Ali AM, et al. - In this study, researchers investigated if patient-related predictors of all-cause, surgical, and return to theater (RTT) readmission after total hip arthroplasty (THA) differ and which predictors are most significant. Findings demonstrated that many patient-related risk factors for surgical and RTT readmission differ from those for all-cause readmission, despite the latter being the only measure in widespread use. These alternative readmission metrics should be considered by clinicians and policy makers when planning strategies for risk reduction and cost savings.

Methods

• Researchers analyzed all primary THAs recorded in the National Health Service (NHS) Hospital Episode Statistics database from 2006 to 2015.
• Using multilevel logistic regression analysis, they assessed the impact of patient-related factors on 30-day readmission risk.
• All acute NHS hospitals in England and all patients receiving primary THA were included in the analysis.
• Main outcomes and measures included 30-day readmission rate for all-cause, surgical (defined using International Statistical Classification of Diseases and Related Health Problems, Tenth Revision primary admission diagnoses), and readmissions resulting in RTT.

Results

• A total of 514 455 procedures were recorded across all hospitals.
• Data showed that 79 % of patients were older than 60 years, 40.3% were men, and 59.7% were women.
• Findings demonstrated that there were 30 489 all-cause readmissions (5.9%), 16 499 surgical readmissions (3.2%), and 4286 RTT readmissions (0.8%); 54.1% of readmissions were for surgical causes.
• Researchers found that comorbidities with the highest odds ratios (ORs) of RTT included those likely to affect patient behavior: drug abuse (OR, 2.22; 95% CI, 1.34-3.67; P = .002), psychoses (OR, 1.83; 95% CI, 1.16-2.87; P = .009), dementia (OR, 1.57; 95% CI, 1.11-2.22; P = .01), and depression (OR, 1.52; 95% CI, 1.31-1.76; P < .001).
• Furthermore, they observed that obesity had a strong and independent association with RTT (OR, 1.46; 95% CI, 4.45-6.43; P < .001), with one of the highest population attributable fractions of the comorbidities (3.4%).
• Results also revealed that return to theater in the index episode was related to a significantly increased risk of RTT readmission (OR, 5.35; 95% CI, 4.45-6.43; P < .001).
• In addition, it was demonstrated that emergency readmission to the hospital in the preceding 12 months increased the risk of readmission significantly, with the link being most pronounced for all-cause readmission (for >2 emergency readmissions, OR, 2.33; 95% CI, 2.11-2.57; P < .001).
• Compared with cemented implants, hip resurfacing was related to a lower risk of RTT (OR, 0.69; 95% CI, 0.54-0.88; P = .002), however, for other types of readmission, implant type had no significant association with readmission risk.
• Furthermore, it was observed that increasing age and length of stay were strongly associated with all-cause readmission.