Abstract
Objectives:
Value based decision making regarding nonoperative management vs. early surgical stabilization for first-time anterior shoulder instability (ASI) events remains controversial. Thus, the purpose of this study was to perform 1) a systematic review of the current literature and 2) a Markov model-based cost-effectiveness analysis comparing an initial trial of nonoperative management to arthroscopic Bankart repair (ABR) for first-time ASI.
Methods:
A Markov Chain Monte Carlo probabilistic model (Figure 1) was developed to evaluate the outcomes and costs of 1,000 simulated patients (average age » 20 years old) with first-time ASI undergoing nonoperative management vs. ABR. Utility values, recurrence rates, and transition probabilities were derived from the published literature. Costs were determined based on the typical patient undergoing each treatment strategy at our institution. Outcome measures included costs, quality-adjust life-years (QALYs), and the incremental cost-effectiveness ratio (ICER).
Probabilities of recurrence as well as the utility of each treatment strategy were obtained from the literature search as described above. Probabilities were pooled across studies to obtain a weighted average for both nonoperative treatment and ABR. Similarly, studies reporting scores on the Western Ontario Shoulder Instability Index (WOSI) scale were utilized to approximate shoulder-related quality of life after each treatment strategy and outcome. Costs for each treatment strategy and transition state in the model were considered from the payer perspective (commercial or government) and obtained from institutional data at a large, academic medical center.
Results:
The Markov model with Monte Carlo microsimulation demonstrated average (± standard deviation) costs for nonoperative management and ABR of $38,649 ± 10,521 and $43,052 ± 9,352, respectively. Total QALYS acquired over the 10-year time horizon were 7.7 ± 0.4 and 8.4 ± 0.5 for nonoperative management and ABR, respectively. The ICER comparing ABR to nonoperative management was found to be just $5,725/QALY, which falls substantially below the $50,000 willingness-to-pay (WTP) threshold (Figure 2). The mean number of recurrences were 2.6 ± 0.3 and 1.2 ± 0.2 for patients initially assigned to the nonoperative and ABR treatment groups, respectively. Out of 1,000 samples run over 1,000 trials, ABR was the optimal strategy in 98.7% of cases, with nonoperative management the optimal strategy in 1.3% of cases (Figure 3).
Conclusions:
The primary findings of this systematic review and cost-effectiveness analysis were as follows: 1) when compared to nonoperative management, arthroscopic Bankart repair (ABR) substantially reduces the risk of recurrent dislocations, 2) ABR results in greater shoulder function and higher WOSI scores than does nonoperative management, and 3) despite substantially higher upfront costs, ABR proved to be more cost-effective than an initial trial of nonoperative management, which can be attributed to both fewer recurrent dislocations and greater utility over the long-term.
