Study Identifies Risk Factors for 30-day Readmission in Older Hip Fracture Patients
And unfortunately, many factors associated with readmission and increased length of stay are outside the healthcare provider’s control.
Philipp Leucht, MD, and Mark Gage, MD
Basques BA, Bohl DD, Golinvaux NS, Leslie MP, Baumgaertner MR, Grauer JN. Postoperative length of stay and 30-day readmission after geriatric hip fracture: an analysis of 8434 patients. J Orthop Trauma. 2015 Mar;29(3):e115-20.
A 10% readmission rate within the first 30 days was reported in a study of a national database of older hip fracture surgery patients. Three modifiable risk factors for readmission were identified:
- Preoperative time to surgery
- Anesthesia type
- Implant selection
This study utilized the American College of Surgeons’ National Surgical Quality Improvement Program database, which includes data from more than 370 participating hospitals throughout the US. Using postoperative ICD-9 codes for hip fracture fixation, the study authors identified 8,434 patients, ages 70 years or older, who were admitted with a hip fracture over a 2-year period (2011-2012). This included codes for fracture fixation, hemiarthroplasty (HA), and total hip arthroplasty (THA). Demographic data, medical comorbidities, functional status, and anesthesia type were included in the database analysis.
The study population had an average age of 83.8 years and an average BMI of 24.3. Fifty-five percent of the patients underwent surgery for a femoral neck fracture type; half of the cohort underwent either HA or THA. The majority of the remaining cohort was comprised of intertrochanteric fractures, with one-third treated with plate/screw fixation and two-thirds with an intramedullary implant. The average postoperative length of stay (LOS) was 5.6 days.
Increased LOS was associated with the following factors:
- Male gender
- American Society of Anesthesiologists (ASA) class 3 and 4
- 2- or 3-day delay from admission to surgery
- Non-general anesthesia
- Procedure type – hemiarthroplasty, intramedullary implants, and plate/screw fixation were associated with increased LOS
In a subgroup analysis of intertrochanteric hip fractures, plate and screw fixation led to increased LOS when compared with intramedullary implants.
Readmission rates were increased in patients who were male, had an elevated ASA class, had a BMI >35, had a history of pulmonary disease or hypertension, and had partial or fully dependent functional status.
Postoperative LOS and readmission after hip fracture repair are important measures of outcomes for patients and providers.
The most clinically significant and modifiable risk factor associated with increased LOS is time from admission to surgery, which, in this study, had the greatest association with increased postoperative LOS. It is well established in the literature that a delay to surgery in this patient population is associated with increased complications and LOS. While there are some inherent confounding variables with these patients that place them at higher risk, a delay in operating room availability is a major factor that can be addressed by the surgeon.
Contrary to the conclusions of previous literature, non-general anesthesia was associated with an increase in LOS after surgery. According to the article, this may be related to an increased rate of urinary retention. Further research is warranted before any legitimate recommendations can be drawn regarding the optimal anesthesia technique for these patients.
With regard to LOS and its association with implants used, it is difficult to reach any clinically relevant conclusions. The database utilized does not classify based on fracture type, which makes patient and fracture severity stratification difficult.
Additionally, hemiarthroplasty was identified as a risk factor for increased LOS, which is certainly expected given the high-risk comorbidities typically associated with this population and is unlikely to be related to the surgery itself.
Going forward, outcomes for hip fractures will influence reimbursement for the hospital and the surgeon. Identifying risk factors that affect LOS and readmission rates is critical for optimizing results. Although several of the risk factors identified in this study are modifiable, most are not.
This calls into question the use of readmission and LOS as benchmarks for hip fracture reimbursement, as many risk factors are outside the provider’s control.
Philipp Leucht, MD, is an Assistant Professor of Orthopaedic Surgery and Cell Biology, at NYU Langone Medical Center – Hospital for Joint Diseases, New York, New York. Mark Gage, MD, is an orthopaedic surgery resident, NYU Langone Medical Center – Hospital for Joint Diseases, New York, New York.