Different patient-reported outcomes in immigrants and patients born in Sweden: 18,791 patients with 1 year of follow-up in the Swedish Hip Arthroplasty Register

Background and purpose

Some patients have persistent symptoms after total hip arthroplsty (THA). We investigated whether the proportions of inferior clinical results after total hip arthroplasty—according to the 5 dimensions in the EQ-5D form, and pain and satisfaction according to a visual analog scale (VAS)—are the same in immigrants to Sweden as observed in those born in Sweden.

Methods

Records of total hip arthroplasties performed between 1992 and 2007 were retrieved from the Swedish Hip Arthroplasty Register (SHAR) and cross-matched with data from the National Board of Health and Welfare and also Statistics, Sweden. 18,791 operations (1,451 in immigrants, 7.7%) were eligible for analysis. Logistic and linear regression models including age, sex, diagnosis, type of fixation, comorbidity, surgical approach, marital status, and education level were analyzed. Outcomes were the 5 dimensions in EQ-5D, EQ-VAS, VAS pain, and VAS satisfaction. Preoperative data and data from 1 year postoperatively were studied.

Results

Preoperatively (and after inclusion of covariates in the regression models), all immigrant groups had more negative interference concerning self-care. Immigrants from the Nordic countries outside Sweden and Europe tended to have more problems with their usual activities and patients from Europe and outside Europe more often reported problems with anxiety/depression. Patients born abroad showed an overall tendency to report more pain on the VAS than patients born in Sweden.After the operation, the immigrant groups reported more problems in all the EQ-5D dimensions. After adjustment for covariates including the preoperative baseline value, most of these differences remained except for pain/discomfort and—concerning immigrants from the Nordic countries—also anxiety/depression. After the operation, pain according to VAS had decreased substantially in all groups. The immigrant groups indicated more pain than those born in Sweden, both before and after adjustment for covariates.

Conclusion

The frequency of patients who reported moderate to severe problems, both before and 1 year after the operation, differed for most of the dimensions in EQ-5D between patients born in Sweden and those born outside Sweden.Some patients have persistent symptoms after total hip arthroplasty and are not satisfied with the procedure, with variation from a few up to as much as 30% (Greenwald 1991, Anakwe et al. 2011). In a Swedish nationwide prospective observational study, 5% of patients reported a clinically meaningful reduction in health-related quality of life (HRQoL) and EQ-5D (Rolfson et al. 2011). The outcome of THA surgery may depend on several factors such as the type and severity of the hip disease itself, patient selection, choice of implant, the quality of the surgery, and postoperative rehabilitation. Patient-related factors including ethnicity, cultural and socioeconomic background, educational level, and expectations regarding the procedure are also important (Hawker 2006, Francis et al. 2009, Krupic et al. 2013). Several studies have compared HRQoL between racial/ethnic groups and have documented important disparities, especially related to the experience and management of pain (Tamayo-Sarver et al. 2004, Ezenwa et al. 2006). Chronic pain adversely affects the HRQoL status of black Americans to a greater extent than it affects the HRQoL status of white Americans (Green et al. 2003).Patient-related factors have gained increased acceptance in assessment of the outcome of THA surgery. The Swedish Hip Arthroplasty Register (SHAR) assesses patient satisfaction, pain relief, and HRQoL using the EuroQol System (EQ-5D) (EuroQol 1990, Burstrom et al. 2001, Eisler et al. 2002, Herberts et al. 2004, Garellick et al. 2008, Rolfson et al. 2009). Understanding preoperative information about a THA may be more difficult if the patient is not sufficiently familiar with the language of the country, due to his/her immigrant status. We used the patient-reported outcomes in the SHAR to examine the hypothesis that patients who live in Sweden but have been born outside the country report worse outcome in the EQ-5D score both before and 1 year after hip replacement surgery.