National trends in melanoma-related hospitalizations, admission characteristics, and in-hospital outcomes in the United States, 2018–2022.

e21573 Background: Melanoma remains the most lethal form of skin cancer and contributes substantially to inpatient morbidity and healthcare utilization. Contemporary national data describing hospitalization patterns, admission characteristics, and outcomes for melanoma are limited, particularly in the modern treatment era. Methods: A serial cross-sectional analysis was conducted using the 2018–2022 Healthcare Cost and Utilization Project National Inpatient Sample. Adult (≥18 years) hospitalizations with a principal diagnosis of melanoma (ICD-10-CM C43) were included; all analyses were performed at the hospitalization level. National estimates incorporated discharge-level survey weights (DISCWT) with stratification (NISSTRATUM) and clustering by hospital (HOSPNIS). Outcomes included hospitalization volume, admission type (elective vs non-elective), in-hospital mortality, length of stay (LOS), and inflation-unadjusted hospitalization cost estimated using HCUP cost-to-charge ratios. Temporal patterns in mortality were summarized using annual survey-weighted proportions. Results: From 2018–2022, the NIS represented 32. 4 million unweighted hospitalizations, corresponding to 162. 2 million weighted hospitalizations nationally. Within this population, 1, 817 unweighted hospitalizations had a principal diagnosis of melanoma, corresponding to an estimated 9, 085 weighted melanoma hospitalizations nationwide and accounting for 26. 8% of all principal skin cancer hospitalizations. Most melanoma hospitalizations were elective (56. 6%; 95% CI 54. 1–59. 0), while 43. 4% were non-elective. Overall in-hospital mortality was 5. 3% (95% CI 4. 2–6. 6). Mean LOS was 4. 8 days (95% CI 4. 5–5. 1), and mean hospitalization cost was 20, 524 (95% CI 19, 140–21, 907). Annual in-hospital mortality ranged from 3. 9% to 6. 4% without a monotonic change across the study period. Conclusions: Melanoma principal hospitalizations represent a substantial component of inpatient skin cancer care in the United States. More than half of admissions were elective, in-hospital mortality remained consistently near 5% over five years, and hospitalization costs were considerable despite relatively short LOS. These national benchmarks characterize the contemporary inpatient burden of melanoma and support ongoing evaluation of care delivery pathways to optimize resource utilization and shift appropriate management to outpatient settings.