Impact of Physiological Stress and Reserve on the Cost of Care: Operative Stress Score and Frailty.

Background: Physiological stress and reserve negatively impact surgical patients.

Methods: Patients undergoing elective surgery were included. Operative stress was defined by operative stress score (OSS) and frailty by RAI.

Results: 6,182 patients were included. When OSS score of 5, patients were older (67 vs. 65.4), more likely male (70.2 vs 53.9), had longer length of stay (9.7 days vs 3.3 days), and higher mortality (30 days- 3.9 vs. 0.7, 90 days- 6.27 vs. 1.37, and 120 days- 8.24 vs.1.8). Frail patients were older (76 versus 65.4 years), more likely male (68.9 versus 53.9), had higher mortality (30 days- 1.6 versus 0.7, 90 days- 4.4 versus 1.73, and 120 days- 4.7 versus 1.8,), and longer length of stay (4.8 versus 3.3 days). Costs increased with OSS. Net income differed between OSS categories; the highest was OSS of 4 ($9,350 vs. mean $5,213, p < 0.001). Total charges and costs increased with increasing frailty (p < 0.0001). There is a decrease in net income with frailty. Overall, for frail patients, there was a net negative income ($-3,658 vs. $5231, p < 0.0001). Trends were similar with each OSS category (1/2, 3, 4, and 5). Net income was negative for almost all OSS categories in frail (1/2 $-3,658, 3 $-4,440, 4 $971, and 5 $-9,932). Net income was positive for commercially insured but negative for most with Medicare.

Conclusions: Increasing OSS was associated with increased costs and profit, and frailty was associated with increased costs and decreased profit. Most with Medicare are cared for at a loss.