A simple and robust parametric shared frailty model for recurrent events with the competing risk of death: An application to the Carvedilol Prospective Randomized Cumulative Survival trial.

Many non-fatal events can be considered recurrent in that they can occur repeatedly over time, and some researchers may be interested in the trajectory and relative risk of non-fatal events. With the competing risk of death, the treatment effect on the mean number of recurrent events is non-identifiable since the observed mean is a function of both the recurrent event and terminal event processes. In this paper, we assume independence between the non-fatal and the terminal event process, conditional on the shared frailty, to fit a parametric model that recovers the trajectory of, and identifies the effect of treatment on, the non-fatal event process in the presence of the competing risk of death. Simulation studies are conducted to verify the reliability of our estimators. We illustrate the method and perform model diagnostics using the Carvedilol Prospective Randomized Cumulative Survival trial which involves heart-failure events.

The Impact of Medicare Health Insurance Coverage on Lung Cancer Screening.

BACKGROUND: Annual lung cancer screening via low-dose computed tomography can reduce lung cancer mortality among high-risk adults by 20%; however, screening take-up remains low. Inadequate insurance coverage or access to care may be a barrier to screening. OBJECTIVE: The objective of this study was to estimate the effect of nearly universal access to Medicare coverage on annual lung cancer screening. RESEARCH DESIGN: A regression discontinuity design was used to estimate the causal effect of nearly universal access to Medicare at age 65. Data come from the 2017 to 2019 Behavioral Risk Factor Surveillance System in 28 states that adopted the optional module on lung cancer screening and lung cancer risk. SUBJECTS: A total of 11,163 individuals at high risk for lung cancer just above and below age 65. MEASURE: Self-reported use of low-dose computed tomography to screen for lung cancer in the past 12 months. RESULTS: A total of 10,951 people at high lung cancer risk (45.7% women, response rate=98.1%) reported lung cancer screening information. Nearly universal access to Medicare increased lung cancer screening by 16.2 percentage points among men (95% confidence interval: 2.4%-30.0%, P=0.02), compared with a baseline screening rate of 11.1% just younger than age 65. Women had a baseline screening rate of 18.2% and experienced no statistically significant change in screening (1.6 percentage point increase, 95% confidence interval: -19.8% to 23.0%, P=0.88). CONCLUSIONS: Gaining Medicare coverage at age 65 increased lung cancer screening take-up among men at high lung cancer risk. Lack of insurance or inadequate access to care hinders screening.