Cost Drivers After Surgical Management of Proximal Humerus Fractures in Medicare Patients

A nationwide analysis of geriatric proximal humerus fractures: trends, outcomes, and cost

Background

In the USA, proximal humerus fractures (PHF) are the third most common fracture among the elderly. Although most geriatric PHF are treated conservatively, surgical management remains an option. This retrospective study compares annual trends, patient outcomes, and hospital costs between operatively and non-operatively managed geriatric PHF.

Methods

The Healthcare Cost and Utilization Project Nationwide Inpatient Sample was queried from 2012 to 2015. Geriatric patients with PHF were identified and those who underwent operative or non-operative management were compared in trends, outcomes and costs.

Results

In total, 137 810 patients met inclusion criteria, of which 51 795 (37.6%) underwent operative management. The operative cohort was younger (76.6 vs 80.9, p<0.001) with a greater proportion of females (81.8% vs 77.6%, p<0.001). The operative cohort demonstrated less frailty and lower Elixhauser Comorbidity Scores (both p<0.001). The operative cohort was also more likely to be discharged home (30.4% vs 13.9%, p<0.001). There was no significant linear trend in age-adjusted and sex-adjusted proportions of operative versus non-operative geriatric PHF (p=0.071), but a positive linear trend was statistically significant for total cost of operative geriatric PHF (p<0.001). Multivariable analyses demonstrated similar overall complication rates between cohorts (OR 0.95, 95% CI 0.89 to 1.00; p=0.06), although surgical intervention increased length of stay (LOS) by 0.15 days (95% CI 0.03 to 0.27; p<0.001) and median cost of hospitalization by US$10 684 (95% CI US$10 384 to US$10 984; p<0.001).

Conclusions

This study identifies a positive linear trend in total cost of operatively managed geriatric PHF from 2012 to 2015. Operative management of geriatric PHF is associated with a similar overall complication rate and greater likelihood of being discharged home. Although non-operative management is associated with decreased LOS and hospital expenses, providers should consider surgical PHF treatment options when available and appropriate in the context of patient-focused outcomes, particularly long-term disposition after intervention.

Level of Evidence

This level IV retrospective study identifies.

Renal disease is a risk factor for complications and mortality after open reduction internal fixation of proximal humerus fractures

Background

Renal osteodystrophy predisposes renal disease patients to fracture. Proximal humerus fractures (PHFs) frequently undergo open reduction internal fixation (ORIF); however, the effect of renal disease on outcomes is unknown.

Methods

A retrospective review of the Nationwide Readmissions Database used International Classification of Diseases, 9th Revision, codes to identify patients who underwent ORIF for closed PHF from 2010 to 2014 with no renal disease, predialysis chronic renal disease (CRD), and end-stage renal disease (ESRD).

Results

A total of 85,433 patients were identified, including 5498 (6.4%) CRD and 636 (0.7%) ESRD. CRD and ESRD patients had increased age, comorbidities, and rates of Medicare insurance. After adjusting for differences, CRD and ESRD patients were at increased risk of any complication (odds ratio [OR] 2.48, 1.66), blood transfusion (OR 1.85, 3.31), respiratory complications (OR 1.14, 1.59), acute renal failure (OR 4.80, 1.67), systemic infection (OR 2.00, 3.14), surgical site infection (OR 1.52, 3.87), longer length of stay (7.1 and 12.9 days vs. 5.9 days), and higher cost ($21,669 and $35,413 vs. $20,394) during index hospitalization, as well as surgical site infection (OR 1.43, 3.03) and readmission (OR 1.61, 3.69) within 90 days of discharge, respectively, compared with no renal disease patients. During index hospitalization, CRD patients also had increased risk for periprosthetic fracture (OR 4.97) and cardiac complications (OR 1.47), whereas ESRD patients had increased risk of mortality (OR 5.79), wound complication (2.67), and deep vein thrombosis (OR 16.70).

Conclusion

These findings suggest renal patients are at increased risk for complications after PHF ORIF, highlighting the importance of close perioperative monitoring and appropriate patient selection in this population, including strong consideration of nonoperative management.

Influence of medical comorbidity and surgical indication on total elbow arthroplasty cost of care

BACKGROUND

Movement toward providing value-based musculoskeletal care requires understanding the cost associated with surgical care as well as the drivers of these costs. The aim of this study was to investigate the effect of common medical comorbidities and specific total elbow arthroplasty (TEA) indications on reimbursement costs throughout the 90-day TEA episode of care. The secondary aim was to identify the drivers of these costs.

METHODS

Administrative health claims for patients who underwent orthopedic intervention between 2010 and 2020 were queried using specific disease classification and procedural terminology codes from a commercially available national database of 53 million patients. Patients with commercial insurance were divided into various cohorts determined by different surgical indications and medical comorbidities. The reimbursement costs of the surgical encounter, 89-day postoperative period, and total 90-day period in each cohort were evaluated. The cost drivers for the 89-day postoperative period were also determined. Analyses were performed using descriptive statistics and the Kruskal-Wallis test for comparison.

RESULTS

A total of 378 patients who underwent TEA were identified. The mean reimbursement cost of the surgical encounter ($13,393 ± $8314) did not differ significantly based on patient factors. The mean reimbursement cost of the 89-day postoperative period ($4232 ± $2343) differed significantly when stratified by surgical indication (P < .0001) or by medical comorbidity (P < .0001). The indication of rheumatoid arthritis ($4864 ± $1136) and the comorbidity of chronic kidney disease ($5873 ± $1165) had the most expensive postoperative period. In addition, the total 90-day reimbursement cost ($16,982 ± $4132) differed significantly when stratified by surgical indication (P = .00083) or by medical comorbidity (P < .0001), with the indication of acute fracture ($18,870 ± $3971) and the comorbidity of chronic pulmonary disease ($19,194 ± $3829) showing the highest total 90-day cost. Inpatient costs related to readmissions represented 38% of the total reimbursement cost. The overall readmission rate was 5.0%, and the mean readmission cost was $16,296.

CONCLUSION

TEA reimbursements are significantly influenced by surgical indications and medical comorbidities during the postoperative period and the total 90-day episode of care. As the United States transitions to delivering value-based health care, the need for surgeons and policy makers to understand treatment costs associated with different patient-level factors will expand.

Interventions for treating proximal humeral fractures in adults

BACKGROUND

Fractures of the proximal humerus, often termed shoulder fractures, are common injuries, especially in older people. The management of these fractures varies widely, including in the use of surgery. This is an update of a Cochrane Review first published in 2001 and last updated in 2015.

OBJECTIVES

To assess the effects (benefits and harms) of treatment and rehabilitation interventions for proximal humeral fractures in adults.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, trial registries, and bibliographies of trial reports and systematic reviews to September 2020. We updated this search in November 2021, but have not yet incorporated these results.

SELECTION CRITERIA

We included randomised and quasi-randomised controlled trials that compared non-pharmacological interventions for treating acute proximal humeral fractures in adults.  DATA COLLECTION AND ANALYSIS: Pairs of review authors independently selected studies, assessed risk of bias and extracted data. We pooled data where appropriate and used GRADE for assessing the certainty of evidence for each outcome. We prepared a brief economic commentary for one comparison.

MAIN RESULTS

We included 47 trials (3179 participants, mostly women and mainly aged 60 years or over) that tested one of 26 comparisons. Six comparisons were tested by 2 to 10 trials, the others by small single-centre trials only. Twelve studies evaluated non-surgical treatments, 10 compared surgical with non-surgical treatments, 23 compared two methods of surgery, and two tested timing of mobilisation after surgery. Most trials were at high risk of bias, due mainly to lack of blinding. We summarise the findings for four key comparisons below. Early (usually one week post injury) versus delayed (after three or more weeks) mobilisation for non-surgically-treated fractures Five trials (350 participants) made this comparison; however, the available data are very limited. Due to very low-certainty evidence from single trials, we are uncertain of the findings of better shoulder function at one year in the early mobilisation group, or the findings of little or no between-group difference in function at 3 or 24 months. Likewise, there is very low-certainty evidence of no important between-group difference in quality of life at one year. There was one reported death and five serious shoulder complications (1.9% of 259 participants), spread between the two groups, that would have required substantive treatment. Surgical versus non-surgical treatment Ten trials (717 participants) evaluated surgical intervention for displaced fractures (66% were three- or four-part fractures). There is high-certainty evidence of no clinically important difference between surgical and non-surgical treatment in patient-reported shoulder function at one year (standardised mean difference (SMD) 0.10, 95% confidence interval (CI) -0.07 to 0.27; 7 studies, 552 participants) and two years (SMD 0.06, 95% CI -0.13 to 0.25; 5 studies, 423 participants). There is moderate-certainty evidence of no clinically important between-group difference in patient-reported shoulder function at six months (SMD 0.17, 95% CI -0.04 to 0.38; 3 studies, 347 participants). There is high-certainty evidence of no clinically important between-group difference in quality of life at one year (EQ-5D (0: dead to 1: best quality): mean difference (MD) 0.01, 95% CI -0.02 to 0.04; 6 studies, 502 participants). There is low-certainty evidence of little between-group difference in mortality: one of the 31 deaths was explicitly linked with surgery (risk ratio (RR) 1.35, 95% CI 0.70 to 2.62; 8 studies, 646 participants). There is low-certainty evidence of a higher risk of additional surgery in the surgery group (RR 2.06, 95% CI 1.21 to 3.51; 9 studies, 667 participants). Based on an illustrative risk of 35 subsequent operations per 1000 non-surgically-treated patients, this indicates an extra 38 subsequent operations per 1000 surgically-treated patients (95% CI 8 to 94 more). Although there was low-certainty evidence of a higher overall risk of adverse events after surgery, the 95% CI also includes a slightly increased risk of adverse events after non-surgical treatment (RR 1.46, 95% CI 0.92 to 2.31; 3 studies, 391 participants). Open reduction and internal fixation with a locking plate versus a locking intramedullary nail Four trials (270 participants) evaluated surgical intervention for displaced fractures (63% were two-part fractures). There is low-certainty evidence of no clinically important between-group difference in shoulder function at one year (SMD 0.15, 95% CI -0.12 to 0.41; 4 studies, 227 participants), six months (Disability of the Arm, Shoulder, and Hand questionnaire (0 to 100: worst disability): MD -0.39, 95% CI -4.14 to 3.36; 3 studies, 174 participants), or two years (American Shoulder and Elbow Surgeons score (ASES) (0 to 100: best outcome): MD 3.06, 95% CI -0.05 to 6.17; 2 studies, 101 participants). There is very low-certainty evidence of no between-group difference in quality of life (1 study), and of little difference in adverse events (4 studies, 250 participants) and additional surgery (3 studies, 193 participants). Reverse total shoulder arthroplasty (RTSA) versus hemiarthroplasty There is very low-certainty evidence from two trials (161 participants with either three- or four-part fractures) of no or minimal between-group differences in self-reported shoulder function at one year (1 study) or at two to three years' follow-up (2 studies); or in quality of life at one year or at two or more years' follow-up (1 study). Function at six months was not reported. Of 10 deaths reported by one trial (99 participants), one appeared to be surgery-related. There is very low-certainty evidence of a lower risk of complications after RTSA (2 studies). Ten people (6.2% of 161 participants) had a reoperation; all eight cases in the hemiarthroplasty group received a RTSA (very low-certainty evidence).

AUTHORS' CONCLUSIONS

There is high- or moderate-certainty evidence that, compared with non-surgical treatment, surgery does not result in a better outcome at one and two years after injury for people with displaced proximal humeral fractures. It may increase the need for subsequent surgery. The evidence is absent or insufficient for people aged under 60 years, high-energy trauma, two-part tuberosity fractures or less common fractures, such as fracture dislocations and articular surface fractures. There is insufficient evidence from randomised trials to inform the choices between different non-surgical, surgical or rehabilitation interventions for these fractures.

Readmission, Reoperation, and Non-home Discharge Rates in Patients Receiving Surgical Treatment for Proximal Humerus Fractures

Background

Proximal humerus fractures (PHFs) are generally surgically treated with open reduction internal fixation (ORIF), hemiarthroplasty (HA), or total shoulder arthroplasty (TSA). Diverse fracture patterns and a high prevalence in the elderly population make it difficult to establish objective guidelines for the decision to undergo surgical treatment. The purpose of this study was to investigate risk factors associated with readmission, reoperation, and nonhome discharge following ORIF, HA, and TSA for PHFs.

Methods

Data on all patients who underwent ORIF, TSA, or HA for treatment of closed PHF between 2015 and 2017 were obtained by querying the American College of Surgeons National Surgical Quality Improvement database. Rates of postoperative readmission, nonhome discharge, and reoperation within 30 days were collected. Multivariate logistic regression was employed to identify predictors of readmission, nonhome discharge, and reoperation.

Results

A total of 2825 patients were included in this study: 1829 underwent ORIF, 707 underwent TSA, and 289 underwent HA. The significant predictors for readmission were having an American Society of Anesthesiologists class ≥ 3 (odds ratio [OR] 1.95, P = .003) and being of dependent functional status (OR 3.15, P < .001). The significant predictors for reoperation were male sex (OR 2.41, P < .001) and dependent functional status (OR 2.92, P = .006). The significant predictors for nonhome discharge were age 66-80 years (OR 7.00, P < .001), age ≥ 81 years (OR 16.31, P < .001), American Society of Anesthesiologists ≥3 (OR 2.34, P < .001), dependent functional status (OR 2.48, P < .001), and inpatient status (OR 3.32, P < .001). TSA showed slightly higher rates of nonhome discharge than HA and ORIF.

Conclusion

Significant risk factors for readmission, reoperation, and nonhome discharge within 30 days following surgical treatment for PHF were identified. Additionally, TSA was significantly associated with nonhome discharge compared with HA and ORIF.

In-hospital Complications Are More Likely to Occur After Reverse Shoulder Arthroplasty Than After Locked Plating for Proximal Humeral Fractures

BACKGROUND

Currently, there seems to be a paradigm change in the surgical treatment of proximal humeral fractures in patients aged 65 years and older, with a considerable increase in the use of reverse total shoulder arthroplasty (RTSA) compared with angular stable internal fixation (locking plate fixation). However, even among shoulder specialists there is controversy regarding the best treatment strategy.

QUESTIONS/PURPOSES

To evaluate for (1) a greater risk of in-hospital major adverse events, (2) a greater risk for in-hospital surgical complications, and (3) a greater risk of 30-day mortality, locking plate fixation and RTSA were compared for the treatment of proximal humerus fractures of patients aged 65 years and older after controlling for potentially confounding variables in a large-database analysis.

METHODS

Health claims data of the largest German insurance company including approximately one-third of the population (26.5 million policyholders) between 2010 and 2018 were analyzed. This database was chosen because of its size, nationwide distribution, and high quality/completeness. In total, 55,070 patients (≥ 65 years of age) treated with locking plate fixation (75% [41,216]) or RTSA (25% [13,854]) for proximal humeral fracture were compared. As primary endpoints, major adverse events (including acute myocardial infarction, stroke, organ failure, resuscitation, and death) and surgical complications (infection, hematoma, loss of reduction, dislocation, and revision surgery) were analyzed. The risk of all endpoints was analyzed with multivariable logistic regression models in the context of comorbidities to address existing group differences.

RESULTS

After controlling for potentially confounding variables such as age, sex, and risk profile, RTSA was associated with a higher risk for major adverse events (OR 1.40 [95% CI 1.29 to 1.53]; p < 0.001) and surgical complications (OR 1.13 [95% CI 1.05 to 1.21]; p < 0.01) compared with locking plate fixation. There was no evidence for an increase in mortality (OR 0.98 [95% CI 0.86 to 1.12]; p = 0.81).

CONCLUSION

The increased in-hospital risk for major adverse events and surgical complications may moderate the enthusiasm associated with RTSA for proximal humeral fractures in patients 65 years and older. Treatment decisions should be based on individual risk estimation to avoid potential harmful events. Future studies must include long-term outcomes and quality of life to enlighten these findings in a broader context.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Outpatient Surgical Fixation of Proximal Humerus Fractures Can Be Performed Without Increased Rates of Short-Term Complications or Readmissions

OBJECTIVE

To delineate differences in short-term complications between outpatient versus inpatient open reduction and internal fixation (ORIF) of proximal humerus fractures.

DESIGN

Retrospective database review.

SETTING

Hospitals participating in the American College of Surgeons National Surgical Quality Improvement Program database.

PATIENTS

Patients in the National Surgical Quality Improvement Program database with proximal humerus fractures from 2005 to 2017.

INTERVENTION

Proximal humerus fracture ORIF.

MAIN OUTCOME MEASUREMENTS

Thirty-day readmission, reoperation, thromboembolic events, and other complications.

RESULTS

In total, 920 outpatient and 2490 inpatient ORIF cases were identified. The proportion of outpatient proximal humerus fracture ORIF increased throughout the years from 6.67% in 2007 to 34.89% in 2017. Each outpatient case was propensity-score-matched with one inpatient case by age, sex, functional status, American Society of Anesthesiologists classification, smoking status, diabetes mellitus type, hypertension, chronic obstructive pulmonary disease, and dyspnea on exertion. After matching, there were 920 outpatient and 920 inpatient cases. Statistical analysis revealed no significant difference in complications including reoperation (1.63% vs. 2.50%), thromboembolic events (0.65% vs. 0.65%), and 30-day readmissions (2.93% vs. 2.69%) between outpatient versus matched inpatient procedures (all P > 0.05). The only significant finding was a lower rate of blood transfusion in outpatient procedures (0.54%) compared with inpatient procedures (4.02%) (P < 0.001).

CONCLUSIONS

The perioperative outcomes assessed here support the conclusion that ORIF for proximal humerus fractures can be performed in the outpatient setting without increased rates of 30-day perioperative complications or readmissions compared with inpatient procedures. However, it is worth noting that the majority of outpatient cases were younger than the average geriatric proximal humerus fracture patient.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Can We Stratify Quality and Cost for Older Patients With Proximal and Midshaft Humerus Fractures?

Introduction:

This study sought to investigate whether a validated trauma triage tool can stratify hospital quality measures and inpatient cost for middle-aged and geriatric trauma patients with isolated proximal and midshaft humerus fractures.

Materials and Methods:

Patients aged 55 and older who sustained a proximal or midshaft humerus fracture and required inpatient treatment were included. Patient demographic, comorbidity, and injury severity information was used to calculate each patient’s Score for Trauma Triage in the Geriatric and Middle-Aged (STTGMA). Based on scores, patients were stratified to create minimal, low, moderate, and high risk groups. Outcomes included length of stay, complications, operative management, ICU/SDU-level care, discharge disposition, unplanned readmission, and index admission costs.

Results:

Seventy-four patients with 74 humerus fractures met final inclusion criteria. Fifty-eight (78.4%) patients presented with proximal humerus and 16 (21.6%) with midshaft humerus fractures. Mean length of stay was 5.5 ± 3.4 days with a significant difference among risk groups (P = 0.029). Lower risk patients were more likely to undergo surgical management (P = 0.015) while higher risk patients required more ICU/SDU-level care (P < 0.001). Twenty-six (70.3%) minimal risk patients were discharged home compared to zero high risk patients (P = 0.001). Higher risk patients experienced higher total inpatient costs across operative and nonoperative treatment groups.

Conclusion:

The STTGMA tool is able to reliably predict hospital quality measures and cost outcomes that may allow hospitals and providers to improve value-based care and clinical decision-making for patients presenting with proximal and midshaft humerus fractures.

Level of Evidence:

Prognostic Level III.

Cost-Minimization Analysis and Treatment Trends of Surgical and Nonsurgical Treatment of Proximal Humerus Fractures

PURPOSE

Recent evidence demonstrated similar outcomes between nonsurgical and surgical management of displaced proximal humerus fractures. We analyzed treatment trends and performed a cost-minimization analysis comparing nonsurgical treatment, open reduction and internal fixation, reverse total shoulder arthroplasty, and hemiarthroplasty. We hypothesized that rates of surgical treatment have increased and that the costs associated with surgery are greater compared with nonsurgical management of proximal humerus fractures.

METHODS

We used a US private-payer claims database of 22 million patient records from 2007 to 2016 to compare (1) cost for the episode of care from the payer perspective between each surgical group and nonsurgical treatment of proximal humerus fractures, and (2) annual trends and complication rates of each group. Cost data, including facility fees, physician fees, physical therapy, and clinic visits, were used to complete a cost-minimization analysis.

RESULTS

Nonsurgical treatment was associated with lower average total costs compared with surgical intervention. Facility and physician fees accounted for most of this difference. Physical therapy costs and number of physical therapy visits were higher in each surgical group compared with nonsurgical treatment. Surgical treatment was associated with higher complications, revision rates, and length of stay. There was a small but statistically significant decrease in nonsurgical management of proximal humerus fractures between 2007 and 2016. No change was observed in rates of open reduction and internal fixation, whereas rates of reverse total shoulder arthroplasty increased and rates of hemiarthroplasty decreased.

CONCLUSIONS

Nonsurgical management of proximal humerus fractures decreased during the study period. In the setting of treatment equipoise, cost-minimization analysis favors nonsurgical management of proximal humerus fractures. Surgical management is associated with higher complication rates, revision rates, and length of stay.

TYPE OF STUDY/LEVEL OF EVIDENCE

Economic Decision Analysis IV.

Use and Cost of Reverse Shoulder Arthroplasty Versus Hemiarthroplasty for Acute Proximal Humerus Fractures

Although reverse total shoulder arthroplasty (RTSA) may outperform hemiarthroplasty (HSA) for acute proximal humerus fractures (PHF), both the RTSA implant and the procedure are more expensive. The goal of this study was to compare the use and longitudinal cost of care for RTSA vs HSA for the treatment of PHF. Patients were selected from a private payer database with a surgical date between 2010 and 2015. The International Classification of Diseases, 9th Revision, Clinical Modification(ICD-9-CM), codes were used to identify patients who underwent RTSA and HSA for PHF. The 1-year cost follow-up was guaranteed. During the study period, a total of 1038 patients underwent RTSA and 1046 patients underwent HSA for the treatment of PHF. A total of 601 patients who underwent RTSA and 431 patients who underwent HSA with at least 1 year of follow-up were matched by age and sex. The average Charlson Comorbidity Index for the RTSA and HSA groups was 4, indicating similar health status. From 2010 to 2015, the use of RTSA increased linearly (R²=0.986), whereas the use of HSA decreased linearly (R²=0.796). The average index admission cost was higher for RTSA than for HSA ($15,263 vs $14,356, respectively; mean difference [MD], $907; 95% confidence interval [CI], $58-$1760; P=.04). At 1 year postoperatively, however, no statistically significant difference was noted in cost (P=.535). The 1-year physical and occupational therapy cost per patient was higher after HSA than after RTSA (MD, $723; CI, $718-$728; P<.001), but no difference was noted in discharge disposition or 1-year revision or readmission rates. The results of this study suggest that despite the higher initial cost of RTSA, the total cost of care in the year after RTSA and HSA is similar. Therefore, RTSA should be considered in the appropriate clinical setting. [Orthopedics. 2020;43(2):119-125.].

Healthcare utilization and direct costs of non-infectious comorbidities in HIV-infected patients in the USA

OBJECTIVE

To estimate the incremental healthcare utilization and costs associated with common non-infectious comorbid conditions among commercially and Medicaid-insured HIV-infected patients in the US.

METHODS

US administrative claims were used to select adult HIV patients with chronic kidney disease (CKD), cardiovascular disease (CVD) events, or fracture/osteoporosis, three common comorbidities that have been associated with HIV and HIV treatment, between 1 January 2004 and 30 June 2013. Propensity score matched controls with no CKD, no CVD events, and no fracture/osteoporosis were identified for comparison. All-cause healthcare utilization and costs were reported as per patient per month (PPPM).

RESULTS

The commercial cohort comprised 381 CKD patients, 624 patients with CVD events, and 774 fracture/osteoporosis patients, and 1013, 1710, and 2081 matched controls, respectively; while the Medicaid HIV cohort comprised 207 CKD and 271 CVD cases, and 516 and 735 matched controls, respectively. There was insufficient Medicaid data for fracture analyses. Across both payers, HIV patients with CKD or CVD events had significantly higher healthcare utilization and costs than controls. The average incremental PPPM costs in HIV patients with CKD were $1403 in the commercial cohort and $3051 in the Medicaid cohort. In those with CVD events, the incremental costs were $2655 (commercial) and $4959 (Medicaid) for HIV patients compared to controls (p < .001).

CONCLUSIONS

The results suggested a considerable increase in healthcare utilization and costs associated with CKD, CVD and fracture/osteoporosis comorbidities among HIV patients in the past decade. Because these conditions have been associated with treatment, it is critical to consider their impact on costs and outcomes when optimizing patient care.

Perioperative Risk Adjustment for Total Shoulder Arthroplasty: Are Simple Clinically Driven Models Sufficient?

BACKGROUND

There is growing interest in value-based health care in the United States. Statistical analysis of large databases can inform us of the factors associated with and the probability of adverse events and unplanned readmissions that diminish quality and add expense. For example, increased operating time and high blood urea nitrogen (BUN) are associated with adverse events, whereas patients on antihypertensive medications were more likely to have an unplanned readmission. Many surgeons rely on their knowledge and intuition when assessing the risk of a procedure. Comparing clinically driven with statistically derived risk models of total shoulder arthroplasty (TSA) offers insight into potential gaps between common practice and evidence-based medicine.

QUESTIONS/PURPOSES

(1) Does a statistically driven model better explain the variation in unplanned readmission within 30 days of discharge when compared with an a priori five-variable model selected based on expert orthopaedic surgeon opinion? (2) Does a statistically driven model better explain the variation in adverse events within 30 days of discharge when compared with an a priori five-variable model selected based on expert orthopaedic surgeon opinion?

METHODS

Current Procedural Terminology codes were used to identify 4030 individuals older than 17 years of age who had TSA in which osteoarthritis was the primary etiology. A logistic regression model for adverse event and unplanned readmission within 30 days was constructed using (1) five variables chosen a priori based on clinic expertise (age, American Society of Anesthesiologists classification ≥ 3, body mass index, smoking status, and diabetes mellitus); and (2) by entering all variables with p < 0.10 in bivariate analysis. We then excluded 870 patients (22%) based on preoperative factors felt to make large discretionary surgery unwise to focus our research on appropriate procedures. Infirm patients have more pressing needs than alleviation of shoulder pain and stiffness. Among the remaining 3160 patients, logistic regression models for adverse event and unplanned readmission within 30 days were constructed in a similar manner to the complete models. The five a priori risk factors used in each model based on clinical expertise were selected by consensus of an expert orthopaedic surgeon panel.

RESULTS

When patients unfit for discretionary surgery were excluded, the clinically driven model found no risk factors and accounted for 1.4% of the variation in unplanned readmission. In contrast, the statistically driven model explained 4.6% of the variation and found operating time (hours) (odds ratio [OR], 1.26; 95% confidence interval [CI], 1.04-1.53) and hypertension requiring medications (OR, 1.95; 95% CI, 1.01-3.76) were associated with unplanned readmission accounting for all other factors. However, neither the clinically driven model (pseudo R², 1.4%) nor statistically driven model (pseudo R², 4.6%) provided much explanatory power. When patients unfit for discretionary surgery were excluded, no factors in the clinically driven model were significant and the model accounted for 0.95% of the variation in adverse events. In the statistically driven model, age (OR, 1.03; 95% CI, 1.01-1.06), men (OR, 1.64; 95% CI, 1.05-2.57), operating time (hours) (OR, 1.27; 95% CI, 1.07-1.52), and high BUN (OR, 3.12; 95% CI, 1.35-7.21) were associated with adverse events when accounting for all other factors, explaining 3.3% of the variation. However, neither the clinically driven model (pseudo R², 0.95%) nor the statistically driven model (pseudo R², 3.3%) provided much explanatory power.

CONCLUSIONS

The observation that a statistically derived risk model performs better than a clinically driven model affirms the value of research based on large databases, although the models derived need to be tested prospectively.

CLINICAL RELEVANCE

Clinicians can utilize our results to understand that clinician intuition may not always offer the best risk adjustment and that factors impacting TSA unplanned readmission and adverse events may be best derived from large data sets. However, because current analyses explain limited variation in outcomes, future studies might look to better define what factors drive the variation in unplanned readmission and adverse events.