The association of body mass index with same-day hospital admission, postoperative complications, and 30-day readmission following day-case eligible joint arthroscopy: A national registry analysis

Abstract

Study objectiveWe examined the association of body mass index (BMI) with hospital admission, same-day complications, and 30-day hospital readmission following day-case eligible joint arthroscopy. DesignRetrospective cohort study. SettingMulti-institutional. PatientsAdult patients undergoing arthroscopy of the knee, hip or shoulder in the outpatient setting. InterventionNone. MeasurementsUsing the American College of Surgeons National Surgical Quality Improvement Program dataset from 2012 to 2016, we examined seven BMI ranges: normal BMI (≥20 kg/m2 and <25 kg/m2), underweight (<20 kg/m2), overweight (≥25 kg/m2 and <30 kg/m2), Class 1 and 2 obese (≥30 kg/m2 and <40 kg/m2, reference variable), and severe obesity, which we divided into the following BMI ranges: ≥40 kg/m2 and <50 kg/m2, ≥50 kg/m2 and <60 kg/m2, and ≥60 kg/m2. The primary outcome was hospital admission. Secondary outcomes included same-day postoperative complications and 30-day hospital readmission. We performed multivariable logistic regression and reported odds ratios (OR) and their associated 95% confidence interval (CI) and considered a p-value of <0.05 as statistically significant. Main resultsThere were a total of 99,410 patients included in the final analysis, in which there was a 2.6% rate of hospital admission. When compared to class 3 obesity, only those with BMI ≥50 kg/m2(OR 1.55, 95% CI 1.18–2.01, p = 0.005) had increased odds of hospital admission. There were no differences in 30-day hospital readmission or same-day postoperative complications. ConclusionWe found that only patients with BMI ≥50 kg/m2 had increased odds for same-day hospital admission even when patient's comorbid conditions are optimized, suggesting that a BMI ≥50 kg/m2 may be used as a sole factor for patient selection in patients undergoing joint arthroscopy. For patients with BMI <50 kg/m2, we recommend that BMI alone should not be solely used to exclude patients from having joint arthroscopies performed in an outpatient setting, especially since this patient group makes up a significant proportion of joint arthroscopy.