Monday, March 29, 2021

Increasing clarity about benefits and harms of screening for diabetes

Affecting about 6 percent of pregnancies in the United States, gestational diabetes increases risks of preeclampsia, shoulder dystocia, and macrosomia, and is associated with a 10-fold greater risk of developing type 2 diabetes mellitus in later life. In a recent draft statement, the U.S. Preventive Services Task Force (USPSTF) affirmed its previous recommendation to screen pregnant persons for gestational diabetes at or after 24 weeks of gestation. Historically, there have been two screening options: a non-fasting 50 gram oral glucose challenge test followed by a fasting 100 gram glucose tolerance test if the first test result exceeds a threshold value (typically 130-140 mg/dL), or a single fasting 75 gram glucose tolerance test. Although two-step screening is more commonly used in the U.S., until recently the comparative outcomes of these approaches were uncertain. This evidence gap is important because the diagnosis is associated with increased psychological and emotional burden; labeling more persons as having gestational diabetes with the one-step screening approach would only be justified if doing so resulted in better pregnancy outcomes than the two-step approach.

A pragmatic, randomized trial recently compared the one-step and two-step approaches in more than 23,000 women who received prenatal care at Kaiser Permanente Northwest and Kaiser Permanente Hawaii. Researchers evaluated five primary outcomes: "diagnosis of gestational diabetes, large-for-gestational-age infants, a perinatal composite outcome (stillbirth, neonatal death, shoulder dystocia, bone fracture, or any arm or hand nerve palsy related to birth injury), gestational hypertension or preeclampsia, and primary cesarean section." As expected, a diagnosis of gestational diabetes was more common in participants who underwent one-step screening (16.5%) compared to the two-step approach (8.5%). However, intention-to-treat analyses found no statistically significant differences in any perinatal or maternal complications. Although the trial was not designed to measure potential long-term benefits of post-pregnancy risk-reduction strategies to prevent type 2 diabetes, the results suggest that the two-step approach produces equivalent benefits, and fewer harms, than the one-step approach.

The USPSTF is also updating its recommendation on screening for prediabetes and type 2 diabetes in nonpregnant adults. Compared to its 2015 statement, which recommends screening overweight or obese adults between the ages of 40 and 70, the updated draft statement lowers the age range to include persons aged 35 to 39 years. Although the focus of the Task Force's old and new diabetes screening guidelines is identifying persons with prediabetes in order to prevent them from developing diabetes and its complications, the utility of the term "prediabetes" is controversial, as Dr. Jennifer Middleton discussed in a previous AFP Community Blog post. In older adults, prediabetes is extremely common. In a prospective cohort study of community-dwelling adults aged 71 to 90 years, 73 percent met one or both of the diagnostic criteria for prediabetes (hemoglobin A1c level of 5.7% to 6.4%, impaired fasting glucose of 100-125 mg/dL). After 6.5 years of follow-up, persons with prediabetes at baseline were substantially more likely to revert to normoglycemia or to die than to progress to diabetes. Based on these findings, stopping diabetes screening after age 70 will avoid overdiagnosis and unnecessary treatment.


This post first appeared on the AFP Community Blog.

Sunday, March 14, 2021

Can Choosing (more) Wisely prevent chronic low back pain?

More than a dozen Choosing Wisely campaign recommendations concern what not to do for patients with acute low back pain. Based on a clinical practice guideline from the American College of Physicians, the American Society of Anesthesiologists and several other groups recommend avoiding imaging studies within the first six weeks in patients without red flags or specific clinical indications. The American Academy of Orthopedic Surgeons and the American Academy of Physical Medicine and Rehabilitation (AAPMR) advise avoiding opioids for these patients unless other alternatives have not provided pain relief. The AAPMR and the North American Spine Society discourage bed rest as treatment for acute low back pain. These recommendations are intended to reduce downstream harms and costs: for example, a spurious finding on MRI could lead to unnecessary surgery; use of opioids could lead to physical dependence and opioid use disorder; bed rest and avoidance of physical activity could increase the risk of long-term disability.

Can guideline-discordant care for patients with acute low back pain increase the risk of progression to chronic low back pain? In an inception cohort study published in JAMA Network Open, researchers enrolled 5233 adults with acute low back pain from 77 U.S. primary care practices, assessed their baseline risk of transition to chronic pain using the Subgroups for Targeted Treatment (STarT) Back prognostic tool, and followed them for 6 months. 32% of participants met clinical criteria for chronic low back pain at the study's end. Characteristics associated with transition to chronic pain included obesity (adjusted odds ratio, 1.52), tobacco use (aOR, 1.56), severe baseline disability (aOR, 1.82), and a depression and/or anxiety diagnosis (aOR, 1.66). Researchers also examined associations between chronic low back pain and inappropriate care processes within 21 days of the initial visit: 1) any opioid prescriptions, or benzodiazepines or systemic steroids prescribed without an NSAID or skeletal muscle relaxant; 2) diagnostic imaging; 3) medical subspecialty referral for back pain. Compared to the 52% of participants who received none of these, patients with 1, 2, or 3 inappropriate care processes were 1.39, 1.88, and 2.16 times more likely to develop chronic low back pain after controlling for clinical characteristics.

Although adherence to Choosing Wisely recommendations was associated with a lower risk of patients developing chronic low back pain in this study, it is disappointing that almost half of them received at least some inappropriate care. Is care for back pain an outlier, or does it reflect national trends? A recent cross-sectional study examined the use of 32 low-value health services in Medicare fee-for-service beneficiaries. The study found modest progress from 2014 to 2018 in the percentage of persons receiving any low-value service (declined from 36.3% to 33.6%), number of low-value services per 1000 persons (declined from 678 to 633), and spending per 1000 persons on low-value care (declined from $52,766 to $46,922). Three services comprised about two-thirds of low-value care: preoperative laboratory testing, opioids for back pain, and antibiotics for upper respiratory infections. While preoperative testing decreased during the study period, opioid and antibiotic prescribing both increased.

Since the campaign's inception in 2012, Choosing Wisely recommendations have been widely disseminated in American Family Physician (AFP), FPM (formerly Family Practice Management), and other family medicine journals. The American Academy of Family Physicians periodically updates and adds new "don't do" recommendations, most recently in 2018. Other studies have recognized that clinicians in underserved or "safety net" practices are as likely to provide low-value care as clinicians in better resourced settings. A 2018 AFP editorial by Dr. Jennifer Middleton recognized that increasing awareness of best practices is necessary but not sufficient to drive implementation: "For meaningful change to occur, the workflows and systems we operate within must change so that new habits become routine." The Medicare study suggests that workflows and systems have not changed enough in the past decade to undo entrenched low-value practices.


This post first appeared on the AFP Community Blog.

Thursday, March 4, 2021

Misinformation can be as contagious and harmful as COVID-19

At the end of August 2020, when around 1,000 Americans were dying from COVID-19 each day, I posted on my personal Facebook account a straightforward translation of the deaths statistic: averaged over 24 hours (86,400 seconds), one U.S. resident was dying every 86 seconds. In another post, I expressed my concern for the mental health and safety of hundreds of public health officials all over the country who were being threatened and harassed for recommending or enforcing measures aimed at stemming these horrifying losses, such as restricting restaurant capacity, banning large gatherings, and mandating mask-wearing when social distancing wasn't possible.

It didn't occur to me that either of these posts would be the least bit controversial among my friends and family. But later that night, a friend from college whom I've known for more than a quarter of a century commented that I was greatly exaggerating the death toll and "fear mongering." Do the math, I responded. He countered by claiming that doctors were inflating COVID-19 death counts for financial benefit and that just because thousands were dying with COVID, they weren't necessarily dying of COVID. The flu kills 100,000 people every year, he wrote, and we don't shut down the country for that. I gently pointed out that according to official CDC statistics, no more than 60,000 people have died in a single influenza season for the past decade, and those numbers are estimates, not actual case counts. We went back and forth like this for a while. Finally, exasperated, I observed that my friend is a lawyer, while I have medical and public health degrees and was probably a little bit more informed than he was. "Elitist," he taunted, your fancy education doesn't mean anything. The great thing about social media is that it's the ultimate equalizer - no one needs to "bow down" to your supposed expertise. By the way, he wrote, right before I wished him well and blocked him from posting more misinformation on my page, those public health officials you support all march in lockstep with the Democratic Party, so as for the harassment, well, they had it coming.

Six months later, more than half a million Americans have died from the pandemic, and though new infections have fallen from their post-holiday peak, we're still losing about 2,000 people every day (or one every 43 seconds). Despite the greatly increased pace of vaccination since President Biden took office, as of today less than 10 percent of the U.S. population is fully vaccinated, and less than 20 percent has received at least one dose of the Pfizer or Moderna two-dose vaccines (the Johnson & Johnson vaccine is a single dose). Nonetheless, the misinformed governors of Texas and Mississippi have declared victory, discarding their mask mandates and restrictions on businesses and sending the message that if COVID-19 was ever a serious public health problem, it isn't any longer.

Of course, online misinformation abounded well before COVID, infamously leading many parents to refuse the measles, mumps, and rubella vaccine for their children because they feared, based on a single fraudulent, discredited and retracted scientific article, that it might cause autism. And I'm deeply concerned that the crazy myths now proliferating online about COVID vaccines - that they make changes to your DNA, they cause infertility, they contain tiny microchips to allow Bill Gates can track your movements, that their side effects are worse than the disease - pose a huge obstacle to achieving herd immunity through vaccinating 70 percent or more of the population. (And don't get me started on the barbaric "let's achieve herd immunity through natural infection." One might as well go back to the days of bloodletting and Hippocrates' four humors, for the immense harms that strategy would cause.) Let me be clear: I don't think that vaccination should be mandatory for every adult (or child, when it is shown to be safe and effective in children), but those who decline it for themselves or on someone else's behalf should do so because they have concerns that medicine can't yet answer (e.g., are there any side effects that don't show up for a year or more?), not because they fall for misinformation or conspiracy theories.