# The association between hospital volume and overall survival in adult AML patients treated with intensive chemotherapy

## TL;DR

Hospitals that treat more adult AML patients with intensive chemotherapy are linked to better long-term survival rates.

## Contribution

This study identifies a volume–outcome relationship in AML treatment, suggesting higher hospital volumes correlate with improved long-term patient survival.

## Key findings

- An increase of 10 ICT-treated patients annually was associated with an 8% lower mortality risk.
- The volume–outcome association became significant after 100-day overall survival but not at 30-day or 42-day survival.
- Centralizing AML care is complex and requires balancing healthcare provider and patient implications.

## Abstract

Acute myeloid leukemia (AML) requires specialized care, particularly when administrating intensive remission induction chemotherapy (ICT). High-volume hospitals are presumed more adept at delivering this complex treatment, resulting in better overall survival (OS) rates. Despite its potential implications for quality improvement, research on the volume–outcome relationship in ICT administration for AML is scarce. This nationwide, population-based study in the Netherlands explored the volume–outcome relationship in AML.

Data from the Netherlands Cancer Registry on adult (≥18 years of age) ICT-treated AML patients, diagnosed between 2014 and 2018, were analyzed. Hospital volume was assessed against OS using mixed-effects Cox regression, adjusting for patient and disease characteristics (i.e. case mix), with hospital as a random effect.

Our study population consisted of a total of 1761 patients (57% male), with a median age of 61 years. The average annual number of ICT-treated patients varied across the 24 hospitals (range 1-56, median 13, and interquartile range 8-20 patients per hospital per year). Overall, an increase of 10 ICT-treated patients annually was associated with an 8% lower mortality risk [hazard ratio (HR) 0.92, 95% confidence interval (CI) 0.87-0.98, P = 0.01]. This association was not significant at 30-day (HR 1.02, 95% CI 0.89-1.17, P = 0.75) and 42-day (HR 0.96, 95% CI 0.85-1.08, P = 0.54) OS but became apparent after 100-day OS (HR 0.91, 95% CI 0.83-0.99, P = 0.05).

There is a volume–outcome association within AML care. This finding could support hospital volume as a metric in AML care. However, it should be acknowledged that centralizing care is a complex process with implications for health care providers and patients. Therefore, any move toward centralization must be judiciously balanced.

•There is an association between hospital volume and longer term outcomes (i.e. 100-day OS).•Further research is needed to define specific care processes and structural measures that lead to better outcomes.•Centralization of care is a complex process with many implications for health care providers and patients.

There is an association between hospital volume and longer term outcomes (i.e. 100-day OS).

Further research is needed to define specific care processes and structural measures that lead to better outcomes.

Centralization of care is a complex process with many implications for health care providers and patients.