A study conducted by Robert Barrack, MD, and colleagues from the Washington University School of Medicine found that lower income individuals were more likely to report higher levels of dissatisfaction and poorer function than those with higher incomes after knee replacement surgery. The study aimed to determine if socioeconomic factors were linked with less successful outcomes of knee replacement surgery. The research team analyzed more than 600 patients who had undergone total knee replacement surgery at one of five major joint centers in the U.S.
Each participant in the study had a mean age of 54 and was asked about various socioeconomic variables, such as education and income. The participants also completed a retrospective questionnaire to assess their level of satisfaction with the results of the surgery. In participants with an annual income of less than $25,000, the study showed less satisfaction with results and greater functional limitations after the knee surgery. The study notes that no other socioeconomic factor was related to their level of satisfaction.
The authors of the study offer a number of explanations for these results, including prior studies citing similar associations have suggested that patients from lower income households less post-acute care rehabilitation, which may impact the outcome. The authors of the study, which was published in Clinical Orthopaedics and Related Research, conclude, "It is certainly possible, based on our results, that socioeconomic factors, particularly household income, may be strongly associated with satisfaction and functional results."
The authors also note that further studies should be directed to determine the cause of this association and if the hypothesis is confirmed, then "studies of clinical results after total knee arthroplasty should consider stratifying patients by socioeconomic status."