Prescription drug use over a lifetime

That is the topic of an interesting paper by Ho (2023). Prescription drug use has reached historic highs in the United States—a trend linked to increases in medicalization, institutional factors relating to the health care and pharmaceutical industries, and population aging and growing burdens of chronic disease. Despite the high and rising prevalence of use,…

Dual eligibles: A statistical overview

Medicare covers largely elderly individuals, the disabled, and individuals with end stage kidney disease. Medicaid covers low-income individuals. So who are dual eligibles, that qualify for both programs? The Medicaid and CHIP Payment and Access Commission (MACPAC) and the Medicare Payment Advisory Commission (MedPAC) put out a report last year providing a summary of the…

Should you adjust for baseline characteristics within randomized controlled trials?

At first glance, one may think the answer is no. Randomization should insure that baseline characteristics are balanced across trial arms. In practice, however, sometimes baseline characteristics due differ somewhat by trial arm simply by chance, especially in smaller randomized controlled trials (RCTs). A JAMA Guide to Statistics and Methods by Holmberg et al. 2022…

What is collider bias?

A paper by Holmberg et al. (2022) in JAMA provides a number of examples of how collider bias can lead to problematic causal inference. The term collider bias is often invoked when using directed acyclic graphs (DAGs) to map the causal pathway. Collider bias occurs when you aim to measure the impact of A on…

How to justify your survival curve extrapolation methodology

Clinical trials are typically of (relatively) short duration, but innovative treatments may impact patient survival over multiple years. Health economists and outcomes researchers often are faced with the challenge of extrapolating clinical trial survival curves to estimate long-term survival gains for the typical patient. These estimates may be done parameterically (e.g., exponential, Weibull, Gompertz, log-logistic,…

Who pays for health care? Who uses it?

Ultimately, individuals and households pay for health care. Whether payments are made directly to providers, via taxes or through commercial insurance, households are the sole source of health care financing. Further, all treatments are ultimately provided on behalf of individuals and households. A key question, however, is which types of individuals pay more for health…