A novel machine learning approach to identify social risk factors associated with textbook outcomes after surgery

Identifying social determinants of health has become a priority for many researchers, health care providers, and payers. The vast amount of patient and population-level data available on social determinants creates, however, both an opportunity and a challenge as these data can be difficult to synthesize and analyze.

Medicare beneficiaries who underwent 1 of 4 common operations between 2013 and 2017 were identified. Using a machine learning algorithm, the primary independent variable, surgery social determinants of health index, was derived from 15 common, publicly available social determents of health measures. After development of a surgery social determinants of health index, multivariable logistic regression was used to estimate the association of this index with textbook outcomes, as well as the component metrics of textbook outcomes.

A novel surgery social determinants of health index was developed with factor component weights that varied relative to their impact on postoperative outcomes. Factors with the highest weight in the algorithm relative to postoperative outcomes were the proportion of noninstitutionalized civilians with a disability and persons without high school diploma, while components with the lowest weights were the proportion of households with more people than rooms and persons below poverty. Overall, an increase in surgery social determinants of health index was associated with 6% decreased odds (95% confidence interval: 0.93-0.94) of achieving a textbook outcome. In addition, an increase in surgery social determinants of health index was associated with increased odds of each of the individual components of textbook outcome; ranging from 3% increased odds (95% confidence interval: 1.03-1.04) for 90-day readmission to 10% increased odds (95% confidence interval: 1.09-1.11) for 90-day mortality. Further, there was 6% increased odds (95% confidence interval: 1.05-1.07) of experiencing a complication and 7% increased odds (95% confidence interval: 1.06-1.07) of having an extended length of stay. Minority patients from a high surgery social determinants of health index had 38% lower odds (95% confidence interval: 0.60-0.65) of achieving a textbook outcome compared with White/non-Hispanic patients from a low surgery social determinants of health index area.

Using a machine learning approach, we developed a novel social determents of health index to predict the probability of achieving a textbook outcome after surgery.