Hannah Wunsch's research focuses on the organization and outcomes associated with critical care. She provided some of the earliest data comparing ICU beds per capita across high income countries, and used large, national databases to elucidate risks of long-term outcomes after critical illness. Her recent work focuses on pharmacoepidemiology, in particular the prescribing of opioids and sedatives to patients in the ICU and the use of vasopressors for treatment of patients in septic shock.