|Abstract / Summary
Total hip arthroplasty (THA) is an effective procedure for reducing pain and improving quality of life for patients suffering from osteoarthritis in the hip joint. In orthopedic surgery, the quality of care and the outcomes after surgery are closely correlated to socioeconomic status (SES). Socioeconomic inequality in health is increasingly recognized as an important public health issue. However, previous research concerning utilization and postoperative complications after THA is limited by assessing SES only by a single marker, no distinction between outcomes, or area-based measurements.
In this thesis, we aimed to study the association between SES and the utilization of THA across different age groups and over time (Study I). Following the utilization of THA, we aimed to study whether SES was associated with revision and mortality rates after THA within 90 and 365 days (Study II) and whether SES was associated with the risk of hospitalization due to infections and cardiovascular disease after THA within 30 and 90 days (Studies III and IV).
In Study I, we conducted a population-based case-control study. We reported associations between SES and the risk of THA using odds ratios, and found that patients who were married, were cohabitating, patients with the lowest attained education, and patients with the lowest income had an increased risk of receiving a THA compared to patients who never married, were living alone, patients with the highest attained education, and patients with the highest income. Further, we found that the association between low level of education, low level of income, and higher risk of THA was observed among the youngest age group. This association decreased with increasing age. We found inequality in the risk of THA by education, and that this decreased over calendar time. The inequality found by income was, however, persistent.
In Study II, we conducted a cohort study and found that within 90 and 365 days, the adjusted hazard ratio for any revision was highest for patients living alone vs. cohabiting, was highest for patients with low income vs. high income among patients 65 years. We also found that living alone, low education, low income, and low liquid assets all were associated with increased mortality rate within both 90 and 365 days.
In Studies III and IV, we conducted a cohort study. The results show that living alone, low education, low income, and low liquid assets were all associated with higher risks of hospital-treated infections and cardiovascular disease after THA.
In conclusion, we found that the utilization of THA and the risk of severe postoperative complications after THA are associated with substantial socioeconomic inequalities. This was done by examining important SES markers all directly contributing to healthcare disparities. Our findings highlight that socioeconomic disadvantage is a risk factor for inferior quality of care and inferior outcomes after surgery, emphasizing the importance of patient-, surgeon-, and policy practice when addressing inequalities in THA outcome.