Monday, August 12, 2019

Is "prediabetes" a useful term?

- Jennifer Middleton, MD, MPH

The ADA's goal in defining prediabetes,"blood glucose levels that are higher than normal but not yet high enough to be diagnosed as diabetes," is to identify those persons who would benefit from interventions to reduce their risk of developing type 2 diabetes. While reducing the incidence of type 2 diabetes is a laudable goal, the term "prediabetes" may be problematic; a 2017 meta-analysis found that "[a]s screening is inaccurate, many people will [receive] an incorrect diagnosis and be referred on for interventions while others will be falsely reassured and not offered the intervention." The imprecise label of "prediabetes" may be hampering efforts to identify effective interventions to delay or prevent the onset of type 2 diabetes.

A pair of editorials in the current issue of AFP explore the controversy surrounding metformin prescribing in persons determined to have prediabetes. Dr. Lin reviews these editorials and their evidence base in a recent tweetorial; in summary, asserting that metformin is beneficial in prediabetes, Dr. Tannaz Moin cites the Diabetes Prevention Program (DPP) which found that, in obese persons with prediabetes, metformin delayed onset of type 2 diabetes over three years (number needed to treat = 14). Dr. Moin advocates, however, for considering more than just a prediabetes test result when considering metformin treatment: "higher A1C (i.e., 6.0% to 6.4%), but also other important risk factors, such as family history of diabetes, higher fasting plasma glucose levels, and higher triglyceride levels, may predict greater risk of progression to diabetes." 

Arguing against the use of metformin is Dr. Steven Brown, who describes his concern with using prediabetes as an impetus to prescribe medication. He cites the above-mentioned 2017 meta-analysis' findings that, "[c]ompared with the reference standard of an oral glucose tolerance test, a single A1C measurement is 49% sensitive and 79% specific for prediabetes." He interprets the DPP findings differently:
 At four years, the average A1C was 5.9% in the metformin or lifestyle groups and 6.1% in the placebo group. Although these surrogate outcome differences are statistically significant, they are not clinically meaningful. Treating borderline glucose values does not improve quality of life, mortality, or any other patient-oriented outcomes.
It's quite possible that the DPP's findings were less significant because of the inherent imprecision in the "prediabetes" label. As Dr. Lin wrote in an earlier post on the Community Blog, "the term prediabetes is misleading: many of these patients will not develop diabetes." A more precise risk elucidation may be found in that same 2017 meta-analysis, where "those most at risk of developing diabetes had both impaired fasting glucose and impaired glucose tolerance." 

A reasonable middle ground may be to consider glucose readings between the ranges of normal and diabetic as just one risk factor among many for developing type 2 diabetes. There's an AFP By Topic on Diabetes: Type 2 if you'd like to read more about diabetes screening and diagnosis, and there's an AFP Department Collection with more Controversies in Family Medicine with more pro/con editorial pairs, too.

Monday, August 5, 2019

The continuing plague of gun violence: what family physicians can do

- Kenny Lin, MD, MPH

Family physicians have long recognized that gun violence is a national public health epidemic. In 2015, a coalition of nine medical, public health, and legal organizations, including the American Academy of Family Physicians and the American Bar Association, endorsed several specific recommendations for preventing firearm-related injury and death. These measures included universal criminal background checks for all firearm purchases; educating patients about gun safety and intervening in those at risk of self-harm or harm to others; improving access to mental health care; regulating civilian use of firearms with large capacity magazines; and supporting more research on evidence-based policies to prevent gun violence. A 2014 editorial in AFP also reviewed the role of primary care clinicians in counseling about gun safety based on the best available evidence.

After the February 2018 massacre of 17 people at Marjory Stoneman Douglas High School in Parkland, Florida by a 19 year-old former student wielding a legally purchased semiautomatic AR-15-style rifle, the medical editors of AFP felt that we needed to do more to empower clinicians. Surely, when the Founding Fathers endorsed the necessity of a "well-regulated Militia" in the Second Amendment to the U.S. Constitution, they did not envision mentally disturbed teenagers toting weapons with enough firepower to overwhelm entire regiments of Minutemen.

In a special editorial published online ahead of print, Dr. Sexton and the AFP medical editors argued that family medicine's emphasis on care of the whole person creates a duty to "confront the epidemic of violence by persons using guns." We reviewed the evidence of the effects of firearm regulations, mental health counseling, and active shooter training on gun safety and violence:

A 2018 RAND review of U.S. studies on gun policy published since 2003 concluded that child-access prevention laws (e.g., safe gun storage) reduce self-inflicted and unintentional firearm deaths and nonfatal injuries among youth, and may reduce unintentional firearm injuries among adults. The review also found moderate evidence that laws requiring background checks and prohibiting firearm purchases by individuals with mental illness reduce violent crime and deaths. In contrast, state stand-your-ground laws are associated with increased homicide rates. There was insufficient evidence to determine whether any laws prevent mass shootings. 

Notably, almost two-thirds of the 36,000 firearm-related deaths in the U.S. each year are suicides, leading to our recommendation that "strategies to mitigate firearm suicides should include depression screening and nonjudgmentally asking anyone with depression whether they have a gun in the home." Useful clinical tools include the FIGHTS screening tool for adolescent firearm carrying, the SAD PERSONS suicide risk assessment scale, and the Violence Screening and Assessment of Needs tool for assessing risk of violence in military veterans.

Finally, we encouraged family physicians to address the epidemic by making their voices heard in community meetings, online forums, and local publications and communicating with elected state and federal officials to advocate for funding research to study ways to reduce gun violence: "Whether it is speaking up in clinical settings, within our community, or with our elected officials, our voices can make a meaningful difference for our patients, our communities, and our nation."

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This post first appeared on the AFP Community Blog on July 17, 2018. Since then, approximately 40,000 more Americans have died from firearm suicide or homicide, including 31 in two separate terrorist attacks in Dayton and El Paso within a 24-hour period this past weekend.