Age, ASA physical status and surgical outcomes: insights from a nationwide cohort study

With over 300 million surgical procedures performed worldwide annually and an ageing population with increasing comorbidities, peri-operative risk assessment is more important than ever. Whilst the ASA physical status is used widely to assess surgical risk, its association with age remains underexplored in contemporary, broad surgical populations. This study examines the relationship between ASA physical status, age and postoperative mortality in an adult surgical cohort.

This nationwide cohort study analysed data from the Swedish Perioperative Register on patients aged ≥ 18 y undergoing major non-cardiac surgery from January 2019 to March 2023. Data on comorbidities, socioeconomic factors and mortality were retrieved from national health registries. The primary outcome was 30-day mortality. Secondary outcomes were 365-day mortality and days at home alive at 30 days.

A total of 262,938 elective and 197,108 acute procedures were analysed, with median ages of 66 and 68 y, respectively. Crude mortality rates in elective surgery were 1369 (0.5%) at 30 days and 10,437 (4.0%) at 365 days. For acute surgery, mortality was 10,602 (5.4%) at 30 days and 27,912 (14.2%) at 365 days. Adjusted odds ratios (OR) for 30-day mortality indicated a 14-fold increased risk for ASA physical status 3 compared with ASA physical status 1 in both elective (OR 13.7, 95%CI 7.5-25.0) and acute (OR 14.0, 95%CI 10.2-19.3) surgeries. Correspondingly, ASA physical status ≥ 4 was associated with odds ratios of 62.2 (95%CI 33.5-115.5) for elective and 51.1 (95%CI 37.1-70.3) for acute surgery.

As populations age and surgical demand increases, continuous evaluation of risk assessment tools like the ASA physical status is essential. This study shows a strong association between ASA physical status and mortality across all ages in a contemporary adult surgical cohort. These findings could enhance our understanding of peri-operative risk stratification in the context of shifting demographic trends.