenerative Meniscal Tear

Arthroscopic partial meniscectomy is the most common orthopedic procedure in the US with an annual direct medical cost estimated at $4 billion.   However, a recent randomized control trial demonstrated that arthroscopic partial meniscectomy with physical therapy provided no additional benefit to physical therapy alone.  In this randomized trial, 146 patients with symptoms consistent with degenerative medial meniscus tear but no knee osteoarthritis were assigned to receive arthroscopic partial meniscectomy or sham surgery.  Intention-to-treat analysis revealed no significant difference after 12 months between the groups for all primary outcomes including Lysholm score (between-group difference −1.6 points, 95% CI −7.2 to 4.0), WOMET score (between-group difference −2.5 points, 95% CI −9.2 to 4.1), and score for knee pain after exercise (between-group difference −0.1, 95% CI −0.9 to 0.7).  This study therefore showed no significant benefit to arthroscopic partial meniscectomy over sham surgery.

Cognitive Behavioral Therapy Plus Amitriptyline for Chronic Migraine in Children and Adolescents

Currently there are no FDA-approved drug treatments for chronic migraines in young persons, which has resulted in a lack of durable, evidence-based management strategies. Cognitive behavioral therapy (CBT) has also been shown to be effective for chronic and recurrent pain in children and adolescents.  Amitriptyline is a leading drug used for headache prophylaxis in adults and children.  In this randomized trial, 135 patients between the ages of 10-17 years old with chronic migraine were assigned to CBT with amitriptyline or to headache education plus amitriptyline.  Investigators found that at 20 weeks, there was a significantly increased reduction in days with headaches in the intervention group (11.5 day reduction vs. 6.8, difference 4.7 days, 95% CI 1.7-7.7 days, p = 0.002) as well as a reduction in the Pediatric Migraine Disability Assessment Score (PedMIDAS) (52.7 point reduction vs. 38.6, difference 14.1 points, 95% CI 3.3-24.9 points, p = 0.01).  These results support the efficacy of using CBT over normal headache education in the treatment of chronic migraine for children and adolescents.

Association between change in daily ambulatory activity and cardiovascular events in people with impaired glucose tolerance (NAVIGATOR trial): a cohort analysis

Lifestyle interventions have been shown to reduce the risk of developing type 2 diabetes.  However, there has been little study of the effect of lifestyle on risks associated with diabetes in patients with impaired glucose tolerance.  In this cohort study, investigators studied prospective data from the NAVIGATOR (Nateglinide and Valsartan in Impaired Glucose Tolerance Outcomes Research) trial, which included 45,211 person-years of follow-up in individuals who had impaired glucose tolerance and cardiovascular disease.  This study found that baseline ambulatory activity (HR per 2000 steps per day 0.90, 95% CI 0.84-0.96) and change in ambulatory activity (HR 0.92, 95% CI 0.86-0.99), objectively measured by pedometers, were inversely associated with the risk of having a cardiovascular event.  This therefore shows that for individuals with impaired glucose tolerance and cardiovascular disease, reducing daily ambulatory activity may be associated with an increased risk of suffering a cardiovascular event.

Tafenoquine plus chloroquine for the treatment and relapse prevention of Plasmodium vivax malaria (DETECTIVE): a multicentre, double-blind, randomised, phase 2b dose-selection study

Malaria caused by Plasmodium vivax is hampered by poor compliance, as the current treatment regimen requires chloroquine for 3 days followed by primaquine for up to 14 days.  This study researched the efficacy and safety profile of chloroquine and a single dose of tafenoquine for P. vivax cure.  In this randomized trial, 329 patients with P. vivax infection were randomly assigned to receive chloroquine plus tafenoquine (50, 100, 300 or 600mg), chloroquine plus primaquine, or chloroquine alone.  The percentage of patients without relapse at 6 months was 57.7% (95% CI 43-70) with tafenoquine 50 mg, 54.1% (40-66) with tafenoquine 100 mg, 89.2% (77-95) with tafenoquine 300 mg, 91.9% (80-97) with tafenoquine 600 mg, 77.3% (63-87) with primaquine, and 37.5% (23-52) with chloroquine alone.  Tafenoquine at 300mg and 600mg had a significantly better efficacy than chloroquine alone (treatment differences 51.7%, p<0.001 and 54.5%, p<0.001 respectively).  The profile of adverse events was not significantly different among the regimens.  Single-dose 300mg tafenoquine and chloroquine has thus been chosen for further assessment in a phase 3 trial.

Risk Assessment, Genetic Counseling, and Genetic Testing for BRCA-Related Cancer in Women: U.S. Preventive Services Task Force Recommendation Statement

A woman’s risk of breast cancer is 45-65% by 70 years old if the patient has clinically significant mutations in either BRCA gene.  Detecting BRCA mutations is therefore an important cancer screening test in certain patient populations.  The 2005 USPSTF guidelines recommended that women with a family history that is suggestive of an increased risk for deleterious BRCA1 or BRCA2 mutations be referred for genetic counseling and genetic testing, and that women without such a family history should not be referred for testing.  For this 2013 recommendation statement, the committee reviewed 18 studies that had been published in the interim addressing the utility of genetic counseling and testing in asymptomatic women with a family history of breast or ovarian cancer but no personal history of cancer or known potentially harmful BRCA mutations in their family.

The updated 2013 USPTF recommendation reaffirms the 2005 statement in the context of current treatment options as well as updated and improved family history risk stratification tools.  The tools that were studied in this assessment were the Ontario Family History Assessment Tool, the Manchester Scoring System, the Referral Screening Tool, Pedigree Assessment Tool, and FHS-7.

By Neal Yuan and David Ouyang

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