Sensitivity Analysis for Unmeasured Confounding: E-Values for Observational Studies

Annals Understanding Clinical Research: Evaluating the Meaning of a Summary Estimate in a Meta-analysis

The Relationship of Health Insurance and Mortality: Is Lack of Insurance Deadly?

About 28 million Americans are currently uninsured, and millions more could lose coverage under policy reforms proposed in Congress. At the same time, a growing number of policy leaders have called for going beyond the Patient Protection and Affordable Care Act to a single-payer national health insurance system that would cover every American. These policy debates lend particular salience to studies evaluating the health effects of insurance coverage. In 2002, an Institute of Medicine review concluded that lack of insurance increases mortality, but several relevant studies have appeared since that time. This article summarizes current evidence concerning the relationship of insurance and mortality. The evidence strengthens confidence in the Institute of Medicine's conclusion that health insurance saves lives: The odds of dying among the insured relative to the uninsured is 0.71 to 0.97.

Risk-Targeted Lung Cancer Screening: A Cost-Effectiveness Analysis: Annals of Internal Medicine: Vol 168, No 3

Background: Targeting low-dose computed tomography (LDCT) for lung cancer screening to persons at highest risk for lung cancer mortality has been suggested to improve screening efficiency. Objective: To quantify the value of risk-targeted selection for lung cancer screening compared with National Lung Screening Trial (NLST) eligibility criteria. Design: Cost-effectiveness analysis using a multistate prediction model. Data Sources: NLST. Target Population: Current and former smokers eligible for lung cancer screening. Time Horizon: Lifetime. Perspective: Health care sector. Intervention: Risk-targeted versus NLST-based screening. Outcome Measures: Incremental 7-year mortality, life expectancy, quality-adjusted life-years (QALYs), costs, and cost-effectiveness of screening with LDCT versus chest radiography at each decile of lung cancer mortality risk. Results of Base-Case Analysis: Participants at greater risk for lung cancer mortality were older and had more comorbid conditions and higher screening-related costs. The incremental lung cancer mortality benefits during the first 7 years ranged from 1.2 to 9.5 lung cancer deaths prevented per 10 000 person-years for the lowest to highest risk deciles, respectively (extreme decile ratio, 7.9). The gradient of benefits across risk groups, however, was attenuated in terms of life-years (extreme decile ratio, 3.6) and QALYs (extreme decile ratio, 2.4). The incremental cost-effectiveness ratios (ICERs) were similar across risk deciles ($75 000 per QALY in the lowest risk decile to $53 000 per QALY in the highest risk decile). Payers willing to pay $100 000 per QALY would pay for LDCT screening for all decile groups. Results of Sensitivity Analysis: Alternative assumptions did not substantially alter our findings. Limitation: Our model did not account for all correlated differences between lung cancer mortality risk and quality of life. Conclusions: Although risk targeting may improve screening efficiency in terms of early lung cancer mortality per person screened, the gains in efficiency are attenuated and modest in terms of life-years, QALYs, and cost-effectiveness. Primary Funding Source: National Institutes of Health (U01NS086294).

Antithyroid Drugs and Congenital Malformations: A Nationwide Korean Cohort Study: Annals of Internal Medicine: Vol 168, No 6

Background: Untreated or insufficiently treated Graves disease in pregnancy may pose risks to both mother and fetus. Antithyroid drugs (ATDs) are the treatment mainstay, but the potential teratogenic effect of these drugs has prompted clinicians to question the safe management of this vulnerable population. Objective: To examine the association between maternal prescriptions for ATDs and congenital malformations in live births. Design: Nationwide cohort study. Setting: Korean National Health Insurance database. Participants: A cohort of 2 886 970 completed pregnancies linked to live-born infants in 2 210 253 women between 2008 and 2014. Intervention: Maternal prescriptions for ATDs in the first trimester. Measurements: The risk for overall and organ-specific congenital malformations in offspring, with logistic regression models used to control for potential confounders. Results: 12 891 pregnancies (0.45%) were exposed to ATDs during the first trimester. The prevalence of malformations in exposed offspring was 7.27%, compared with 5.94% in offspring of women who were not prescribed ATDs during pregnancy (P < 0.001) (adjusted odds ratio, 1.19 [95% CI, 1.12 to 1.28]). Absolute increases in the prevalence of congenital malformations per 1000 live births were 8.81 cases (CI, 3.92 to 13.70 cases) for propylthiouracil alone, 17.05 cases (CI, 1.94 to 32.15 cases) for methimazole (MMI) alone, and 16.53 cases (CI, 4.73 to 28.32 cases) for propylthiouracil and MMI, compared with pregnancies without ATD prescriptions. In the MMI group, a high cumulative dose (>495 mg) during the first trimester was associated with an increased risk for malformations compared with a low dose (1 to 126 mg) (adjusted odds ratio, 1.87 [CI, 1.06 to 3.30]). Limitation: The study used a prescription claims database to assess ATD exposure. Conclusion: Exposure to ATDs during the first trimester was associated with increased risk for congenital malformations, particularly for pregnancies in which women received prescriptions for MMI or both ATDs. Primary Funding Source: None.

Should We Screen This Patient for Carotid Artery Stenosis?: Grand Rounds Discussion From Beth Israel Deaconess Medical Center: Annals of Internal Medicine: Vol 167, No 7

In July 2014, the U.S. Preventive Services Task Force (USPSTF) published a clinical guideline on screening for asymptomatic carotid artery stenosis. The guideline recommended against screening in asymptomatic adults, based primarily on the results of 3 large randomized trials (grade D recommendation). The principal screening test was carotid ultrasonography, and the intervention in the 3 trials was carotid endarterectomy for patients with stenosis exceeding 50% to 60%. In a meta-analysis, carotid endarterectomy reduced rates of 1) perioperative stroke, death, or subsequent ipsilateral stroke and 2) perioperative stroke, death, or any subsequent stroke. The corresponding absolute risk differences were –2.0% (95% CI, –3.3% to –0.7%) and –3.5% (CI, –5.1% to –1.8%), respectively. However, perioperative stroke and death were substantially less common among the 3 randomized trials than in contemporaneous cohort studies (1.9% vs. 3.3%). In addition to stroke or death in patients receiving carotid endarterectomy, a harm of screening included the risk for angiography prompted by abnormal results on carotid ultrasonography. In this article, 2 discussants address the risks and benefits of screening for carotid artery disease as well as how to apply the guideline to an individual patient who is deciding whether to be screened.

Yellow Fever Vaccine Shortages in the United States and Abroad: A Critical Issue

Mid- and Long-Term Health Risks in Living Kidney Donors: A Systematic Review and Meta-analysis: Annals of Internal Medicine: Vol 168, No 4

Background: Long-term health risks for adults who donate kidneys are unclear. Purpose: To summarize evidence about mid- and long-term health risks associated with living kidney donation in adults. Data Sources: PubMed, Embase, Scopus, and PsycINFO without language restriction from April 1964 to July 2017. Study Selection: Observational studies with at least 1 year of follow-up that compared health outcomes in adult living kidney donors versus nondonor populations. Data Extraction: Two investigators independently extracted study data and assessed study quality. Data Synthesis: 52 studies, comprising 118 426 living kidney donors and 117 656 nondonors, were included. Average follow-up was 1 to 24 years. No evidence suggested higher risk for all-cause mortality, cardiovascular disease, hypertension, type 2 diabetes, or adverse psychosocial health outcomes in living kidney donors than in nondonor populations. Donors had higher diastolic blood pressure, lower estimated glomerular filtration rates, and higher risk for end-stage renal disease (ESRD) (relative risk [RR], 8.83 [95% CI, 1.02 to 20.93]) and preeclampsia in female donors (RR, 2.12 [CI, 1.06 to 4.27]). Despite the increased RR, donors had low absolute risk for ESRD (incidence rate, 0.5 event [CI, 0.1 to 4.9 events] per 1000 person-years) and preeclampsia (incidence rate, 5.9 events [CI, 2.9 to 8.9 events] per 100 pregnancies). Limitation: Generalizability was limited by selected control populations, few studies reported pregnancy-related outcomes, and few studies were from low- and middle-income countries. Conclusion: Although living kidney donation is associated with higher RRs for ESRD and preeclampsia, the absolute risk for these outcomes remains low. Compared with nondonor populations, living kidney donors have no increased risk for other major chronic diseases, such as type 2 diabetes, or for adverse psychosocial outcomes. Primary Funding Source: National Health Service Blood and Transplant and National Institute for Health Research. (PROSPERO: CRD42017072284)

Variability in the Relationship of Hemoglobin A1c and Average Glucose Concentrations: How Much Does Race Matter?

A Call for Open-Source Cost-Effectiveness Analysis