Chung, Andrew S.

Background: The minimum clinically important difference (MCID) attempts to define the patient’s experience of treatment outcomes. Efforts at calculating the MCID have yielded multiple and inconsistent MCID values. The purposes of this review were to describe the usage of the MCID in the most recent orthopaedic literature, to explain the limitations of its current uses, and to clarify the underpinnings of MCID calculation. Subsequently, we hope that the information presented here will help practitioners to better understand the MCID and to serve as a guide for future efforts to calculate the MCID. The first part of this review focuses on the upper-extremity orthopaedic literature. Part II will focus on the lower-extremity orthopaedic literature. Methods: A review was conducted of the 2014 to 2016 publications in The Journal of Arthroplasty, The Journal of Bone & Joint Surgery, The American Journal of Sports Medicine, Foot & Ankle International, Journal of Orthopaedic Trauma, Journal of Pediatric Orthopaedics, and Journal of Shoulder and Elbow Surgery . Only clinical science articles utilizing patient-reported outcome measure (PROM) scores were included in the analysis. A keyword search was then performed to identify articles that calculated or referenced the MCID. Articles were then further categorized into upper-extremity and lower-extremity publications. MCID utilization in the selected articles was subsequently characterized and recorded. Results: The MCID was referenced in 129 (7.5%) of 1,709 clinical science articles that utilized PROMs: 52 (40.3%) of 129 were related to the upper extremity, 5 (9.6%) of 52 independently calculated MCID values, and 47 (90.4%) of 52 used previously published MCID values as a gauge of their own results. MCID values were considered or calculated for 16 PROMs; 12 of these were specific to the upper extremity. Six different methods were used to calculate the MCID. Calculated MCIDs had a wide range of values for the same PROM (e.g., 8 to 36 points for Constant-Murley scores and 6.4 to 17 points for American Shoulder and Elbow Surgeons [ASES] scores). Conclusions: Determining useful MCID values remains elusive and is compounded by the proliferation of PROMs in the field of orthopaedics. The fundamentals of MCID calculation methods should be critically evaluated. If necessary, these methods should be corrected or abandoned. Furthermore, the type of change intended to be measured should be clarified: beneficial, detrimental, or small or large changes. There should also be assurance that the calculation method actually measures the intended change. Finally, the measurement error should consistently be reported. Clinical Relevance: The MCID is increasingly used as a measure of patients’ improvement. However, the MCID does not yet adequately capture the clinical importance of patients’ improvement.

Objectives: Low serum albumin levels (hypoalbuminemia) have classically been used to identify malnutrition. The effect of increasing severity of malnutrition on postoperative outcomes in patients undergoing hip fracture surgery has not been well delineated on a large scale. Design: Retrospective. Setting: Multicenter. Patient/Participants: A total of 12,373 patients undergoing hip fracture surgery from 2006 to 2013 National Surgery Quality Improvement Project data were identified. Intervention: Patient demographic, comorbidity, and preoperative laboratory data and complication, reoperation, and readmission data were collected. Main Outcome Measurements: Multivariate logistic regression was used to determine the effect of increasing severity of malnutrition on rates of 30-day postoperative complications, readmissions, and reoperations. Results: A total of 12,373 hip fractures met inclusion criteria. A total of 6506 (52.6%) patients had normal albumin levels (albumin ≥3.5 g/dL), 3205 (25.9%) patients were mildly malnourished (albumin 3.1–3.49 g/dL), 2265 (18.3%) were moderately malnourished (albumin 2.4–3.1 g/dL), and 397 (3.2%) patients were severely malnourished (albumin <2.4 g/dL). Mean age was similar between the 4 cohorts (P < 0.001). Severe malnutrition was associated with a 2-fold increase in the odds of postoperative complications and mortality when compared with mild malnutrition (P < 0.001). Increasing severity of malnutrition was associated with significantly longer lengths of stay and higher odds of experiencing a related readmission (P < 0.001). Conclusions: Increasing severity of hypoalbuminemia is independently associated with poorer outcomes in the 30 days after hip fracture surgery. Level of Evidence: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Study Design: Retrospective cohort study. Objectives: Epidemiologic studies suggest that the prevalence of moderate to severe obstructive sleep apnea (OSA) is increasing. OSA has been linked to increased rates of postoperative complications following surgery. Large studies, however, regarding surgical outcomes in this patient population, particularly in the spine literature, are limited. Consequently, the purpose of this study was to assess the prevalence of and postoperative risks conferred by OSA in the elective spine population. Methods: Using data from the National Inpatient Sample from 2008 to 2012, an estimated 56 372 (5.1%) patients with OSA undergoing elective cervical and thoracolumbar spine surgery were selected and compared to 1 052 837 patients without OSA undergoing the same procedures. Our primary outcome measures included postoperative complication rates, inpatient mortality, length of stay, and total hospital charges. Results: Patients with OSA were, on average 2.6 years older than those without OSA ( P < .001) and had a higher comorbidity burden. The prevalence of OSA increased between 2008 and 2012 from 3.5% to 6.8%; P < .001. OSA was associated with a 3-fold increase in major complications ( P < .001) and was confirmed as an independent risk factor for major complications based on multivariate analysis (odds ratio [OR] = 2.82; 95% CI = 2.59-2.79; P < .001). Rates of deep venous thrombosis were doubled in patients with OSA. OSA was determined to be an independent predictor of pulmonary complications (OR = 2.69; 95% CI = 2.59-2.79; P < .001). OSA did not increase the risk of postoperative mortality. Conclusions: Patients with OSA often have multiple concomitant comorbidities and consequently are at increased risk of experiencing a more difficult postoperative course following elective spine surgery. Specifically, increased risks of pulmonary complications and deep venous thrombosis should be anticipated.

Study Design. A retrospective cohort study. Objective. The aim of this study was to evaluate the effect of metabolic syndrome (MetS) on 30-day morbidity and mortality following elective lumbar spinal fusion. Summary of Background Data. MetS is a variable combination of hypertension, obesity, elevated fasting plasma glucose, and dyslipidemia. MetS has been associated with an increased risk of postoperative morbidity and mortality in multiple surgical settings. To our knowledge, the effect of MetS on 30-day outcomes following elective lumbar spinal fusion has not been well studied. Methods. An analysis of ACS-NSQIP data was performed between 2006 and 2013. Patients undergoing elective posterior lumbar fusion were identified. Emergency procedures, infections, tumor cases, and revision surgeries were excluded. Patients were defined as having MetS if they had a history of hypertension requiring medication, diabetes, and a body mass index (BMI) ≥30 kg/m2. Results. One thousand five hundred ninety (10.2%) patients with MetS were identified. A mild increase in major (P = 0.040) and minor complications (P = 0.003) in patients with MetS was noted. MetS was associated with increased rates of pulmonary complications (1.9% compared with 1.0%; P = 0.001), sepsis (1.7% compared with 0.9%; P = 0.005), and acute post-op renal failure (0.4% compared with 0%; P < 0.001). Multivariate analysis confirmed MetS to be an independent predictor of pulmonary complications [odds ratio (OR) 1.51; 95% confidence interval (95% CI 1.00–2.27); P = 0.048], sepsis (OR 1.56; 95% CI 1.01–2.42; P = 0.039), and acute postoperative renal failure (OR 6.95; 95% CI 2.23–21.67; P = 0.001). MetS status was associated with a mild increase in total hospital length of stay (4.38 compared with 3.81 days; P < 0.001). Conclusion. While MetS is a predictor of postoperative acute renal failure, it only slightly increases the risk of overall complications and is not associated with increased rates of 30-day reoperations or readmissions following elective lumbar fusion. Level of Evidence: 3

ABSTRACT Pneumonia due to methicillin-resistant Staphylococcus aureus (MRSA) is associated with poor outcomes and frequently merits empirical antibiotic consideration despite its relatively low incidence. Nasal colonization with MRSA is associated with clinical MRSA infection and can be reliably detected using the nasal swab PCR assay. In this study, we evaluated the performance of the nasal swab MRSA PCR in predicting MRSA pneumonia. A retrospective cohort study was performed in a tertiary care center from January 2009 to July 2011. All patients with confirmed pneumonia who had both a nasal swab MRSA PCR test and a bacterial culture within predefined time intervals were included in the study. These data were used to calculate sensitivity, specificity, positive predictive value, and negative predictive value for clinically confirmed MRSA pneumonia. Four hundred thirty-five patients met inclusion criteria. The majority of cases were classified as either health care-associated (HCAP) (54.7%) or community-acquired (CAP) (34%) pneumonia. MRSA nasal PCR was positive in 62 (14.3%) cases. MRSA pneumonia was confirmed by culture in 25 (5.7%) cases. The MRSA PCR assay demonstrated 88.0% sensitivity and 90.1% specificity, with a positive predictive value of 35.4% and a negative predictive value of 99.2%. In patients with pneumonia, the MRSA PCR nasal swab has a poor positive predictive value but an excellent negative predictive value for MRSA pneumonia in populations with low MRSA pneumonia incidence. In cases of culture-negative pneumonia where initial empirical antibiotics include an MRSA-active agent, a negative MRSA PCR swab can be reasonably used to guide antibiotic de-escalation.