Ali AM, et al. - This study aimed at assessing 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. For surgical and RTT readmission, many patient-related risk factors differ from those for all-cause readmission despite the latter being the only measure in widespread use. Researchers recommend clinicians and policy makers to consider these alternative readmission metrics in strategies for risk reduction and cost savings.

Methods

• From 2006 to 2015, THAs recorded in the National Health Service (NHS) Hospital Episode Statistics database were analyed.
• Researchers here evaluated the effect of patient-related factors on 30-day readmission risk by multilevel logistic regression analysis.
• All acute NHS hospitals in England and all patients receiving primary THA were included in this analysis.
• Main Outcomes assessed were thirty-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

• 514 455 procedures were documented across all hospitals. 79% of the patients were ≥ 60 years of age, 40.3% were men, and 59.7% were women.
• Observations revealed 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.
• Highest odds ratios (ORs) of RTT were observed related to comorbidities 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).
• With one of the highest population attributable fractions of the comorbidities (3.4%), obesity had a strong independent association with RTT (OR, 1.46; 95% CI, 4.45-6.43; P < .001).
• There appeared an association of return to theater in the index episode with a significantly increased risk of RTT readmission (OR, 5.35; 95% CI, 4.45-6.43; P<.001).
• A significant increase in the risk of readmission was observed with emergency readmission to the hospital in the preceding 12 months, with the association being most pronounced for all-cause readmission (for >2 emergency readmissions, OR, 2.33; 95% CI, 2.11-2.57; P < .001).
• A lower risk of RTT was evident with hip resurfacing when compared with cemented implants (OR, 0.69; 95% CI, 0.54-0.88; P = .002) but for other types of readmission, implant type had no significant association with readmission risk.
• Increasing age and length of stay indicated a strong association with all-cause readmission.