The COVID-19 pandemic significantly affected healthcare systems. The most immediate effect was the increased demand for healthcare resources. This study aimed to conduct a case-mix analysis at one of the teaching hospitals in Malaysia to understand the economic implications of the pandemic.

Admissions related to COVID-19, either as a primary or secondary diagnosis, were extracted and given ICD-10 codes for diagnosis and ICD9-CM codes for procedures. The combined ICD-10 and ICD9-CM codes were imported into a case-mix grouper to generate the case-mix codes. The codes used for COVID-19 were A-4-13-I, A-4-13-II, and A-4-13-III for mild, moderate, and severe disease, respectively. Clinical pathways were collected and healthcare resource utilization was estimated by combining top-down and bottom-up costing approaches. Discounting and inflation were based on guidelines and official rates. The cost data were reported in US dollars (price year 2021).

A total of 4,889 patients with a COVID-19 diagnosis were admitted to the hospital in 2021. Of these, 4,813 patients (98%) had a primary diagnosis of COVID-19. The remaining 76 patients (2%) were admitted for other medical reasons but were found to be positive for SARS-Cov-2 during admission. Therefore, for these patients, infection with the virus was considered a secondary diagnosis during the treatment episode.

Among the 4,813 patients, 3,909 (81%) were admitted with mild COVID-19 (A-4-13-I), 630 (13%) had moderate COVID-19 (A-4-13-II), and 274 (6%) had severe disease (A-4-13-III). More than half (56%) of the patients with a secondary diagnosis of COVID-19 were admitted for elective procedures. The average length of hospital stay (LOS) for mild disease was 9 days, with cumulative hospital costs of USD1,543. The average LOS for both moderate and severe disease was 21 days, and the cumulative hospital costs were USD23,527 and USD26,731 respectively. The total costs incurred for COVID-19 were estimated at USD19,259,153.

COVID-19 has considerable economic implications. This study provided information as part of a health technology assessment in the hospital to inform evidence-based healthcare decisions.